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Lignocellulose-Based Bioeconomy in Japan
C H A P T E R
11 Lignocellulose-Based Bioeconomy in Japan Satoshi Hirata National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan
INTRODUCTION In this chapter, a summary of the lignocellulose-based bioeconomy in Japan is provided. There are many lignocellulose resources in Japan and lignocellulose has already been used in lumber, wood processing, and pulp and paper industries. Some chemicals, like rosin and turpentine, are manufactured from lignocellulose. Additionally, energy industries are large consumers of lignocellulose. Much research and development for new uses of lignocellulose have been performed. From 2000 to 2010, research for liquid or gaseous fuel from lignocellulose was actively done in Japan. However, there is no commercial facility in operation currently. The reason for this is that these processes did not have feasibility to continue. It is more expensive to produce these products commercially compared to producing them technically in a laboratory. It is crucial that the bioeconomy process can be produced economically. Meanwhile, the production of biopower, that is, power generation from biomass, has increased since 2012. The serious accident of the atomic power generation in 2011 became the trigger to enhance the feed-in tariff scheme for renewable energy in 2012. Using lignocellulose as a resource for biopower fuel is insufficient in Japan. After 2012, much research into new uses of lignocellulose were launched in the field of nanocellulose and lignin. The Japanese government uses approximately US$46 million per year for nanocellulose research and development. We will discuss the current situation of these new processes.
Lignocellulose for Future Bioeconomy DOI: https://doi.org/10.1016/B978-0-12-816354-2.00013-X
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© 2019 Elsevier Inc. All rights reserved.
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LIGNOCELLULOSE RESOURCES IN JAPAN In Japan, forests cover 251 3 103 km2 which is about 66% of the land area. Natural forests cover 134 3 103 km2, artificial plantations 103 3 103 km2, and bamboo forests 1.6 3 103 km2. The total forest area including natural, artificial and bamboo have not changed for 46 years (The forest and forestry white paper, 2017). The cumulative proportion of forests was 49 3 108 m3 in 2012, which represents an increase in volume of 2.6 times over 46 years, mostly through artificial plantations. However, matured planted trees were not used and should be cut down. In 2014, the production of lumber in Japan was 2365 3 104 m3 and 95% of that was used for lumber, pulp and fuel. The demand for woods as lumber, pulp and fuel in Japan was 7458 3 104 m3 and the rate of self-sufficiency was only 30%. Lumber has three major uses: (1) in the lumber and wood processing industries it is used for houses, buildings, and furniture; (2) for the pulp and paper; and (3) for energy. The first and second are traditional industries and they use a large amount of lumber.
LIGNOCELLULOSE FOR TRADITIONAL INDUSTRIES Lumber Industry and Wood Processing Industry Almost all the lignocellulosic biomass is used in the traditional industries of lumber and wood processing and pulp and paper production. The flow of lumber in the lumber and a wood processing industries is shown in Fig. 11.1. The production of lumber in Japan was 2224 3 104 m3 year21 and 95% was used in the country. 534 3 104 m3 of lumber and 1933 3 104 m3 of lumber-processing products were
FIGURE 11.1 Flow of lumber in lumber and wood processing industries.
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imported. In the lumber and wood processing industries, the rate of self-sufficiency was only 47%. Even though there is enough stock from forest resources in Japan, the import ratio is high. The reasons for this high import ratio are that the cost for felling and transportation is expensive, the people engaging in forestry became older and their number decreased, and it is difficult to get uniform lumber in Japan. Cedar is a major plantation species; however, the quality of the wood differs according to area from which it is harvested. It is not easy achieve uniform quality even when the wood is dried. Consequently, the forestry and wood processing industries declined substantially and there is an urgent need for improvement in quality, property, price, and supply stability. There were 5456 lumber mills in Japan by the end of 2014 and this number decreased by 4% each year. There are many small-scale mills and almost of them are proceeding to shutdown. Although the number of smaller mills has decreased, large mills with a processing capacity of more than 10 3 104 m3 year21 have been built. In the wood processing industry, cross laminated timber (CLT) has attracted attention and the Japanese government is making various efforts to harness the interest in this product. Large buildings using CLT have been planned to be built successively and the production facilities of CLT of 50 3 104 m3 year21 should be operational by 2024.
Pulp and Paper Industry The flow of material in the pulp and paper industry in Japan is shown in Fig. 11.2. 477 3 104 tons year21 of domestic lumber was used
FIGURE 11.2
Material flow of pulp and paper industries in Japan.
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in 2016 for the pulp and paper industry. The demand for lumber for pulping was 1610 3 104 tons year21 and 1152 3 104 tons year21 was imported. Besides this, 136 3 104 tons of imported pulp and 1714 3 104 tons of recycled paper were used. Using these materials, 1417 3 104 tons of paper and 1157 3 104 tons of board were produced in Japan in 2016. Japan’s paper and pulp production was the third highest in the world after the United States and China. However, the rate of self-sufficiency of pulp was only 25%. As a large amount of paper and board was produced from domestic recycled paper, the rate of self-efficiency of pulp and paper materials was 72%. Although the production of pulp and paper is decreasing, that of board is increasing because there is a high demand for board for food packaging, home-electronics, mail order, and deliveries to homes.
ENERGY INDUSTRIES Solid Fuel Table 11.1 shows the heat value and carbon ratio of solid fuel made from lignocellulose. Wood chips are most commonly used as the solid fuel of lignocellulose. There are four kinds of chips: crushed chips and cutting chips according to its shape; and dried chips and undried chips according to its moisture content. Production, transportation, and energy conversion are universal technologies and the demand for wood chips is increasing. Wood pellets as a solid fuel of lignocellulose are used in certain parts of Japan. In 2015, the production of wood pellets was 12 3 104 tons year21. The total production in the world was 2800 3 104 tons year21. Japan imported 23 3 104 tons which is almost double the quantity of domestic production; see WBA Global Bioenergy Statistics (2017). The main supply destination is for pulverized coal boilers in thermal power stations. A smaller proportion is used for small-scale, hot-water boilers and stoves. In Japan, the price of wood pellets is expensive, namely US $275 642 per ton, while combustors are also expensive. In addition, as TABLE 11.1
Characteristics of Solid Fuel Made From Lignocellulose Wood chip (not dried)
Wood pellet
Torrefaction pellet
Biocokes
Low heat value (MJ kg )
7
17 18
20 24
17 18
Carbon ratio (%)
25
50
45
50
21
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the demand for heating is not high in Japan, the utilization rate of combustors is low. For these reasons, wood pellets are not popular in Japan. Currently, research and development for the advancement of solid fuels from lignocellulose is being carried out in Japan. One of these solid-fuel products are torrefaction pellets. Torrefaction can be called half carbonization and treatment conditions entail atmospheric pressure, no oxygen, and 473 573 K for 10 30 minutes. By this treatment, a volatile organic compound is released by lignocellulose and the weight goes down by 30% and the energy decreases by 10%. As a result, the energy per weight increases 1.3 times by this treatment. The heat value of wood pellets is 17 18 MJ kg21 and that of torrefaction pellets is 20 24 MJ kg21. In addition, the water resistance and frangibility of pellets are improved by torrefaction, therefore, the ratio of torrefaction pellets can be increased via cocombustion with coal rather than traditional wood pellets. Transportation costs can be decreased due to the increase in energy density. This technology is under development mainly in Europe; however, the Japanese government subsidized Nippon Paper Industries Co., Ltd. (Nippon Paper) and Forestry and Forest Products Research Institute (FFPRI) to research this technology. Nippon Paper developed a production technology for torrefaction pellets and are doing a large-scale demonstration test in Thailand that entails cocombustion in a pulverized coal boiler for power generation. FFPRI manufactured torrefaction pellets in a trial for burning them in a small boiler and pellet stove. Torrefaction pellets cannot be used in a traditional pellet boiler or stove because the energy from torrefaction pellets is different from that of traditional pellets, therefore, it may be impossible for torrefaction pellets to be used by consumers in Japan because even traditional pellets are not popular. Another solid-fuel product is biocokes, which were developed by Professor Ida of Kindai University. Biocokes are produced from many kinds of dried biomass, including lignocellulose, via high pressure and high temperature. The condition for production is 20 MPa and 453 473 K for 20 40 minutes. There are no changes in weight and energy through this treatment although the volume decreases by 1/5. Therefore, the low-heat value of biocokes manufactured from lignocellulose is the same as that of woody pellets, that is, 17 18 MJ kg21. Apparent specific gravity is 1.2 1.4 g cm23, which is double that of woody pellets and the crushing strength is 60 100 MPa. The reason is that hemicellulose and lignin soften and then harden, including the fibrous celluloses, during treatment and biocokes become a hard three-dimensional structure. Biocokes are so hard that it is not broken down during transportation and storage. As it also has water-resistant properties and is not biodegradable, it is suitable for long-term storage.
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In Japan, radioactive substances released into the atmosphere by the Fukushima atomic power disaster attached to the biomass and soil around the power station. The polluted biomass and soil have been collected and will be turned into biocokes to decrease its volume and be stored safely for a long time. When the radiation dose becomes low, the biocokes can be burnt in a managed boiler. After long storage, these biocokes could be used as solid fuel. Kindai University manufactured biocokes from lignocellulose, coffee grounds, and tea grounds, and demonstrated their use as a substitution for cokes. In Malaysia, Kindai University and Osaka Gas Engineering plan to manufacture biocokes from empty palm fruit bunches and import them for shaft kilns.
