Applied Energy 86 (2009) S1–S10
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Biofuels in Asia
1. Introduction The past decade witnessed the unprecedented rise of the biofuels industry. Between 2001 and 2006 alone, the global annual production of biodiesel and ethanol grew by 43% and 23%, respectively [1]. Compared to 2007, global fuel ethanol production grew 31% to 35 million tons of ethanol (toe) (1.2 million barrels daily) in 2008, with the distribution in North America (52.2%), South America (39.4%), Europe (3.8%) and Asia Pacific (4.6%) [2]. The global biofuel industry will continue to experience rapid growth in succeeding years [3]. The motivations for governments to aggressively pursue biofuel development are complex and multidimensional. Biofuel development has potentials in addressing issues related to energy and food security, climate change, and rural development. Firstly, biofuels can be regarded as integral part of emerging bio-economy and have potential to increasingly replace materials including fuels from fossil oil in the future. Secondly, as a renewable energy, biofuels are derived from plant materials which can contribute to the reduction of greenhouse gas (GHG) emissions when replacing fossil oil if they are sustainably managed. Thirdly, biofuels production is often associated with farmers in rural and/or poor areas. It has the potential to produce new incomes for farmers while generating new jobs and new business to alleviate poverty and improve farmers’ life standards. Debates on biofuels, however, have been intensively discussed in both the scientific world and the media. Opportunities, challenges, and even threats have been raised. Some biofuels, especially those linked to first-generation biofuels, have received considerable criticisms recently—most notably the biofuel potential to increase food prices; their relatively low greenhouse gas (GHG) abatement capacity yet high marginal carbon abatement costs; their continuing need for significant government support and subsides; their direct and indirect impacts on land use change and related greenhouse gas emissions [4]. It is even more critically important to address these issues in Asia where large population and fast economic growth have resulted in high-energy demand, increased GHG emissions, and urgent needs for poverty reduction. Asian countries vary greatly in terms of population size, state of development, average income, existing patterns of land use, and quality of governance. Environmental and social aspects associated with biofuel production are intricately interrelated to biofuels, as shown in Fig. 1, and they need to be carefully addressed. The issues include, for example, energy consumption, GHG emissions, land use change, water consumption, biodiversity, air quality, nutrient and pesticide applications, feedstock, food security, job creation, and poverty alleviation. There will be trade-offs among the different impacts 0306-2619/$ - see front matter Ó 2009 Published by Elsevier Ltd. doi:10.1016/j.apenergy.2009.07.004
because some might offer benefits to one or more aspects while negatively affecting another. To ensure the sustainability of biofuels, different regions including the European Union [5,6], the Unites States [7], and other countries are developing their national strategies on biofuel development. The United States National Biofuel Action Plan has covered the whole chain of the biofuel production process, including feedstock production and logistics, conversion technologies, distribution, and end use while, at the same time, addressing the biofuel sustainability issues. New regulations on biofuels are, however, under-developed [8]. The EU sets out seven strategic policy areas for the production and use of biofuels, including measures of stimulating demand for biofuels, ensuring environmental benefits, developing the production and distribution of biofuels, expanding feedstock supplies, enhancing the trade opportunities of biofuels, supporting developing countries, as well as supporting research and innovation activities [5,6]. Sustainable criteria of biofuels have also been intensively discussed and addressed in the EU. Biofuel production has been rising drastically in many Asian countries in recent years. This is driven primarily by the government’s pursuit of energy security, economic development (particularly, improvement of trade balances and expansion of the agriculture sector), and poverty alleviation. Most Asian countries have their biofuel strategies focused around the country’s main agricultural product and new business opportunities. Other potentially important issues that have received less attention include environmental and social impacts of biofuels. Dedicated discussions on Asian biofuel development are important but not well addressed yet. A system that continuously monitors the production of biofuel crops, especially plantation sites and conditions, should be put in place to prevent serious damage to the environment. These issues are critically important for Asia, where the region’s impressive economic growth has boosted demand for energy and put corresponding strains and pressure on the environment, including climate change. However, differences in the production methods, such as the location of cultivated lands and the feedstocks used, determine biofuel advantages and disadvantages. To bring about a more varied discussion, as well as provide better decision data for various organizations, more information and innovative knowledge need to be developed and disseminated, and the various arguments for and against biofuels have to be reviewed critically [9]. The main objective of this Supplementary Issue, Biofuels in Asia, is thus to initiate discussions and stimulate new ideas on biofuels development, with special focus on Asia. In this light, scholars were invited to submit research papers aimed at finding innovative solutions that would help understand and identify, as well as solve some of the challenges relating to the future of biofuels develop-
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Fig. 1. Driving forces and challenges of biofuels development.
ment. In this special volume, the papers have been selected based on peer review results from over 50 submitted manuscripts. It covers a wide array of topics including biofuel feedstocks, land use change (LUC), conversion technologies, sustainability assessments such as life cycle assessment (LCA) of the biofuel production chain, policy strategies, social impacts, and other issues. A few issues raised by this special volume, which could highlight plausible topics for future studies are: Will biofuels be able to contribute to sustainable development in Asia? What are the positive and negative impacts of biofuels development in Asia? Is availability of feedstock resources the bottleneck in Asia? Can net energy production and GHG emission reduction actually be realized from the whole chain of the biofuel production? Will biofuel development offer a new opportunity for poverty alleviation and rural development? Are the conversion technologies economically viable and technically feasible? What are the research needs for the future development of biofuels in Asia? More questions and issues can be added into the above list because biofuels development involves complex aspects and encompasses many sectors including industry, agriculture, and trading business. The complexity of the various factors associated with biofuels development makes it difficult to cover all aspects in one special issue. We hope this special issue will be able to give some answers or jumpstart discussions for further studies on the above issues and others that may emerge during the development and deployment of biofuels. 2. Current status of biofuels development in Asia Presently, the largest biofuel producers in the region are (the) People’s Republic of China, India, Indonesia, Malaysia, the Philippines, and Thailand [9]. Thailand, (the) PRC, and India focus largely on the production of ethanol, while Indonesia and Malaysia dominate Asia’s biodiesel production. Biofuel trade in Asia is still in its early stages. (the) PRC is now the third largest bioethanol producer in the world, after the US and Brazil [2,3]. The bulk of (the) PRC’s bioeth-
