Economics and cost analysis of waste biorefineries

Economics and cost analysis of waste biorefineries

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Kondusamy Dhamodharan1, Saumya Ahlawat2, Mehak Kaushal3 and Karthik Rajendran4 1 Department of Civil Engineering, Indian Institute of Technology Guwahati, Guwahati, India, 2Department of Bioscience and Bioengineering, Indian Institute of Technology Guwahati, Guwahati, India, 3System Biology for Biofuel Group, International Centre for Genetic Engineering and Biotechnology, New Delhi, India, 4Department of Environmental Science, SRM University—AP, Amaravati, Andhra Pradesh, India

25.1

Introduction

Economics and cost analysis plays a major role in any kind of industries for its sustainability and benefits. The increasing of waste generation in developing countries leads to major environmental issues and resource shortage. If due steps are taken, this waste can be a source for revenue generation, that is, through reuse of material that can be recycled or by conversion of biomass to energy or value-added products. The biological fraction from wastes generated in developing countries is 50% higher when compared with developed nations. So, waste-based biorefineries play a vital role in the economy of developing countries. Waste can be a potential raw material for biorefinery technologies such as aerobic or anaerobic fermentation and combustion of waste in presence (incineration) or absence of oxygen (pyrolysis), resulting in pollution-free gasification. Industrial waste based biorefineries have more scope in both revenue generation and waste minimization. Identification and implementation of proper technology for biorefinery are mostly depended on how much revenue it can generate and its payback period. Waste biorefineries if integrated into the infrastructure of developing countries could generate new entrepreneurs, more job opportunity, cost cutoff for waste management, waste to energy generation, less landfill, lower greenhouse gas (GHG) emissions, eco-friendly products production, and more benefits. Cost analysis for the applicability of waste biorefinery technologies is more critical due to its sensitivity to social and environmental issues. Cost analysis is to cut down the unnecessary investments for improper technology or to find the market feasibility of waste biorefinery products. Many biorefinery technologies are energycentric besides capital. Waste biorefineries focused on resource recovery in various forms instead of energy could improve the capital investment in this sector. Resource recovery also cuts down the raw material cost of various products, reduces its market price, and increases the consumers. This chapter deals with Refining Biomass Residues for Sustainable Energy and Bioproducts. DOI: https://doi.org/10.1016/B978-0-12-818996-2.00025-9 © 2020 Elsevier Inc. All rights reserved.

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economic barriers and its solutions for waste biorefinery implementation, cost analysis to improve technology and product value, and case studies of successful waste biorefinery industry.

25.2

Biomass cost

While the cost of energy crops is specific to each crop and is influenced by the available cultivation land, maximum attainable yield under natural conditions, and production cost involved, cost of agricultural and forest residues is specific to each region and is controlled by the availability of the residue, handling, and transportation facility, and accessibility to the nearest biorefinery via different modes of transport. In India the most common feedstock for bioethanol biorefineries is molasses that is a byproduct in sugar processing. The market price of molasses fluctuated from US$18 to US$92 per ton in the last decade. Agricultural residues are also not immune to such fluctuations, for example, rice husk price observed similar fluctuations between US $18 and US$74 per ton in 2010 (Sharma, 2010). Rice straw, bagasse, rice husks also observed variation in their market price albeit the fluctuations were on the lower side (Hamadion, 2012; Sharma, 2010). Market price fluctuated between (US$ per ton): rice straw 11 13, bagasse 12 14, and rice husks 22 30 (Hamadion, 2012). In India, food-grain straw is mainly used as cattle feed followed by used in industry as packaging material, construction material, straw board, and paper and hardboard units. At harvest time, market price for wheat or bajra straw varies among different states in India (CSE, 2015). In 2010, while the price (per ton) in Rajasthan ranged between US$92 and US$111, it was US$74 US$92 and US $83 US$102 in Gujarat and Maharashtra, respectively (CSE, 2015). Cost of agricultural/forestry residue is dependent on various parameters such as biomass production, preprocessing, handling, and transport. It comes out to be considerable when thorough analysis of all these parameters is undertaken (Tripathi et al., 1998). The market price of barley straw and arhar stalks depending upon different travel distance from the farm (15, 50, and 100 km) is shown in Fig. 25.1. Cost of residues fluctuated between US$14 and US$34 per ton, minimum being for bajra straw and maximum for arhar stalks. In another scenario, when the travel distance was 100 km from the farms, cost fluctuated from US$36 to US$55 per ton for bajra straw and arhar stalks, respectively, highlighting the influence of transportation on market price of residues. The dashed line in the figure shows bioenergy generation on grassland considering only lignocellulosic crops (Fig. 25.1). The production cost of agricultural products is attained by implementing the best agricultural practices. Fig. 25.1 shows the cost and availability of different agro biomass in India.

25.3

Logistics and availability of biomass

Biomass can be defined as the organic material derived from plants, algae, or animal manure. Wood and its waste (64%) comprise the majority of biomass energy

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Figure 25.1 Region-wise distribution and cost of agricultural biomass feedstock in India.

source followed by municipal solid waste (MSW) (24%), agricultural waste (5%), and landfill gases (5%) (Demirbas, 2009). India is known for its biomass diversity, which can be categorized as grasses, woody plants, fruits, vegetables, manures, and aquatic plants. Biodiesel manufacturers have also started using algae and jatropha as feedstock. These available biomass sources can be broadly divided into three categories: energy crops, agricultural crop residues, and municipal and industrial waste (Williams et al., 1997).

25.3.1 Energy crops Energy crops are dedicated crops, such as sugarcane and corn, cultivated to serve as feedstock for biorefineries. Biofuels produced using these crops are termed as firstgeneration (1G) biofuels. Depending upon the abundance in cultivation, different countries have different energy crops which are frontrunners for biorefinery feedstock. For example, in North America, corn and soybean serve as the main biomass

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source for bioethanol and biodiesel biorefineries, respectively (Hoekman, 2009). Similar to North America, Brazil has soybean-based biodiesel biorefineries; however, sugarcane is the main feedstock in bioethanol biorefineries. While China produces 80% of its bioethanol using corn as the dedicated energy crop (International Institute for Sustainable Development, 2007), India is dependent on molasses, left after sugar processing, for most of its bioethanol production. Malaysia and Germany have established biodiesel biorefineries based on palm oil and rape oilseed, respectively. Other energy crops that can find application in biorefineries include sweet potato, cassava, barley, and sweet sorghum. Apart from these, several other oilseeds such as canola, sunflower, safflower, cottonseed, and jatropha are also being investigated. Biorefineries based on dedicated energy crops are more developed in comparison to lignocellulosic biorefineries (Kokossis and Yang, 2010). It is because energy crops are easy to use, have high energy content, and give a better return on investment; however, they also serve as food for the human population and give rise to the food-versus-fuel debate. This also leads to increased pricing of food, for example, sugar prices increased in Brazil since the start of sugarcane-based bioethanol biorefineries. Certain nonfood energy crops compete with food grains for other resources such as land and water. Further, generating additional land and other resources for cultivation of energy crops may lead to loss of biodiversity and more harm to the environment (Fargione et al., 2008). It needs to be seen how a balance is attained between 1G biofuel production and overall sustainability.

