- Email: [email protected]
Potential feedstock for renewable aviation fuel in Brazil
Environmental Development 15 (2015) 52–63
Contents lists available at ScienceDirect
Environmental Development journal homepage: www.elsevier.com/locate/envdev
Potential feedstock for renewable aviation fuel in Brazil Heitor Cantarella a,n, André Meloni Nassar b, Luis Augusto Barbosa Cortez c, Ricardo Baldassin Juniorc a Agronomic Institute of Campinas, Soils and Environmental Resources Center, P.O. Box 28, 13001-970 Campinas, SP, Brazil b Secretary of Agricultural Policy, Ministry of Agriculture, Livestock and Food Supply, 70043-900 Brasilia, DF, Brazil c School of Agriculture Engineering, State University of Campinas, 13083-970 Campinas, SP, Brazil
a r t i c l e in f o
a b s t r a c t
Article history: Received 15 May 2015 Accepted 20 May 2015
The aviation industry worldwide is committed to reduce CO2 emissions. The present goal is towards Carbon Neutral Growth (CNG) by 2020 and 50% reduction in net CO2 emissions over 2005 levels by 2050. There are not easy alternatives to liquid fuels for airplanes; therefore, biofuels are necessarily part of the solution. However, the specifications for jet biofuel rule out ethanol and biodiesel, the most common biofuels in the market. There are several routes for the production of aviation biofuel allowing the use of a wide range of biomasses. The conversion and refining technology pathways will be determinant for the choice of feedstock. At present, most jet biofuel tested in airplanes are derived from oils, but not taking into account conversion technologies, the best options to start an aviation biofuel industry in Brazil are sugarcane, eucalyptus, and soybean, of the sugar, cellulose, and oil crop groups. The main reasons are the established production chains, high yields, competitive prices, and possibility of greenhouse gases abatement. Other crops may be feasible options depending on specific regional conditions, further agronomic improvements, and cost reduction. Taking as reference the energy content of ethanol, around 30 Mha of land would be necessary to supply sugarcane to meet 50% of the present global consumption of jet fuel. This is less than the 64 Mha of land suitable for sugarcane in Brazil, mostly replacing pasture and
Keywords: Jet biofuel Sugarcane Land availability Bioenergy CO2 abatement
n
Corresponding author. Tel.: þ55 19 2137 0766. E-mail addresses: [email protected] (H. Cantarella), [email protected] (A.M. Nassar), [email protected] (L.A.B. Cortez), [email protected] (R. Baldassin Junior). http://dx.doi.org/10.1016/j.envdev.2015.05.004 2211-4645/& 2015 Elsevier B.V. All rights reserved.
H. Cantarella et al. / Environmental Development 15 (2015) 52–63
53
without using environmentally sensitive areas. This area may be less as biomass yields increase and the energy of other plant parts is more efficiently used. The opportunity costs of final products derived from the biomass feedstock may place the price of the energy of jet biofuel above that of the fossil jet fuel. Appropriate public policies and tax treatment may be necessary to stimulate an emerging aviation biofuel industry. & 2015 Elsevier B.V. All rights reserved.
1. Biofuels and the aviation industry The aviation industry consumes around 1.5 billion barrels of jet fuel annually, by 1397 airlines companies, operating a fleet of 25,000 aircraft, serving 3864 airports through a network of several million kilometers (ATAG, 2014). Aviation depends on liquid fuels because there are no alternative sources of energy in site for aircrafts flying long distances. Jet fuels are mostly derived from fossil oil. In 2012, 253 Mm3 of jet fuel were produced, or 6.5% of all the oil refined worldwide (IEA, 2014). Brazil accounts for only 2.8% of the world consumption, approximately 7 Mm3 in 2011 (ANP, 2012). The demand for jet fuel is foreseen to continue to expand by 3–3.5% globally (ICAO, 2013), but more strongly (5%) in emergent markets such as Brazil (EPE, 2011). The environmental impact associated with the utilization of fossil fuel is of concern for the aviation industry. Nowadays, the aviation industry contributes 2% of global anthropogenic CO2 emissions and fuels represent on average 33% of operating costs (IATA, 2010). Aiming to reduce these impacts, this industry has set goals to reduce fuel consumption not only to lower costs but also to reduce greenhouse gases (GHG) emissions and take part of the effort to mitigate global warming (OAG, 2012). The aviation industry plans to have carbon neutral growth by 2020 and a 50% reduction in net CO2 emission in 2050, taking as reference the 2005 (IATA, 2013). The actions to reach these targets include improving fuel efficiency by 2% per year and the use of renewable fuels (ICAO, 2013). Jet fuels must follow stringent regulations according to international standards (ASTM, 2013) for safety reasons and because aircrafts fly over and are refueled in different countries. Any alternative jet fuel, including biofuels, must comply with the same performance standards of the conventional jet fuels. In this way, jet biofuels must have properties that characterize them as “drop in” i.e. have to be completely interchangeable or blended with conventional jet fuels, so that no adaptations of current aircraft engines are necessary (ASTM, 2009). This poses limitations and adds complexity to jet biofuels production. For instance, ethanol or biodiesel – the most common biofuels used nowadays for transportation – cannot be considered options without further processing, although ethanol is used in small scale in small airplanes (SNA, 2014). Large quantities of biofuel and, therefore, biomass, will have to be generated in order to meet the 2020 and 2050 aviation industry goals. As Brazil is a country with great potential for increasing biomass production because of land availability and favorable climate conditions the objective of this paper is to discuss the options and limitations of feedstock to support a new aviation biofuel industry.
2. Feedstock for jet biofuel There is a wide range of organic materials from different sources that can be used to produce biofuels through various biomass converting technologies, which include gasification of carbonaceous materials, fast pyrolysis of biomass into liquid products, liquefaction, enzymatic hydrolysis, fermentation of sugar and starches to alcohols, and production of lipids from carbohydrates (Schuchardt et al., 2014; Hari et al., 2015). Further processing of the products of the above conversion processes are required in order to meet the specifications of drop in jet biofuels (Cortez et al., 2014; Schuchardt et al., 2014) and will not be discussed in the present text.
54
H. Cantarella et al. / Environmental Development 15 (2015) 52–63
Feedstock can be classified in groups which include sugars and starch (i.e. sugarcane, corn, cassava), oil crops (soybeans, palm, sunflower, castorbean, rapeseed, jatropha, camelina, algae), cellulosic materials (sugarcane bagasse and trash, grasses, plant residues, wood and wood byproducts), and wastes (municipal solid wastes, sewage, flue gas) (Cortez et al., 2014). In this paper emphasis will be placed on biomass from agricultural origin, given the Brazilian land resources and its agricultural and forestry traditions.
3. Land available for biomass production The need of land to meet the present and future demand for food for a growing population and the requirement that bioenergy be produced in a way that effectively reduces greenhouse gases (GHG) emission compared to the fossil fuels have guided the debates on the role that bioenergy will play in the world's energy supply in the future. Recent studies have supported the view that there is land in many countries that can be dedicated to bioenergy without jeopardizing other uses, including preservation of the natural ecosystem (Cornelissen et al., 2012; Prieler et al., 2013). This seems more evident in some regions of the world as is the case of Brazil. This country is one of the largest producers and exporters of several agricultural commodities such as sugar, soybean, coffee, wood products, meat and others (Pereira et al., 2012). In addition, in 2010 Brazil produced 2.4 Mm3 of biodiesel (82% from soybean and 13% from tallow) and 28 Mm3 of ethanol. Energy from sugarcane products, including ethanol and electricity accounted for 19.3% of the country's primary energy, helping renewable energy to reach almost 48% of its energy matrix (EPE, 2011). Notwithstanding, only 7.1% of the Brazilian territory is used for agriculture and planted forests (Table 1). Despite the large production of bioenergy only a small part of the Brazilian territory is required: sugarcane is grown in 8.5 Mha which corresponds to about 1% of the total area or 3.3% of the 259 Mha occupied with pasture, crops and planted forests (Table 1). Only half of the sugarcane is used for ethanol; the other half goes to sucrose. Brazil has 553 Mha of agricultural lands (65% of the national territory) (EMBRAPA, 2009) but a small part is presently cultivated. Permanently protected areas in private properties, legal reserves, and conservation units plus indigenous reserves account for almost 60% of the Brazilian area, including the Amazon (Table 1). The Brazilian Forest Code demands that at least 20% (80% in the Amazon region) should be set aside as environmental protection areas (EPA) in private properties in addition to permanent protection areas (PPA), which comprises strips of land around water bodies, high slopes and tops of hills (Brasil, 2012). In this way, Brazil has one of the most restrictive nature preservation legislation in the world but its enforcement is not always granted given the size of the Table 1 Structure of land use in Brazila. Adapted from Cortez et al. (2014). Land uses Protected areas (conservation units and reserves) Permanently protected areas and legal reserves in private properties Urban areas Remaining native vegetation Pastureland Agriculture and planted forests Soybean (40.0%) Corn (25.0%) Sugarcane (14.2%) Planted forest (10.8%) Cassava (4.5%) Palm (0.2%) Castorbean (0.2%) Other crops (5.1%) Total a
Brazil total area is 852 Mha (IBGE, 2010).