anol has been made from corn, wheat, and cassava. The sweet sorghum is another potential feedstock in the future. (the) PRC also promotes biodiesel production, but its total production is minimal compared to its bioethanol production [10]. At present, India is the world’s 6th largest energy consumer; with the energy demand registering an annual growth rate of 4.8% [11] India’s bioethanol production is largely based on molasses [10]. Its biodiesel market is less mature with very minimal production. Jatropha has been identified as the most suitable non-edible feedstock for biodiesel. In Thailand, the Government is promoting the production of both liquid (bioethanol and biodiesel) and solid biofuel (from biomass). For bioethanol production, molasses feedstock is primarily used [12]. For biodiesel production, palm oil is currently the only crop used as feedstock [13]. Whereas Indonesia is currently the world’s largest producer of palm oil and the second largest exporter, Malaysia is the world’s second largest producer as well as the world’s largest exporter of palm oil. Thus, biofuel development in these two countries is focused on the production of palm oil based biodiesel, while their ethanol production is both negligible [10]. The Philippines, on the other hand, is promoting both ethanol and biodiesel. Given that it is the world’s largest coconut oil producer and the second largest producer of coconut, the country is able to produce a unique form of biodiesel, known as coconut methyl ester [10]. Ethanol production in the Philippines is primarily based on sugarcane. In the Greater Mekong Sub-region (GMS), countries like Viet Nam and Myanmar have started biofuel production on a limited scale, whereas others like Cambodia and the Lao People’s Democratic Republic have experimental production scales [14]. An overview of biofuels policies in selected Asian countries is presented in Table 1. Strategies and policies for biofuel development vary from numerical targets to blending mandate, as well as economic measures such as subsidies, fiscal incentives, and tax exemptions. In Asia, (the) PRC and Thailand have relatively more advanced level of biofuel development compared to other countries in the region. Interestingly, as the developed country in Asia, Japan does not have a unified strategy or set of policies to promote biofuels. Instead, it has several national strategies and plans to promote them such as the Biomass Nippon Strategy, the Kyoto Protocol Target Achievement Plan, and the New National Energy Strategy. Through these various national strategies, Japan’s biofuel strategies and plans address several of Japan’s national objectives, i.e., global warming mitigation, energy security, regional development, and the development of a recycle-based economy [15]. The
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unbalanced economic development in Asia should also be considered when developing biofuel strategy. Malik et al. (2009) argues that biofuel, in particular the first-generation biofuels, will and should stay as a key development activity of the rural GMS [16]. The rationale and reasons for promoting biofuels in the GMS, justification of feedstock selection, and the strategic recommendation have been addressed. The results highlight the importance of involving small producers in the market chain and stress the sustainability issues particularly on the use of marginal land areas. 3. Key drivers and impacts of biofuel development in Asia 3.1. Security of energy supply Security of energy supply means that energy can be adequately, affordably and reliably supplied. For most countries in the Asian region, the primary reason for joining the biofuel bandwagon is energy security. As home to 60% of the global population, Asia’s future energy needs are predicted to escalate in response primarily to increase in demand from the transport sector. For example, the transport sector of non-member countries of the Organisation for Economic Co-operation and Development (OECD) in Asia is predicted to increase by 4% annually as compared to the average increase of 1.4% in the world for the period leading to 2030 [19]. (the) PRC and India are the two largest energy consumers in Asia. Since 1990, energy consumption as a share of total world energy use has increased significantly in both countries. (the) PRC and India together accounted for about 10% of the world’s total energy consumption in 1990. But, in 2006, their combined share grew to 19%, and is expected to increase further to 28% of world energy consumption in 2030 in the reference case [19]. To satisfy domestic energy demand, Asian countries are likely to increase their dependence on imported oil. For example, (the) PRC and India are projected to sharply increase their oil imports in the next 20 years— from 50% in 2007 to 80% in 2030 for (the) PRC, and from 70% to 92% over the same period for India [10]. Even countries with domestic oil production, like (the) PRC and Indonesia, have shifted from being a net exporter of oil to being a net oil importer. This is largely because production levels of their existing oil fields are
slowly dwindling, and resources needed for new oil exploration projects are sorely lacking. Transport has become the main driver for increasing the liquid fuel demand, which was predicted to grow mainly in non-OECD Asian countries. In 2006, non-OECD countries consumed about 16 million barrels of fuel per day, while North America accounted for about 25 million barrels per day. However, in 2030, non-OECD countries are predicted to utilize about 30 million barrels of fuel per day, overtaking North America which is expected to maintain its fuel consumption at current levels [19]. Asia’s energy security is considered one of the most fragile in the world because the region is heavily dependent upon imported oil to satisfy the demand of its transport sector. Therefore, the development of renewable energy technologies and policy, particularly those that promote the expansion of biofuel production, is believed to be one of the paths to achieving energy security. Based on studies by the International Energy Agency (IEA) [20], biofuel for transport represents a key source of diversification from petroleum. Biofuels from grain and beet play an important role in temperate regions, but they are relatively expensive and their benefits, in terms of energy efficiency and carbon dioxide (CO2) savings, are variable. Biofuels from sugarcane and other highly productive tropical crops are substantially more competitive and beneficial. But all first-generation biofuels ultimately compete with food production for land, water, and other resources. Greater efforts are required to develop and deploy second-generation biofuel technologies, such as biorefineries and lignocelluloses, to enable the flexible production of biofuels and other products from non-edible plant materials. However, energy security improvements through biofuel development are likely to vary in different countries due to differences in energy resources and energy consumption mix. It is thus imperative for the governments of Asian countries to implement policies targeted at incorporating biofuels into their respective national energy mix. Indonesia’s National Energy Policy, for example, has stipulated to reduce the country’s dependence on fossil fuel from the current 66% of final energy demand, of which oil accounts for 52% of the energy mix, to 53% of energy demand in 2025, of which 20% is oil [10]. By 2025, biofuel contribution to Indonesia’s energy mix is aimed at 5%. The case of Japan, though, presents a different
Table 1 Biofuels policies in selected Asian countries. Country
Targets for 1st-generation biofuels and plans for 2nd-generation biofuels
Blending mandate
Economic measures
(the) PRC [17]
Take non-grain path to biofuel development
Ethanol: trial period of 10% blending mandates in some regions
Ethanol: incentives, subsidies and tax exemption for production Diesel: tax exemption for biodiesel from animal fat or vegetable oil
India [10,11]
No target identified Promotion of jatropha
Ethanol: blending 5% in gasoline in designated states in 2008, to increase to 20% by 2017
Ethanol: excise duty concession Ethanol and diesel: set minimum support prices for purchase by marketing companies
Indonesia [10]
Domestic biofuel utilization: 2% of energy mix by 2010, 3% by 2015, and 5% by 2025 Seriously considering jatropha and cassava
Diesel: blending is not mandatory but there is a plan to increase biodiesel blend to 10% in 2010
Diesel: subsidies (at the same level as fossil fuels)
Japan [15]
Plan to replace 500 ML/year of transportation petrol with liquid biofuels by 2010 Promotion of biomass-based transport fuels
No blending mandate upper limits for blending are 3% for ethanol and 5% for biodiesel
Ethanol: subsidies for production and tax exemptions
Malaysia [10]
No target identified Promotion of jatropha, nipa, etc.