25.3.2 Agricultural crop residues Agricultural residues encompass all the organic materials generated as a by-product of unit operations undertaken during the postharvest processing of agricultural crops. These agricultural residues can be classified as primary and secondary residue (Murali et al., 2008). Primary residues are the by-products obtained on site (field) at the time of harvest such as rice straw and sugarcane tops. They have alternate applications as manures or animal feed and are less available as bioenergy feedstocks. On the other hand, secondary residues are the by-products obtained at the processing units’ postharvest such as rice husk and sugarcane bagasse. They are available in large quantities, don’t have applications as animal feed/manures, and hence can be used as a bioenergy feedstock. India is among the top nations in terms of agricultural land and production of several crops (Food and Agriculture Organization of the United Nations, n.d.), which, in turn, result in amassing huge amounts of agricultural residues. These residues can be potential raw materials for biorefineries, and Fig. 25.2A and B shows the type and quantity of agricultural biomass available in India.

25.3.3 Municipal and industrial waste India is one of the fastest developing economies with ever-increasing population. This translates into a generation of abundant municipal and industrial waste.

Economics and cost analysis of waste biorefineries

Figure 25.2 Types and mass of agro biomass availability in India. (A) Greater than 10,000 kt/year, (B) less than 10,000 kt/year.

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Development of a waste-based biorefinery serves the dual purpose of waste treatment and continuous supply of feedstock. Some examples of wastes which can be used in biorefineries are as follows: MSW: Each year a huge amount of solid waste, ranging in millions of tons, is collected from household and disposed of in fields. In India, approximately 80% of total MSW comprises paper and plastics. Anaerobic digestion or direct combustion can be used for the conversion of these wastes to energy (TIDE, 2004). Municipal and industrial wastewater: Huge amount of wastewater is generated through the day-to-day household and industrial activities. Various sources of wastewater include water used in the cleaning of fruits, vegetables, meat, fish, and poultry; black liquor generated from paper and pulp industry; liquids discharged from milk-processing units, beverage industry; and animal manure (Ravindranath et al., 2005). Indiscriminate dumping of wastewater into the water stream and land leads to serious water and soil pollution. This further causes health problems among the human population and other terrestrial and aquatic life. Municipal and industrial wastewater contains dissolved organic material that is one of the pollution causing contaminants. Since the organic matter is in the form of sugars and starch, which are easily utilizable carbon sources, it is possible to use these potential contaminants as biomass feedstock for biorefineries. Several waste-based biorefineries exist, which are used for bioethanol and biogas production through fermentation and anaerobic digestion, respectively (Zafar, 2009; Varshney et al., 2010). Food industry wastes: Food industry waste mainly comprises waste generated from the food-processing industry and food services such as hotels, restaurants, and catering. While waste from food-processing industry includes fruits and vegetables scrap, nonstandard food, pulp, and fiber remaining after processing and filter sludge; service industry waste mainly includes stale or unconsumed food and fruits and vegetable rejected during cooking. These carbon-rich wastes, which are generally dumped in landfills, can be a source of biomass in anaerobic digestion (Reddy, 1995). Animal wastes: India ranked first in the world in terms of milk production (165 MT in 2017 18) and second in cattle population (190 million in 2012) (Food and Agriculture Organisation of the United Nations, 2016). As a result, a large amount of animal waste is generated, which can be a potential feedstock for biorefineries.

It comprises organic material, moisture, and ash that can be decomposed either aerobically or anaerobically to produce stabilized organic materials and methane, respectively. India has a huge potential for methane production due to its animal manure production, but it was not effectively utilized (Varshney et al., 2010).

25.3.4 Logistics One of the bottlenecks involved in commercialization of biorefineries is the cost involved in logistics, which include several discrete processes, detailed as follows (Allen et al., 1998): G

G

Harvesting and collection of biomass on site, that is, cultivation field or forest. Storage of biomass: Proper storage of biomass is of paramount importance to ensure their round the year availability, even though they are harvested at a different time of the year. Location of the storage space can be at the collection site, biorefinery, or at any place in between the two sites. Biomass storage at the collection site is a low-cost option and

Economics and cost analysis of waste biorefineries

G

G

G

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considered by many researchers (Allen et al., 1998; Huisman et al., 1997; Sokhansanj et al., 2006). However, there are certain disadvantages associated with it such as loss of biomass material due to degradation; uncontrolled moisture content of biomass leading to processing difficulties; chances of contamination due to spore formation or fungal infection; and finally low storage period as the farmers need the land for cultivation of next crop (Allen et al., 1998; Nilsson, 1999; Sokhansanj et al., 2006). Biomass storage is a critical stage in the biomass supply chain; hence, the location and facility should be decided based on a holistic analysis of respective storage units. Processing of biomass: Low energy content of biomass in comparison to fossil fuels coupled with low density means that comparatively large amount of biomass is required to obtain a similar amount of energy. This poses severe handling and transportation problems. Compacting of biomass through several processing or pretreatment steps is advantages as it reduces the volume of biomass and improves the storage, handling, and transportation efficiency. Through densification techniques, the harvested biomass can be processed into bales, pellets, cubes, pucks, briquettes, and wood chips. Technically processing can be undertaken at any stage; however, the advantages are maximized if it is done after harvesting/collection stage. Transfer of biomass from the collection point to a common point from where the transportation can be initiated. It also involves loading of biomass into the transportation vehicles and unloading them once the biomass reaches the biorefinery. Transportation: Biomass feedstocks have geographically varied locations, low energy content, and density, which makes transportation of the cost-intensive step of the supply chain. Cost input during transportation is dependent on travel distance, travel time, and biomass density. Travel distance affects the cost involved in fuel purchased for vehicles and also the travel time involved. Travel time, in turn, affects the cost involved in hiring manpower, maintenance of the vehicles, and insurance. Travel time includes the time spent on a round trip and the waiting time during the loading and unloading of biomass at the site and biorefinery, respectively. Hence, the larger the distance between the two sites, larger the travel time, and higher the capital allocation toward manpower and maintenance. Another factor affecting the transportation cost is biomass density. The low density of biomass means a large volume of biomass needs to be transported, hence more number of vehicle required or multiple trips to be undertaken by a limited number of vehicles. This increases the cumulative travel distance and time and ultimately the cost.