Area (% of total) 24.7 32.2 4.5 8.2 23.3 7.1 2.8 1.8 1.0 0.8 0.3 0.01 0.01 0.4 7.1
100.0
H. Cantarella et al. / Environmental Development 15 (2015) 52–63
55
country and the conflicts it raises because of liabilities generated by past laws. Notwithstanding, land occupation expansion to produce food, fiber, bioenergy or other goods must abide by the present legislation given the commitment of the Brazilian government and the concerns of the international community with the Forest Code. Good land governance and sustainability are key issues for bioenergy production (Souza et al., 2015). Brazil has almost 200 Mha of pasturelands, including non-exploited areas, most of it with low yields. This is much higher than the 60 Mha presently cultivated with crops and forests. Increasing pasture productivity is one way of freeing land for other uses, including bioenergy; the yield gap in animal production makes this a real possibility. The area of pastureland dedicated to beef production in Brazil decreased from 174.5 Mha in 1980 to 159.8 Mha in 2006. In this same period meat production increased from 2.09 Mt to 6.89 Mt, following the increase in productivity from 11.9 to 43.4 kg ha 1 of carcass equivalent (Martha et al., 2012). These authors argued that the productivity gains in beef production supported a land-saving effect of 525 Mha from 1950 to 2006. But there is much room for improvement because the average Brazilian stocking rate was just 1.08 head ha 1 (Martha et al., 2012). A recent territorial zoning showed that Brazil has 64 Mha suitable for sugarcane cultivation (EMBRAPA, 2009), which excludes the Amazon and Pantanal biomes, and the Upper Paraguay River basin in order to protect sensitive areas and preserve biodiversity. The zoning also excluded lands with slopes higher than 12%, which cannot be mechanized (EMBRAPA, 2009). Of this 64 Mha, 24.3 Mha are already cultivated and most of the rest is under pasture, sometimes degraded pastureland. The foreseen increased demand for food with expanding world population has raised concerns about the impact that large scale biofuel production may have on food production. The competition food x fuel over land and resources is intrinsically mingled into the bioenergy expansion debate (van Noorden, 2013) but many recent studies have indicated that it is possible to reconcile the need to increase food production and, at the same time, renewable bioenergy (Cornelissen et al., 2012; Horta Nogueira and Capaz, 2013; Lynd and Woods, 2011; Prieler et al., 2013; Woods et al., 2010). Agriculture modernization and intensification can play an important role here and is closely associated with the great expansion of food production that Brazil has gone through in the last 20 years (Horta Nogueira and Capaz, 2013; Martha, 2012). Grain output increased by 266% whereas the land used increased by only 49% (Table 2). This enormous increase in food production took place at the same time of that of ethanol, which has doubled, and that of sugar, which increased by 266% (Table 2) when Brazil became the leading exporter of this product. In this same period, the use of fertilizer increased by 218%, from 9.3 to 29.5 Mt yr 1 of NPK (MAPA, 2012, 2013a) along with other modern agriculture inputs that drove yields up. Brazil has resources to support the expansion of jet biofuel production without clearing forest or using sensitive lands given the large areas with pasture. In this sense, the issues of land use change (LUC) and indirect land use change (ILUC) could be less relevant than previously considered. However, a correct accounting must be made of the GHGs emissions and of the possible negative impacts associated with biofuel production and changes in land use because the sustainability requirements for biofuel production tend to be strict (Souza et al., 2015; EU, 2013) and must be complied with.
Table 2 Evolution of grain, sugar, ethanol, and land use in Brazil in the last 20 years. Sources: Grain and cultivated area: CONAB (2013a, 2013b), Ethanol: IBGE (2014). Indicator
1992
2012
Change (%)
Grain (Mt) Sugar (Mt) Ethanol (Mm3) Land for grain (Mha) Land for sugarcane (Mha)
68.3 10.1 11. 7 35.6 4.2
183.6 37.0 23.2a 53.0 8.5
þ 159 þ 266 þ 99 þ 49 þ 102
a Ethanol production in 2012 was much lower than that of 2008/09 or 2010/2011 (27.6 Mm3) because of climate and economic reasons.
56
H. Cantarella et al. / Environmental Development 15 (2015) 52–63
Table 3 Potential feedstock for bioenergy in Brazil and basic energy balance and greenhouse gases emission indicators (adapted from Cortez et al., 2014). Original references: see Supplementary material. Feedstock
Planted area
Fresh mass yield
Energy content
Energy balance GHG
Main Feedstockþ cofeedstock product
Sugarcane Corn Cassava Soybeans Peanut Castor bean Palm Eucalyptus (m3) Elephant grass a b c
Emission
Saving
1000 ha
t ha 1 yr 1
GJ ha 1 yr 1
MJ MJ 1 Exported
g CO2eq MJ 1
% Reduction
8521 15,018 2673 24,088 99 119 109 4874
84 4.8 38 3.1 4.2 1.5 22 40a
145.2 92.7 169.6 22.2 70.9 31.5 180.0 –
448.3 119.2 262.9 60.0 89.6 31.5 243.3 321.1
8.3 – 2.7 4.5 – – 8.7 –
24 37–43 45 50–58 – – 32–37 17–22
71% 56–49% 46% 40–31% – – 62–56% 80–74%
–
25b
c
397.7
7.7
15
82%
Cubic meters per hectare per year. Elephant grass: dry matter yield. Data not available.
Assuming the energy content of fuels, in order to supply 50% of the energy ( 4.4 EJ yr 1) of present global aviation kerosene consumption (253 Mm3 or 8.8 EJ per year, considering 34.8 MJ L 1) a volume equivalent to 207 Mm3 of ethanol would be necessary,1 requiring around 30 Mha of land. Sugarcane ethanol is a convenient reference because the energy of the industrial plant comes from the bagasse (Horta Nogueira and Leal, 2012). This area could be supplied by Brazil alone using part of the 64 Mha of suitable land for sugarcane, mostly replacing pasture and without invading environmentally sensitive areas (EMBRAPA, 2009). Processing and refining technologies for jet fuels are different from those of ethanol and net energy yields may be less than those for ethanol; in this case, more land will be required. However, yield and technological improvements can greatly reduce the amounts of land needed. From 1978 to 2010 the combined gains in biomass and ethanol per hectare were on average 3.1% per year (Horta Nogueira and Capaz, 2013). In the above calculation only the energy content of ethanol was considered. This represents roughly 75% of the energy of sugars contained in the stalks, which, on the other hand, is only 1/3 of the total energy in the sugarcane plant; the other 2/3 is in the stalk fibers (bagasse) and straw fibers (Horta Nogueira and Leal, 2012). Not all the energy of the bagasse is needed to run the industry and part is exported to the grid (Horta Nogueira and Leal, 2012). The yield potential of sugarcane is above 300 t ha 1 (Waclawovsky et al., 2010), much above current yields and modern biotechnology tools will facilitate the incorporation of desirable traits and help to increase yield gains in plant breeding programs (Ferreira et al., 2013). Currently only energy of the sugars of the stem and bagasse are used to produce ethanol and electricity, respectively, but as second generation and other technologies start to become viable, more energy will be obtained from the biomass produced in the same area (Horta Nogueira and Leal, 2012; Service, 2014). Productivity of other plants has also improved. For instance, yields of soybeans have been steadily increasing from 1.7 t ha 1 in 1980 to 3.1 t ha 1 in 2011 (MAPA, 2013a); the same has been reported for eucalyptus (ABRAF, 2013).
1 Heating value of ethanol: 21.2 MJ L 1; ethanol yield: 86.7 L t 1 sugarcane (Macedo et al., 2008); average sugarcane yield: 80 t ha 1; 7000 L ha 1 ethanol.
H. Cantarella et al. / Environmental Development 15 (2015) 52–63
57
4. Options of feedstock from agriculture and urban areas Although many plant species can supply biomass for bioenergy, those that are already cultivated in large scale with high yields are the ones with greater chance of supporting a jet fuel industry in the short term. Some of the main candidates are listed in Table 3. Sugarcane and soybeans are already used to produce ethanol and biodiesel, respectively; therefore, there is already a production chain in place. Corn is not employed for bioenergy in Brazil so far but there are plans to start corn ethanol production in Central Brazil in 2015 integrated with sugarcane ethanol whose industrial plants remain idle outside the sugarcane harvesting season. Eucalyptus, an exotic species in Brazil, is grown in almost 5 Mha to produce wood, paper and pulp. The eucalyptus forestry industry in Brazil is highly efficient due to favorable climate conditions and investment in research (ABRAF, 2013), has the highest average hardwood yields in the world (Table 4), and probably one of the lowest production costs. The energy content of selected feedstock accumulated per hectare per year (Table 3) is higher for sugarcane, elephant grass, eucalyptus, palm oil and cassava. The highest energy yields are for long cycle C4 grasses (sugarcane, elephant grass) and trees (eucalyptus). Data is presented both for the main feedstock (i.e. sucrose in sugarcane, grain in corn, oil in soybeans and palm) or also considering the co-products (bagasse and part of the trash in sugarcane, dried distilled grain and soluble – DDGS in corn, soybean meal, palm kernel oil and empty bunches, and whole plant for eucalyptus and elephant grass) – see Supplementary material. Although some of the co-products are not transformed in fuels, their energy content should be taken into account because it will serve other purposes, such as animal feed. As sustainability indicators are important components of the feedstock, the energy balance (energy contained in the final product minus the energy used to produce it) and the GHGs savings were also included in Table 3. The best indicators were again for C4 grasses and trees. Data from literature for these calculations are quite variable, as with any estimates of life cycle analysis, and were based on assumptions that may not be uniform for all feedstock – see Supplementary material. Sugarcane can be converted to jet fuels through several routes because it is a source of sugar, ethanol, and cellulosic material (Schuchardt et al., 2014; Hari et al.,2015). Eucalyptus and its byproducts, and elephant grass will enter the routes that use cellulose. Sugarcane and eucalyptus will be the frontrunners for the reasons already discussed. However, if those routes are proved to be efficient many other feedstock can be considered, such as other tropical grasses, other tree species, sorghum (also through the starch and sugar routes), the so-called energy cane (varieties being developed to produce more biomass and less sugar) and crop residues. Elephant grass and other tropical grasses have no history of large scale production; the removal of great amounts of nutrients from the fields may affect sustainability indicators (Morais et al., 2009) and logistics and storability may be constraints. However, their high biomass yields are an important feature. Energy cane has also great potential for biomass production and may require fewer cuttings than forage grasses such as elephant grass. Sorghum has a short cycle; this may be an advantage if Table 4 Yields of planted forests in several countries. Source: ABRAF (2013). Country
Hardwood yield (m3 ha 1 yr 1)
Sweden Finland Portugal Southern USA South Africa Chile Australia Indonesia China Brazil
6 6 12 15 18 20 22 25 31 40
58
H. Cantarella et al. / Environmental Development 15 (2015) 52–63
integrated in other feedstock chains but a negative aspect if considered as main source of biomass. Crop residues are relatively inexpensive but the cost of collection and logistics may be high if yields are low. The need to recycle nutrients and provide organic carbon to maintain long term soil quality limit the amounts of crop residues that can be sustainably collected (Huggins et al., 2011; Liska et al., 2014; Tarkalson et al., 2011). This will be an option for crops such as sugarcane and, perhaps high yielding corn, that can spare part of the residues without jeopardizing soil fertility (Cantarella et al., 2013; Fortes et al., 2013; Franco et al., 2013; Gollany et al., 2011). Palm oil is a promising feedstock because of the high oil yields but it requires hot climate and abundant rainfall, which prevails only in the Northern Brazilian forests of the Amazon, a sensitive region for expansion of bioenergy production. Logistics, because of the distance from the main markets, and lack of infra-structure may also be a problem in that region. However, an agro ecological zoning has been proposed for palm oil in the cleared lands of the Amazon, taking into account the economic, social, and environmental benefits of this crop (Ramalho Filho and da Motta, 2010). Among the oil crops, soybeans, despite the small oil yield, shall remain the most viable option of feedstock for jet biofuel in the short term. In 2012/13 27.7 Mha of land were grown with this crop, yielding 81.5 Mt of grain (MAPA, 2013b). In 2010 6.9 Mm3 of soy oil was produced and 2.2 Mm3 was directed to biodiesel; beef tallow was the second feedstock for biodiesel in Brazil – 13%, followed by cottonseed oil – 3.4% (Horta Nogueira and Capaz, 2013). Approximately 0.89 Mha of land is cultivated with cotton and 0.97 Mha with peanuts; other potential oil crops are cultivated at a much lesser extent: castor bean 0.09 Mha and sunflower 0.07 Mha (MAPA, 2013b). Although the expansion of bioenergy crops in Brazil are not likely to affect food supply – as discussed above – jet biofuels are for the global market and some countries may raise restrictions to fuels made with food crops. In this case, corn, cassava, soybeans and other feedstock may have limitations. In fact, some airline companies have promoted and tested jet biofuels made out of nonfood crops and residues such as camelina, jatropha, and used cooking oil (ICAO, 2011). However, the availability of cooking oil will hardly support large scale jet fuel production. Camelina is an oil crop grown in cold and dry areas of North America and Europe (Moser, 2010). Yields are relatively small (less than 2.5 t ha 1) under those conditions but sometimes marginal lands can be used and camelina is an option for rotation with wheat and other winter cereals. Varieties of camelina are being tested in Brazil as a second season crop (Cortez et al., 2014) but its economic viability as a feedstock for jet fuel is still to be proven. Jatropha curcas is a perennial crop with high oil content seeds. This plant was inadequately promoted as being capable of producing high yields in low fertility soils, tolerant to water stress, pests, and diseases but many cases of crop failures in Asia and Africa have been reported and its attractiveness as a biofuel feedstock has decreased substantially (Kant and Wu, 2011; Kumar et al., 2012; Openshaw, 2000; Mubonderi, 2012). Cases of discontinued production of jatropha following crop failures were also reported in Brazil (Cortez et al., 2014). Efforts to generate improved varieties through breeding, modern biotechnology, and agronomic practices are being made in order to reinsert jatropha (Cortez et al., 2014), but much work seems necessary before it can be widely cultivated. If the technological routes that employ vegetable oils prevail there will be opportunities for most oil crops to supplement the major feedstock – probably soybean in Brazil – depending on regional crop adaptation and costs. In addition to feedstock from agriculture, urban residues may also supply biomass for jet biofuel. Countries with large urban areas produce plenty of residues. In Brazil it is estimated that 195 Gg of municipal solid wastes (MSW) are generated daily of which 26.3 Gg only in the state of São Paulo (Secretary of Energy, 2014). Presently only 22 biogas plants produce methane from MSW (Secretary of Energy, 2013) indicating that there is great potential to generate biofuels with these materials.