Diesel: blending of 5% palm oil in diesel
Diesel: plans to subsidize prices for blended diesel
Philippines [10]
No target identified
Ethanol: 5% by 2008; 10% by 2010
Ethanol and diesel: tax exemptions and priority in financing
Studies and pilot projects for jatropha
Diesel: 1% coconut blend; 2% by 2009
Thailand [18]
Plan to replace 20% of vehicle fuel consumption with biofuels and natural gas by 2012 Utilization of cassava
Ethanol: 10–20% by 2008 (Gasohol 95)
Source: See the Reference [17,10,11,15,18]
Diesel: 5% (B5) mix in 2007 and 10% (B10) by 2011
Ethanol: price incentives through tax exemptions
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picture. About half of Japan’s total energy supply comes from imported oil, of which almost 90% is imported from the Middle East. Japan’s transport sector is almost entirely dependent on oil. Given that Japan is totally dependent upon imported oil, switching from oil to biofuels would not substantially change the country’s situation. This is mainly because Japan would still need imported biofuels. Hence, the ability of biofuels—including imports—to contribute to Japan’s energy security, in particular the goal of reducing oil dependency in the transport sector by 80% as set by the New National Energy Strategy, could be relatively limited [15]. Still, as biofuels can be blended easily with fossil fuels, they remain a viable alternative to meeting energy demand. 3.2. Climate change The GHG emissions from Asian countries rose more rapidly as compared to emissions from countries in other regions [21]. Prompting this trend may be the significant growth in Asia’s energy consumption in response to the region’s large population size and rapid urbanization, industrialization, and economic development. According to the most recent estimates [22], (the) PRC has become the world’s largest emitter of carbon dioxide, while India is foreseen to rank third by the end of 2008. Biofuel proponents argue that unlike fossil fuels which release carbon dioxide that has been stored for millions of years beneath the earth‘s surface, biofuels produced from biomass have the potential to be ‘‘carbon-neutral” over their life cycles as their combustion only returns to the atmosphere the CO2 absorbed from the air by feedstock crops through photosynthesis. It thus has the potential to replace fossil fuels and contribute to the mitigation of GHG emissions [23,24]. Japan’s biofuel development has been motivated by the country’s climate change mitigation target [15]. In the long run, the Japanese government has a GHG emission reduction target of 60–80% by 2050 from its current level, as stated in the Action Plan for Achieving a Low-carbon Society. How to achieve this ambitious reduction and the contribution of biofuels will be significantly dependent upon the technology breakthrough of the second-generation biofuels. Unlike Japan, however, fighting climate change is not considered as a main driver in most Asian countries since they are non-Annex 1 countries and are thus not required by the Kyoto Protocol to cap their emissions [10]. The impact of biofuels on climate change widely varies, i.e., it may not necessarily be positive, or as positive as is often initially assumed. Depending on the methods used to produce the feedstock and process the fuel, some crops can even generate more GHG than do fossil fuels. Assessing the net effect of biofuels on reducing climate impact requires an analysis of all GHG emissions throughout the life-cycle stages of biofuels: planting and harvesting of crops (including fertilizer and pesticide use, irrigation technology, and soil treatment); processing the feedstock into biofuel; transporting the feedstock and final fuel; storing, distributing, and retailing biofuel. It is also important to investigate biofuels together with other options of bioenergy. Takeshita (2009) explores in detail the cost-effective strategy for introducing modern bioenergy into developing Asia over the period 2010–2100 under stringent climate stabilization constraint [21]. An integrated model, including bioresources, conversion technologies, and final products is used for scenario analysis. The model also includes the combination of bioenergy and CO2 capture and storage (CCS), which can yield negative CO2 emissions [25–27]. The study on the Southeast Asia suggests that using woody biomass to replace the use of fossil fuels for energy generation could prevent carbon emissions of about 169.0–281.7 TgC per year between 1990 and 2020 [28]. Another study shows that 9–38% of
the total carbon currently emitted each year in Indonesia could be avoided by replacing the fossil fuels with bio-methanol/fuel cells. In contrast, substituting this same amount of bio-methanol for gasoline could provide all of the annual gasoline needs of Indonesia and contribute towards reducing their carbon emissions by about 8–35% [29]. As presented in this special issue, there is potential to further reduce the climate impact associated with biofuels through various means, such as improved yields with existing feedstocks, improved process efficiencies, new energy crop or new technologies. Yet, the long-term potential of biofuels to contribute to GHG reduction goals will depend not only on the rates of technological development of the second-generation biofuels but also on the development of other advanced vehicles, such as the ‘‘flex-fuel” vehicles which can run on petrol or on ethanol blends of up to E100 [30]. 3.3. Land use changes and food security With the increasing demand for biofuels, Asia is now experiencing supply constraints and expansion challenges related to growing concerns of competing uses of land as well as water resources. In fact, lack of land for feedstock cultivation is one of the major supply constraints in biofuel expansion. Another major issue on resource use is the dilemma of utilizing land to cultivate feedstock crops instead of growing crops for food, fodder, or as raw material for paper. This land could also be used for biodiversity conservation. The paper by Kostka et al. (2009) reports that (the) PRC and India face serious limitations in finding suitable available land for the further expansion of sugarcane plantation, and they also experience difficulties in increasing yield output per hectare [31]. However, based on (the) PRC’s current land use, Tian et al. (2009) made an analysis of the potential of marginal land for biofuel feedstock plantation [32]. Other relevant factors such as soil conditions, water resources, and feedstock types are not dealt with in this study, but these factors need to be carefully studied in the future. Land substitution effects of biofuel side products and implications on the land area requirement for EU 2020 biofuel targets were analyzed [33], which shall be useful for carrying out similar analysis for Asia in the future. Given that development of biofuels will continue to exert upward pressure on agricultural commodity prices, it is important to explore the implications of biofuel development for food security and poverty levels in Asia’s developing countries. Among the important considerations in food security discussions are availability of food, access to food, and stability of supply [34]. Concerns on rising food prices and food security may slow down the momentum of biofuel development in Asia. As biofuels could offer the potential of significant new markets for agricultural producers, demand for agricultural feedstock for use in biofuel development could divert a large portion of the region’s food supply away from traditional food marketing channels. For example, the use of food crops, like sugarcane and cassava, as biofuel feedstock can cause problems in the food sector. Non-food crops used in biofuel production, such as sweet sorghum and jatropha, could still compete with food crops in terms of resource (land) use for cultivation. For these reasons, (the) PRC is shifting its national biofuel development from the current grain-based to non-grain-based feedstocks, and from feedstocks cultivated in arable land to those grown in marginal land [17,32]. The growing demand for biofuels and the ensuing increase in agricultural commodity prices will, in the short run, adversely affect the household food security of the poor. However, if governments are able to establish appropriate policies to enhance agricultural productivity and safety nets to ensure food access by the poor and vulnerable, the expansion of biofuel production can,