Biomass sources are mostly located in farms or forests and are typically transported through road by using a third-party chartered trucks or agricultural equipment; views are split on which mode of road transport is more economical than the other (Allen et al., 1998; Huisman et al., 1997; Tatsiopoulos and Tolis, 2003). While road transport is advantageous when short-distance travel is required and provides higher flexibility as compared to other modes such as a train or ship, the latter is potentially useful when long-distance travel is undertaken.

25.4

Policy support for commercialization

Commercialization of a biofuel biorefinery requires staunch policy support, which would affect production levels, production methods, type feedstocks. Policies

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framed to support different types of biofuels vary in different countries based on region-specific goals and potential. There are certain common drivers of bioenergy policy, described as in the following subsections, followed by an overview of bioenergy policies in different countries.

25.4.1 Drivers for bioenergy policy Key driving factors behind the interest in bioenergy are fuel prices, energy security, climate change, and rural development. Fuel prices are increasing as a response to increasing demand due to energy-intensive lifestyle and reduced supply partly due to disruptive political issues, creating a need to look for alternate energy sources. The year 2007 saw a 2.9-fold increase in average price of oil, reaching 80 (USD per barrel) from $27 in 2002. Many nations aim to increase their energy security in order to limit exposure to the fluctuating energy supply and soaring costs. Using bioenergy diversifies the energy supplies, reduces dependency on fossil fuels, and decreases strain on a national budget, especially in nations dependent on import to meet their energy requirements. Japan is moving toward using ethanol because dependence on natural gas import from Russia is a potential energy security risk; similarly, United Kingdom is switching to bioenergy as it is observing decreasing natural gas supply and possible depletion of its North Sea oil fields in the coming decades. The third driving force toward bioenergy growth is the increased GHG emissions leading to global climate change. Nations are committing to reducing their overall carbon footprint including GHG emissions and thereby lower the rate of increase in global temperature. The European Union (EU), during council decision in March 2007, mandated a 20% reduction in GHG emissions by 2020. Bioenergy provides an alternate in terms of reducing GHG emissions and through technological interventions has the potential to become cost-effective in comparison to other energy sources. The fourth driving factor is rural development, whereby bioenergy development may contribute through employment generation and maintenance, poverty alleviation, and revitalization of the agriculture sector. Other drivers for bioenergy include air pollution, soil protection, and land reclamation, and waste management. Apart from releasing GHGs into the atmosphere, fossil fuel burning also contributes toward air pollution by emitting heavy metals, carcinogenic substances, and particulates, which contribute to photochemical smog. Biofuels have lower polluting emissions and classify as clean energy sources. With a growing global population and industrialization, the amount of waste generated is on the rise every successive year. There exist several traditional uses of the generated waste, for example, animal feed, manures, and composting; however, a large amount of waste is either burnt or dumped in landfills. This can be put to good use as a feedstock for biorefineries. Landfill directive in the EU mandates uses of organic matter in the MSW for bioenergy generation in order to reduce the amount of waste being dumped. Similar policies will be required in developing countries to manage increasing industrialization led to waste generation.

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Figure 25.3 Key policy mechanisms adopted in different countries.

25.4.1.1 Overview of policies in different countries Different countries have their own goals and aim to fulfill while framing individual bioenergy policies; however, many of them, to an extent, follow similar policy instruments. Key policy mechanisms which are employed in varied degree are mentioned briefly in Fig. 25.3. The concept of Fig. 25.3 was adapted from the report of FAO (2005).

25.4.2 India It was in 1948 with the passing of the Indian Power Alcohol Act that the first laws were made regarding the biofuel usage in India (Saravanan et al., 2018). This was done as a push toward the “power alcohol” industry in India. However, the 1948 Act was revoked in 2000, which was followed by the launching of the Ethanol Blending Programme (EBP) in 2002. The key feature of the notification was a mandatory blending of 5% ethanol with petrol. The mandate was applied in nine of the sugarcane-producing states and three union territories. EBP was later proved ineffective due to unavailability of raw material, inability in the implementation of ethanol pricing formula, delays to the various state agencies, etc. Further, the Government of India launched The National Biodiesel Mission (NBM) in 2003 with the key focus on the cultivation of jatropha on wastelands. NBM too failed to materialize successfully due to various bottlenecks such as deficiency in seed production, collection and extraction, and absence of mutual understanding between

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farmers and industry players. Finally, the “National Policy on Biofuels,” 2008, was launched and approved in 2009. The policy was formulated with prime emphasis on encouraging the use of biofuels in the transport sector in India with the aim of achieving 20% blending by the end of 2017 as mandatory biofuel target (United States Department of Agriculture, 2017). The government has revised the National Policy on Biofuels, 2009, and the new version was approved by the cabinet in 2018.

25.4.2.1 Salient features of National Policy on Biofuels, 2018 1. Under the policy, biofuels are categorized as basic and advanced biofuels. 1G bioethanol and biodiesel come under the basic biofuels, while second generation (2G) ethanol, MSW to drop-in fuels, third-generation biofuels, bio-CNG, etc. are clubbed under the advanced biofuel group. This has been done so that suitable financial incentives are given under each category. 2. The policy has allowed the use of sugarcane juice, various sugar-containing supplies of sugar beet, sweet sorghum, starch comprising supplies such as corn, cassava, damaged wheat, broken rice, and rotten potatoes for ethanol production. 3. During the excess production season, the price of food grains falls, and this directly affects the farmers since they don’t get the appropriate price for their produce. To overcome the same, policy motivates the use of excess grains for ethanol production to be used for blending with gasoline. 4. In order to boost the production and usage of advanced biofuels, the policy has proposed a Rs. 5000 crores funding for 2G ethanol biorefineries along with tax incentives and higher purchase price in comparison to 1G biofuels. 5. Supply chain mechanisms have been proposed to be set up which will boost the production of biodiesel from nonedible oilseeds, used cooking oil and fast-growing crops. 6. To provide fair prices to the farmers, the policy encourages a minimum support price for oilseeds along with the provision of regular revisions. 7. The policy instructs the financing agencies such as National Bank of Agriculture and Rural Development and Small Industries Development Bank of India to be involved aggressively in lending loans to farmers for plantation or for that matter any other activity related to the entire biofuel production process. 8. The policy provides tax and excise duty rebates on bioethanol plant and machinery while giving an exemption to biodiesel along with an extended concession on nonindigenously manufactured biofuel compatible engine vehicles. 9. The policy instructs the state governments to elect or formulate an agency, which will be authorized and funded to work for the expansion and promotion of biofuels in their states. 10. The state governments are instructed by the policy to decide on the land/wasteland/ degraded land/nonforest land to be used for the cultivation of nonedible oilseed bearing plants or other feedstocks of biofuel production.