Liquid Fuel and Gaseous Fuel Research and development for liquid fuel production from lignocellulose has been actively carried out from 2000 to 2010 in Japan. Although demonstration facilities of bench- or pilot-scale were built and operated, there is no facility currently in operation. Various processes have been used and these can be divided into two groups, bioprocesses and thermo-chemical processes. Most major bioprocesses entail bioethanol production by acid hydrolysis and fermentation. Lignocellulose contains cellulose, hemicellulose, and lignin. Through acid hydrolysis, glucose and xylose are mainly produced. Normally, yeast is used for ethanol fermentation; however, traditional yeast, which is used for alcohol beverage production, cannot change xylose into ethanol. Gene-recombinant microorganisms which can use both glucose and xylose were developed and demonstrated. However, the sugar contents in hydrolyzed solution from lignocellulose is so low that the ethanol concentration after fermentation is also low. This process has lower efficiency than the traditional bioethanol process from sugarcane and corn. Ethanol can be produced by these processes; however, the cost is more expensive than traditional bioethanol and gasoline processes. Therefore, these processes cannot currently be commercialized. Some thermo-chemical processes, for example, biomethanol and biomass to liquid (BTL) processes have been studied actively and consists of gasification and chemical synthesis using catalysis. Firstly, lignocellulose is decomposed into hydrogen, carbon monoxide, methane, and other gases, tar, and solid parts. This process is called gasification or pyrolysis and the gas produced is called synthesis gas or syngas. We can classify many kinds of gasification processes according to reaction temperature, pressure, scale, and type of gasifier. The gasification
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process has already been commercialized for coal, exhaust, and some kinds of biomass; however, gasification is not a proven technology for lignocellulose. Many kinds of liquid fuel can be synthesized from hydrogen and carbon monoxide. The production process for methanol is the most simple. Methanol can be used as fuel for internal-combustion engines; however, methanol has causticity for metals and would require a special engine. For this reason, a methanol vehicle did not become popular. Methanol is also used as fuel for fuel-cell vehicles; however, hydrogen became the dominant fuel because methanol requires reforming at 523 K. In Japan, a pilot-scale demonstration plant from lignocellulose to methanol was in operation around 1990; however, it has been turned into a research facility for the BTL process. In the BTL process, a mixture of hydrocarbon with varying molecular weight is produced. The content depends on the type of catalysis, reaction temperature, and pressure to produce, for example, diesel, gasoline, kerosene, and wax. In our institute, the BTL process was studied to produce biodiesel as substitute for fossil fuel. Diesel can be produced from lignocellulose; however, it was very expensive which nullifies its competitive power in the fuel market. There have been many trials where syngas was used as a gaseous fuel for internal-combustion engines. The efficiency of gasification is about 60% 75% and it is not dependent on its scale. In other words, 60% 75% energy of lignocellulose can be recovered as gaseous fuel even at a small scale. This technology is suitable for a small-scale decentralized cogeneration system. A cogeneration system can be built consisting of a gasifier, gas purifier, and gas-engine generator. Various demonstration facilities were built between 2000 and 2010; however, a cogeneration system has not been commercialized. Many technical problems exist in this process. In a gasifier, strictly dried and homogeneous wood chips must be used to produce stable and tar-free gas. In a gas purifier, the tar in syngas must be completely removed and water treatment is also necessary. In addition, there is a huge financial restraint in this process because the fuel and facilities are expensive as well as the operator’s labor cost while the income from heat and power is not significant. However, decentralized heat and power have enormous potential demand in the world, therefore, research into this process must continue.
Electricity In July 2012, the “Act on Special Measures Concerning Procurement of Renewable Electric Energy by Operators of Electric
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Utilities” was enforced in Japan. Electricity generated from renewable resources produced from renewable resources like solar, windpower, and biomass should be bought at a fixed price by operators of electric utilities. As a result, the generation capacity of renewable electricity increased after 2012. Solar power was increased dramatically; however, biomass power increased little because the facility was expensive and necessary for the supplier of the fuels. The purchase price of biomass electricity is higher than the price of traditional electricity, therefore, the cost is transferred to the users. As the purchase prices are only a little higher than the generation cost from renewable resources, the profit is small. This is the reason the generation capacity of renewable electricity must be increased. In biomass power generation, the fuel cost is around 70% of the generation cost. It is, thus, important to improve its feasibility. The purchase price for wood was decided according to the cost when waste wood from lumber mills and the wood processing industry were used. However, palm kernel shell (PKS) and palm oil from South-East Asia were generally used with domestic waste wood because they were cheaper than domestic waste wood. Palm oil was used in 54% of authorized facilities and PKS was used in 72%; however, palm oil has not used since September 2017. The Japanese government revised the purchase prices in March, 2018. The purchase price of electricity from the facilities using biomass liquid fuel was decided by tenders. The purchase prices of renewable electricity from biomass are listed in Table 11.2.
TABLE 11.2 May 2018
Purchase Prices of Renewable Electricity From Biomass in Japan as of
Resource
Capacity
Purchase price excluding tax
Biomass liquid fuel
All
Tender from FY2018
Wood
^10000 kW
Tender from FY2018
Wood not including biomass liquid fuel
,10,000 kW
22 cents kWh21
Methane-gas generation
All
36 cents kWh21
Lumber from thinning
^2000 kW
37 cents kWh21
Lumber from thinning
,2000 kW
29 cents kWh21
Building material waste
All
12 cents kWh21
Waste and other biomass
All
16 cents kWh21
$1 5 109 JPN.
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CHEMICALS AND CHEMICAL MATERIALS Rosin and Turpentine Rosin (fossilized resin) and turpentine are chemicals from lignocellulose which have been used for a long time. Rosin is a purified material from the vegetable fat of pine trees and is manufactured commercially. It is widely used as a sizing agent (a papermaking chemical) and for printing ink, synthetic rubber, adhesive agent, paints, and others. Rosin is classified into three kinds depending on the collection method. Gum rosin is manufactured via the distillation of raw rosin collected from pine trees. Through distillation, turpentine is evaporated and separated. Tall rosin is manufactured via the purification of raw tall oil, which is coproduced by the kraft pulping of pine trees. Wood rosin is manufactured via solvent extraction and distillation from pine chips. Gum rosin is used the most, while most wood rosin is not employed. In 2016, 17 3 103 tons of rosin was manufactured; in contrast, 69 3 103 tons of rosin was consumed in Japan (Website of Harima Chemicals Group Inc). Turpentine is a pale-yellow liquid which is extracted from pine chips via a heating process and contains mainly α-pinene and β-pinene. In the air, turpentine is gradually oxidized which increases its viscosity to become similar to resin. Turpentine is used as a solvent for paint and varnish and as a material for adhesives and other chemicals.
NANOCELLULOSE What Is Nanocellulose? Nanocellulose is composed predominantly of cellulose, with external dimensions being in the nanoscale. It can also be defined as a material having internal structure or surface structure in the nanoscale, with the internal structure or surface structure composed predominantly of cellulose. Nanoscale means that the length range of 50% of the materials is approximately from 1 to 100 nm. The terms cellulose nanomaterial and cellulosic nanomaterial are synonymous with nanocellulose (Nanotechnologies, 2017). There are many kinds of nanocellulose, such as cellulose nanofibril (CNF), cellulose nanocrystal (CNC), and bacteria cellulose. Most nanocellulose is produced from lignocellulose. The relationship between wood and nanocellulose is illustrated in Fig. 11.3. Cellulose microfibril is a fundamental unit of nanocellulose. The diameter is from 3 to 4 nm. Cellulose microfibril entails bundles of 30 40 molecular chains of cellulose; however, this molecular chain cannot be
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FIGURE 11.3 The relationship between wood and nanocellulose.
obtained separately. According to its manufacturing process and component, nanocellulose is roughly divided into three kinds: (1) CNF; (2) lingo-CNF; and (3) CNC. In Japan, CNF is usually called cellulose nanofiber. CNF has been actively studied in North America, Europe, and Asia and more than 20 enterprises supply these products or samples. CNC has been studied extensively in North America and Israel, and some CelluForce and Melodea manage commercial plants. In Japan there are no companies that manufacture CNC. In the next section, current research, development, and industrialization of nanocellulose in Japan will be discussed. Nanocellulose has special properties. The tensile strength of cellulose microfibril is five times stronger than that of steel, while the weight of CNF is one-fifth of that of steel. A solution or sheet of isolated CNF or CNC are not scattered by visible light and they are transparent. They have a huge specific surface area and also have functional groups on their surface, therefore, chemical loading and surface modification is easy. The coefficient of the thermal expansion of nanocellulose is 0.1 ppm K21 which is the same level as quartz glass. Laminate of nanocellulose sometimes has a gas barrier property and its pore size may be controllable. A solution of nanocellulose has thixotropy. Viscosity is controllable through the addition of nanocellulose. Using these properties, many kinds of low materials and products are developing, for example light-weight and high-strength composite materials, transparent materials, electronic materials, packaging materials, filter materials, caring materials, thickeners, gelatinizers, and dispersion stabilizers for emulsion.
Production of Nanocellulose In Japan, more than 10 enterprises manufacture CNF and Ligno-CNF from lignocellulose. The manufacturing processes are different according to the enterprises and some of them have not disclosed their
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FIGURE 11.4
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TEM micrograph of TEMPO-oxidized CNF.
processes. Some of the known processes will be discussed. Cellulose microfibril is a fundamental unit of nanocellulose. Some CNF exist as isolated cellulose microfibrils and other CNF exist as bundles of cellulose microfibrils. The diameter of an isolated microfibril is 3 4 nm; however other types fall in the range of 3 100 nm. Isolated CNF is manufactured via chemical treatment and then defibrated mechanically. The most popular chemical treatment is oxidation using TEMPO catalysis. TEMPO is 2,2,6,6-tetramethylpiperidine 1-oxyl and CH2OH base on the surface of cellulose microfibrils is changed to COONa base. As a result, cellulose microfibrils are dispersed easily. This process was invented by Dr. Isogai of the University of Tokyo and Nippon Paper Industries Co., Ltd., and DKS Co. Ltd. manufactures TEMPO oxidized CNF under the license of Dr. Isogai. Oji Holdings Corporation uses phosphorylation as a chemical treatment and Oji also manufactures isolated CNF. It is easy to measure the diameter and length of isolated CNF and the quality is considered to be good. A TEM micrograph of TEMPO-oxidized CNF is shown in Fig. 11.4. Another process used to manufacture CNF is by mechanical defibration. These CNF are not defibrated to single cellulose microfibrils and most CNF are bundles of cellulose microfibrils. Therefore, it is a mixture of bundles of cellulose microfibrils which have different diameters. The diameter of CNF is in the range of 3 100 nm and can have various distribution according to the products. Moreover, CNF is sometimes ramified. It is not easy to measure its diameter and length.