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in the longer run, help promote agriculture as an engine of growth for poverty alleviation. The impact in boosting agricultural productivity and enhancing local food security has been analyzed [11], using a case study of a community lift irrigation practiced in India. Their findings suggest that the lift-irrigation model of growing food crops in the drylands of India can be adopted for the expansion of biofuel crops, which, in turn, has the potential of eradicating poverty among farming communities, if appropriate sustainable development measures are carefully implemented. Svrk and Elder (2009) likewise argue that there are straightforward, practical, feasible measures that can be implemented immediately in order to reduce the pressure of biofuels on the environment and the food supply, while at the same time increasing food production [35]. The key is to focus on increasing resource use efficiency and productivity in agriculture using current and new technologies. For example, an increase in rice productivity from the current level of 3.8 tons per hectare (the average productivity in India, Indonesia, Thailand, Viet Nam, and Malaysia, which are major rice growing countries and promoters of first-generation biofuels) to 6.3 tons per hectare (the current level recorded in (the) PRC) would make available 23 million hectares of land for other purposes. Increasing the productivity of land can free up a substantial amount of land resources for a variety of alternative uses, including cultivation of energy crops for biofuel production. Improving yields of existing food crops, oil seeds, and pulses could also open up more potential for biofuel development in the region. These productivity increases could help save large tracts of land from deforestation and other ecologically-destructive economic uses. Increasing land-use efficiency also contributes to more efficient management of other agricultural inputs. Such findings clearly highlight the importance of cooperation between technology and knowledge transfer in the Asian region. Governments need to invest more on education and training of farmers in order to help them understand the importance of increasing resource use efficiency through appropriate technologies and practices. 3.4. Rural development and poverty alleviation The synergies among biofuel development, energy policies, and economic, social and environmental policies need to be carefully investigated. In most countries in Asia, however, energy policies have been considered in isolation from the policies associated with rural development and poverty alleviation. In fact, those interactions, together with other factors, are closely connected. Poverty, for instance, is often associated with the lack of access to electricity. The paper by Urban et al. (2009) reveals that there are about 72 million households in rural India without access to electricity, and thus primarily rely upon the traditional biomass [36]. They investigate how rural electrification could be achieved in India using different energy sources, and their consequent effects on climate change mitigation. Regional Energy Model (REM) has been applied to develop scenarios for rural electrification for the period 2005–2030 and to assess the effects on GHG emissions, primary energy use, and costs. Business-as-usual (BAU) set-up with different electrification scenarios have been compared based on electricity from renewable energy, diesel, and the grid. The impacts of renewable energy on climate change and their costs for rural electrification have been addressed with policy recommendations. Agoramoorthy et al. (2009) address the connection between agriculture and biofuel production to reduce poverty through a case study of a tribal community in India’s drylands [11]. Biofuel development may offer income-generating opportunities for farmers, as well as promote smallholder participation in biofuel crop production. The cultivation and harvest of feedstock crops, for example, require extensive labour and manual work, thereby increasing employment in the agricultural sector. For
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example, the Malaysia Palm Oil Council states that the palm oil industry provides employment to more than half a million people and a livelihood to an estimated one million people [10]. In India, the National Biofuel Mission was expected to generate 127.6 million person-days in employment by 2007 and further support the sugarcane industry, which is the biggest agro-industry in the country, employing 45.5 million people [10]. These benefits, however, require active engagement of and commitment by the governments to support public investments in crucial services such as infrastructure, research extension, rural finance, market information, market institutions, and legal systems. In order to minimize risk for bioenergy development, it is important to fully analyze the different aspects of bioenergy development. Zhou and Thomson (2009) studied in general perspectives on the strategic policy of biofuels in Asia [10]. Phalan (2009) provides an overview of social and environmental impacts of biofuels in Asia [30]. The results suggest that careful considerations of various sustainability biofuels in terms of land use change, greenhouse gas emissions, biodiversity, water resources, etc. shall be included when developing biofuels. Further research on the strategic assessments and mapping to ensure that land-use plans and standards and to develop incentives which are calculated to avoid negative impacts and deliver societal benefits. Biofuel is not a single product in bioenergy systems. It has close relationship with food and trade. Yang et al. (2009) made the analysis of biofuels in the GMS on the impacts on prices, production and trade [14]. The GMS has an abundant labour and natural resource but limited supply of fossil fuels which continues to serve as a constraint to economic growth. Five crops have been selected to be further developed and use for biofuel production in the GMS, namely sugarcane, cassava, oil palm, sweet sorghum and Jatropha curcas. The expanded use of sugarcane, cassava, and oil palm for biofuel production can cause problems in the food sector. The other two crops, sweet sorghum and J. curcas, are non-food crops but could still compete with the food crops in terms of resource use for production. In all cases, the GMS needs to formulate a sustainable strategy for the biofuel development that will not compete with the food sector but will rather help achieve energy security, promote rural development and protect the environment. Except for (the) PRC and Thailand that already have fairly developed biofuel sub-sector, the other GMS countries are either poised to start (Laos and Cambodia) or ready to enhance existing initiatives on biofuel production (Myanmar and Viet Nam), with support from their respective governments. Biofuel development in these countries has to be strongly integrated with smallholder producers in order to have an impact on improving livelihood. At this initial stage, the sub-sector does not need to compete on a price basis but should rather aim to put up small-scale biofuel processing plants in remote rural areas that can offer an alternative to highpriced diesel and kerosene for local electricity grids serving homes and small enterprises. The social and economic multiplier effects are expected to be high when farmers that produce the energy crops also produce the biofuels to generate affordable and reliable energy. To make this happen, there is a need for conscious effort and investment support from development agencies and the government working in partnership with the private sector, research institutions and the farmers. 4. Potential feedstock for biofuel development Biofuels cover a wide variety of products which can be produced from different feedstocks, including crops for sugar, starch and oil. Lignocelluloses (such as agriculture and forest residues) and forest co-products (waste parts of the plant) can also be used. However, there are a number of technological challenges to overcome before lignocellulosic biomass will be competitive with other