25.4.2.2 Brazil Brazil has led the world in use of bioethanol for transportation and implemented the National Ethanol Fuel Program in the 1970s. The program was initiated to deal with declining national sugar price and to reduce the dependency on imported oil. Brazil guaranteed the execution of the program through financial aids such as

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support to maintain a balanced production cost among regions with varying degree of development and tax benefits for alternative fuel vehicles. In 2004 the Brazilian government announced the National Biodiesel Production Program to encourage biodiesel production and use. The program forced the suppliers of biodiesel to get vegetable oil from small-scale farmers (Langevin, 2010) and provided tax incentives according to the feedstock used, the capacity of producer, and location (FAO, 2016). The Brazilian government, in 2017, implemented a tariff rate quota to restrict bioethanol imports that were threatening the market for locally produced bioethanol due to competitive pricing. According to the tariff rate quota, bioethanol imports beyond 600 million liters were subject to 20% tariff (United States Department of Agriculture, 2018). National Biofuels Policy of Brazil, also termed as RenovaBio, came into effect in December 2017. The underlying objectives of the policy are to reduce GHG emission and promote energy security through local biofuel production and use. The new regulation will be framed till 2019 and may come into effect by early 2020 (RenovaBio, 2011). Current Brazilian bioethanol and biodiesel blend stand at 27% (E27) and 10% (B10), respectively, along with the import tariff quota which would be reassessed in September 2019 (United States Department of Agriculture, 2018; Voegele, 2018).

25.4.2.3 China China is the most populous country in the world and since 2010 also ranks first in terms of energy consumption and CO2 emission, which have provided the impetus for bioenergy friendly policies. Dedicated biofuel programs, introduced in the early 2000s provided incentives for food crop-based bioethanol, are now obsolete; nevertheless, subsidies for nonfood crop based bioethanol remain in place (United States Department of Agriculture, 2015). China is targeting overall 15% biofuel usage by 2020, and many provinces are moving toward mandated 10% blending (Lane, 2016). In addition to mandated blending and financial incentives, national biofuel standards also play an important role in the development of the bioenergy industry. Hence, China has four national standards established for Denatured Fuel Ethanol, Ethanol Gasoline for Motor Vehicles (E10), Biodiesel Blend Stock (BD100) for Diesel Engine Fuels (GBT 20828), and Biodiesel Fuel Blend (B5) (GBT 25199), which have been updated regularly depending upon technical and commercial scenario. The Chinese government, both at the central and province level, is extensively involved in mitigating GHG emissions and promoting renewable energy. The broad inclination is toward gradual discontinuation of financial subsidies and transition from the 1G to advanced biofuels.

25.4.2.4 European Union EU Energy and Climate Change Package (CCP) 2009 details the rules for biofuel usage in transportation (EC, 2016). The CCP prescribed that by 2020, 20% of the total energy requirement should be fulfilled through bioenergy. Through the Renewable Energy Directive (RED), it also specified that in order to make biofuels

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sustainable, several factors need to be considered including but not limited to GHG reduction and environmental concerns, land management, and socioeconomic factors (USDA Foreign Agricultural Service, 2016). The European Commission, in 2015, mandated that by 2020 1G biofuel usage in transportation would be limited to a maximum of 7% of the total energy consumption (USDA Foreign Agricultural Service, 2019). RED mandated 10% biofuel blending (of which 7% can be the 1G) by 2017 for all member states and gave an optional 5% blending target for advanced biofuels on a national basis.

25.4.2.5 United States The first renewable fuel program of the United States, also known as Renewable Fuel Standard (RFS1) program, was established through the Energy Policy Act of 2005 (govinfo, n.d.). This policy mandated the blending of a minimum volume of biofuel with gasoline every year but not biofuel production. The required blending volume needs to be announced in the month of November for the next year in case of biofuels blended with gasoline and 14 months prior in case of biodiesel, by the regulatory agency US Environmental Protection Agency (Bracmort, 2016a,b). RFS1 was revised in 2007, by the Energy Independence and Security Act, to form RFS2. The revised policy mandated a minimum of 9.0 billion gallons biofuel production and consumption from 2008, along with increasing the minimum blending volume to 36 billion gallons per year by 2022 (Bracmort, 2016a). It also demarcated the categories of biofuels that can be used and restricted their respective blending volume. Out of 36 billion gallons biofuel to be blended by 2022, 15 billion gallons can be derived from corn bioethanol, and rest 21 billion gallons can be cumulatively obtained from cellulosic biofuels, biodiesel, and advanced biofuels. Biofuel blending and production is motivated through central and state government biofuel policies. While central policy offers tax credits for blending, reduce taxes on bioethanol import, and provides monetary benefits to non-1G biofuel producers, the state policy arranges for financial incentives, mandates use of biofuel vehicles for governmental use, and establishes fuel blend standards (FAO, 2016).

25.5

Bottlenecks in commercialization and profitability possibilities

Despite evident necessity, policy support, advantages, biorefinery deployment has not achieved widespread commercialization due to several bottlenecks such as biomass availability; supply chain and transportation; process automation; scale-up challenges; technical competence; and financial aspects and dearth of investment.

25.5.1 Feedstock availability One of the major economic concerns for the continual operation of biorefineries is the availability of inexpensive lignocellulosic biomass. Being dependent on single

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biomass may affect round the year functioning; hence, it’s imperative that the lignocellulosic biorefinery can utilize multiple biomass sources subject to their availability. Brazil primarily uses sugarcane residues (bagasse and straw) as lignocellulosic feedstock. Now, corn stover is advancing as a potential 2G ethanol feedstock due to policy support by RenovaBio, a new biofuel policy of Brazil. In the United States, corn stover is the primary biorefinery feedstock; other feedstocks such as forestry waste, energy crops, and other agro-residues (miscanthus, switchgrass, poplar, etc.) are also used depending upon their availability (Somerville et al., 2010). Judicious use of these biomass sources has the potential of replacing B30% of the current petroleum consumption by the year 2030. India and China are one of the top producers of sugarcane and other major agricultural crops, hence possess the capability of exploring multiple/mixed feedstocks in biorefineries (Chandel and Singh, 2011). In 2015 India produced approximately 200 MT agro-residues that were burnt in considerable amount leading to air pollution and loss of potential feedstock material. Cost of raw material accounts for more than 50% of the total capital requirement in a biorefinery (Junqueira et al., 2016). Hence, biomass availability and cost need to be examined in detail as a part of the economic assessment of lignocellulosic biorefineries.