5. Costs and competing uses of feedstock The choice of feedstock will necessarily take into account its production cost because biomass usually represent 70% or more of the overall biofuel price (Horta Nogueira and Capaz, 2013). In
H. Cantarella et al. / Environmental Development 15 (2015) 52–63
59
addition, jet fuels comprise, on average, about 1/3 of the operation costs of airlines (IATA, 2010) which means that jet biofuel prices are expected to be competitive with those derived from fossil sources. Some indicators of the three most relevant feedstock alternatives for jet biofuel in Brazil are shown in Table 5. Storability of grain and wood products are high, an important characteristic to maintain the industrial plant running for the whole year. However, sugarcane stalks, presently used to produce ethanol, have to be processed in less than one week. This has not been a big problem for the ethanol industry but it means that the industrial plants will operate only during the harvesting season, which is up to nine months per year. Storability will also be high if bagasse and harvesting plant residues are used in second generation or other conversion and refining technologies. Soybeans and sugarcane are important in the food market, both for internal consumption and for export, although they are already used to produce biofuels in large scale. Restrictions in some markets may apply because of the food vs fuel competition (EU, 2013). A sizeable proportion of the Brazilian wood production is exported as paper and pulp. Presently, biodiesel from soybeans – despite of 2 Mm3 used for this purpose – is not a significant part of the Brazilian energy matrix, whereas sugarcane products and woods are (Table 5), meaning that if shifted to jet biofuel production they will displace other energy sources. Feedstock resources are not likely to be a constraint because production can be greatly expanded not only by using new land – as previously discussed in this text – but through yield increases. However, the large scale uses that they already have will tend to set price limits and competition for the feedstock. The opportunity costs of feedstock vary with time and are different if one considers the price of the agricultural product or that of the final product (Fig. 1). The opportunity cost of the feedstock is the value that would have to be given up if sold to alternative markets in order to direct such feedstock to produce biofuels. The reference is the price of petroleum kerosene. In order to make comparisons easier the opportunity costs are expressed in US$/GJ. For the conditions of this study, all agricultural products, except soybean grain, have lower costs per unit of energy than aviation kerosene; i.e. depending on logistics, processing and refining costs, jet biofuel may be competitive with present kerosene prices. On the other hand, if prices of final products of agricultural feedstock are taken, only bagasse and wood have opportunity costs below those of aviation kerosene (Fig. 1). This means that other uses of the final product feedstocks would yield more revenues than producing aviation kerosene at 2012 prices. This reflects the added value of industrialization. Palm and soybean vegetable oils and ethanol have opportunity costs slightly higher than those of kerosene and, eventually, may become competitive. However, sugar and cassava flour have prices too high to justify their use as feedstock for jet fuel. In general, even in a country such as Brazil which is very competitive in the international agriculture commodity markets, the opportunity costs of most feedstock will make it difficult to produce jet biofuel at prices equal or lower than those of fossil oil. The relative costs of different feedstock classes (Fig. 2) indicate that wood and perennial C4 plants are less expensive than oil crops. Eucalyptus and sugarcane products also have good sustainability indicators (Table 3). However, the technical difficulties of the refining technology must also be taken into account (not discussed in detail this text). Depending on how these technologies evolve, other classes of feedstock may
Table 5 Potential feedstock for jet biofuel in Brazil: present production and competing uses (adapted from Cortez et al., 2014). Characteristic
Annual production Feedstock storability Importance for food production and export Importance in Brazilian energy matrix
Feedstock Soybean
Sugarcanea
Wood (eucalyptus and pinus)
81 Mt Very high High Low (biodiesel 1%)
650 Mt Difficult High High ( 20%)
254 Mm3 Very high None High ( 10%)
a Yield of sugarcane refers to fresh stalk used for sucrose and ethanol production. Storability time is very short after harvest (up to 3 days) but sugar can be used as feedstock for biofuels and fiber residues have high storability.
H. Cantarella et al. / Environmental Development 15 (2015) 52–63
60 50 40 30
AgriculturalProducts
30.3
32.7
38.2
54.1
Ethanol (anhydrous)
Soy oil
Sugar
Cassava flour
26.6 13.0
Palm Oil
Bagasse
Wood (from cellulose)
26.3
Soy (bean)
8.1
24.1
Cassava root
20.8
Sugarcane (TRS)
Corn (grain)
13.9
Palm (FFB)
8.5
Sugarcane (TRS and bagasse)
Aviation Kerosene
0
Eucalyptus 5.1
10
14.0
20 24.5
Competitiveness Agrcultural & Final Products (US$/GJ)
60
Final Products
Fig. 1. Opportunity costs of feedstock based on their energy value: comparison between agricultural products and final products. Costs are expressed in US$/GJ of energy content of the agricultural or final product. Data, yields, prices, and assumptions are the same as those of Table 3 and its Supplementary material. Price of aviation kerosene is used as reference. Prices are for 2012. Adapted from Cortez et al. (2014).
Fig. 2. Relative cost of different classes of feedstock and technical effort to convert them to aviation biofuels. Position of feedstock in the circles reflects the general opinion of the Sustainable Aviation biofuels for Brazil Project research team (Cortez et al., 2013). The closer a particular feedstock is from the inner circle, the higher its cost; conversely, the farther from the center the greater is the refining technology efforts. See also (Cortez et al., 2014; Schuchardt et al., 2014). Figure from Cortez et al. (2013) with permission.
H. Cantarella et al. / Environmental Development 15 (2015) 52–63
61
eventually prove to be equally viable. In this sense, Brazil has the conditions to support an aviation bioenergy industry with a range of biomasses. Although sugarcane and eucalyptus showed favorable conditions to start a jet biofuel industry in Brazil, so far fuel processing routes using oils and fats such as the hydroprocessing of esters and fatty acids (HEFA) are ahead of others and will probably be the first to reach commercial production: over 1500 commercial flights have been performed using fuel blends with up to 50% of oil-based biofuel (Souza et al., 2015). However, the cost of oil feedstock is usually higher than that of sugars, lignicellulosic, and waste materials whereas the technical efforts are higher to refine the later feedstocks (Fig. 2). The lack of competitiveness of biofuels made with several feedstocks as compared with jet kerosene has also been reported in other studies (SAFN, 2011). However, this may be balanced out by premium prices that society may be willing to pay for biojet fuels in order to have lower GHGs emissions. Taxes on carbon schemes may also provide funds. In addition, appropriate public policies and special tax treatments will likely be necessary to stimulate an emerging aviation biofuel industry not only to equilibrate costs but also to avoid destructive competition with other bioenergy or biofuel markets, until new technological progress and the scale up of operations make it economically sustainable. The possibility of reducing GHGs emissions, creating jobs, promoting rural development, and new markets for agricultural products justify the necessary incentives.
Acknowledgments This work is part of The Sustainable Aviation Biofuels for Brazil Project, funded by São Paulo Research Foundation (FAPESP) (Grant No. 2012/50009-1), Boeing, and Embraer. Sponsors did not interfere with the design of the work or the interpretation of data. The views and opinion in this paper are of the authors and may not reflect those of the private sponsors.
Appendix A. Supporting information Supplementary data associated with this article can be found in the online version at http://dx.doi. org/10.1016/j.envdev.2015.05.004.