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feedstock. In Asia, biofuel production primarily uses agricultural crops as feedstocks. Crops that are high in sugar or starch are fermented to produce ethanol; whereas, oil crops such as rapeseed and palm oil are used for biodiesel production. As demand for feedstock resources soar, many Asian countries are currently looking at alternative biofuel feedstocks. Jansson et al. (2009) analyze the potential of cassava as feedstock for bioethanol production especially in (the) PRC [37]. Cassava, which ranks as fifth among crops in the global starch production, has high drought and heat tolerance, little requirement to agricultural fertilizers, and high starch content. The study shows that (the) PRC has significant potential for the productivity improvement of cassava compared to other Asian countries. Economic benefits for small farmers are also attractive. They also address the importance of the future research by metabolic engineering, e.g., to increase the efficiency of photosynthetic CO2 assimilation into storage and structural products, and to reduce input costs for the conversion of cassava biomass into biofuels. Sweet sorghum is also another alternative feedstock crop for bioethanol production. Like cassava, it is a high-yielding crop with high tolerance to drought and barren land as well as a potentially higher conversion efficiency rate [17,32]. Sugarcane can also be considered as another potential feedstock for bioethanol production. Kostka et al. (2009) investigate the potential and constraints of sugarcane production in (the) PRC and India [31]. The results show that supply side constraints vary significantly in the two countries. (the) PRC and India both face serious limitations in regards to suitable available land for the further expansion of sugarcane production. Equally they are both faced with challenges to increasing yield output per hectare, albeit different ones. With regard to productivity, (the) PRC achieved 2.7% annual yield growth since 1997, while India has seen yield decreases of 0.1% per annum over the same period. The historical difference in the development pattern between India and (the) PRC highlights the importance of policy incentives and technology development. The authors conclude that sugarcane used as a feedstock to meet the rising energy demand will come at the expense of converting fertile land for non-food purposes. For biodiesel production, palm oil is the primary crop used as feedstock in Indonesia, Malaysia, and Thailand because of its abundant supply and relatively low production cost. From the LCA conducted in the study [38], it was found that palm biodiesel generates an energy yield ratio of 4.16 (output energy/input energy). The study also showed that combustion of palm biodiesel is more environment-friendly than petroleum-derived diesel, with a reported 38% reduction in CO2 emission per litre of biodiesel combusted. Agriculture and forest residues provide a large potential as alternative feedstock, especially if the second-generation biofuel technology is applied. They may also have better sustainability in terms of contribution to GHG emission reduction and food security. In (the) PRC, for example, the agriculture and forestry wastes are estimated to be about 1 billion ton annually. Assuming that 4 tons of waste can produce 1 ton of ethanol, (the) PRC’s ethanol production potential is roughly 375 million tons [17]. Sasaki et al. (2009) investigate the bioenergy potentials in Southeast Asia between 1990 and 2020 [28]. They developed a forest land use model, projected changes in area of natural forests and forest plantations, biomass change and harvest models to estimate woody biomass availability in the forests under the current management regime. The results show that the annual decline can be about 1.5%. Without incentives to reduce deforestation and forest degradation, and to promote forest rehabilitation and plantations, woody biomass as well as wood production and carbon stocks will continue to decline. This would put sustainable development in the region at risk as the majority of the population depend mostly on
forest ecosystem services for daily survival. However, in another study [29], the potential to sustainably collect and convert forest materials to methanol for use in energy production in Indonesia has also been examined. Using the annually available aboveground forest biomass, roughly 40–168 billion litres of bio-methanol could be produced for use as a transportation fuel and/or to supply fuel cells to produce electricity. When a lower forest biomass availability estimate was used to determine how much electricity (methanol fed into fuel cells) could be produced in Indonesia, more than 10 million households or about 12,000 villages (20% of the total rural villages in Indonesia) would be supplied annually with electricity. Collecting forest biomass at the higher end of the estimated available biomass and converting it to methanol to supply fuel cells could provide electricity to more than 42 million households annually. This would be approximately 52,000 villages, or 86% of the total rural villages in Indonesia. When electricity is produced with bio-methanol/fuel cells, it could potentially supply from half to all of the current electricity consumed in Indonesia. 5. Conversion technologies and integrated system Biofuels conversion system is one of the important steps in the whole biofuel production chain. Factors such as high yields and low energy consumption are important to consider in promoting the future competitiveness of biofuels to fossil fuels in the market. Depending on the feedstocks used and the final fuel output produced, biofuel conversion can be done through various routes using a range of biological, chemical, and thermal conversion processes, as shown in Fig. 2. Feedstocks for biofuels production can be categorized into three main groups namely plant oils, sugars/ starches, and lignocelluloses. Optimization of the biofuel productions will be determined by the type of feedstock, conversion efficiency, costs, and GHG emissions reduction. Lignocelluloses based biofuel conversion technology, so called the second-generation technology, has been paid more attention for the future development because of the large feedstock resources, food security and climate change benefits. 5.1. Biodiesel and bioethanol conversion technologies Biodiesel is currently produced from a variety of vegetable oils and/or animal fats through transesterification process. In (the) PRC, biodiesel is primarily produced from used vegetable cooking oil; in India from Jatropha; in Indonesia, Malaysia and Thailand from palm oil. Another potential feedstock, which could offer much higher yields than conventional oil crops, is the micro-algae. However, growing micro-algae in bioreactors could be very expensive, and cultivating them in open ponds could encounter several technical problems; hence, it is unlikely that they will be used to produce biodiesel on a commercial scale within the next decade [40]. Ethanol production involves the cooking of starches before being ‘‘enzymatically hydrolyzed” to glucose, and then fermenting the resulting glucose and other sugars to produce ethanol. The technology of producing ethanol from either starchy feedstocks (e.g., corn, wheat) or sugary feedstocks (e.g., sugarcane, molasses) is a mature technology. Ethanol production from starch is a traditional first-generation ethanol conversion technology, whereas ethanol production from sweet sorghum stalks is an emerging technology, and from lignocelluloses a future technology. The use of lignocelluloses biomass from agricultural residues, wood, fast-growing trees, perennial grasses, macro-algae and municipal waste is the future technology of ethanol conversion. Lignocelluloses need to be broken down by a combination of physical, chemical or enzymic steps to sugars which may subsequently be fermented to produce biofuel, or they can be converted into synthetic biofuels by thermochemical routes. This
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Fig. 2. Biofuel conversion routes from feedstock to end products (Source: see Reference [39]).