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FIGURE 11.5 Major facilities for nanocellulose production in Japan.
Different defibration processes are used by the various manufacturers. The major equipment needed for defibration are a high-pressure homogenizer, refiner (mill), supermasscolloider (mill), twin screw extruder, water-jet crusher, bead mill, and micro fluidizer. The characteristics of CNF is totally different depending on the materials and equipment used, as well as the defibration conditions like water to solid ratio, reaction time, pressure, and temperature. A third CNF is ligno-CNF, which is manufactured not from delignificated pulp, but from lignocellulose. As ligno-CNF contains lignin on the surface of cellulose fibers, the diameter is larger than CNF from pulp and the diameter varies according to position. It is usually ramified and, therefore, it is quite difficult to measure both diameter and length. CNF is so hydrophilic that it is difficult to mix CNF uniformly with resin and elastomer; however, lingo-CNF is relatively easy to mix with resin and elastomer because lignin is hydrophobic. Fig. 11.5 shows the major facilities for nanocellulose production and its capacity in Japan.
Application Development and Products Application development of nanocellulose has been actively pursued using its property and now six types of products are sold in Japan. The first is an aqueous solution of CNF manufactured by Gaulin
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homogenizer with a solid content of 10% 35%. The diameter of the fibers is 10 100 nm and it is used as a binder for powder and fibrous materials, paper-strong agent in paper making, food additive to improve food feeling, a kind of filter aid agent for liquor, and as a cosmetic additive to improve water holding properties. Although these products are authorized as a food additive, unfortunately which consumer products use this CNF is not disclosed. Secondly, there is a gel-ink pen which uses TEMPO-oxidized CNF as a thickener. This product benefits from the thixotropy of CNF. Thixotropy is when fluidity increases when pressure increases and vice versa which allows a smooth flow of ink without having to press hard onto paper. The third product is a diaper and urine leakage pad for adults. CNF has a huge specific surface area and much functional groups on their surface. In these products, a high deodorization seat is used which holds silver ions with an antibacterial deodorization effect on the surface of the TEMPO-oxidized CNF. The deodorization power of these products is triple that of the conventional products. The fourth is a speaker and headphone in which a new vibration board using CNF is applied. This CNF is made from bamboo and the products benefit from the high rigidity of CNF. In these products, the response is good and it realizes low tone reproduction to stand up. The fifth is a disposable cleaning sheet for toilet bowls. This product uses the originally developed CNF produced by the energy-saving process. This product is harder to tear than existing products. The sixth product is cosmetics using carboxymethylated CNF. A fragrance gel, body and hand cream, and skin water are manufactured and sold. Carboxymethylated CNF is probably used for viscosity control and improvement of water-holding properties. These six products are consumer products except of first one. The dose of CNF in the products is likely to be very low. In Japan, much research in the possible applications of CNF are underway and some prototypes of additional products have been released, for example, safety boots in which CNF was mixed with rubber for added strength, paper containers for foods which with smell and oxygen barrier characteristics, a super low density porous body which assumed to apply for catalysis loading material, an insulation material, a cell culture matrix, and an adsorbent. The Japanese government spends US$460 million per a year on research and development of nanocellulose. This budget has allowed many projects to be pushed forward. The government has invested in automobile parts, household electric appliances, and a housing component because the markets of these fields are large and the consumption of CNF is also large.
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JAPANESE GOVERNMENT PROJECTS The main research subjects are the production, modification, and composite-making with resin and elastomer. The ministry of Economy, Trade and Industries intends to construct a consistent process from lignocellulose to CNF reinforced resin in collaboration with Kyoto University. This reinforced resin is intended to be used for automobile parts, the body of household electric appliances, and housing components. In the project, the technical target is that the coefficient of elasticity and strength of reinforced resin increases to double the original resin by 10% CNF addition. The cost target for lingo-CNF for injection molding is $12,000 per dry ton and lingo-CNF for extrusion molding is $9200 per dry ton by March 2020. Weight reduction and the low carbonization of the products in these industries will be achieved and, consequently, the emission of greenhouse gases will be decreased. The aim is to replace the metal used in vehicles, household electric appliances, and buildings with CNFreinforced resin. The budget is US$36 million per year as FY 2018. The consistent process from lignocellulose to CNF-reinforced resin developed by Kyoto University is called the “Kyoto Process” and consists of the production of lingo-CNF, modification of its surface, and mixing with resin. There are three key points in this process. Firstly, the material, namely wood chips, are used and then lignin remains on the surface of nanofibers. As a result, heat-resistant ability and hydrophobicity is improved as CNF made from pulp. The second point is the chemical modification of lingo-CNF to increase its heat-resistant ability. The third is that defiberization of cellulose fibers and mixing with resin are done simultaneously by an extruder and then this process is simplified. The process flow of the Kyoto process is shown in Fig. 11.6. Firstly, wood chips are cooked and washed to remove most hemicellulose and the majority of lignin. After preliminary defiberization under high pressure by a refiner and then removal of large fibers in a screening process, the fine fibers are made into sheet foam and dried. In order to mix lingo-CNF and resin uniformly, heat-resistant ability is necessary. In this process, by acetylation of the dried sheet, 1% weight loss temperature increases approximately 10 20 K. The acetylated sheet of fine fibers is crushed into powder and then mixed with resin by a twinscrew extruder to obtain pellets of reinforced resin. These resin pellets are used for injection molding. For resin from 90% polypropylene and 10% lingo-CNF, the modulus of elongation increased 1.3 times, tensile strength increased 1.5 times, bend elastic constant increased 1.4 times, and bending strength increased 1.3 times. In addition, a hot-pressed product was manufactured by way of trial and its bending strength was
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FIGURE 11.6
The process flow of the “Kyoto process.”
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217 MPa and its bend elastic constant was 10.7 GPa. For industrialization, Nippon Paper built a new plant for CNF-reinforced resin for which the production capacity is 10 tons year21.
FUTURE PROSPECTS The sales prices of CNF is in the range of US$180 US$460 per kg in Japan. As there are many kinds of CNFs and their purities vary, the prices of all CNFs are not in this price zone; it is rather expensive. There are plans to use CNF as a filler for commodity plastic and studies are proceeding actively. The price of commodity plastic is about US$2 per kg. The production cost of CNF should be decreased to spread CNF for the filler purpose. As material prices are unlikely to go down, it is necessary for the manufacturing cost to go down by improving the manufacturing process. There are many manufacturing processes of CNF in Japan. Among them, some processes are quite difficult to scale up and automate and they will potentially be restructured by international competition. On the other hand, 75% of pulp consumed in Japan is imported mainly due to cost. From the point of view of scale merit and logistic cost, the production of CNF or the material used for CNF in other countries may become a better option in the future. It is important that Japanese CNF maintains a good cost performance and high quality which can be differentiated from others. Moreover, new application development in which the improvement of the performance is higher than the increase of the cost is equally important. When CNF is used, performance is improved; however, it does not usually balance the cost increase. It is easier to apply this balance with expensive products and in specialized fields, for example, medical materials, cosmetics, and electric parts. The prospective demands for nanocellulose announced by a researcher in the United States are listed in Table 11.3. This reflects the potential rather than concreate demand worldwide. In this research, the potential demand of nanocellulose is 23.1 3 106 tons year21 and 20.0 3 106 tons of this are for paper industries and 1.0 3 106 tons are for textile industries. The potential demand for other applications is 2.1 3 106 tons year21. On the other hand, the Japanese government intends to utilize CNF for structural materials and to replace exhaustible resources. In a report which the government consigned to a research company, CNF will mainly be used as materials for automobile, electric appliance and housing component industries and the use of reinforced materials is expected to be 442 3 103 tons year21 by 2030, as shown in Table 11.4. 66% of this will be used for window frame sashes.