25.5.2 Feedstock management and transportation Lignocellulose feedstock management and transportation are critical issues for economic biorefinery operation; hence, it is essential that an agreement is reached between biomass suppliers and processing units regarding long-term round the year supply of feedstock, at both localized and centralized biorefineries (Richard, 2010; Valdivia et al., 2016). Key steps involved in the biomass supply chain of a biorefinery are as follows: biomass collection, biomass storage, preprocessing of biomass, transportation, and postprocessing (Sharma et al., 2013). Approximately 40% 60% of the cost incurred during large-scale biofuel production accounts for agro-residues and energy crops price, storage, processing, and transport infrastructure (Humbird et al., 2011; Miao et al., 2013). 2G biorefineries cannot become economical unless developments in feedstock logistics, storage, and transport are undertaken directed toward minimization of transportation cost and energy input. The distance between biorefinery and biomass production sites is proportional to the overall transportation cost and should be considered when investigating the feasibility of biorefinery operation (Balan, 2014). Each biorefinery differs from another in terms of biomass collection, storage, and transport logistics. In sugar industries, the majority of sugarcane bagasse generated is utilized in the boiler to produce heat and power, while the rest can be a source of biomass for production of biofuels or biochemical. Comparatively lower bulk density of agroresidues and grassy crops, around 50 100 kg dry matter/m3, in comparison to corn (721 kg dry matter/m3), hinders their efficient supply. Therefore it is important to systemize the supply chain through model-based systems approach in a biorefinery operation (Miao et al., 2013). Biomass supply chains should strive to achieve a

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balance between economic gains and environmental aspects, empower the stakeholders (farmers, locals, and investors), thereby accomplishing the purpose of setting up a biorefinery (Richard, 2010).

25.5.3 Advanced processes The success of a petroleum biorefinery depends on process automation and mechanization. Similarly, biorefineries must have automation and mechanization at all the process steps, that is, biomass handling, pretreatment, enzyme hydrolysis, filtration, fermentation, and product recovery, in order to achieve successful operation at large scale (Fernando et al., 2006). Ethanol production using sugarcane juice or corn grains is commercialized at a large scale. Largescale production of cellulosic ethanol has also been started in many countries; however, their success has been hindered due to process automation and mechanical difficulties. Lignocellulosic biorefineries utilize each component of the biomass to produce multiple products (Haro et al., 2014) and as a result deal with the flow of heterogeneous material in different processes right from biomass screening to product recovery (Parisutham et al., 2017). Large-scale processes are continuously operated, and hence, it is essential that the transfer of feedstock one step to another is unperturbed such as movement of biomass for pretreatment, pretreated slurry for filtration, filtered liquid for enzymatic hydrolysis, and eventual convergence of different 2G sugar streams, 1G sugar streams or molasses at the fermentation stage followed by product separation. These operations require complete automation and mechanization to achieve higher yields and productivities and ensure profitability.

25.5.4 Scale up difficulties Demand for bio-based products is increasing at the rate of 3% 4% per year, making scale-up of biorefineries necessary. Studies have been undertaken to examine bio-based products in terms of their global production levels (Dammer et al., 2013) and their technological and commercialization status (Choi et al., 2015). To that end, identification and mitigation of bottlenecks associated with scale-up are of paramount importance. Biorefineries, such as petroleum refinery, also involve a large amount of heterogeneous material processing and the data obtained in laboratories may not be reproducible at an industrial level, thus making its scale-up challenging. An approach for addressing the bottlenecks is process modeling and simulation targeted toward life cycle and risk assessment, economic and cost sensitivity analysis (Junqueira et al., 2016). Another important requirement for scale-up of biorefineries is innovation in manufacturing and downstream-processing infrastructures aligned to the regulatory norm, that is, development of efficient steel factories. While scaling up a biomassprocessing unit, it is also of essence that suitable process design is used for the biomass feedstock. For example, the steam explosion has been successful for C5 (in liquid) and C6 (in fiber) sugar recovery from sugarcane bagasse; ammonium

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hydroxide has shown better results for corn stover. In conclusion, critical factors affecting the scale-up of biorefineries are as follows (Sanford et al., 2016): G

G

G

G

G

G

G

G

G

Nature of biomass, composition, and pretreatment conditions Process integration Selection of products Life cycle assessment Risk factor analysis Safety and regulatory norms Cost sensitivity analysis and reproducible economic modeling Water usage, minimum waste generation, and zero waste discharge policy Judicious use of equipment/human resource

25.5.5 Technical maturity One of the key hindrances in the commercial deployment of lignocellulosic biorefineries is the lack of requisite technical advancement. In spite of success at a laboratory scale a competent technology that can be established at an industrial scale is unavailable. A possible reason is scaled up issues involved when technology is transferred from laboratory to industry, and these issues exist at every step of a biorefinery operation such as biomass processing, hydrolysis, fermentation, and downstream processing. In addition, biomass storage, handling and transport, and biomass sorting and cleaning prior to pretreatment prove to be a demanding task considering the scale at which they are undertaken. In order to be fermented, biomass needs to be broken into simpler components, which start with a breakdown at pretreatment step. Pretreatment is the key process that requires major technological advancement. One of the critical challenges associated with pretreatment at large scale is the maintenance of the high-pressure flow of untreated and pretreated biomass through transfer lines for different unit operations such as pretreatment, filtration, and hydrolysis. This is further complicated due to the heterogeneous nature of the pretreated slurries and the presence of a high concentration of total solids (Elliott et al., 2015). Few companies such as Abengoa, Poet-DSM, Du-Pont, Beta renewables, Raizen, and Granbio have set lignocellulosic biorefineries at commercial scale using different pretreatment processes. Abengoa and Poet-DSM use single-stage and two-stage dilute acid based pretreatment strategies, respectively; Du-Pont has employed ammonia hydroxide for pretreatment. Beta Renewables, Raizen, and Granbio use steam explosion for pretreatment, similar to CTC-Piracicaba that has a demonstration plant in Sao Manoel, Brazil. Important factors involved in the steam explosion are the maintenance of a steady biomass feed continuously, maintenance of the optimum steam pressure for the required period of time, and prevention of steam loss during the process. Recovery percentage is high for C5 sugars in liquid and for C6 sugars in fiber, albeit with impurities in the form of acetic acid, formic acid, and lignin-derived phenolics. While every technology comes with its own set of pros and cons, pretreatment methods involving steam and acid and/or alkali usage pose economic and environmental issues.