References ABRAF, 2013. Anuário Estatístico da ABRAF 2013 ano base 2012. ABRAF Associação Brasileira de Produtores de Florestas Plantadas, Brasilia146. ANP, 2012. Petroleum, Natural Gas and Biofuels Estatistical Yearbook – 2012. Brazilian National Agency of Petroleum, Natural Gas and Biofuels, Rio de Janeiro. ASTM, 2009. ASTM D4054-09: standard practice for qualification and approval of new aviation turbine fuels and fuel additives. ASTM International, West Conshohocken. ASTM, 2013. ASTM D 1655, standard specification for aviation turbine fuels. ASTM International, West Conshohocken. ATAG, 2014. Facts & Figures. Air Transport Action Group. 〈http://www.atag.org/facts-and-figures.html〉. Brasil, 2012. Lei 12651 - Código Florestal Brasileiro. In: Brazil: Presidency of the Republic (Ed.), Lei 12651 de 25 de maio de 2012. Brasilia: Diário Oficial da União. Cantarella, H., Cerri, C.E.P., Carvalho, J.L.N., Magalhaes, P.S.G., 2013. Editorial: how much sugarcane trash should be left on the soil. Sci. Agric. 70, 1–2. CONAB, 2013. Séries Históricas, Brasil – por Produtos. Companhia Nacional de Abastecimento, Brasilia. CONAB, 2013. Séries Históricas, Cana-de-Açúcar. Companhia Nacional de Abastecimento, Brasilia. Cornelissen, S., Koper, M., Deng, Y.Y., 2012. The role of bioenergy in a fully sustainable global energy system. Biomass Bioenergy 41, 21–33. Cortez, L.A.B., Nigro, F.E.B., Nassar, A.M., Cantarella, H., Horta Nogueira, L.A., Moraes, M.A.F.D., Leal, R.L.V., Franco, T.T., Schuchardt, U., 2013. Flighpath to Aviation Biofuels in Brazil: Action Plan. FAPESP, São Paulo56. Cortez, L.A.B., Nigro, F.E.B., Nassar, A.M., Cantarella, H., Nogueira, L.A.H., Moraes, M.A.F.D., Leal, R.L.V., Franco, T.T., Schuchardt, U., 2014. Roadmap for sustainable aviation biofuels for Brazil. Blucher, São Paulo272. EMBRAPA, 2009. In: Manzatto, C.V., Assad, E.D., Bacca, J.F.M., Zaroni, M.J., Pereira, S.E.M. (Eds.), Zoneamento Agroecológico da Cana-de-açúcar. Embrapa, Rio de Janeiro, pp. 58.
62
H. Cantarella et al. / Environmental Development 15 (2015) 52–63
EPE, 2011. Plano Decenal de Expansão de Energia 2020. Empresa de Pesquisa Energética, Brasília. EU, 2013. European parliament backs switchover to advance biofuels. European Union Press. Service Available at www.europarl. europa.eu/pdfs/news/expert/infopress/201309061PR18831/2013090618831_en.pdf/download. (accessed on 08.05.15.). Ferreira, S.S., Nishiyama Jr., M.Y., Paterson, A.H., Souza, G.M., 2013. Biofuel and energy crops: high-yield Saccharinae take center stage in the post-genomics era - review. Genome Biol. 14, 210. Fortes, C., Vitti, A.C., Otto, R., Ferreira, D.A., Franco, H.C.J., Trivelin, P.C.O., 2013. Contribution of nitrogen from sugarcane harvest residues and urea for crop nutrition. Sci. Agric. 70, 313–320. Franco, H.C.J., Pimenta, M.T.B., Carvalho, J.L.N., Magalhaes, P.S.G., Rossell, C.E.V., Braunbeck, O.A., Vitti, A.C., Kolln, O.T., Neto, J.R., 2013. Assessment of sugarcane trash for agronomic and energy purposes in Brazil. Sci. Agric. 70, 305–312. Gollany, H.T., Rickman, R.W., Liang, Y., Albrecht, S.L., Machado, S., Kang, S., 2011. Predicting agricultural management influence on long-term soil organic carbon dynamics: implications for biofuel production. Agron. J. 103, 234–246. Hari, T.K., Yaakob, Z., Binitha, N.N., 2015. Aviation biofuel from renewable resources: routes, opportunities and challenges. Renew. Sustain. Energy Rev. 42, 1234–1244. Horta Nogueira, L.A., Capaz, R.S., 2013. Biofuels in Brazil: evolution, achievements and perspectives on food security. Glob. Food Secur. 2, 117–125. Horta Nogueira, L.A., Leal, M.R.L.V., 2012. Sugarcane bioethanol and bioelectricity. In: Poppe, M.K., Cortez, L.A.B. (Eds.), Sustainability of Sugarcane Bioenergy. CGEE, Brasilia, pp. 89–126. Huggins, D.R., Karow, R.S., Collins, H.P., Ransom, J.K., 2011. Introduction: evaluating long-term impacts of harvesting crop residues on soil quality. Agron. J. 103, 230–233. IATA, 2010. Annual Report 2010. International Air Transport Association, Berlin. IBGE, 2010. Produção Agrícola e Municipal, volume 36, ano 2009. Instituto Brasileiro de Geografia e Estatística. 〈http://www. ibge.gov.br/home/estatistica/economia/pam/2009/PAM2009_Publicacao_completa.pdf〉. IATA, 2013. IATA Technology Roadmap, 4th ed. IATA - International Air Transport Association: 86, Montreal. IBGE, 2014. Séries Históricas e Estatísticas, Temas e Subtemas. Instituto Brasileiro de Geografia e Estatística, Agropecuária. ICAO, 2013. ICAO Environmental Report 2013 – Aviation and Climate Change Available at. International Civil Aviation Organization, Montreal (accessed 28.01.13.). ICAO, 2011. ICAO Review: Sustainable Alternative Fuels for Aviation Available online at. ICAO International Civil Aviation Organization, Québec, Canada56 (accessed 28.01.13.). IEA, 2014. Key World Energy Statistics 2014. International Energy Agency, Paris. Kant, P., Wu, S., 2011. The extraordinary collapse of Jatropha as a global biofuel. Environ. Sci. Technol. 45, 7114–7225. Kumar, S., Chaube, A., Jain, S.K., 2012. Critical review of jatropha biodiesel promotion policies in India. Energy Policy 41, 775–781. Liska, A.J., Yang, H., Milner, M., Goddard, S., Blanco-Canqui, H., Pelton, M.P., Fang, X.X., Zhu, H., Suyker, A.E., 2014. Biofuels from crop residue can reduce soil carbon and increase CO2 emissions. Nat. Clim. Chang. 4, 398–401. Lynd, L.R., Woods, J., 2011. A new hope for Africa. Nat. Outlook 474, S20–S21. Macedo, I.C., Seabra, J.E.A., Silva, J.E.A.R., 2008. Green house gases emissions in the production and use of ethanol from sugarcane in Brazil: the 2005/2006 averages and a prediction for 2020. Biomass Bioenergy 32, 582–595. MAPA, 2012. Produção Brasileira em números - Anuário 2005. Ministério da Agricultura, Pecuária e Abastecimento, Brasilia. MAPA, 2013. Estatísticas e Dados Básicos de Economia Agrícola - Dezembro de 2013. Ministério da Agricultura, Pecuária e Abastecimento, Brasília. MAPA, 2013. Statistical Yearbook of Agrienergy 2012. Ministério da Agricultura Pecuária e Abastecimento, Brasilia284. Martha Jr., G.B., 2012. Brazilian agriculture development and changes. Embrapa, Brasilia164. Martha Jr., G.B., Alves, E., Contini, E., 2012. Land-saving approaches and beef production growth in Brazil. Agric. Syst. 110, 173–177. Morais, R.F., Souza, B.J., Leite, J.M., Soares, L.H.B., Alves, B.J.R., Boddey, R.M., Urquiaga, S., 2009. Elephant grass genotypes for bioenergy production by direct biomass combustion. Pesqui. Agropecu. Bras. 44, 133–140. Moser, B.R., 2010. Camelina (Camelina sativa L.) oil as a biofuels feedstock: golden opportunity or false hope. Lipid Technol. 22 (12), 270. Mubonderi, J., 2012. Jatropha: the broom of poverty; mith or reality. A critical analysis of the Zimbabwean jatropha programme in Mutoko district. In: Molony, T., Chinigo, D. (Eds.), PISCES – Policy Innovations Systems for Cleaner Energy Security. Edinburgh, Department of International Development, UK Aid. OAG, 2012. The European Union Emission Trading Scheme Report. Official Airline Guide, London 2012. Openshaw, K., 2000. A review of Jatropha curcas: an oil plant of unfulfilled promise. Biomass Bioenergy 19, 1–15. Pereira, P.A.A., Martha Jr., G.B., Santana, C.A.M., Alves, E., 2012. The development of Brazilian agriculture: future technological challenges and opportunities. Agric. Food Secur. 1 (4), 1–12. Prieler, S., Fischer, G., van Velthuizen, H., 2013. Land and the food–fuel competition: insights from modeling. Wiley Interdiscip. Rev.: Energy Environ. 2, 199–217. Ramalho Filho, A., da Motta, P.E.F., 2010. Zoneamento agroecológico do dendezeiro para as áreas desmatadas da Amazônia Legal. Embrapa, Rio de Janeiro44p. SAFN – Sustainable Aviation Fuels Northwest, 2011. Sustainable aviation fuels northwest: powering next generation of flight. Report S.1. www.wedc.wa.gov/Download%20files/SAFN_2011Report.pdf. (accessed 03.01.13.). Schuchardt, U., Franco, T.T., Melo, J.C.P., Cortez, L.A.B., 2014. Sustainable aviation fuels for Brazil. Biofuels Bioprod. Biorefining 8, 151–154. Secretary of Energy, 2013. Renewable energy. Executive Summary – 3rd Trimester 2013. Government of the State of São Paulo – Secretary of Energy. 23p. Available at 〈http://www.energia.sp.gov.br/portal.php/resumo_executivo_energias_renovaveis〉. Secretary of Energy, 2014. Solid residues Available at. Government of the State of São Paulo – Secretary of Energy. (accessed 14.11.14.). Service, R.F., 2014. Cellulosic ethanol at last: large volumes of fuel from crop wastes will soon start flowing in the U.S. - unless policymakers balk. Science 345 (6201), 1111. SNA, 2014. Embraer celebrates 10 years of agricultural airplane run on ethanol (In Portuguese). Sociedade Nacional de Agricultura – SNA. Available at 〈http://sna.agr.br/embraer-celebra-dez-anos-do-aviao-agricola-movido-a-etanol〉. (accessed 8.05.15.).
H. Cantarella et al. / Environmental Development 15 (2015) 52–63
63
Souza, G.M., Victoria, R.L., Joly, C.A., Verdade, L.M., (Eds.), 2015. Bioenergy and sustainability: bridging the gaps. São Paulo, SCOPE and FAPESP. Available at 〈http://bioenfapesp.org/scopebioenegy/index.php/chapters〉 Downloaded on 17 Apr 2015. Tarkalson, D.D., Brown, B., Kok, H., Bjorneberg, D.L., 2011. Small grain residue management effects on soil organic carbon: a literature review. Agron. J. 103, 147–252. van Noorden, R., 2013. EU debates U-turn on biofuels policy. Nature 499, 13–14. Waclawovsky, A.J., Sato, P.M., Lembke, C.G., Moore, P.H., Souza, G.M., 2010. Sugarcane for bioenergy production: an assessment of yield and regulation of sucrose content. Plant Biotechnol. J. 8, 263–276. Woods, J., Williams, A., Hughes, J.K., Black, M., Murphy, R., 2010. Energy and the food system. Philos. Trans. R. Soc. - B 365, 2991–3006.