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FUTURE PROSPECTS
TABLE 11.3 Prospective Demand of Nanocellulose in the World (Jack Miller, Market-Intell LLC, 2017)
Industries
Market ( 3 106 tons year21)
Dosage of nanocellulose (%)
Demand of nanocellulose ( 3 106 tons year21)
Paper, board
400.0
5
20.0
Textile
50.0
2
1.0
Paint, coating
40.0
2
0.8
Carbon black
15.0
2
0.3
Film
9.7
2
0.2
Composite of resin
9.0
2
0.2
Oil and gas drilling
17.5
1
0.2
Nonwoven fabric
7.0
2
0.1
Water treatment
4.7
2
0.1
Pharmaceutical additive
4.6
2
0.1
Cement
15.0
0.5
0.1
Adhesive
0.5
2
0.01
Cosmetics
0.3
1
0.003
Separator of battery
0.06
2
0.001
Total
23.1
CNF is mixed with polyvinyl chloride which may decrease the weight of the sash by 20%. CNF-reinforced polyamide will be used for many automobile parts and then the weight may be decreased by 57.7%. As CNF will be used for tires, the weight may be decreased by 20%. In 2030, if these parts are used for 17% of automobiles manufactured in Japan, the use of CNF-reinforced resin and rubber will be 12 3 104 tons in total. Moreover, CNF-reinforced polypropylene will be used for refrigerator parts, laundry machines, and air-conditioners, and then the use of CNF-reinforced resin will be expected to be less than 3 3 104 tons. The ratio of CNF in the resin and rubber is not described in the report. If it is 5%, then the demand for CNF is 22 3 103 tons year21. If it is just 0.2% of the production and imported amount of pulp in Japan, which was 1017 3 104 tons in 2012. Finally, CNF confronts the share competition with CNC and cellulose filament (CF), which are cheaper than CNF. CNC and CF are mainly produced commercially in North America and can be dried easily. There are few application studies for CNC and CF in Japan. In the case
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TABLE 11.4 Prospective Demand of CNF-Reinforced Materials by 2030 in Japan (FY, 2017) Weight of parts (kg)
Alternative materials
Amount to use (kg)
Penetration ratio (%)
Number of shipments (year21)
Total amount of use (tons year21)
Main body, sub frame
260.7
CNF 1 PA
110.2
17.2
688,000
75,900
Industries
Parts
Automobile
Electric appliance
Housing component
Side-door, bonnet
50.0
CNF 1 PA
21.1
14,500
Back door
30.0
CNF 1 PA
12.6
8700
Roof
5.6
CNF 1 PA
2.36
1600
Instrument’s panel
7.1
CNF 1 PA
5.0
3400
Tire
32.0
CNF 1 Rubber
25.6
17,600
Body of refrigerator
14.0
CNF 1 PP
5.9
Pulsator of washing machine
4.0
CNF 1 PP
Fans in outdoor unit of air-conditioner
2.0
Frame of resin sash
22.0
40.0
2,000,000
11,800
2.0
2,800,000
5600
CNF 1 PP
2.0
3,800,000
11,400
CNF 1 PVC
18.0
Building:30.0
2,341,000
52,400
Renovating:15.0
13,350,000
239,000 441,900
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where there is not a large deference in the performance among CNF, CNC, and CF, the cheaper one will be adopted. It is important to differentiate domestic CNF for Japan.
Integrated Biorefinery Process Lignocellulose has three components: cellulose, hemicellulose, and lignin. The most industrialized process using the components of lignocellulose is the pulp and paper industry. In this industry, technology innovation has been performed to improve how to separate cellulose fibers efficiently from lignocellulose and the process has been almost completed. In this process, the separated components, namely hemicellulose and lignin, are used as fuel for soda recovery boilers. On the other hand, almost all block chemicals are produced from naphtha and 23% of the crude oil imported by Japan is used as materials for chemicals. Petroleum resources will be exhausted in the future and all petroleum resources are imported in Japan. Moreover, during the manufacture process, the use and disposal of chemicals cause greenhouse gas emissions which is unfavorable for global warming. The Japanese government launched a research project so that the materials of the chemicals change from naphtha to nonedible biomass resources. Nonedible biomass means lignocellulose including agricultural wastes and weeds. In the biorefinery process during the commercial stage, sugars as starch are used for materials; however, 60% 70% of sugars and almost 100% of corn are imported in Japan (Report for demand and supply, 2017). To establish an integrated biorefinery process from lignocellulose, the research and development project started in 2013 and will continue for seven years. There are many research subjects and many organizations have joined it. In the next section, only the main subjects are presented.
Separation of Three Components To use the three components of lignocellulose as materials for highvalued substances, new separation technologies are being studied. Promising tree species are cedar and eucalyptus, because cedar is the main species in plantation in Japan and eucalyptus is the main species in plantation in foreign countries by Japanese enterprises. The numerical target of a new separation technology is that total recovery of the three components should be 70%, the recovery of cellulose is 70%, that of hemicellulose is 50%, and that of lignin is 70%. After the research, a revised alkaline cooking process was adopted. The separation process and conventional conversion process are shown in Fig. 11.7.
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FIGURE 11.7 Separation process and conventional conversion process.
The revised alkaline cooking method entails soda cooking with 2% anthraquinone. For cedar, when the concentration of anthraquinone is 0.1%, the recovery of hemicellulose was 45%; however, when the concentration of anthraquinone is 2%, the recovery of cellulose was increased to 83%, that of hemicellulose was 55%, and that of lignin was 96%, and so the numerical target can be reached. The mean molecular weight of lignin was 2890, and it was too high to use as material for resin. It is quite difficult to develop a new separation process by which all components can be used as materials for chemicals. Although the numerical target was accomplished in this project, it has not been commercialized yet.
Lignin Many approaches to utilize lignin for chemical materials have been conducted. When sulfur is included in the lignin fraction, it is difficult to use the lignin as chemical materials. Therefore, kraft cooking (the most popular pulping method) is not suitable for this purpose because kraft cooking uses Na2S. To use the lignin fraction as chemical materials, the ratio of lignin with a molecular weight under 1000 is necessary for more than 50%; however, it was difficult to decrease its molecular weight. At this stage, lignin for resin materials has not been obtained. When the lignin fraction from the revised alkaline cooking becomes acidic, deposition of raw lignin occurs; however, hemicellulose includes more than 2% in softwood and more than 10% in hardwood. Hemicellulose becomes an inhibitor when lignin is uses as chemical
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materials, and should be removed. By adjusting the pH and solubility of lignin fraction, hemicellulose was successfully removed.
Separation by Acetone and the Water Method This method is to recover both cellulose and lignin from lignocellulose. It is carried out at 493 K under 5 9 MPa for 1 hour and the solid concentration is 30% in 50% acetone and 50% water solution. Lignin and hemicellulose are soluble in the acetone mixture and cellulose is recovered as a solid. From the acetone/water solution, acetone is recovered by evaporation. Lignin is recovered from the acetone fraction and hemicellulose is recovered from the water fraction. The mean molecular weight of lignin was 700 and the softening temperature of lignin was 373 383 K, therefore, the lignin can be used for resin materials.
Furfural and Tetrahydrofuran When diluted sulfuric acid is added to lignocellulose and then heated, hemicellulose is hydrolyzed to pentose-like xylose. Furfural is obtained via the dehydration reaction of pentose. Furfural is commercially manufactured from the waste of corn, wheat, oats, bagasse, and saw dust. The total production amount was 37 3 104 tons worldwide including 30 3 104 tons in China in 2012. In Japan, 2 3 103 tons was consumed (Kanematsu Chemicals Corporation Homepage). Furfural is used as a solvent in the petro chemistry industry and is changed to furfuryl alcohol via hydrogen reduction, which is used as the material for furan resin. Furan resin is widely used as a hardening agent of silica sand in casting, lining agent for containers and tanks, and material for resin cement. The world’s largest production country of furfuryl alcohol is China which produces 12 3 104 tons year21 (Kanematsu Chemicals Corporation Homepage). Furfural is not manufactured in Japan and gross quantities are imported. Oji Holdings Corporation announced that commercial production technology of furfural was developed in 2012. The process was used as material for hemicellulose which was coproduced during dissolving pulp-making from wood chips (News release, 2015). This development was carried out with a subsidy from the Japanese government. After making dissolving pulp by sulfuric acid decomposition, steam of 453 K was blown over it and then the steam including furfural was recovered. In this process, 40% of coproduced hemicellulose can be converted to furfural and the purity of furfural was 98.6% (Project records (public version), 2017). Commercialization is expected; however, at the moment there is no information concerning its commercialization. The target cost of furfural
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FIGURE 11.8 THF production from furfural.
was US$1.10 per kg; however, it is difficult to produce under this cost. In recent years, the price of furfural has increased and the import price was US$2.86 per kg as of February 2018 (Foreign trade statistics, 2018). Mitsubishi Chemical Corporation has developed a new process in which tetrahydrofuran (THF) was manufactured by catalytic reaction. In this process, furan was manufactured via a decarbonylation reaction from furfural and then THF was manufactured by hydrogenation, as shown in Fig. 11.8. In the first reaction, the newly developed Pd-loaded catalysis was used. By using this process, THF could be manufactured from the furfural with 92.5% efficiency. Almost all THF is manufactured from crude oil via butadiene or from coal and natural gas via acetylene and its manufacturing cost is US$2.75 US$3.20 per kg.