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Post pretreatment, the biomass slurry (unfiltered or filtered) undergoes enzymatic hydrolysis, using cellulase enzyme, which is the final step in the breakdown of carbohydrates in simple sugars which are readily fermentable. To improve the efficiency of hydrolysis and obtain concentrated sugar solutions, the optimal amount of suitable cellulolytic enzyme concoction is required to act upon high biomass loading. However, using more than 20% of biomass loading poses technical problems and need technological intervention. Several enzyme production companies such as Novozymes, VTT, DSM, and Du-Pont have developed cellulases concoctions; among them, the enzyme cocktail of Cellic CTec 3 and Cellic HTec3 produced by Novozymes is the most successful. Commercial availability of enzymes developed by VTT, DSM, and Du-Pont is unclear, and hence, it is essential that a consensus is reached between suppliers and buyer to avoid monopolization of the market by a single entity. Enzyme hydrolysis is followed by fermentation of released sugar into desired products. An alternative to this can be simultaneous saccharification and fermentation (SSF) where hydrolysis of cellulose and fermentation of sugars takes place simultaneously in the same vessel. Sometimes both processes are carried out by the same microorganism and sometimes cofermentation is performed where hydrolysis is carried out by one microorganism and fermentation by another. In the case of SSF, it is advantageous that the microorganism used is able to consume both C5 and C6 sugars as it maximizes the yield of product per gram biomass used. Native organisms using both C5 and C6 sugars as substrates to give high product titer and productivity are difficult to find. Hence, several companies such as Genomatica, Global yeast, Taurus, Xylome are developing recombinant microorganisms having desired phenotypes, which will be commercially available for use in biorefineries. Another step that requires special attention in terms of technological advancement is the downstream processing. Typical processes employed for product recovery after fermentation are distillation or centrifugation, purification and concentration, and crystallization, depending upon the type of product synthesized. Generally, the lignin cake obtained is used energy generation in boilers as it has high energy content and adds economic value to the biorefinery. However, it can also be valorized into the high-value product, research on which is still at the nascent stage. Once the suitable technical know-how is developed, lignin processing will provide a huge economic boost to the commercialization of lignocellulosic biorefinery (Ragauskas et al., 2014).

25.5.6 Financial aspects, profitability and dearth of investment Another bottleneck associated with biorefinery commercialization is lack of investment and other economic aspects. Reasons that hinder the status of agricultural residue based biorefineries as a lucrative investment option are high capital and operational cost, uncertainty associated with biorefinery operation, low growth and product yield of biological organisms (Chandel et al., 2010). Biomass availability and cost are responsible for operational uncertainty and operational cost, respectively, which deters the investors from investing in lignocellulosic biorefineries. Total biomass cost incurred is cumulative of selling price quoted by supplier,

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storage cost, and logistics and transportation cost and is subject to availability at certain time of year and region (Thorsell et al., 2004). Pretreatment and hydrolysis constitute a major part of the economic investment in a lignocellulosic biorefinery, of which only a small proportion is borne by a refinery using 1G feedstocks. Pretreatment contributes 30% 50% and 20% 25% to total capital and operational expenditure, while enzymes used in hydrolysis account for 30% of the total processing expenditure. Pretreatment, hydrolysis, and fermentation form the central triad of a lignocellulosic biorefinery. While pretreatment and hydrolysis depend upon the type of feedstock used, fermentation depends on the enzyme/organism used and the product being synthesized. Technological interventions through efficient pretreatment or simultaneous hydrolysis and fermentation may reduce the operational input of lignocellulosic biorefineries. Costs incurred during downstream-processing operations are also dependent on the type of product recovered, for example, ethanol distillation set up contributes around 15% 20% to the total capital invested in equipment. Further, the lignin cake obtained from the processing step can be valorized into low-cost carbon fiber/nanotubes, plastics, foams, polymers, paints/adhesives, and membranes, all of which currently require technological advancement but have potential to improve the economic output of a biorefinery (Ragauskas et al., 2014). Another application of lignin that is quite established is used as fuel in boilers which saves US$5 US$10 per ton through energy generation. In order to achieve the commercial success of biorefineries, it is imperative that the capital investments are increased and partnerships are fostered at every level. Collaboration in the form of joint partnerships, technology transfer, logistics, services, sales, and marketing will improve dialog between different stakeholders, thereby increase the technical know-how and upsurge the investments.

25.6

Conclusion

For biorefineries and bio-based products to be commercially viable, several factors and stakeholders need to work together. This includes increasing the yield and decreasing the cost of biomass production, developing efficient technologies that can utilize the biomass to produce various products. Apart from technologies and logistics, a key driving factor that can help biorefinery commercialization will be the policy dimension. An efficient policy can allow technologies to compete against each other, help them innovate and reduce the cost, which eventually can bring down the cost of biorefineries.

References Allen, J., Browne, M., Hunter, A., Boyd, J., Palmer, H., 1998. Logistics management and costs of biomass fuel supply. Int. J. Phys. Distrib. Logist. Manage. 28 (6), 463 477. Available from: https://doi.org/10.1108/09600039810245120.