so-called thermochemical conversion technology utilizes gasification and pyrolysis. Thermochemical gasification is the conversion of biomass at high temperature into ‘‘syngas”, a mixture of mostly carbon monoxide and hydrogen. Syngas can be converted into a variety of different fuels, including biodiesel by the Fischer–Tropsch process, or into methanol, hydrogen or dimethyl ether. Pyrolysis is another technology for converting biomass to bio-oil, along with the useful by-product bio-char. Like cellulosic ethanol, a wide range of biomass feedstocks is suitable for use in either gasification or pyrolysis technology. These technologies, however, are still not sufficiently cost-effective nor efficient for commercial biofuel production. Zhang et al. (2009) have made a detailed study on rice straw hydrolysis, one of the important steps for the conversion of lignocelluloses to bioethanol [41]. Solid-state fermentation (SSF) for biofuel is another potential technology for increasing the conversion efficiency and reducing the production costs [42]. 5.2. Integrated system and bio-refineries During the conversion process, other products for example, heat and electricity, lignin and other materials can be produced. Thus, there is a need for an integrated approach to conversion processes through biomass upgrading and biorefinery technologies [43]. A biorefinery is a facility that integrates biomass conversion processes to produce fuels, power, and chemicals from biomass. The processes for biomass upgrading include fractionation, liquefaction, pyrolysis, hydrolysis, fermentation, and gasification. An integrated biorefinery facilitates the diversification of feedstocks and products. By using mixed integer linear programming model to determine the optimal number and geographic locations of biodiesel plants, Leduc et al. (2009) analyze the whole biodiesel supply chain—from biomass harvesting to biodiesel delivery to the consumers [44]. Optimization is based on minimization of the costs of the supply chain with respect to the biomass, production, and transportation costs. Emissions of the supply chain are also considered. The results of the analysis show that biomass cost has the most influence on biodiesel cost (an increase of feedstock cost increases the biodiesel cost by about 40%) and a lesser effect on the investment cost and the glycerol price. Moreover, choosing the right set of production plant locations highly depends on the scenarios that have the highest probability to occur, for which the production plant locations still produce a competitive biodiesel cost and emissions from the transportation are minimum.
A case study of sugarcane-based bioenergy system has been undertaken [45]. The system is a polygeneration system with both electricity/heat and biofuel products. The results show that promoting sugarcane for energy would make a real contribution to fossil energy savings via increased energy credits created from the substitution of renewable electricity and ethanol for fossil electricity and gasoline, respectively. The magnitude of the savings potential offered by ethanol depends on two factors: (i) the efficient utilization of the bagasse for energy in an integrated system of sugar milling and ethanol conversion; and (ii) the utilization of ethanol distillery spent wash for energy via biogas recovery. Such positive energy benefit, however, would be fully realized if land use change potentially resulting from bioenergy promotion is to be minimized or even avoided. This can be done by increasing bioenergy productivity so that the pressure on land, and thus land conversion, is reduced. At the same time, efforts have to be made to develop second-generation or advanced biofuels. Suntana et al. (2009) made the study on the potential of integrating large bioenergy system, such as pulp and paper mills, in Indonesia [29]. The results show that such integration will change the industry through additional products, biofuel or biomaterials. 6. Sustainability assessment including LCA of biofuel production Interactions of various sustainability issues make the assessment of biofuel development difficult and complicated. The complexity during the whole chain of the biofuel production— including the various feedstock resources, the land and water uses, conversion processes, and end utilizations—generates significantly different assessment results due to the differences in input data, methodologies applied, and local geographical conditions. A useful tool for addressing sustainability issues is the Life Cycle Assessment (LCA), which has been applied to different biofuels, with varying results [9,46,47]. The majority of these LCA studies show that biofuels provide significant GHG emissions savings when compared to fossil fuels such as petroleum and diesel. An assessment of the impacts of increased cassava ethanol demand in Thailand on land use and GHG emissions has been carried out by Silalertruksa et al. (2009) [18]. Six different cropping systems to increase cassava production including converting unoccupied land to cropland, yield improvement, displacement of area currently under sugarcane cultivation and the other potential changes in cropping systems in Viet Nam and Australia are modelled and assessed. The comparative results show that there are
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significant differences in land use and GHG emissions from the various possible cropping systems. To minimize the impacts of bioethanol policy target in Thailand, the study recommended several measures to mitigate land use change and greenhouse gas emissions, and it also identified suitable combination of cropping systems. The paper by Ou et al. (2009) presents the LCA of energy consumption and GHG emissions of (the) PRC’s current 6 biofuel pathways including corn-, cassava-, and sweet sorghum-derived ethanol; and soybean-, jatropha fruit-, and waste cooking oil (WCO)-derived biodiesel [48]. Results of the study show that (the) PRC’s biofuel pathways (i) have no energy-saving merits from the energy input and output LCA; (ii) can reduce fossil fuel consumption but increase GHG emission compared with conventional petroleum-based gasoline and diesel pathways; and (iii) have to increase feedstock productivity level, reduce fertilizer and energy consumption during the cultivation and transportation stages in order to achieve the goals of energy balance and GHG emission reduction. Another study by Yu and Tao (2009) shows that emissions tests of three bioethanol products in (the) PRC resulted in less CO2 and volatile organic compound (VOC) life cycle emissions than conventional gasoline [49]. However, wheatbased E10 and cassava-based E10 are found to have more emissions of CO, CH4, N2O, NOx, SO2, PM10; and corn-based E10 has more emissions of CH4, N2O, NOx, SO2, and PM10. The evaluation and comparisons have been made in terms of economic viability and the long-term investment risks, energy efficiency and environmental emissions. Monte Carlo based LCA simulation tool is applied in the study. A similar study has been made using the LCA to understand the whole chain of the biodiesel production from palm oil in Thailand [12] and in Malaysia [38]. Pleanjai et al. (2009) investigate the energy consumption of palm methyl ester (PME) production in Thailand as compared to other possible oil crops for biodiesel production including jatropha and coconut. The main contributors to energy use are cultivation, oil production, transesterification and transportation. Taking into account only fossil fuel or petroleum inputs in the production cycle, the energy analysis provides results in favour of PME in Thailand. The net energy balance and net energy ratio (NER) of PME and co-products are 100.84 GJ/ha and 3.58, respectively. The NER of PME without co-products is 2.42. The results highlight the importance of selecting an appropriate feedstock for biodiesel production. Another study considers three steps including agricultural activities, oil milling, and transesterification process relating to the production of biodiesel [38]. The results show that the utilization of palm biodiesel would generate an energy yield ratio (output energy/input energy) of 3.53, indicating a net positive energy generated compared to rapeseed-based biodiesel of 1.44. Moreover, the study finds combustion of palm biodiesel to contribute to a 38% reduction of CO2 emissions when compared to petroleum-derived diesel. A discrete-time input–output model has been developed by Cruz et al. (2009) for the analysis of the dynamics of bioenergy supply chains [50]. The main feature of the dynamic model is that each sector in the system adjusts its output level based on the weighted influences of the surplus or deficit of the flows of products, intermediate goods, emissions or natural resources throughout the system in the previous time period. One of the key insights drawn from the input–output model is that the dynamics of bioenergy systems depend not only on the physical linkages between technological processes and information flows but also on behavioural responses among sectors regarding deficits and surpluses of relevant products, resources or emissions. The paper also concludes that, in order to eliminate instability and reduce fluctuations in production levels, the dynamic behaviour of such systems can be controlled through appropriate policy- or market-based interventions.