References Foreign trade statistics. (2018). Ministry of Finance. The forest and forestry white paper in FY 2016. (2017) The Ministry of Agriculture, Forestry and Fisheries. FY. (2017). Report of commissioned program to prepare the plan to promote the recycling model projects using cellulose nanofiber. EX Research Institute Ltd. Retrieved from https:// www.env.go.jp/earth/ondanka/cnf/mat27_1.pdf Jack Miller, Market-Intell LLC. (2017). International conference on nanotechnology for renewable materials. Kanematsu Chemicals Corporation Homepage. Retrieved from https://kccjp.co.jp/ products/furfural/what.html Nanotechnologies. (2017) Standard terms and their definition for cellulose nanomaterial. ISO/TS 20477:2017. News release. (2015). Oji Holdings Corporation, December 16. Project records (public version). (2017). Technology Development of Chemicals Manufacturing Processes from Non-edible Botanical Biomass, Development of Practical Use Technology for Manufacturing from Non-edible Biomass to Chemicals, the Development of Consistent Manufacturing Process from woody biomass to chemicals, the New Energy and Industrial Technology Development Organization. Report for demand and supply of foreign foods in 2016. (2017). The Ministry of Agriculture, Forestry and Fisheries. WBA global bioenergy statistics 2017. (2017). World Bioenergy Association. Retrieved from http://worldbioenergy.org/uploads/WBA%20GBS%202017_lq.pdf Website of Harima Chemicals Group Inc. Retrieved from https://www.harima.co.jp/ pine_chemicals/rosin5.html
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11 Lignocellulose-Based Bioeconomy in Japan Satoshi Hirata National Institute of Advanced Industrial Science and Technology, Tsukuba, Japan
INTRODUCTION In this chapter, a summary of the lignocellulose-based bioeconomy in Japan is provided. There are many lignocellulose resources in Japan and lignocellulose has already been used in lumber, wood processing, and pulp and paper industries. Some chemicals, like rosin and turpentine, are manufactured from lignocellulose. Additionally, energy industries are large consumers of lignocellulose. Much research and development for new uses of lignocellulose have been performed. From 2000 to 2010, research for liquid or gaseous fuel from lignocellulose was actively done in Japan. However, there is no commercial facility in operation currently. The reason for this is that these processes did not have feasibility to continue. It is more expensive to produce these products commercially compared to producing them technically in a laboratory. It is crucial that the bioeconomy process can be produced economically. Meanwhile, the production of biopower, that is, power generation from biomass, has increased since 2012. The serious accident of the atomic power generation in 2011 became the trigger to enhance the feed-in tariff scheme for renewable energy in 2012. Using lignocellulose as a resource for biopower fuel is insufficient in Japan. After 2012, much research into new uses of lignocellulose were launched in the field of nanocellulose and lignin. The Japanese government uses approximately US$46 million per year for nanocellulose research and development. We will discuss the current situation of these new processes.
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LIGNOCELLULOSE RESOURCES IN JAPAN In Japan, forests cover 251 3 103 km2 which is about 66% of the land area. Natural forests cover 134 3 103 km2, artificial plantations 103 3 103 km2, and bamboo forests 1.6 3 103 km2. The total forest area including natural, artificial and bamboo have not changed for 46 years (The forest and forestry white paper, 2017). The cumulative proportion of forests was 49 3 108 m3 in 2012, which represents an increase in volume of 2.6 times over 46 years, mostly through artificial plantations. However, matured planted trees were not used and should be cut down. In 2014, the production of lumber in Japan was 2365 3 104 m3 and 95% of that was used for lumber, pulp and fuel. The demand for woods as lumber, pulp and fuel in Japan was 7458 3 104 m3 and the rate of self-sufficiency was only 30%. Lumber has three major uses: (1) in the lumber and wood processing industries it is used for houses, buildings, and furniture; (2) for the pulp and paper; and (3) for energy. The first and second are traditional industries and they use a large amount of lumber.
LIGNOCELLULOSE FOR TRADITIONAL INDUSTRIES Lumber Industry and Wood Processing Industry Almost all the lignocellulosic biomass is used in the traditional industries of lumber and wood processing and pulp and paper production. The flow of lumber in the lumber and a wood processing industries is shown in Fig. 11.1. The production of lumber in Japan was 2224 3 104 m3 year21 and 95% was used in the country. 534 3 104 m3 of lumber and 1933 3 104 m3 of lumber-processing products were
FIGURE 11.1 Flow of lumber in lumber and wood processing industries.
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imported. In the lumber and wood processing industries, the rate of self-sufficiency was only 47%. Even though there is enough stock from forest resources in Japan, the import ratio is high. The reasons for this high import ratio are that the cost for felling and transportation is expensive, the people engaging in forestry became older and their number decreased, and it is difficult to get uniform lumber in Japan. Cedar is a major plantation species; however, the quality of the wood differs according to area from which it is harvested. It is not easy achieve uniform quality even when the wood is dried. Consequently, the forestry and wood processing industries declined substantially and there is an urgent need for improvement in quality, property, price, and supply stability. There were 5456 lumber mills in Japan by the end of 2014 and this number decreased by 4% each year. There are many small-scale mills and almost of them are proceeding to shutdown. Although the number of smaller mills has decreased, large mills with a processing capacity of more than 10 3 104 m3 year21 have been built. In the wood processing industry, cross laminated timber (CLT) has attracted attention and the Japanese government is making various efforts to harness the interest in this product. Large buildings using CLT have been planned to be built successively and the production facilities of CLT of 50 3 104 m3 year21 should be operational by 2024.
Pulp and Paper Industry The flow of material in the pulp and paper industry in Japan is shown in Fig. 11.2. 477 3 104 tons year21 of domestic lumber was used
FIGURE 11.2
Material flow of pulp and paper industries in Japan.
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in 2016 for the pulp and paper industry. The demand for lumber for pulping was 1610 3 104 tons year21 and 1152 3 104 tons year21 was imported. Besides this, 136 3 104 tons of imported pulp and 1714 3 104 tons of recycled paper were used. Using these materials, 1417 3 104 tons of paper and 1157 3 104 tons of board were produced in Japan in 2016. Japan’s paper and pulp production was the third highest in the world after the United States and China. However, the rate of self-sufficiency of pulp was only 25%. As a large amount of paper and board was produced from domestic recycled paper, the rate of self-efficiency of pulp and paper materials was 72%. Although the production of pulp and paper is decreasing, that of board is increasing because there is a high demand for board for food packaging, home-electronics, mail order, and deliveries to homes.
ENERGY INDUSTRIES Solid Fuel Table 11.1 shows the heat value and carbon ratio of solid fuel made from lignocellulose. Wood chips are most commonly used as the solid fuel of lignocellulose. There are four kinds of chips: crushed chips and cutting chips according to its shape; and dried chips and undried chips according to its moisture content. Production, transportation, and energy conversion are universal technologies and the demand for wood chips is increasing. Wood pellets as a solid fuel of lignocellulose are used in certain parts of Japan. In 2015, the production of wood pellets was 12 3 104 tons year21. The total production in the world was 2800 3 104 tons year21. Japan imported 23 3 104 tons which is almost double the quantity of domestic production; see WBA Global Bioenergy Statistics (2017). The main supply destination is for pulverized coal boilers in thermal power stations. A smaller proportion is used for small-scale, hot-water boilers and stoves. In Japan, the price of wood pellets is expensive, namely US $275 642 per ton, while combustors are also expensive. In addition, as TABLE 11.1
Characteristics of Solid Fuel Made From Lignocellulose Wood chip (not dried)
Wood pellet
Torrefaction pellet
Biocokes
Low heat value (MJ kg )
7
17 18
20 24
17 18
Carbon ratio (%)
25
50
45
50
21
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the demand for heating is not high in Japan, the utilization rate of combustors is low. For these reasons, wood pellets are not popular in Japan. Currently, research and development for the advancement of solid fuels from lignocellulose is being carried out in Japan. One of these solid-fuel products are torrefaction pellets. Torrefaction can be called half carbonization and treatment conditions entail atmospheric pressure, no oxygen, and 473 573 K for 10 30 minutes. By this treatment, a volatile organic compound is released by lignocellulose and the weight goes down by 30% and the energy decreases by 10%. As a result, the energy per weight increases 1.3 times by this treatment. The heat value of wood pellets is 17 18 MJ kg21 and that of torrefaction pellets is 20 24 MJ kg21. In addition, the water resistance and frangibility of pellets are improved by torrefaction, therefore, the ratio of torrefaction pellets can be increased via cocombustion with coal rather than traditional wood pellets. Transportation costs can be decreased due to the increase in energy density. This technology is under development mainly in Europe; however, the Japanese government subsidized Nippon Paper Industries Co., Ltd. (Nippon Paper) and Forestry and Forest Products Research Institute (FFPRI) to research this technology. Nippon Paper developed a production technology for torrefaction pellets and are doing a large-scale demonstration test in Thailand that entails cocombustion in a pulverized coal boiler for power generation. FFPRI manufactured torrefaction pellets in a trial for burning them in a small boiler and pellet stove. Torrefaction pellets cannot be used in a traditional pellet boiler or stove because the energy from torrefaction pellets is different from that of traditional pellets, therefore, it may be impossible for torrefaction pellets to be used by consumers in Japan because even traditional pellets are not popular. Another solid-fuel product is biocokes, which were developed by Professor Ida of Kindai University. Biocokes are produced from many kinds of dried biomass, including lignocellulose, via high pressure and high temperature. The condition for production is 20 MPa and 453 473 K for 20 40 minutes. There are no changes in weight and energy through this treatment although the volume decreases by 1/5. Therefore, the low-heat value of biocokes manufactured from lignocellulose is the same as that of woody pellets, that is, 17 18 MJ kg21. Apparent specific gravity is 1.2 1.4 g cm23, which is double that of woody pellets and the crushing strength is 60 100 MPa. The reason is that hemicellulose and lignin soften and then harden, including the fibrous celluloses, during treatment and biocokes become a hard three-dimensional structure. Biocokes are so hard that it is not broken down during transportation and storage. As it also has water-resistant properties and is not biodegradable, it is suitable for long-term storage.
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In Japan, radioactive substances released into the atmosphere by the Fukushima atomic power disaster attached to the biomass and soil around the power station. The polluted biomass and soil have been collected and will be turned into biocokes to decrease its volume and be stored safely for a long time. When the radiation dose becomes low, the biocokes can be burnt in a managed boiler. After long storage, these biocokes could be used as solid fuel. Kindai University manufactured biocokes from lignocellulose, coffee grounds, and tea grounds, and demonstrated their use as a substitution for cokes. In Malaysia, Kindai University and Osaka Gas Engineering plan to manufacture biocokes from empty palm fruit bunches and import them for shaft kilns.