562

Refining Biomass Residues for Sustainable Energy and Bioproducts

Balan, V., 2014. Current challenges in commercially producing biofuels from lignocellulosic biomass. ISRN Biotechnol. 2014 (i), 1 31. Available from: https://doi.org/10.1155/ 2014/463074. Bracmort, K., 2016a. The Renewable Fuel Standard (RFS): In Brief. Retrieved from: ,https://digital.library.unt.edu/ark:/67531/metadc958630/.. Bracmort, K., 2016b. The Renewable Fuel Standard (RFS): Waiver Authority and Modification of Volumes. Retrieved from: ,https://digital.library.unt.edu/ark:/67531/ metadc824757/.. Chandel, A.K., Singh, O.V., 2011. Weedy lignocellulosic feedstock and microbial metabolic engineering: advancing the generation of “Biofuel.”. Appl. Microbiol. Biotechnol. Available from: https://doi.org/10.1007/s00253-010-3057-6. Chandel, A.K., Singh, O.V., Chandrasekhar, G., Rao, L.V., Narasu, M.L., 2010. Key drivers influencing the commercialization of ethanol-based biorefineries. J. Commer. Biotechnol. 16 (3), 239 257. Available from: https://doi.org/10.1057/jcb.2010.5. Choi, S., Song, C.W., Shin, J.H., Lee, S.Y., 2015. Biorefineries for the production of top building block chemicals and their derivatives. Metab. Eng. 28, 223 239. Available from: https://doi.org/10.1016/J.YMBEN.2014.12.007. CSE, 2015. Why is Fodder So Expensive? Battle for Delhi. DownToEarth. pp. 1 6. Retrieved from: ,https://www.downtoearth.org.in/coverage/why-is-fodder-so-expensive-802.. Dammer, L., Carus, M., Raschka, A., Scholz, L., December 2013. Market developments of and opportunities for biobased products and chemicals. In: Markets and Trends of BioBased Products. pp. 1 69. Demirbas, A., 2009. Biohydrogen: For Future Engine Fuel Demands. Springer. EC, 2016. 2020 Climate and Energy Package. Retrieved January 22, 2019, from: ,https://ec. europa.eu/clima/policies/strategies/2020_en.. Elliott, D.C., Biller, P., Ross, A.B., Schmidt, A.J., Jones, S.B., 2015. Hydrothermal liquefaction of biomass: developments from batch to continuous process. Bioresour. Technol. 178, 147 156. Available from: https://doi.org/10.1016/j.biortech.2014.09.132. FAO, 2005. Bioenergy in the Global Energy Context. Retrieved from: ,http://www.fao.org/ docrep/pdf/010/a1348e/a1348e02.pdf.. FAO, 2016. FAOSTAT. Retrieved January 22, 2019, from: ,http://www.fao.org/faostat/en/ #home.. Fargione, J., Hill, J., Tilman, D., Polasky, S., Hawthorne, P., 2008. Land clearing and the biofuel carbon debt. Science 319 (5867), 1235 1238. Available from: https://doi.org/ 10.1126/science.1152747. Fernando, S., Adhikari, S., Chandrapal, C., Murali, N., 2006. Biorefineries: Current Status, Challenges, and Future Direction. ,https://doi.org/10.1021/EF060097W.. Food and Agriculture Organization of the United Nations, n.d. India at a glance. In: FAO in India. Retrieved January 22, 2019, from: ,http://www.fao.org/india/fao-in-india/indiaat-a-glance/en/.. Food and Agriculture Organization of the United Nations. 2016. India at a glance. In: FAO in India. Food and Agriculture Organization of the United Nations. Retrieved January 19, 2019, from: ,http://www.fao.org/india/fao-in-india/india-at-a-glance/en/.. govinfo, n.d. Public Law 109-58—Energy Policy Act of 2005—Content Details—PLAW109publ58. Retrieved January 20, 2019, from: ,https://www.govinfo.gov/app/details/ PLAW-109publ58.. Hamadion, H., 2012. Renewable Energy Technologies: Cost Analysis Series. IRENA. Retrieved from: ,http://www.academia.edu/12663204/RENEWABLE_ENERGY_ TECHNOLOGIES_COST_ANALYSIS_SERIES..

Economics and cost analysis of waste biorefineries

563

´ .L., Arjona, R., Ollero, P., 2014. Thermochemical biorefiHaro, P., Villanueva Perales, A neries with multiproduction using a platform chemical. Biofuels Bioprod. Biorefin. 8 (2), 155 170. Available from: https://doi.org/10.1002/bbb.1465. Hoekman, S.K., 2009. Biofuels in the U.S. challenges and opportunities. Renew. Energy 34 (1), 14 22. Available from: https://doi.org/10.1016/J.RENENE.2008.04.030. Huisman, W., Venturi, P., Molenaar, J., 1997. Costs of supply chains of Miscanthus giganteus. Ind. Crops Prod. 6 (3 4), 353 366. Available from: https://doi.org/10.1016/ S0926-6690(97)00026-5. Humbird, D., Davis, R., Tao, L., Kinchin, C., Hsu, D., Aden, A., et al., 2011. Process Design and Economics for Biochemical Conversion of Lignocellulosic Biomass to Ethanol: Dilute-Acid Pretreatment and Enzymatic Hydrolysis of Corn Stover. Golden, CO. ,https://doi.org/10.2172/1013269.. International Institute for Sustainable Development, 2007. Biofuels At What Cost? Government Support for Ethanol and Biodiesel in Selected OECD Countries. International Institute of Sustainable Development, ISBN: 978-1-894784-22-1. Junqueira, T.L., Cavalett, O., Bonomi, A., 2016. The virtual sugarcane biorefinery—a simulation tool to support public policies formulation in bioenergy. Ind. Biotechnol. 12 (1), 62 67. Available from: https://doi.org/10.1089/ind.2015.0015. Kokossis, A.C., Yang, A., 2010. On the use of systems technologies and a systematic approach for the synthesis and the design of future biorefineries. Comput. Chem. Eng. 34 (9), 1397 1405. Available from: https://doi.org/10.1016/J.COMPCHEMENG. 2010.02.021. Lane, J., 2016. Biofuels Mandates Around the World: 2016. Retrieved January 22, 2019, from: ,http://www.biofuelsdigest.com/bdigest/2016/01/03/biofuels-mandates-aroundthe-world-2016/.. Langevin, M.S., 2010. The Brazilian biodiesel program. J. Energy Secur. (December). Retrieved from: http://www.ensec.org/index.php?option 5 com_content&view 5 article&id 5 273:brazilian-biodiesel-program&catid 5 112: energysecuritycontent&Itemid 5 367. Miao, Z., Grift, T.E., Hansen, A.C., Ting, K.C., 2013. Energy requirement for lignocellulosic feedstock densifications in relation to particle physical properties, preheating, and binding agents. Energy Fuels 27 (1), 588 595. Available from: https://doi.org/10.1021/ ef301562k. Murali, S., Shrivastava, R., Saxena, M., 2008. Quantification of agricultural residues for energy generation—a case study—India Environment Portal | News, reports, documents, blogs, data, analysis on environment & development | India, South Asia. J. Inst. Public Health Eng. 3, 27. Nilsson, D., 1999. SHAM—a simulation model for designing straw fuel delivery systems. Part 1: Model description. Biomass Bioenergy 16 (1), 25 38. Available from: https:// doi.org/10.1016/S0961-9534(98)00076-2. Parisutham, V., Chandran, S.-P., Mukhopadhyay, A., Lee, S.K., Keasling, J.D., 2017. Intracellular cellobiose metabolism and its applications in lignocellulose-based biorefineries. Bioresour. Technol. 239, 496 506. Available from: https://doi.org/10.1016/J. BIORTECH.2017.05.001. Ragauskas, A.J., Beckham, G.T., Biddy, M.J., Chandra, R., Chen, F., Davis, M.F., et al., 2014. Lignin valorization: improving lignin processing in the biorefinery. Science. Available from: https://doi.org/10.1126/science.1246843. Ravindranath, N.H., Somashekar, H.I., Nagaraja, M.S., Sudha, P., Sangeetha, G., Bhattacharya, S.C., et al., 2005. Assessment of sustainable non-plantation biomass