Contents lists available at ScienceDirect
Environmental Development journal homepage: www.elsevier.com/locate/envdev
Potential feedstock for renewable aviation fuel in Brazil Heitor Cantarella a,n, André Meloni Nassar b, Luis Augusto Barbosa Cortez c, Ricardo Baldassin Juniorc a Agronomic Institute of Campinas, Soils and Environmental Resources Center, P.O. Box 28, 13001-970 Campinas, SP, Brazil b Secretary of Agricultural Policy, Ministry of Agriculture, Livestock and Food Supply, 70043-900 Brasilia, DF, Brazil c School of Agriculture Engineering, State University of Campinas, 13083-970 Campinas, SP, Brazil
a r t i c l e in f o
a b s t r a c t
Article history: Received 15 May 2015 Accepted 20 May 2015
The aviation industry worldwide is committed to reduce CO2 emissions. The present goal is towards Carbon Neutral Growth (CNG) by 2020 and 50% reduction in net CO2 emissions over 2005 levels by 2050. There are not easy alternatives to liquid fuels for airplanes; therefore, biofuels are necessarily part of the solution. However, the specifications for jet biofuel rule out ethanol and biodiesel, the most common biofuels in the market. There are several routes for the production of aviation biofuel allowing the use of a wide range of biomasses. The conversion and refining technology pathways will be determinant for the choice of feedstock. At present, most jet biofuel tested in airplanes are derived from oils, but not taking into account conversion technologies, the best options to start an aviation biofuel industry in Brazil are sugarcane, eucalyptus, and soybean, of the sugar, cellulose, and oil crop groups. The main reasons are the established production chains, high yields, competitive prices, and possibility of greenhouse gases abatement. Other crops may be feasible options depending on specific regional conditions, further agronomic improvements, and cost reduction. Taking as reference the energy content of ethanol, around 30 Mha of land would be necessary to supply sugarcane to meet 50% of the present global consumption of jet fuel. This is less than the 64 Mha of land suitable for sugarcane in Brazil, mostly replacing pasture and
Keywords: Jet biofuel Sugarcane Land availability Bioenergy CO2 abatement
n
Corresponding author. Tel.: þ55 19 2137 0766. E-mail addresses: [email protected] (H. Cantarella), [email protected] (A.M. Nassar), [email protected] (L.A.B. Cortez), [email protected] (R. Baldassin Junior). http://dx.doi.org/10.1016/j.envdev.2015.05.004 2211-4645/& 2015 Elsevier B.V. All rights reserved.
H. Cantarella et al. / Environmental Development 15 (2015) 52–63
53
without using environmentally sensitive areas. This area may be less as biomass yields increase and the energy of other plant parts is more efficiently used. The opportunity costs of final products derived from the biomass feedstock may place the price of the energy of jet biofuel above that of the fossil jet fuel. Appropriate public policies and tax treatment may be necessary to stimulate an emerging aviation biofuel industry. & 2015 Elsevier B.V. All rights reserved.
1. Biofuels and the aviation industry The aviation industry consumes around 1.5 billion barrels of jet fuel annually, by 1397 airlines companies, operating a fleet of 25,000 aircraft, serving 3864 airports through a network of several million kilometers (ATAG, 2014). Aviation depends on liquid fuels because there are no alternative sources of energy in site for aircrafts flying long distances. Jet fuels are mostly derived from fossil oil. In 2012, 253 Mm3 of jet fuel were produced, or 6.5% of all the oil refined worldwide (IEA, 2014). Brazil accounts for only 2.8% of the world consumption, approximately 7 Mm3 in 2011 (ANP, 2012). The demand for jet fuel is foreseen to continue to expand by 3–3.5% globally (ICAO, 2013), but more strongly (5%) in emergent markets such as Brazil (EPE, 2011). The environmental impact associated with the utilization of fossil fuel is of concern for the aviation industry. Nowadays, the aviation industry contributes 2% of global anthropogenic CO2 emissions and fuels represent on average 33% of operating costs (IATA, 2010). Aiming to reduce these impacts, this industry has set goals to reduce fuel consumption not only to lower costs but also to reduce greenhouse gases (GHG) emissions and take part of the effort to mitigate global warming (OAG, 2012). The aviation industry plans to have carbon neutral growth by 2020 and a 50% reduction in net CO2 emission in 2050, taking as reference the 2005 (IATA, 2013). The actions to reach these targets include improving fuel efficiency by 2% per year and the use of renewable fuels (ICAO, 2013). Jet fuels must follow stringent regulations according to international standards (ASTM, 2013) for safety reasons and because aircrafts fly over and are refueled in different countries. Any alternative jet fuel, including biofuels, must comply with the same performance standards of the conventional jet fuels. In this way, jet biofuels must have properties that characterize them as “drop in” i.e. have to be completely interchangeable or blended with conventional jet fuels, so that no adaptations of current aircraft engines are necessary (ASTM, 2009). This poses limitations and adds complexity to jet biofuels production. For instance, ethanol or biodiesel – the most common biofuels used nowadays for transportation – cannot be considered options without further processing, although ethanol is used in small scale in small airplanes (SNA, 2014). Large quantities of biofuel and, therefore, biomass, will have to be generated in order to meet the 2020 and 2050 aviation industry goals. As Brazil is a country with great potential for increasing biomass production because of land availability and favorable climate conditions the objective of this paper is to discuss the options and limitations of feedstock to support a new aviation biofuel industry.
2. Feedstock for jet biofuel There is a wide range of organic materials from different sources that can be used to produce biofuels through various biomass converting technologies, which include gasification of carbonaceous materials, fast pyrolysis of biomass into liquid products, liquefaction, enzymatic hydrolysis, fermentation of sugar and starches to alcohols, and production of lipids from carbohydrates (Schuchardt et al., 2014; Hari et al., 2015). Further processing of the products of the above conversion processes are required in order to meet the specifications of drop in jet biofuels (Cortez et al., 2014; Schuchardt et al., 2014) and will not be discussed in the present text.
54
H. Cantarella et al. / Environmental Development 15 (2015) 52–63
Feedstock can be classified in groups which include sugars and starch (i.e. sugarcane, corn, cassava), oil crops (soybeans, palm, sunflower, castorbean, rapeseed, jatropha, camelina, algae), cellulosic materials (sugarcane bagasse and trash, grasses, plant residues, wood and wood byproducts), and wastes (municipal solid wastes, sewage, flue gas) (Cortez et al., 2014). In this paper emphasis will be placed on biomass from agricultural origin, given the Brazilian land resources and its agricultural and forestry traditions.
3. Land available for biomass production The need of land to meet the present and future demand for food for a growing population and the requirement that bioenergy be produced in a way that effectively reduces greenhouse gases (GHG) emission compared to the fossil fuels have guided the debates on the role that bioenergy will play in the world's energy supply in the future. Recent studies have supported the view that there is land in many countries that can be dedicated to bioenergy without jeopardizing other uses, including preservation of the natural ecosystem (Cornelissen et al., 2012; Prieler et al., 2013). This seems more evident in some regions of the world as is the case of Brazil. This country is one of the largest producers and exporters of several agricultural commodities such as sugar, soybean, coffee, wood products, meat and others (Pereira et al., 2012). In addition, in 2010 Brazil produced 2.4 Mm3 of biodiesel (82% from soybean and 13% from tallow) and 28 Mm3 of ethanol. Energy from sugarcane products, including ethanol and electricity accounted for 19.3% of the country's primary energy, helping renewable energy to reach almost 48% of its energy matrix (EPE, 2011). Notwithstanding, only 7.1% of the Brazilian territory is used for agriculture and planted forests (Table 1). Despite the large production of bioenergy only a small part of the Brazilian territory is required: sugarcane is grown in 8.5 Mha which corresponds to about 1% of the total area or 3.3% of the 259 Mha occupied with pasture, crops and planted forests (Table 1). Only half of the sugarcane is used for ethanol; the other half goes to sucrose. Brazil has 553 Mha of agricultural lands (65% of the national territory) (EMBRAPA, 2009) but a small part is presently cultivated. Permanently protected areas in private properties, legal reserves, and conservation units plus indigenous reserves account for almost 60% of the Brazilian area, including the Amazon (Table 1). The Brazilian Forest Code demands that at least 20% (80% in the Amazon region) should be set aside as environmental protection areas (EPA) in private properties in addition to permanent protection areas (PPA), which comprises strips of land around water bodies, high slopes and tops of hills (Brasil, 2012). In this way, Brazil has one of the most restrictive nature preservation legislation in the world but its enforcement is not always granted given the size of the Table 1 Structure of land use in Brazila. Adapted from Cortez et al. (2014). Land uses Protected areas (conservation units and reserves) Permanently protected areas and legal reserves in private properties Urban areas Remaining native vegetation Pastureland Agriculture and planted forests Soybean (40.0%) Corn (25.0%) Sugarcane (14.2%) Planted forest (10.8%) Cassava (4.5%) Palm (0.2%) Castorbean (0.2%) Other crops (5.1%) Total a
Brazil total area is 852 Mha (IBGE, 2010).