Liquid Fuel and Gaseous Fuel Research and development for liquid fuel production from lignocellulose has been actively carried out from 2000 to 2010 in Japan. Although demonstration facilities of bench- or pilot-scale were built and operated, there is no facility currently in operation. Various processes have been used and these can be divided into two groups, bioprocesses and thermo-chemical processes. Most major bioprocesses entail bioethanol production by acid hydrolysis and fermentation. Lignocellulose contains cellulose, hemicellulose, and lignin. Through acid hydrolysis, glucose and xylose are mainly produced. Normally, yeast is used for ethanol fermentation; however, traditional yeast, which is used for alcohol beverage production, cannot change xylose into ethanol. Gene-recombinant microorganisms which can use both glucose and xylose were developed and demonstrated. However, the sugar contents in hydrolyzed solution from lignocellulose is so low that the ethanol concentration after fermentation is also low. This process has lower efficiency than the traditional bioethanol process from sugarcane and corn. Ethanol can be produced by these processes; however, the cost is more expensive than traditional bioethanol and gasoline processes. Therefore, these processes cannot currently be commercialized. Some thermo-chemical processes, for example, biomethanol and biomass to liquid (BTL) processes have been studied actively and consists of gasification and chemical synthesis using catalysis. Firstly, lignocellulose is decomposed into hydrogen, carbon monoxide, methane, and other gases, tar, and solid parts. This process is called gasification or pyrolysis and the gas produced is called synthesis gas or syngas. We can classify many kinds of gasification processes according to reaction temperature, pressure, scale, and type of gasifier. The gasification
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process has already been commercialized for coal, exhaust, and some kinds of biomass; however, gasification is not a proven technology for lignocellulose. Many kinds of liquid fuel can be synthesized from hydrogen and carbon monoxide. The production process for methanol is the most simple. Methanol can be used as fuel for internal-combustion engines; however, methanol has causticity for metals and would require a special engine. For this reason, a methanol vehicle did not become popular. Methanol is also used as fuel for fuel-cell vehicles; however, hydrogen became the dominant fuel because methanol requires reforming at 523 K. In Japan, a pilot-scale demonstration plant from lignocellulose to methanol was in operation around 1990; however, it has been turned into a research facility for the BTL process. In the BTL process, a mixture of hydrocarbon with varying molecular weight is produced. The content depends on the type of catalysis, reaction temperature, and pressure to produce, for example, diesel, gasoline, kerosene, and wax. In our institute, the BTL process was studied to produce biodiesel as substitute for fossil fuel. Diesel can be produced from lignocellulose; however, it was very expensive which nullifies its competitive power in the fuel market. There have been many trials where syngas was used as a gaseous fuel for internal-combustion engines. The efficiency of gasification is about 60% 75% and it is not dependent on its scale. In other words, 60% 75% energy of lignocellulose can be recovered as gaseous fuel even at a small scale. This technology is suitable for a small-scale decentralized cogeneration system. A cogeneration system can be built consisting of a gasifier, gas purifier, and gas-engine generator. Various demonstration facilities were built between 2000 and 2010; however, a cogeneration system has not been commercialized. Many technical problems exist in this process. In a gasifier, strictly dried and homogeneous wood chips must be used to produce stable and tar-free gas. In a gas purifier, the tar in syngas must be completely removed and water treatment is also necessary. In addition, there is a huge financial restraint in this process because the fuel and facilities are expensive as well as the operator’s labor cost while the income from heat and power is not significant. However, decentralized heat and power have enormous potential demand in the world, therefore, research into this process must continue.
Electricity In July 2012, the “Act on Special Measures Concerning Procurement of Renewable Electric Energy by Operators of Electric
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Utilities” was enforced in Japan. Electricity generated from renewable resources produced from renewable resources like solar, windpower, and biomass should be bought at a fixed price by operators of electric utilities. As a result, the generation capacity of renewable electricity increased after 2012. Solar power was increased dramatically; however, biomass power increased little because the facility was expensive and necessary for the supplier of the fuels. The purchase price of biomass electricity is higher than the price of traditional electricity, therefore, the cost is transferred to the users. As the purchase prices are only a little higher than the generation cost from renewable resources, the profit is small. This is the reason the generation capacity of renewable electricity must be increased. In biomass power generation, the fuel cost is around 70% of the generation cost. It is, thus, important to improve its feasibility. The purchase price for wood was decided according to the cost when waste wood from lumber mills and the wood processing industry were used. However, palm kernel shell (PKS) and palm oil from South-East Asia were generally used with domestic waste wood because they were cheaper than domestic waste wood. Palm oil was used in 54% of authorized facilities and PKS was used in 72%; however, palm oil has not used since September 2017. The Japanese government revised the purchase prices in March, 2018. The purchase price of electricity from the facilities using biomass liquid fuel was decided by tenders. The purchase prices of renewable electricity from biomass are listed in Table 11.2.
TABLE 11.2 May 2018
Purchase Prices of Renewable Electricity From Biomass in Japan as of
Resource
Capacity
Purchase price excluding tax
Biomass liquid fuel
All
Tender from FY2018
Wood
^10000 kW
Tender from FY2018
Wood not including biomass liquid fuel
,10,000 kW
22 cents kWh21
Methane-gas generation
All
36 cents kWh21
Lumber from thinning
^2000 kW
37 cents kWh21
Lumber from thinning
,2000 kW
29 cents kWh21
Building material waste
All
12 cents kWh21
Waste and other biomass
All
16 cents kWh21
$1 5 109 JPN.
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CHEMICALS AND CHEMICAL MATERIALS Rosin and Turpentine Rosin (fossilized resin) and turpentine are chemicals from lignocellulose which have been used for a long time. Rosin is a purified material from the vegetable fat of pine trees and is manufactured commercially. It is widely used as a sizing agent (a papermaking chemical) and for printing ink, synthetic rubber, adhesive agent, paints, and others. Rosin is classified into three kinds depending on the collection method. Gum rosin is manufactured via the distillation of raw rosin collected from pine trees. Through distillation, turpentine is evaporated and separated. Tall rosin is manufactured via the purification of raw tall oil, which is coproduced by the kraft pulping of pine trees. Wood rosin is manufactured via solvent extraction and distillation from pine chips. Gum rosin is used the most, while most wood rosin is not employed. In 2016, 17 3 103 tons of rosin was manufactured; in contrast, 69 3 103 tons of rosin was consumed in Japan (Website of Harima Chemicals Group Inc). Turpentine is a pale-yellow liquid which is extracted from pine chips via a heating process and contains mainly α-pinene and β-pinene. In the air, turpentine is gradually oxidized which increases its viscosity to become similar to resin. Turpentine is used as a solvent for paint and varnish and as a material for adhesives and other chemicals.
NANOCELLULOSE What Is Nanocellulose? Nanocellulose is composed predominantly of cellulose, with external dimensions being in the nanoscale. It can also be defined as a material having internal structure or surface structure in the nanoscale, with the internal structure or surface structure composed predominantly of cellulose. Nanoscale means that the length range of 50% of the materials is approximately from 1 to 100 nm. The terms cellulose nanomaterial and cellulosic nanomaterial are synonymous with nanocellulose (Nanotechnologies, 2017). There are many kinds of nanocellulose, such as cellulose nanofibril (CNF), cellulose nanocrystal (CNC), and bacteria cellulose. Most nanocellulose is produced from lignocellulose. The relationship between wood and nanocellulose is illustrated in Fig. 11.3. Cellulose microfibril is a fundamental unit of nanocellulose. The diameter is from 3 to 4 nm. Cellulose microfibril entails bundles of 30 40 molecular chains of cellulose; however, this molecular chain cannot be
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FIGURE 11.3 The relationship between wood and nanocellulose.
obtained separately. According to its manufacturing process and component, nanocellulose is roughly divided into three kinds: (1) CNF; (2) lingo-CNF; and (3) CNC. In Japan, CNF is usually called cellulose nanofiber. CNF has been actively studied in North America, Europe, and Asia and more than 20 enterprises supply these products or samples. CNC has been studied extensively in North America and Israel, and some CelluForce and Melodea manage commercial plants. In Japan there are no companies that manufacture CNC. In the next section, current research, development, and industrialization of nanocellulose in Japan will be discussed. Nanocellulose has special properties. The tensile strength of cellulose microfibril is five times stronger than that of steel, while the weight of CNF is one-fifth of that of steel. A solution or sheet of isolated CNF or CNC are not scattered by visible light and they are transparent. They have a huge specific surface area and also have functional groups on their surface, therefore, chemical loading and surface modification is easy. The coefficient of the thermal expansion of nanocellulose is 0.1 ppm K21 which is the same level as quartz glass. Laminate of nanocellulose sometimes has a gas barrier property and its pore size may be controllable. A solution of nanocellulose has thixotropy. Viscosity is controllable through the addition of nanocellulose. Using these properties, many kinds of low materials and products are developing, for example light-weight and high-strength composite materials, transparent materials, electronic materials, packaging materials, filter materials, caring materials, thickeners, gelatinizers, and dispersion stabilizers for emulsion.
Production of Nanocellulose In Japan, more than 10 enterprises manufacture CNF and Ligno-CNF from lignocellulose. The manufacturing processes are different according to the enterprises and some of them have not disclosed their
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FIGURE 11.4
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TEM micrograph of TEMPO-oxidized CNF.
processes. Some of the known processes will be discussed. Cellulose microfibril is a fundamental unit of nanocellulose. Some CNF exist as isolated cellulose microfibrils and other CNF exist as bundles of cellulose microfibrils. The diameter of an isolated microfibril is 3 4 nm; however other types fall in the range of 3 100 nm. Isolated CNF is manufactured via chemical treatment and then defibrated mechanically. The most popular chemical treatment is oxidation using TEMPO catalysis. TEMPO is 2,2,6,6-tetramethylpiperidine 1-oxyl and CH2OH base on the surface of cellulose microfibrils is changed to COONa base. As a result, cellulose microfibrils are dispersed easily. This process was invented by Dr. Isogai of the University of Tokyo and Nippon Paper Industries Co., Ltd., and DKS Co. Ltd. manufactures TEMPO oxidized CNF under the license of Dr. Isogai. Oji Holdings Corporation uses phosphorylation as a chemical treatment and Oji also manufactures isolated CNF. It is easy to measure the diameter and length of isolated CNF and the quality is considered to be good. A TEM micrograph of TEMPO-oxidized CNF is shown in Fig. 11.4. Another process used to manufacture CNF is by mechanical defibration. These CNF are not defibrated to single cellulose microfibrils and most CNF are bundles of cellulose microfibrils. Therefore, it is a mixture of bundles of cellulose microfibrils which have different diameters. The diameter of CNF is in the range of 3 100 nm and can have various distribution according to the products. Moreover, CNF is sometimes ramified. It is not easy to measure its diameter and length.