564

Refining Biomass Residues for Sustainable Energy and Bioproducts

resources potential for energy in India. Biomass Bioenergy 29 (3), 178 190. Available from: https://doi.org/10.1016/J.BIOMBIOE.2005.03.005. Reddy, A.K.N., 1995. The blessing of the commons. Energy Sustain. Dev. 2 (1), 48 50. Available from: https://doi.org/10.1016/S0973-0826(08)60112-X. RenovaBio, 2011. RenovaBio The New Brazilian Biofuels Policy. ,https://doi.org/ 10.1360/zd-2013-43-6-1064.. Richard, T.L., 2010. Challenges in scaling up biofuels infrastructure. Science (New York, N. Y.) 329 (5993), 793 796. Available from: https://doi.org/10.1126/science.1189139. Sanford, K., Chotani, G., Danielson, N., Zahn, J.A., 2016. Scaling up of renewable chemicals. Curr. Opin. Biotechnol. 38, 112 122. Available from: https://doi.org/10.1016/J. COPBIO.2016.01.008. Saravanan, A.P., Mathimani, T., Deviram, G., Rajendran, K., Pugazhendhi, A., 2018. Biofuel policy in India: a review of policy barriers in sustainable marketing of biofuel. J. Cleaner Prod. 193, 734 747. Available from: https://doi.org/10.1016/J. JCLEPRO.2018.05.033. Sharma S.P., 2010. Mini-thermal power projects turning unviable in Malwa Raw material, agriculture waste, prohibitively expensive. The Tribune, Chandigarh, India Business. Retrieved January 18, 2019, from: ,https://www.tribuneindia.com/2010/20101221/biz.htm#6.. Sharma, B., Ingalls, R.G., Jones, C.L., Huhnke, R.L., Khanchi, A., 2013. Scenario optimization modeling approach for design and management of biomass-to-biorefinery supply chain system. Bioresour. Technol. 150, 163 171. Available from: https://doi.org/ 10.1016/J.BIORTECH.2013.09.120. Sokhansanj, S., Kumar, A., Turhollow, A.F., 2006. Development and implementation of integrated biomass supply analysis and logistics model (IBSAL). Biomass Bioenergy 30 (10), 838 847. Available from: https://doi.org/10.1016/J.BIOMBIOE.2006.04.004. Somerville, C., Youngs, H., Taylor, C., Davis, S.C., Long, S.P., 2010. Feedstocks for lignocellulosic biofuels. Science 329 (5993), 790 792. Available from: https://doi.org/ 10.1126/science.1189268. Tatsiopoulos, I.P., Tolis, A.J., 2003. Economic aspects of the cotton-stalk biomass logistics and comparison of supply chain methods. Biomass Bioenergy 24 (3), 199 214. Available from: https://doi.org/10.1016/S0961-9534(02)00115-0. Thorsell, S., Epplin, F.M., Huhnke, R.L., Taliaferro, C.M., 2004. Economics of a coordinated biorefinery feedstock harvest system: lignocellulosic biomass harvest cost. Biomass Bioenergy 27 (4), 327 337. Available from: https://doi.org/10.1016/J.BIOMBIOE.2004.03.001. TIDE, 2004. Bioreactors for Organic Fraction of Municipal Solid Waste at Siruguppa. Bangalore. Tripathi, A.K., Iyer, P.V.R., Kandpal, T.C., Singh, K.K., 1998. Assessment of availability and costs of some agricultural residues used as feedstocks for biomass gasification and briquetting in India. Energy Convers. Manage. 39 (15), 1611 1618. Available from: https://doi.org/10.1016/S0196-8904(98)00030-2. United States Department of Agriculture, 2015. China: Biofuels Annual. Retrieved January 22, 2019, from:,https://www.fas.usda.gov/data/china-biofuels-annual-3.. United States Department of Agriculture, 2017. India: Biofuels Annual. Retrieved January 22, 2019, from: ,https://www.fas.usda.gov/data/india-biofuels-annual-1.. United States Department of Agriculture, 2018. Brazil: Biofuels Annual. Retrieved January 22, 2019, from: ,https://www.fas.usda.gov/data/brazil-biofuels-annual-4.. USDA Foreign Agricultural Service, 2016. Malaysia: Biofuels Annual. USDA Foreign Agricultural Service. Retrieved January 20, 2019, from: ,https://www.fas.usda.gov/ data/eu-28-biofuels-annual-0..

Economics and cost analysis of waste biorefineries

565

USDA Foreign Agricultural Service, 2019. EU-28: Biofuel Mandates in the EU by Member State. USDA Foreign Agricultural Service. Retrieved January 16, 2019, from: ,https:// www.fas.usda.gov/data/eu-28-biofuel-mandates-eu-member-state-1.. Valdivia, M., Galan, J.L., Laffarga, J., Ramos, J.-L., 2016. Biofuels 2020: biorefineries based on lignocellulosic materials. Microbial Biotechnol. 9 (5), 585 594. Available from: https://doi.org/10.1111/1751-7915.12387. Varshney, R., Bhagoria, J., Mehta, C., 2010. Small scale biomass gasification technology in India—an overview. J. Eng., Sci. Manage. Educ. 3, 33 40. Retrieved from: http:// 14.139.58.2/ejournalver2/abstract/year2010/volume3/RajivVarshneyJ.L.BhagoriaC.R. Mehta.pdf. Voegele, E., 2018. Report: Ethanol Production in Brazil to Increase 9% in 2018. Retrieved January 22, 2019, from: ,http://ethanolproducer.com/articles/15570/report-ethanol-production-in-brazil-to-increase-9-in-2018.. Williams, T.O., Ferna´ndez-rivera, S., Kelley, T.G., 1997. The influence of socioeconomic factors on the availability and utilization of crop residues as animal feeds. In: Renard, C. (Ed.), Crop Residues in Sustainable Mixed Crop/Livestock Farming Systems. CAB International in Association with the International Crops Research Institute for Semi-arid Tropics and the International Livestock Research Institute, pp. 1 15. Retrieved from: http://oar.icrisat.org/8754/. Zafar, S., 2009. Biomass Wastes. AltEnergyMag. Retrieved January 22, 2019, from: ,https://www.altenergymag.com/article/2009/08/biomass-wastes/530/..