7. Future development perspectives The strength of biofuel expansion in the Asian region will greatly depend on the policies adopted by each country. In keeping pace with the rise in biofuel development, the production of biofuel feedstocks will also substantially increase and subsequently account for a significant portion of total current agricultural production. Expansion of cultivation areas for growing feedstock crops is needed to satisfy the growing demand for biofuel feedstocks. This expansion can be achieved either by shifting the production of land already cultivated for other agricultural crops to feedstocks production, or by converting marginal or uncultivated lands such as grassland and forest land to growing traditional or new sources of biofuel feedstocks. Improving the yields of feedstock crops already in cultivation is another means of increasing biofuel feedstocks production. In terms of ethanol production, the growth in Asia will be led by (the) PRC, India, and Thailand. (the) PRC is currently the world’s third largest ethanol producer after the US and Brazil. Ethanol consumption in (the) PRC is predicted to more than double by 2017, thereby exceeding its domestic production [34]. Production of ethanol in India and Thailand is projected to grow rapidly. The ethanol industry of both countries is based on molasses from sugarcane. In terms of biodiesel production, Indonesia and Malaysia are the major players in Asia’s biodiesel market. As the top two largest producers of palm oil in the world, these countries are expected to also play a major role in the global biodiesel market. Although the issues and concerns surrounding biofuel development remain (particularly the first-generation biofuels), biofuels will continue to be vigorously pursued by countries in the Asian region. Governments can improve their environmental performance without endangering their food security by implementing policy measures promoting resource use efficiency needs. Management of agricultural inputs such as fertilizers and fossil energy forms the key for the Asian region where the resource use efficiency levels are far below the levels observed elsewhere. The paper by Svrk and Elder (2009) [35] listed some of the policy measures which would enable sustainable production of first-generation biofuels in the Asian region, thereby considerably limiting the negative environmental consequences. These measures include: (i) trade liberalization by opening the agricultural markets; (ii) inclusion of input use levels in the biofuel certification systems; (iii) investment in agricultural research and extension systems to translate the science into technology; (iv) promotion of resource conserving technologies; (v) renewable sources of energy in farming; and (vi) channelling subsidies, if cannot be avoided in totality, to needy sections of the society and geographical areas through innovative monitoring systems. Demirbas (2009) also give an overview of the social, political and environmental issues that shall be addressed for the biofuel development [51]. 8. Discussion and conclusions This Supplementary Issue provides an overview of the biofuel development in Asia. Various topics are covered including feedstock, land use, conversion technologies, climate change, poverty alleviation, and other social and environmental impacts. This editorial aims to provide a summary of the detailed and specific studies included in this special issue. However, the complexity of biofuels development, especially in the area of sustainable criteria, calls for continuous study in this field to enhance the benefits of biofuel development, while minimizing its risks and disadvantages. Again, it is interesting to ask our readers to note the results of the studies by different researchers on the varying topics relevant to biofuel development in Asia. The research studies are not supervised because the system boundary and input assumptions are dif-
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ferent. Consistent and coherent sustainability criteria and indicators, which are acceptable by all stakeholders, are therefore necessary. Such efforts have been intensively made by the European Commission to establish a standard framework for biofuel sustainability criteria. Some new analytic tools may need to be introduced for this purpose [52]. There are many issues, probably important, that have not been covered in this Supplementary Issue. For example, soil quality, which is determined by a complex collection of bio-geochemical processes, is vital for the protection and improvement of current and future crops, and thus can be a key area for future research. Similarly, an accurate accounting of GHG emissions and energy consumptions associated with different types of feedstock production is also relevant to better understand the costs and benefits of the various inputs of biofuel production on the ecosystem’s health and the quality of natural resources. Moreover, with the pressure on water supplies expected to aggravate further, research on minimizing not only the use of water resources but nutrient and other containment runoff as well through biomass crops is critical. Biodiversity in maintaining ecosystem services and developing necessary strategies is another key issue to ensure that the production of biofuels increases; adequate supplies of other needed agricultural and forest-based goods are produced. Finally, fully understanding the potential impacts of biofuel production on the landscape ecology and systems interactions requires the extension of field experiments and full-scale studies beyond the small pilot studies. This also entails the expansion of researches from field scales to regional scales, with appropriate validations and interpretations using real world biophysical, economic and societal conditions. Acknowledgements As the guest editors of the Supplementary Issue, we would like to thank Asian Development Bank (ADB) for all supports for this volume. We would also like to thank all authors who submitted their manuscripts. We wish to acknowledge the outstanding efforts of reviewers for their prompt and helpful comments which significantly improve the quality of the final accepted papers. Also the last but not least, we would like to thank Joy QuitazolGonzalez for her excellent research assistance to the special volume. References [1] Birur DK, Hertel TW, Tyner WE. The biofuels boom: implications for world food markets. In: Food economy conference, The Hague, October; 2007. [2] BP. Statistical review of world energy 2009. BP; 2009. [3] Balat M, Balat H. Recent trends in global production and utilization of bioethanol fuel. Appl Energy 2009;86(11):2273–82. [4] Sims R, Taylor M, Saddler J, Mobee W. From 1st- to 2nd-generation biofuel technologies. IEA; 2008. [5] European Union (EU). Communication from the commission: an EU strategy for biofuels, {SEC(2006) 142}, {COM/2006/0034 final}; 2006. [6] European Union (EU). Directive of the European parliament and of the council on the promotion of the use of energy from renewable sources, {COM(2008) 30 final}, {SEC(2008) 57}, {SEC(2008) 85}; 2008. [7] Biomass Research and Development Board. National Biofuels Action Plan. US Department of Agriculture (USDA) and US Department of Energy (DOE); 2008. [8] Environmental Protection Agency (EPA). EPA proposes new regulations for the national renewable fuel standard program for 2010 and beyond. ; 2009 [accessed 21.06.09]. [9] Börjesson P. Good or bad bioethanol from a greenhouse gas perspective – what determines this? Appl Energy 2009;86(5):589–94. [10] Zhou A, Thomson E. The development of biofuels in Asia. Appl Energy 2009;86(Suppl. 1):11–20. [11] Agoramoorthy G, Hsu MJ, Chaudhary S, Shieh PC. Can biofuel crops alleviate tribal poverty in India’s drylands? Appl Energy 2009;86(Suppl. 1):118–24. [12] Pleanjaia S, Gheewala SH. Full chain energy analysis of biodiesel production from palm oil in Thailand. Appl Energy 2009;86(Suppl. 1):209–14. [13] Nguyen TL, Gheewala SH, Garivait S. Full chain energy analysis of fuel ethanol from cane molasses in Thailand. Appl Energy 2008;85(8):722–34.