Area (% of total) 24.7 32.2 4.5 8.2 23.3 7.1 2.8 1.8 1.0 0.8 0.3 0.01 0.01 0.4 7.1
100.0
H. Cantarella et al. / Environmental Development 15 (2015) 52–63
55
country and the conflicts it raises because of liabilities generated by past laws. Notwithstanding, land occupation expansion to produce food, fiber, bioenergy or other goods must abide by the present legislation given the commitment of the Brazilian government and the concerns of the international community with the Forest Code. Good land governance and sustainability are key issues for bioenergy production (Souza et al., 2015). Brazil has almost 200 Mha of pasturelands, including non-exploited areas, most of it with low yields. This is much higher than the 60 Mha presently cultivated with crops and forests. Increasing pasture productivity is one way of freeing land for other uses, including bioenergy; the yield gap in animal production makes this a real possibility. The area of pastureland dedicated to beef production in Brazil decreased from 174.5 Mha in 1980 to 159.8 Mha in 2006. In this same period meat production increased from 2.09 Mt to 6.89 Mt, following the increase in productivity from 11.9 to 43.4 kg ha 1 of carcass equivalent (Martha et al., 2012). These authors argued that the productivity gains in beef production supported a land-saving effect of 525 Mha from 1950 to 2006. But there is much room for improvement because the average Brazilian stocking rate was just 1.08 head ha 1 (Martha et al., 2012). A recent territorial zoning showed that Brazil has 64 Mha suitable for sugarcane cultivation (EMBRAPA, 2009), which excludes the Amazon and Pantanal biomes, and the Upper Paraguay River basin in order to protect sensitive areas and preserve biodiversity. The zoning also excluded lands with slopes higher than 12%, which cannot be mechanized (EMBRAPA, 2009). Of this 64 Mha, 24.3 Mha are already cultivated and most of the rest is under pasture, sometimes degraded pastureland. The foreseen increased demand for food with expanding world population has raised concerns about the impact that large scale biofuel production may have on food production. The competition food x fuel over land and resources is intrinsically mingled into the bioenergy expansion debate (van Noorden, 2013) but many recent studies have indicated that it is possible to reconcile the need to increase food production and, at the same time, renewable bioenergy (Cornelissen et al., 2012; Horta Nogueira and Capaz, 2013; Lynd and Woods, 2011; Prieler et al., 2013; Woods et al., 2010). Agriculture modernization and intensification can play an important role here and is closely associated with the great expansion of food production that Brazil has gone through in the last 20 years (Horta Nogueira and Capaz, 2013; Martha, 2012). Grain output increased by 266% whereas the land used increased by only 49% (Table 2). This enormous increase in food production took place at the same time of that of ethanol, which has doubled, and that of sugar, which increased by 266% (Table 2) when Brazil became the leading exporter of this product. In this same period, the use of fertilizer increased by 218%, from 9.3 to 29.5 Mt yr 1 of NPK (MAPA, 2012, 2013a) along with other modern agriculture inputs that drove yields up. Brazil has resources to support the expansion of jet biofuel production without clearing forest or using sensitive lands given the large areas with pasture. In this sense, the issues of land use change (LUC) and indirect land use change (ILUC) could be less relevant than previously considered. However, a correct accounting must be made of the GHGs emissions and of the possible negative impacts associated with biofuel production and changes in land use because the sustainability requirements for biofuel production tend to be strict (Souza et al., 2015; EU, 2013) and must be complied with.
Table 2 Evolution of grain, sugar, ethanol, and land use in Brazil in the last 20 years. Sources: Grain and cultivated area: CONAB (2013a, 2013b), Ethanol: IBGE (2014). Indicator
1992
2012
Change (%)
Grain (Mt) Sugar (Mt) Ethanol (Mm3) Land for grain (Mha) Land for sugarcane (Mha)
68.3 10.1 11. 7 35.6 4.2
183.6 37.0 23.2a 53.0 8.5
þ 159 þ 266 þ 99 þ 49 þ 102
a Ethanol production in 2012 was much lower than that of 2008/09 or 2010/2011 (27.6 Mm3) because of climate and economic reasons.
56
H. Cantarella et al. / Environmental Development 15 (2015) 52–63
Table 3 Potential feedstock for bioenergy in Brazil and basic energy balance and greenhouse gases emission indicators (adapted from Cortez et al., 2014). Original references: see Supplementary material. Feedstock
Planted area
Fresh mass yield
Energy content
Energy balance GHG
Main Feedstockþ cofeedstock product
Sugarcane Corn Cassava Soybeans Peanut Castor bean Palm Eucalyptus (m3) Elephant grass a b c
Emission
Saving
1000 ha
t ha 1 yr 1
GJ ha 1 yr 1
MJ MJ 1 Exported
g CO2eq MJ 1
% Reduction
8521 15,018 2673 24,088 99 119 109 4874
84 4.8 38 3.1 4.2 1.5 22 40a
145.2 92.7 169.6 22.2 70.9 31.5 180.0 –
448.3 119.2 262.9 60.0 89.6 31.5 243.3 321.1
8.3 – 2.7 4.5 – – 8.7 –
24 37–43 45 50–58 – – 32–37 17–22
71% 56–49% 46% 40–31% – – 62–56% 80–74%
–
25b
c
397.7
7.7
15
82%
Cubic meters per hectare per year. Elephant grass: dry matter yield. Data not available.
Assuming the energy content of fuels, in order to supply 50% of the energy ( 4.4 EJ yr 1) of present global aviation kerosene consumption (253 Mm3 or 8.8 EJ per year, considering 34.8 MJ L 1) a volume equivalent to 207 Mm3 of ethanol would be necessary,1 requiring around 30 Mha of land. Sugarcane ethanol is a convenient reference because the energy of the industrial plant comes from the bagasse (Horta Nogueira and Leal, 2012). This area could be supplied by Brazil alone using part of the 64 Mha of suitable land for sugarcane, mostly replacing pasture and without invading environmentally sensitive areas (EMBRAPA, 2009). Processing and refining technologies for jet fuels are different from those of ethanol and net energy yields may be less than those for ethanol; in this case, more land will be required. However, yield and technological improvements can greatly reduce the amounts of land needed. From 1978 to 2010 the combined gains in biomass and ethanol per hectare were on average 3.1% per year (Horta Nogueira and Capaz, 2013). In the above calculation only the energy content of ethanol was considered. This represents roughly 75% of the energy of sugars contained in the stalks, which, on the other hand, is only 1/3 of the total energy in the sugarcane plant; the other 2/3 is in the stalk fibers (bagasse) and straw fibers (Horta Nogueira and Leal, 2012). Not all the energy of the bagasse is needed to run the industry and part is exported to the grid (Horta Nogueira and Leal, 2012). The yield potential of sugarcane is above 300 t ha 1 (Waclawovsky et al., 2010), much above current yields and modern biotechnology tools will facilitate the incorporation of desirable traits and help to increase yield gains in plant breeding programs (Ferreira et al., 2013). Currently only energy of the sugars of the stem and bagasse are used to produce ethanol and electricity, respectively, but as second generation and other technologies start to become viable, more energy will be obtained from the biomass produced in the same area (Horta Nogueira and Leal, 2012; Service, 2014). Productivity of other plants has also improved. For instance, yields of soybeans have been steadily increasing from 1.7 t ha 1 in 1980 to 3.1 t ha 1 in 2011 (MAPA, 2013a); the same has been reported for eucalyptus (ABRAF, 2013).
1 Heating value of ethanol: 21.2 MJ L 1; ethanol yield: 86.7 L t 1 sugarcane (Macedo et al., 2008); average sugarcane yield: 80 t ha 1; 7000 L ha 1 ethanol.
H. Cantarella et al. / Environmental Development 15 (2015) 52–63
57
4. Options of feedstock from agriculture and urban areas Although many plant species can supply biomass for bioenergy, those that are already cultivated in large scale with high yields are the ones with greater chance of supporting a jet fuel industry in the short term. Some of the main candidates are listed in Table 3. Sugarcane and soybeans are already used to produce ethanol and biodiesel, respectively; therefore, there is already a production chain in place. Corn is not employed for bioenergy in Brazil so far but there are plans to start corn ethanol production in Central Brazil in 2015 integrated with sugarcane ethanol whose industrial plants remain idle outside the sugarcane harvesting season. Eucalyptus, an exotic species in Brazil, is grown in almost 5 Mha to produce wood, paper and pulp. The eucalyptus forestry industry in Brazil is highly efficient due to favorable climate conditions and investment in research (ABRAF, 2013), has the highest average hardwood yields in the world (Table 4), and probably one of the lowest production costs. The energy content of selected feedstock accumulated per hectare per year (Table 3) is higher for sugarcane, elephant grass, eucalyptus, palm oil and cassava. The highest energy yields are for long cycle C4 grasses (sugarcane, elephant grass) and trees (eucalyptus). Data is presented both for the main feedstock (i.e. sucrose in sugarcane, grain in corn, oil in soybeans and palm) or also considering the co-products (bagasse and part of the trash in sugarcane, dried distilled grain and soluble – DDGS in corn, soybean meal, palm kernel oil and empty bunches, and whole plant for eucalyptus and elephant grass) – see Supplementary material. Although some of the co-products are not transformed in fuels, their energy content should be taken into account because it will serve other purposes, such as animal feed. As sustainability indicators are important components of the feedstock, the energy balance (energy contained in the final product minus the energy used to produce it) and the GHGs savings were also included in Table 3. The best indicators were again for C4 grasses and trees. Data from literature for these calculations are quite variable, as with any estimates of life cycle analysis, and were based on assumptions that may not be uniform for all feedstock – see Supplementary material. Sugarcane can be converted to jet fuels through several routes because it is a source of sugar, ethanol, and cellulosic material (Schuchardt et al., 2014; Hari et al.,2015). Eucalyptus and its byproducts, and elephant grass will enter the routes that use cellulose. Sugarcane and eucalyptus will be the frontrunners for the reasons already discussed. However, if those routes are proved to be efficient many other feedstock can be considered, such as other tropical grasses, other tree species, sorghum (also through the starch and sugar routes), the so-called energy cane (varieties being developed to produce more biomass and less sugar) and crop residues. Elephant grass and other tropical grasses have no history of large scale production; the removal of great amounts of nutrients from the fields may affect sustainability indicators (Morais et al., 2009) and logistics and storability may be constraints. However, their high biomass yields are an important feature. Energy cane has also great potential for biomass production and may require fewer cuttings than forage grasses such as elephant grass. Sorghum has a short cycle; this may be an advantage if Table 4 Yields of planted forests in several countries. Source: ABRAF (2013). Country
Hardwood yield (m3 ha 1 yr 1)
Sweden Finland Portugal Southern USA South Africa Chile Australia Indonesia China Brazil
6 6 12 15 18 20 22 25 31 40
58
H. Cantarella et al. / Environmental Development 15 (2015) 52–63
integrated in other feedstock chains but a negative aspect if considered as main source of biomass. Crop residues are relatively inexpensive but the cost of collection and logistics may be high if yields are low. The need to recycle nutrients and provide organic carbon to maintain long term soil quality limit the amounts of crop residues that can be sustainably collected (Huggins et al., 2011; Liska et al., 2014; Tarkalson et al., 2011). This will be an option for crops such as sugarcane and, perhaps high yielding corn, that can spare part of the residues without jeopardizing soil fertility (Cantarella et al., 2013; Fortes et al., 2013; Franco et al., 2013; Gollany et al., 2011). Palm oil is a promising feedstock because of the high oil yields but it requires hot climate and abundant rainfall, which prevails only in the Northern Brazilian forests of the Amazon, a sensitive region for expansion of bioenergy production. Logistics, because of the distance from the main markets, and lack of infra-structure may also be a problem in that region. However, an agro ecological zoning has been proposed for palm oil in the cleared lands of the Amazon, taking into account the economic, social, and environmental benefits of this crop (Ramalho Filho and da Motta, 2010). Among the oil crops, soybeans, despite the small oil yield, shall remain the most viable option of feedstock for jet biofuel in the short term. In 2012/13 27.7 Mha of land were grown with this crop, yielding 81.5 Mt of grain (MAPA, 2013b). In 2010 6.9 Mm3 of soy oil was produced and 2.2 Mm3 was directed to biodiesel; beef tallow was the second feedstock for biodiesel in Brazil – 13%, followed by cottonseed oil – 3.4% (Horta Nogueira and Capaz, 2013). Approximately 0.89 Mha of land is cultivated with cotton and 0.97 Mha with peanuts; other potential oil crops are cultivated at a much lesser extent: castor bean 0.09 Mha and sunflower 0.07 Mha (MAPA, 2013b). Although the expansion of bioenergy crops in Brazil are not likely to affect food supply – as discussed above – jet biofuels are for the global market and some countries may raise restrictions to fuels made with food crops. In this case, corn, cassava, soybeans and other feedstock may have limitations. In fact, some airline companies have promoted and tested jet biofuels made out of nonfood crops and residues such as camelina, jatropha, and used cooking oil (ICAO, 2011). However, the availability of cooking oil will hardly support large scale jet fuel production. Camelina is an oil crop grown in cold and dry areas of North America and Europe (Moser, 2010). Yields are relatively small (less than 2.5 t ha 1) under those conditions but sometimes marginal lands can be used and camelina is an option for rotation with wheat and other winter cereals. Varieties of camelina are being tested in Brazil as a second season crop (Cortez et al., 2014) but its economic viability as a feedstock for jet fuel is still to be proven. Jatropha curcas is a perennial crop with high oil content seeds. This plant was inadequately promoted as being capable of producing high yields in low fertility soils, tolerant to water stress, pests, and diseases but many cases of crop failures in Asia and Africa have been reported and its attractiveness as a biofuel feedstock has decreased substantially (Kant and Wu, 2011; Kumar et al., 2012; Openshaw, 2000; Mubonderi, 2012). Cases of discontinued production of jatropha following crop failures were also reported in Brazil (Cortez et al., 2014). Efforts to generate improved varieties through breeding, modern biotechnology, and agronomic practices are being made in order to reinsert jatropha (Cortez et al., 2014), but much work seems necessary before it can be widely cultivated. If the technological routes that employ vegetable oils prevail there will be opportunities for most oil crops to supplement the major feedstock – probably soybean in Brazil – depending on regional crop adaptation and costs. In addition to feedstock from agriculture, urban residues may also supply biomass for jet biofuel. Countries with large urban areas produce plenty of residues. In Brazil it is estimated that 195 Gg of municipal solid wastes (MSW) are generated daily of which 26.3 Gg only in the state of São Paulo (Secretary of Energy, 2014). Presently only 22 biogas plants produce methane from MSW (Secretary of Energy, 2013) indicating that there is great potential to generate biofuels with these materials.