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FIGURE 11.5 Major facilities for nanocellulose production in Japan.
Different defibration processes are used by the various manufacturers. The major equipment needed for defibration are a high-pressure homogenizer, refiner (mill), supermasscolloider (mill), twin screw extruder, water-jet crusher, bead mill, and micro fluidizer. The characteristics of CNF is totally different depending on the materials and equipment used, as well as the defibration conditions like water to solid ratio, reaction time, pressure, and temperature. A third CNF is ligno-CNF, which is manufactured not from delignificated pulp, but from lignocellulose. As ligno-CNF contains lignin on the surface of cellulose fibers, the diameter is larger than CNF from pulp and the diameter varies according to position. It is usually ramified and, therefore, it is quite difficult to measure both diameter and length. CNF is so hydrophilic that it is difficult to mix CNF uniformly with resin and elastomer; however, lingo-CNF is relatively easy to mix with resin and elastomer because lignin is hydrophobic. Fig. 11.5 shows the major facilities for nanocellulose production and its capacity in Japan.
Application Development and Products Application development of nanocellulose has been actively pursued using its property and now six types of products are sold in Japan. The first is an aqueous solution of CNF manufactured by Gaulin
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homogenizer with a solid content of 10% 35%. The diameter of the fibers is 10 100 nm and it is used as a binder for powder and fibrous materials, paper-strong agent in paper making, food additive to improve food feeling, a kind of filter aid agent for liquor, and as a cosmetic additive to improve water holding properties. Although these products are authorized as a food additive, unfortunately which consumer products use this CNF is not disclosed. Secondly, there is a gel-ink pen which uses TEMPO-oxidized CNF as a thickener. This product benefits from the thixotropy of CNF. Thixotropy is when fluidity increases when pressure increases and vice versa which allows a smooth flow of ink without having to press hard onto paper. The third product is a diaper and urine leakage pad for adults. CNF has a huge specific surface area and much functional groups on their surface. In these products, a high deodorization seat is used which holds silver ions with an antibacterial deodorization effect on the surface of the TEMPO-oxidized CNF. The deodorization power of these products is triple that of the conventional products. The fourth is a speaker and headphone in which a new vibration board using CNF is applied. This CNF is made from bamboo and the products benefit from the high rigidity of CNF. In these products, the response is good and it realizes low tone reproduction to stand up. The fifth is a disposable cleaning sheet for toilet bowls. This product uses the originally developed CNF produced by the energy-saving process. This product is harder to tear than existing products. The sixth product is cosmetics using carboxymethylated CNF. A fragrance gel, body and hand cream, and skin water are manufactured and sold. Carboxymethylated CNF is probably used for viscosity control and improvement of water-holding properties. These six products are consumer products except of first one. The dose of CNF in the products is likely to be very low. In Japan, much research in the possible applications of CNF are underway and some prototypes of additional products have been released, for example, safety boots in which CNF was mixed with rubber for added strength, paper containers for foods which with smell and oxygen barrier characteristics, a super low density porous body which assumed to apply for catalysis loading material, an insulation material, a cell culture matrix, and an adsorbent. The Japanese government spends US$460 million per a year on research and development of nanocellulose. This budget has allowed many projects to be pushed forward. The government has invested in automobile parts, household electric appliances, and a housing component because the markets of these fields are large and the consumption of CNF is also large.
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JAPANESE GOVERNMENT PROJECTS The main research subjects are the production, modification, and composite-making with resin and elastomer. The ministry of Economy, Trade and Industries intends to construct a consistent process from lignocellulose to CNF reinforced resin in collaboration with Kyoto University. This reinforced resin is intended to be used for automobile parts, the body of household electric appliances, and housing components. In the project, the technical target is that the coefficient of elasticity and strength of reinforced resin increases to double the original resin by 10% CNF addition. The cost target for lingo-CNF for injection molding is $12,000 per dry ton and lingo-CNF for extrusion molding is $9200 per dry ton by March 2020. Weight reduction and the low carbonization of the products in these industries will be achieved and, consequently, the emission of greenhouse gases will be decreased. The aim is to replace the metal used in vehicles, household electric appliances, and buildings with CNFreinforced resin. The budget is US$36 million per year as FY 2018. The consistent process from lignocellulose to CNF-reinforced resin developed by Kyoto University is called the “Kyoto Process” and consists of the production of lingo-CNF, modification of its surface, and mixing with resin. There are three key points in this process. Firstly, the material, namely wood chips, are used and then lignin remains on the surface of nanofibers. As a result, heat-resistant ability and hydrophobicity is improved as CNF made from pulp. The second point is the chemical modification of lingo-CNF to increase its heat-resistant ability. The third is that defiberization of cellulose fibers and mixing with resin are done simultaneously by an extruder and then this process is simplified. The process flow of the Kyoto process is shown in Fig. 11.6. Firstly, wood chips are cooked and washed to remove most hemicellulose and the majority of lignin. After preliminary defiberization under high pressure by a refiner and then removal of large fibers in a screening process, the fine fibers are made into sheet foam and dried. In order to mix lingo-CNF and resin uniformly, heat-resistant ability is necessary. In this process, by acetylation of the dried sheet, 1% weight loss temperature increases approximately 10 20 K. The acetylated sheet of fine fibers is crushed into powder and then mixed with resin by a twinscrew extruder to obtain pellets of reinforced resin. These resin pellets are used for injection molding. For resin from 90% polypropylene and 10% lingo-CNF, the modulus of elongation increased 1.3 times, tensile strength increased 1.5 times, bend elastic constant increased 1.4 times, and bending strength increased 1.3 times. In addition, a hot-pressed product was manufactured by way of trial and its bending strength was
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FIGURE 11.6
The process flow of the “Kyoto process.”
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217 MPa and its bend elastic constant was 10.7 GPa. For industrialization, Nippon Paper built a new plant for CNF-reinforced resin for which the production capacity is 10 tons year21.
FUTURE PROSPECTS The sales prices of CNF is in the range of US$180 US$460 per kg in Japan. As there are many kinds of CNFs and their purities vary, the prices of all CNFs are not in this price zone; it is rather expensive. There are plans to use CNF as a filler for commodity plastic and studies are proceeding actively. The price of commodity plastic is about US$2 per kg. The production cost of CNF should be decreased to spread CNF for the filler purpose. As material prices are unlikely to go down, it is necessary for the manufacturing cost to go down by improving the manufacturing process. There are many manufacturing processes of CNF in Japan. Among them, some processes are quite difficult to scale up and automate and they will potentially be restructured by international competition. On the other hand, 75% of pulp consumed in Japan is imported mainly due to cost. From the point of view of scale merit and logistic cost, the production of CNF or the material used for CNF in other countries may become a better option in the future. It is important that Japanese CNF maintains a good cost performance and high quality which can be differentiated from others. Moreover, new application development in which the improvement of the performance is higher than the increase of the cost is equally important. When CNF is used, performance is improved; however, it does not usually balance the cost increase. It is easier to apply this balance with expensive products and in specialized fields, for example, medical materials, cosmetics, and electric parts. The prospective demands for nanocellulose announced by a researcher in the United States are listed in Table 11.3. This reflects the potential rather than concreate demand worldwide. In this research, the potential demand of nanocellulose is 23.1 3 106 tons year21 and 20.0 3 106 tons of this are for paper industries and 1.0 3 106 tons are for textile industries. The potential demand for other applications is 2.1 3 106 tons year21. On the other hand, the Japanese government intends to utilize CNF for structural materials and to replace exhaustible resources. In a report which the government consigned to a research company, CNF will mainly be used as materials for automobile, electric appliance and housing component industries and the use of reinforced materials is expected to be 442 3 103 tons year21 by 2030, as shown in Table 11.4. 66% of this will be used for window frame sashes.