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[14] Yang J, Huang J, Qiu H, Rozelle S, Sombilla M. Biofuels and the greater Mekong subregion: assessing the impact on prices, production and trade. Appl Energy 2009;86(Suppl. 1):37–46. [15] Matsumoto N, Sano D, Elder M. Biofuel initiatives in Japan: strategies, policies, and future potential. Appl Energy 2009;86(Suppl. 1):69–76. [16] Malik US, Ahmed M, Sombilla MA, Cueno SL. Biofuels production for smallholder producers in the greater Mekong sub-region. Appl Energy 2009;86(Suppl. 1):58–68. [17] Li SZ, Chan-Halbrendt C. Ethanol production in (the) PRC: potential and technologies. Appl Energy 2009;86(Suppl. 1):162–9. [18] Silalertruksa T, Gheewala S, Sagisaka M. Impacts of Thai bio-ethanol policy target on land use and greenhouse gas emissions. Appl Energy 2009;86(Suppl. 1):170–7. [19] Energy Information Administration (EIA). The International Energy Outlook 2009 (IEO2009). Energy Information Administration (EIA); 2009. [20] Ölz S, Sims R, Kirchner N. Contribution of renewables to energy security. International energy agency; 2007. [21] Takeshita T. A strategy for introducing modern bioenergy into developing Asia to avoid dangerous climate change. Appl Energy 2009;86(Suppl. 1): 222–32. [22] Intergovernmental Panel on Climate Change (IPCC). Fourth assessment report on mitigation of climate change; 2007. [23] Yan J, Alvfors P, Eidensten L, Svedberg G. A future for biomass. Mech Eng 1997;119(10). [24] Wahlund B, Yan J, Westermark M. Increasing biomass utilisation in regional energy systems: a comparative study of CO2 reduction and cost for different bioenergy processing options. Biomass Bioenergy 2004;26: 531–44. [25] Möllersten K, Yan J, Moreira JR. Potential market niches for biomass energy with CO2 capture and storage – opportunities for energy supply with negative CO2 emissions. Biomass Bioenergy 2003;25:273–85. [26] Möllersten K, Gao L, Yan J. CO2 balances and mitigation costs of advanced CHP systems with CO2 capture in pulp and paper mills. Mitig Adapt Strat Global Change 2006;11:1129–50. [27] Obersteiner M, Azar C, Kauppi P, Möllersten K, Moreira J, Nilsson S, et al. Managing climate risk. Science 2001;294(5543):786–7. [28] Sasaki N, Knorr W, Foster DR, Etoh H, Ninomiya H, Chay S, et al. Woody biomass and bioenergy potentials in Southeast Asia between 1990 and 2020. Appl Energy 2009;86(Suppl. 1):140–50. [29] Suntana AS, Vogt KA, Turnblom EC, Upadhye R. Bio-methanol potential in Indonesia: forest biomass as a source of bio-energy that reduces carbon emissions. Appl Energy 2009;86(Suppl. 1):215–21. [30] Phalan B. The social and environmental impacts of biofuels in Asia: an overview. Appl Energy 2009;86(Suppl. 1):21–9. [31] Kostka G, Polzin C, Scharrer J. The future of sugarcane in (the) PRC and India – supply constraints and expansion potential. Appl Energy 2009;86(Suppl. 1): 100–7. [32] Tian Y, Zhao L, Meng H, Sun L, Yan J. Estimation of un-used land potential for biofuels development in (the) PRC. Appl Energy 2009;86(Suppl. 1):77–85. [33] Özdemir ED, Härdtlein M, Eltrop L. Land substitution effects of biofuel side products and implications on the land area requirement for EU 2020 biofuel targets. Energy Policy 2009;37(8):2986–96. [34] Food and Agriculture Organization of the United Nations (FAO). The state of food and agriculture 2008—biofuels: prospects, risks and opportunities. FAO agriculture series, Rome; 2008. [35] Svrk P, Elder M. Biofuels and resource use efficiency in developing Asia: back to basics. Appl Energy 2009;86(Suppl. 1):30–6. [36] Urban F, Benders RMJ, Moll HC. Energy for rural India. Appl Energy 2009;86(Suppl. 1):47–57. [37] Jansson C, Westerbergh A, Zhang J, Hu X, Sun C. Cassava, a potential biofuel crop in (the) PRC. Appl Energy 2009;86(Suppl. 1):95–9. [38] Yee KF, Tan KT, Abdullah AZ, Lee KT. Life cycle assessment of palm biodiesel: revealing facts and benefits for sustainability. Appl Energy 2009;86(Suppl. 1): 189–96. [39] The Royal Society. Sustainable biofuels: prospects and challenges. The royal society, UK; 2008. [40] Gallagher E, Berry A, Archer G. The Gallagher review of the indirect effects of biofuels production. Renew Fuels Agen 2008. [41] Zhang Q, He G, Wang J, Cai W, Xu Y. Mechanisms of the stimulatory effects of rhamnolipid biosurfactant on rice straw hydrolysis. Appl Energy 2009;86(Suppl. 1):233–7. [42] Wang EQ, Li SZ, Tao L, Geng X, Li TC. Modeling of rotating drum bioreactor for anaerobic solid-state fermentation. Appl Energy 2009. doi:10.1016/ j.apenergy.2009.05.032. [43] Demirbas MF. Biorefineries for biofuel upgrading: a critical review. Appl Energy 2009;86(Suppl. 1):151–61. [44] Leduc S, Natarajana K, Dotzauer E, McCallum I, Obersteiner M. Optimizing biodiesel production in India. Appl Energy 2009;86(Suppl. 1):125–31. [45] Nguyen TL, Hermansen J, Sagisaka M. Fossil energy savings potential of sugarcane bio-energy systems. Appl Energy 2009;86(Suppl. 1):132–9. [46] Thamsiriroj T, Murphy JD. Is it better to import palm oil from Thailand to produce biodiesel in Ireland than to produce biodiesel from indigenous Irish rape seed? Appl Energy 2009;86(5):595–604. [47] Stoeglehner G, Narodoslawsky M. How sustainable are biofuels? Answers and further questions arising from an ecological footprint perspective. Bioresource Technol 2009;100(16):3825–30.
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[48] Ou X, Zhang X, Chang S, Guo Q. Energy consumption and GHG emissions of six biofuel pathways by LCA in (the) PRC. Appl Energy 2009;86(Suppl. 1): 197–208. [49] Yu SR, Tao J. Economic, energy and environmental evaluations of biomassbased fuel ethanol projects based on life cycle, assessment and simulation. Appl Energy 2009;86(Suppl. 1):178–88. [50] Cruz JB, Tan RR, Culaba AB, Ballacillo JA. A dynamic input–output model for nascent bioenergy supply chains. Appl Energy 2009;86(Suppl. 1): 86–94. [51] Demirbas A. Political, economic and environmental impacts of biofuels: a review. Appl Energy 2009;86(Suppl. 1):108–17. [52] Bram S, De Ruyck J, Lavric D. Using biomass: a system perturbation analysis. Appl Energy 2009;86(2):194–201.
J. Yan Royal Institute of Technology, Stockholm, Sweden Mälardalen University, Västerås, Sweden E-mail address:
[email protected] T. Lin Asian Development Bank