5. Costs and competing uses of feedstock The choice of feedstock will necessarily take into account its production cost because biomass usually represent 70% or more of the overall biofuel price (Horta Nogueira and Capaz, 2013). In
H. Cantarella et al. / Environmental Development 15 (2015) 52–63
59
addition, jet fuels comprise, on average, about 1/3 of the operation costs of airlines (IATA, 2010) which means that jet biofuel prices are expected to be competitive with those derived from fossil sources. Some indicators of the three most relevant feedstock alternatives for jet biofuel in Brazil are shown in Table 5. Storability of grain and wood products are high, an important characteristic to maintain the industrial plant running for the whole year. However, sugarcane stalks, presently used to produce ethanol, have to be processed in less than one week. This has not been a big problem for the ethanol industry but it means that the industrial plants will operate only during the harvesting season, which is up to nine months per year. Storability will also be high if bagasse and harvesting plant residues are used in second generation or other conversion and refining technologies. Soybeans and sugarcane are important in the food market, both for internal consumption and for export, although they are already used to produce biofuels in large scale. Restrictions in some markets may apply because of the food vs fuel competition (EU, 2013). A sizeable proportion of the Brazilian wood production is exported as paper and pulp. Presently, biodiesel from soybeans – despite of 2 Mm3 used for this purpose – is not a significant part of the Brazilian energy matrix, whereas sugarcane products and woods are (Table 5), meaning that if shifted to jet biofuel production they will displace other energy sources. Feedstock resources are not likely to be a constraint because production can be greatly expanded not only by using new land – as previously discussed in this text – but through yield increases. However, the large scale uses that they already have will tend to set price limits and competition for the feedstock. The opportunity costs of feedstock vary with time and are different if one considers the price of the agricultural product or that of the final product (Fig. 1). The opportunity cost of the feedstock is the value that would have to be given up if sold to alternative markets in order to direct such feedstock to produce biofuels. The reference is the price of petroleum kerosene. In order to make comparisons easier the opportunity costs are expressed in US$/GJ. For the conditions of this study, all agricultural products, except soybean grain, have lower costs per unit of energy than aviation kerosene; i.e. depending on logistics, processing and refining costs, jet biofuel may be competitive with present kerosene prices. On the other hand, if prices of final products of agricultural feedstock are taken, only bagasse and wood have opportunity costs below those of aviation kerosene (Fig. 1). This means that other uses of the final product feedstocks would yield more revenues than producing aviation kerosene at 2012 prices. This reflects the added value of industrialization. Palm and soybean vegetable oils and ethanol have opportunity costs slightly higher than those of kerosene and, eventually, may become competitive. However, sugar and cassava flour have prices too high to justify their use as feedstock for jet fuel. In general, even in a country such as Brazil which is very competitive in the international agriculture commodity markets, the opportunity costs of most feedstock will make it difficult to produce jet biofuel at prices equal or lower than those of fossil oil. The relative costs of different feedstock classes (Fig. 2) indicate that wood and perennial C4 plants are less expensive than oil crops. Eucalyptus and sugarcane products also have good sustainability indicators (Table 3). However, the technical difficulties of the refining technology must also be taken into account (not discussed in detail this text). Depending on how these technologies evolve, other classes of feedstock may
Table 5 Potential feedstock for jet biofuel in Brazil: present production and competing uses (adapted from Cortez et al., 2014). Characteristic
Annual production Feedstock storability Importance for food production and export Importance in Brazilian energy matrix
Feedstock Soybean
Sugarcanea
Wood (eucalyptus and pinus)
81 Mt Very high High Low (biodiesel 1%)
650 Mt Difficult High High ( 20%)
254 Mm3 Very high None High ( 10%)
a Yield of sugarcane refers to fresh stalk used for sucrose and ethanol production. Storability time is very short after harvest (up to 3 days) but sugar can be used as feedstock for biofuels and fiber residues have high storability.
H. Cantarella et al. / Environmental Development 15 (2015) 52–63
60 50 40 30
AgriculturalProducts
30.3
32.7
38.2
54.1
Ethanol (anhydrous)
Soy oil
Sugar
Cassava flour
26.6 13.0
Palm Oil
Bagasse
Wood (from cellulose)
26.3
Soy (bean)
8.1
24.1
Cassava root
20.8
Sugarcane (TRS)
Corn (grain)
13.9
Palm (FFB)
8.5
Sugarcane (TRS and bagasse)
Aviation Kerosene
0
Eucalyptus 5.1
10
14.0
20 24.5
Competitiveness Agrcultural & Final Products (US$/GJ)
60
Final Products
Fig. 1. Opportunity costs of feedstock based on their energy value: comparison between agricultural products and final products. Costs are expressed in US$/GJ of energy content of the agricultural or final product. Data, yields, prices, and assumptions are the same as those of Table 3 and its Supplementary material. Price of aviation kerosene is used as reference. Prices are for 2012. Adapted from Cortez et al. (2014).
Fig. 2. Relative cost of different classes of feedstock and technical effort to convert them to aviation biofuels. Position of feedstock in the circles reflects the general opinion of the Sustainable Aviation biofuels for Brazil Project research team (Cortez et al., 2013). The closer a particular feedstock is from the inner circle, the higher its cost; conversely, the farther from the center the greater is the refining technology efforts. See also (Cortez et al., 2014; Schuchardt et al., 2014). Figure from Cortez et al. (2013) with permission.
H. Cantarella et al. / Environmental Development 15 (2015) 52–63
61
eventually prove to be equally viable. In this sense, Brazil has the conditions to support an aviation bioenergy industry with a range of biomasses. Although sugarcane and eucalyptus showed favorable conditions to start a jet biofuel industry in Brazil, so far fuel processing routes using oils and fats such as the hydroprocessing of esters and fatty acids (HEFA) are ahead of others and will probably be the first to reach commercial production: over 1500 commercial flights have been performed using fuel blends with up to 50% of oil-based biofuel (Souza et al., 2015). However, the cost of oil feedstock is usually higher than that of sugars, lignicellulosic, and waste materials whereas the technical efforts are higher to refine the later feedstocks (Fig. 2). The lack of competitiveness of biofuels made with several feedstocks as compared with jet kerosene has also been reported in other studies (SAFN, 2011). However, this may be balanced out by premium prices that society may be willing to pay for biojet fuels in order to have lower GHGs emissions. Taxes on carbon schemes may also provide funds. In addition, appropriate public policies and special tax treatments will likely be necessary to stimulate an emerging aviation biofuel industry not only to equilibrate costs but also to avoid destructive competition with other bioenergy or biofuel markets, until new technological progress and the scale up of operations make it economically sustainable. The possibility of reducing GHGs emissions, creating jobs, promoting rural development, and new markets for agricultural products justify the necessary incentives.
Acknowledgments This work is part of The Sustainable Aviation Biofuels for Brazil Project, funded by São Paulo Research Foundation (FAPESP) (Grant No. 2012/50009-1), Boeing, and Embraer. Sponsors did not interfere with the design of the work or the interpretation of data. The views and opinion in this paper are of the authors and may not reflect those of the private sponsors.
Appendix A. Supporting information Supplementary data associated with this article can be found in the online version at http://dx.doi. org/10.1016/j.envdev.2015.05.004.