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TABLE 11.3 Prospective Demand of Nanocellulose in the World (Jack Miller, Market-Intell LLC, 2017)
Industries
Market ( 3 106 tons year21)
Dosage of nanocellulose (%)
Demand of nanocellulose ( 3 106 tons year21)
Paper, board
400.0
5
20.0
Textile
50.0
2
1.0
Paint, coating
40.0
2
0.8
Carbon black
15.0
2
0.3
Film
9.7
2
0.2
Composite of resin
9.0
2
0.2
Oil and gas drilling
17.5
1
0.2
Nonwoven fabric
7.0
2
0.1
Water treatment
4.7
2
0.1
Pharmaceutical additive
4.6
2
0.1
Cement
15.0
0.5
0.1
Adhesive
0.5
2
0.01
Cosmetics
0.3
1
0.003
Separator of battery
0.06
2
0.001
Total
23.1
CNF is mixed with polyvinyl chloride which may decrease the weight of the sash by 20%. CNF-reinforced polyamide will be used for many automobile parts and then the weight may be decreased by 57.7%. As CNF will be used for tires, the weight may be decreased by 20%. In 2030, if these parts are used for 17% of automobiles manufactured in Japan, the use of CNF-reinforced resin and rubber will be 12 3 104 tons in total. Moreover, CNF-reinforced polypropylene will be used for refrigerator parts, laundry machines, and air-conditioners, and then the use of CNF-reinforced resin will be expected to be less than 3 3 104 tons. The ratio of CNF in the resin and rubber is not described in the report. If it is 5%, then the demand for CNF is 22 3 103 tons year21. If it is just 0.2% of the production and imported amount of pulp in Japan, which was 1017 3 104 tons in 2012. Finally, CNF confronts the share competition with CNC and cellulose filament (CF), which are cheaper than CNF. CNC and CF are mainly produced commercially in North America and can be dried easily. There are few application studies for CNC and CF in Japan. In the case
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TABLE 11.4 Prospective Demand of CNF-Reinforced Materials by 2030 in Japan (FY, 2017) Weight of parts (kg)
Alternative materials
Amount to use (kg)
Penetration ratio (%)
Number of shipments (year21)
Total amount of use (tons year21)
Main body, sub frame
260.7
CNF 1 PA
110.2
17.2
688,000
75,900
Industries
Parts
Automobile
Electric appliance
Housing component
Side-door, bonnet
50.0
CNF 1 PA
21.1
14,500
Back door
30.0
CNF 1 PA
12.6
8700
Roof
5.6
CNF 1 PA
2.36
1600
Instrument’s panel
7.1
CNF 1 PA
5.0
3400
Tire
32.0
CNF 1 Rubber
25.6
17,600
Body of refrigerator
14.0
CNF 1 PP
5.9
Pulsator of washing machine
4.0
CNF 1 PP
Fans in outdoor unit of air-conditioner
2.0
Frame of resin sash
22.0
40.0
2,000,000
11,800
2.0
2,800,000
5600
CNF 1 PP
2.0
3,800,000
11,400
CNF 1 PVC
18.0
Building:30.0
2,341,000
52,400
Renovating:15.0
13,350,000
239,000 441,900
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where there is not a large deference in the performance among CNF, CNC, and CF, the cheaper one will be adopted. It is important to differentiate domestic CNF for Japan.
Integrated Biorefinery Process Lignocellulose has three components: cellulose, hemicellulose, and lignin. The most industrialized process using the components of lignocellulose is the pulp and paper industry. In this industry, technology innovation has been performed to improve how to separate cellulose fibers efficiently from lignocellulose and the process has been almost completed. In this process, the separated components, namely hemicellulose and lignin, are used as fuel for soda recovery boilers. On the other hand, almost all block chemicals are produced from naphtha and 23% of the crude oil imported by Japan is used as materials for chemicals. Petroleum resources will be exhausted in the future and all petroleum resources are imported in Japan. Moreover, during the manufacture process, the use and disposal of chemicals cause greenhouse gas emissions which is unfavorable for global warming. The Japanese government launched a research project so that the materials of the chemicals change from naphtha to nonedible biomass resources. Nonedible biomass means lignocellulose including agricultural wastes and weeds. In the biorefinery process during the commercial stage, sugars as starch are used for materials; however, 60% 70% of sugars and almost 100% of corn are imported in Japan (Report for demand and supply, 2017). To establish an integrated biorefinery process from lignocellulose, the research and development project started in 2013 and will continue for seven years. There are many research subjects and many organizations have joined it. In the next section, only the main subjects are presented.
Separation of Three Components To use the three components of lignocellulose as materials for highvalued substances, new separation technologies are being studied. Promising tree species are cedar and eucalyptus, because cedar is the main species in plantation in Japan and eucalyptus is the main species in plantation in foreign countries by Japanese enterprises. The numerical target of a new separation technology is that total recovery of the three components should be 70%, the recovery of cellulose is 70%, that of hemicellulose is 50%, and that of lignin is 70%. After the research, a revised alkaline cooking process was adopted. The separation process and conventional conversion process are shown in Fig. 11.7.
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FIGURE 11.7 Separation process and conventional conversion process.
The revised alkaline cooking method entails soda cooking with 2% anthraquinone. For cedar, when the concentration of anthraquinone is 0.1%, the recovery of hemicellulose was 45%; however, when the concentration of anthraquinone is 2%, the recovery of cellulose was increased to 83%, that of hemicellulose was 55%, and that of lignin was 96%, and so the numerical target can be reached. The mean molecular weight of lignin was 2890, and it was too high to use as material for resin. It is quite difficult to develop a new separation process by which all components can be used as materials for chemicals. Although the numerical target was accomplished in this project, it has not been commercialized yet.
Lignin Many approaches to utilize lignin for chemical materials have been conducted. When sulfur is included in the lignin fraction, it is difficult to use the lignin as chemical materials. Therefore, kraft cooking (the most popular pulping method) is not suitable for this purpose because kraft cooking uses Na2S. To use the lignin fraction as chemical materials, the ratio of lignin with a molecular weight under 1000 is necessary for more than 50%; however, it was difficult to decrease its molecular weight. At this stage, lignin for resin materials has not been obtained. When the lignin fraction from the revised alkaline cooking becomes acidic, deposition of raw lignin occurs; however, hemicellulose includes more than 2% in softwood and more than 10% in hardwood. Hemicellulose becomes an inhibitor when lignin is uses as chemical
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materials, and should be removed. By adjusting the pH and solubility of lignin fraction, hemicellulose was successfully removed.
Separation by Acetone and the Water Method This method is to recover both cellulose and lignin from lignocellulose. It is carried out at 493 K under 5 9 MPa for 1 hour and the solid concentration is 30% in 50% acetone and 50% water solution. Lignin and hemicellulose are soluble in the acetone mixture and cellulose is recovered as a solid. From the acetone/water solution, acetone is recovered by evaporation. Lignin is recovered from the acetone fraction and hemicellulose is recovered from the water fraction. The mean molecular weight of lignin was 700 and the softening temperature of lignin was 373 383 K, therefore, the lignin can be used for resin materials.
Furfural and Tetrahydrofuran When diluted sulfuric acid is added to lignocellulose and then heated, hemicellulose is hydrolyzed to pentose-like xylose. Furfural is obtained via the dehydration reaction of pentose. Furfural is commercially manufactured from the waste of corn, wheat, oats, bagasse, and saw dust. The total production amount was 37 3 104 tons worldwide including 30 3 104 tons in China in 2012. In Japan, 2 3 103 tons was consumed (Kanematsu Chemicals Corporation Homepage). Furfural is used as a solvent in the petro chemistry industry and is changed to furfuryl alcohol via hydrogen reduction, which is used as the material for furan resin. Furan resin is widely used as a hardening agent of silica sand in casting, lining agent for containers and tanks, and material for resin cement. The world’s largest production country of furfuryl alcohol is China which produces 12 3 104 tons year21 (Kanematsu Chemicals Corporation Homepage). Furfural is not manufactured in Japan and gross quantities are imported. Oji Holdings Corporation announced that commercial production technology of furfural was developed in 2012. The process was used as material for hemicellulose which was coproduced during dissolving pulp-making from wood chips (News release, 2015). This development was carried out with a subsidy from the Japanese government. After making dissolving pulp by sulfuric acid decomposition, steam of 453 K was blown over it and then the steam including furfural was recovered. In this process, 40% of coproduced hemicellulose can be converted to furfural and the purity of furfural was 98.6% (Project records (public version), 2017). Commercialization is expected; however, at the moment there is no information concerning its commercialization. The target cost of furfural
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FIGURE 11.8 THF production from furfural.
was US$1.10 per kg; however, it is difficult to produce under this cost. In recent years, the price of furfural has increased and the import price was US$2.86 per kg as of February 2018 (Foreign trade statistics, 2018). Mitsubishi Chemical Corporation has developed a new process in which tetrahydrofuran (THF) was manufactured by catalytic reaction. In this process, furan was manufactured via a decarbonylation reaction from furfural and then THF was manufactured by hydrogenation, as shown in Fig. 11.8. In the first reaction, the newly developed Pd-loaded catalysis was used. By using this process, THF could be manufactured from the furfural with 92.5% efficiency. Almost all THF is manufactured from crude oil via butadiene or from coal and natural gas via acetylene and its manufacturing cost is US$2.75 US$3.20 per kg.
References Foreign trade statistics. (2018). Ministry of Finance. The forest and forestry white paper in FY 2016. (2017) The Ministry of Agriculture, Forestry and Fisheries. FY. (2017). Report of commissioned program to prepare the plan to promote the recycling model projects using cellulose nanofiber. EX Research Institute Ltd. Retrieved from https:// www.env.go.jp/earth/ondanka/cnf/mat27_1.pdf Jack Miller, Market-Intell LLC. (2017). International conference on nanotechnology for renewable materials. Kanematsu Chemicals Corporation Homepage. Retrieved from https://kccjp.co.jp/ products/furfural/what.html Nanotechnologies. (2017) Standard terms and their definition for cellulose nanomaterial. ISO/TS 20477:2017. News release. (2015). Oji Holdings Corporation, December 16. Project records (public version). (2017). Technology Development of Chemicals Manufacturing Processes from Non-edible Botanical Biomass, Development of Practical Use Technology for Manufacturing from Non-edible Biomass to Chemicals, the Development of Consistent Manufacturing Process from woody biomass to chemicals, the New Energy and Industrial Technology Development Organization. Report for demand and supply of foreign foods in 2016. (2017). The Ministry of Agriculture, Forestry and Fisheries. WBA global bioenergy statistics 2017. (2017). World Bioenergy Association. Retrieved from http://worldbioenergy.org/uploads/WBA%20GBS%202017_lq.pdf Website of Harima Chemicals Group Inc. Retrieved from https://www.harima.co.jp/ pine_chemicals/rosin5.html
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