References ABRAF, 2013. Anuário Estatístico da ABRAF 2013 ano base 2012. ABRAF Associação Brasileira de Produtores de Florestas Plantadas, Brasilia146. ANP, 2012. Petroleum, Natural Gas and Biofuels Estatistical Yearbook – 2012. Brazilian National Agency of Petroleum, Natural Gas and Biofuels, Rio de Janeiro. ASTM, 2009. ASTM D4054-09: standard practice for qualification and approval of new aviation turbine fuels and fuel additives. ASTM International, West Conshohocken. ASTM, 2013. ASTM D 1655, standard specification for aviation turbine fuels. ASTM International, West Conshohocken. ATAG, 2014. Facts & Figures. Air Transport Action Group. 〈http://www.atag.org/facts-and-figures.html〉. Brasil, 2012. Lei 12651 - Código Florestal Brasileiro. In: Brazil: Presidency of the Republic (Ed.), Lei 12651 de 25 de maio de 2012. Brasilia: Diário Oficial da União. Cantarella, H., Cerri, C.E.P., Carvalho, J.L.N., Magalhaes, P.S.G., 2013. Editorial: how much sugarcane trash should be left on the soil. Sci. Agric. 70, 1–2. CONAB, 2013. Séries Históricas, Brasil – por Produtos. Companhia Nacional de Abastecimento, Brasilia. CONAB, 2013. Séries Históricas, Cana-de-Açúcar. Companhia Nacional de Abastecimento, Brasilia. Cornelissen, S., Koper, M., Deng, Y.Y., 2012. The role of bioenergy in a fully sustainable global energy system. Biomass Bioenergy 41, 21–33. Cortez, L.A.B., Nigro, F.E.B., Nassar, A.M., Cantarella, H., Horta Nogueira, L.A., Moraes, M.A.F.D., Leal, R.L.V., Franco, T.T., Schuchardt, U., 2013. Flighpath to Aviation Biofuels in Brazil: Action Plan. FAPESP, São Paulo56. Cortez, L.A.B., Nigro, F.E.B., Nassar, A.M., Cantarella, H., Nogueira, L.A.H., Moraes, M.A.F.D., Leal, R.L.V., Franco, T.T., Schuchardt, U., 2014. Roadmap for sustainable aviation biofuels for Brazil. Blucher, São Paulo272. EMBRAPA, 2009. In: Manzatto, C.V., Assad, E.D., Bacca, J.F.M., Zaroni, M.J., Pereira, S.E.M. (Eds.), Zoneamento Agroecológico da Cana-de-açúcar. Embrapa, Rio de Janeiro, pp. 58.
62
H. Cantarella et al. / Environmental Development 15 (2015) 52–63
EPE, 2011. Plano Decenal de Expansão de Energia 2020. Empresa de Pesquisa Energética, Brasília. EU, 2013. European parliament backs switchover to advance biofuels. European Union Press. Service Available at www.europarl. europa.eu/pdfs/news/expert/infopress/201309061PR18831/2013090618831_en.pdf/download. (accessed on 08.05.15.). Ferreira, S.S., Nishiyama Jr., M.Y., Paterson, A.H., Souza, G.M., 2013. Biofuel and energy crops: high-yield Saccharinae take center stage in the post-genomics era - review. Genome Biol. 14, 210. Fortes, C., Vitti, A.C., Otto, R., Ferreira, D.A., Franco, H.C.J., Trivelin, P.C.O., 2013. Contribution of nitrogen from sugarcane harvest residues and urea for crop nutrition. Sci. Agric. 70, 313–320. Franco, H.C.J., Pimenta, M.T.B., Carvalho, J.L.N., Magalhaes, P.S.G., Rossell, C.E.V., Braunbeck, O.A., Vitti, A.C., Kolln, O.T., Neto, J.R., 2013. Assessment of sugarcane trash for agronomic and energy purposes in Brazil. Sci. Agric. 70, 305–312. Gollany, H.T., Rickman, R.W., Liang, Y., Albrecht, S.L., Machado, S., Kang, S., 2011. Predicting agricultural management influence on long-term soil organic carbon dynamics: implications for biofuel production. Agron. J. 103, 234–246. Hari, T.K., Yaakob, Z., Binitha, N.N., 2015. Aviation biofuel from renewable resources: routes, opportunities and challenges. Renew. Sustain. Energy Rev. 42, 1234–1244. Horta Nogueira, L.A., Capaz, R.S., 2013. Biofuels in Brazil: evolution, achievements and perspectives on food security. Glob. Food Secur. 2, 117–125. Horta Nogueira, L.A., Leal, M.R.L.V., 2012. Sugarcane bioethanol and bioelectricity. In: Poppe, M.K., Cortez, L.A.B. (Eds.), Sustainability of Sugarcane Bioenergy. CGEE, Brasilia, pp. 89–126. Huggins, D.R., Karow, R.S., Collins, H.P., Ransom, J.K., 2011. Introduction: evaluating long-term impacts of harvesting crop residues on soil quality. Agron. J. 103, 230–233. IATA, 2010. Annual Report 2010. International Air Transport Association, Berlin. IBGE, 2010. Produção Agrícola e Municipal, volume 36, ano 2009. Instituto Brasileiro de Geografia e Estatística. 〈http://www. ibge.gov.br/home/estatistica/economia/pam/2009/PAM2009_Publicacao_completa.pdf〉. IATA, 2013. IATA Technology Roadmap, 4th ed. IATA - International Air Transport Association: 86, Montreal. IBGE, 2014. Séries Históricas e Estatísticas, Temas e Subtemas. Instituto Brasileiro de Geografia e Estatística, Agropecuária. ICAO, 2013. ICAO Environmental Report 2013 – Aviation and Climate Change Available at. International Civil Aviation Organization, Montreal (accessed 28.01.13.). ICAO, 2011. ICAO Review: Sustainable Alternative Fuels for Aviation Available online at. ICAO International Civil Aviation Organization, Québec, Canada56 (accessed 28.01.13.). IEA, 2014. Key World Energy Statistics 2014. International Energy Agency, Paris. Kant, P., Wu, S., 2011. The extraordinary collapse of Jatropha as a global biofuel. Environ. Sci. Technol. 45, 7114–7225. Kumar, S., Chaube, A., Jain, S.K., 2012. Critical review of jatropha biodiesel promotion policies in India. Energy Policy 41, 775–781. Liska, A.J., Yang, H., Milner, M., Goddard, S., Blanco-Canqui, H., Pelton, M.P., Fang, X.X., Zhu, H., Suyker, A.E., 2014. Biofuels from crop residue can reduce soil carbon and increase CO2 emissions. Nat. Clim. Chang. 4, 398–401. Lynd, L.R., Woods, J., 2011. A new hope for Africa. Nat. Outlook 474, S20–S21. Macedo, I.C., Seabra, J.E.A., Silva, J.E.A.R., 2008. Green house gases emissions in the production and use of ethanol from sugarcane in Brazil: the 2005/2006 averages and a prediction for 2020. Biomass Bioenergy 32, 582–595. MAPA, 2012. Produção Brasileira em números - Anuário 2005. Ministério da Agricultura, Pecuária e Abastecimento, Brasilia. MAPA, 2013. Estatísticas e Dados Básicos de Economia Agrícola - Dezembro de 2013. Ministério da Agricultura, Pecuária e Abastecimento, Brasília. MAPA, 2013. Statistical Yearbook of Agrienergy 2012. Ministério da Agricultura Pecuária e Abastecimento, Brasilia284. Martha Jr., G.B., 2012. Brazilian agriculture development and changes. Embrapa, Brasilia164. Martha Jr., G.B., Alves, E., Contini, E., 2012. Land-saving approaches and beef production growth in Brazil. Agric. Syst. 110, 173–177. Morais, R.F., Souza, B.J., Leite, J.M., Soares, L.H.B., Alves, B.J.R., Boddey, R.M., Urquiaga, S., 2009. Elephant grass genotypes for bioenergy production by direct biomass combustion. Pesqui. Agropecu. Bras. 44, 133–140. Moser, B.R., 2010. Camelina (Camelina sativa L.) oil as a biofuels feedstock: golden opportunity or false hope. Lipid Technol. 22 (12), 270. Mubonderi, J., 2012. Jatropha: the broom of poverty; mith or reality. A critical analysis of the Zimbabwean jatropha programme in Mutoko district. In: Molony, T., Chinigo, D. (Eds.), PISCES – Policy Innovations Systems for Cleaner Energy Security. Edinburgh, Department of International Development, UK Aid. OAG, 2012. The European Union Emission Trading Scheme Report. Official Airline Guide, London 2012. Openshaw, K., 2000. A review of Jatropha curcas: an oil plant of unfulfilled promise. Biomass Bioenergy 19, 1–15. Pereira, P.A.A., Martha Jr., G.B., Santana, C.A.M., Alves, E., 2012. The development of Brazilian agriculture: future technological challenges and opportunities. Agric. Food Secur. 1 (4), 1–12. Prieler, S., Fischer, G., van Velthuizen, H., 2013. Land and the food–fuel competition: insights from modeling. Wiley Interdiscip. Rev.: Energy Environ. 2, 199–217. Ramalho Filho, A., da Motta, P.E.F., 2010. Zoneamento agroecológico do dendezeiro para as áreas desmatadas da Amazônia Legal. Embrapa, Rio de Janeiro44p. SAFN – Sustainable Aviation Fuels Northwest, 2011. Sustainable aviation fuels northwest: powering next generation of flight. Report S.1. www.wedc.wa.gov/Download%20files/SAFN_2011Report.pdf. (accessed 03.01.13.). Schuchardt, U., Franco, T.T., Melo, J.C.P., Cortez, L.A.B., 2014. Sustainable aviation fuels for Brazil. Biofuels Bioprod. Biorefining 8, 151–154. Secretary of Energy, 2013. Renewable energy. Executive Summary – 3rd Trimester 2013. Government of the State of São Paulo – Secretary of Energy. 23p. Available at 〈http://www.energia.sp.gov.br/portal.php/resumo_executivo_energias_renovaveis〉. Secretary of Energy, 2014. Solid residues Available at. Government of the State of São Paulo – Secretary of Energy. (accessed 14.11.14.). Service, R.F., 2014. Cellulosic ethanol at last: large volumes of fuel from crop wastes will soon start flowing in the U.S. - unless policymakers balk. Science 345 (6201), 1111. SNA, 2014. Embraer celebrates 10 years of agricultural airplane run on ethanol (In Portuguese). Sociedade Nacional de Agricultura – SNA. Available at 〈http://sna.agr.br/embraer-celebra-dez-anos-do-aviao-agricola-movido-a-etanol〉. (accessed 8.05.15.).
H. Cantarella et al. / Environmental Development 15 (2015) 52–63
63
Souza, G.M., Victoria, R.L., Joly, C.A., Verdade, L.M., (Eds.), 2015. Bioenergy and sustainability: bridging the gaps. São Paulo, SCOPE and FAPESP. Available at 〈http://bioenfapesp.org/scopebioenegy/index.php/chapters〉 Downloaded on 17 Apr 2015. Tarkalson, D.D., Brown, B., Kok, H., Bjorneberg, D.L., 2011. Small grain residue management effects on soil organic carbon: a literature review. Agron. J. 103, 147–252. van Noorden, R., 2013. EU debates U-turn on biofuels policy. Nature 499, 13–14. Waclawovsky, A.J., Sato, P.M., Lembke, C.G., Moore, P.H., Souza, G.M., 2010. Sugarcane for bioenergy production: an assessment of yield and regulation of sucrose content. Plant Biotechnol. J. 8, 263–276. Woods, J., Williams, A., Hughes, J.K., Black, M., Murphy, R., 2010. Energy and the food system. Philos. Trans. R. Soc. - B 365, 2991–3006.