Authors: Linda Marcela Guio Martinez, Iyad Saba, March 2025
1 Description and History
1.1 Definitions
Biofuels are fuels derived from organic sources such as biomass and organic waste 1. They are an alternative energy source that uses organic matter as the main source for energy production2. They have emerged as a solution to the growing problem of climate change and rising oil prices. Biofuels offer many advantages, such as sustainability, reduction of greenhouse gas emissions, regional development, social structure and agriculture, and security of supply. 3.
Biofuels are classified into three different generations Fig. 1. First-generation biofuels are made using traditional methods that use sources such as sugar, starch, vegetable oils, or animal fats. However, as they use resources that also serve as food, their production is limited to avoid possible food shortages. Second-generation biofuels, on the other hand, are generated from non-edible crops or food crop waste, such as stalks, pods, wood chips, or fruit peels. These have greater advantages in reducing greenhouse gas emissions compared to first-generation biofuels. Finally, third-generation biofuels are obtained from algae, where the process involves fermenting the carbohydrates present in the algae to produce oil or fuel. 4 5.
Biofuels are classified according to their physical state as solid, liquid, or gaseous Fig. 2. The main solid biofuels include firewood, wood chips and pellets, and charcoal. The most prominent liquid biofuels are bioethanol, biodiesel, pyrolysis bio-oil, and drop-in biofuels. Finally, gaseous biofuels include biogas and syngas. Most of the biofuels available on the market today are made from plants.6
There are different processes or technologies for the production of biofuels: Fermentation: Conversion of starches and sugars into ethanol. 7. Transesterification: is a process for producing biodiesel from vegetable oils or animal fats.8
Fermentation: Obtaining ethanol from starch and sugars is one of the oldest biotechnological processes used by humanity and has been the subject of study since the time of Louis Pasteur. This method of biofuel production is based on the fermentation carried out by Saccharomyces1, a yeast capable of quickly and efficiently transforming the glucose, fructose, and sucrose present in sugar cane, as well as the glucose and maltose derived from starch, generating ethanol in high concentrations. In simple terms, this fermentation process occurs thanks to the coordinated action of various enzymes, which convert one glucose molecule into two ethanol molecules and two carbon dioxide molecules, following the chemical reaction7 Fig. 3.:
Transesterification: Transesterification is the key process for converting vegetable oils or animal fats into biodiesel. It consists of the reaction of triglycerides with an alcohol, generally methanol or ethanol, in the presence of a catalytic converter, which results in the formation of fatty acid methyl esters (FAME), which constitute biodiesel, and glycerin as a by-product.8
However, other processes such as gasification, pyrolysis, and anaerobic digestion are also relevant, especially for the production of advanced biofuels (second and third generation).3,9
1.2 History
The use of biofuels has deep roots in the history of humanity, although its large-scale development began in the 19th and 20th centuries. Among the most important biofuels are bioethanol, biodiesel, biogas, and biobutanol, each with its own evolution and relevance in the global energy transition. 7 One of the first records of the use of biofuels dates from 1826 when the inventor Samuel Morey designed an internal combustion engine powered by ethanol and turpentine. Later, in 1860, Nicolaus August Otto developed another engine that used ethanol as fuel. However, with the expansion of oil and the fiscal policies on alcohol, its use as an energy source declined. 10
Biodiesel also has an early history. In 1890, the German engineer Rudolf Diesel invented the diesel engine, and in 1900, one of his engines ran on peanut oil at the Universal Exhibition in Paris, demonstrating the viability of vegetable oils as fuel. After he died in 1913 and the emergence of cheaper fossil fuels, these oils were replaced by petroleum derivatives. However, in 1937, the Belgian Charles Chavanne patented a process for producing biodiesel by transesterification of vegetable oils.10 As for biogas, it is believed that the Assyrians were already using it in the 10th century BC to heat water. However, its systematic use began in the 19th century, when the first biogas digesters were built in New Zealand and India. In 1890, biogas was used in the United Kingdom to power street lamps. 10
Interest in biofuels resurfaced in the 1970s 2, especially after the 1973 oil crisis when many countries began to look for alternative energy sources to reduce their dependence on fossil fuels. In this context, Brazil implemented its program for the production of bioethanol from sugar cane, consolidating its position as a leader in its production. The United States also promoted the use of corn-based bioethanol. 9 By 2014, these two countries dominated world production with 14.3 and 6.2 billion gallons respectively. 10 In parallel, biodiesel production began to grow at the end of the 20th century. Since 2000, global production has increased significantly, reaching more than 6 billion gallons in 2013. Countries such as Brazil, Argentina, the United States, China, and several European Union nations lead its manufacture, using vegetable oils such as soybean and rapeseed.9
During this period, biogas development also expanded, particularly in Europe and China, where millions of digesters have been installed to make use of organic waste. Today, biogas represents a viable alternative for energy generation, and it is estimated that it could replace up to 25% of global natural gas consumption. Since the beginning of the 21st century, biofuels have evolved with new technologies and production processes. One of the most notable advances is the development of “drop-in” biofuels, designed to be integrated directly into the fossil fuel infrastructure without the need for engine modifications.9 Biobutanol, another biofuel of interest, originates from the anaerobic fermentation identified by Louis Pasteur in 1861. In 1912, Chaim Weizmann isolated a bacterium capable of producing biobutanol in large quantities, which allowed its use in the chemical industry. During the Second World War, Japan used biobutanol derived from sugar as jet fuel. Another significant advance has been the development of pyrolysis bio-oil, obtained by heating biomass in the absence of oxygen to replicate the natural process of oil formation. 10
2 Economic Performance
2.1 Evolution of the biofuel industry
The global biofuels market has experienced significant growth in recent decades, driven by tax incentives10, government regulations, and the need to reduce dependence on fossil fuels11. Ethanol is one of the commercially successful biofuels12, and its production grew worldwide from 30.8 billion liters in 2004 to 76 billion liters in 2009, with an average annual growth of 20%. The United States and Brazil dominated the market, Table 1 together accounting for around 88% of total production in 2009. 13 In 2006, the US overtook Brazil as the leading producer of ethanol, reaching more than 18 billion liters, 20% more than the previous year. 13
The trend shows that in 2004 the USA produced 13 billion liters of ethanol, a figure that increased to 41 billion liters in 2009, using corn as a raw material. Brazil, for its part, went from 15 billion liters in 2004 to 26 billion in 2009, with sugarcane as its main input. In the European Union, countries such as France and Germany have contributed significantly, with France producing 1.2 billion liters in 2009 from sugar beet, and Germany reaching 0.8 billion liters from wheat. 13
In the case of biodiesel, despite facing the challenge of high marketing costs and lower production compared to ethanol 14, it has experienced even more accelerated growth, going from 2.3 billion liters in 2004 to 17 billion in 2009, with an average annual growth of 50%. Germany, France, and Italy have been the main producers within the European Union, although in 2006 the USA overtook France and became the second largest producer of biodiesel, after Germany Table 2. The EU plays a key role in biodiesel production, with an increase from 9.5 billion liters in 2007 to 14.7 billion in 2009. Germany led European production with 3.02 billion liters in 2006, while France reached 2.06 billion in 2008. In the United States, soybean-based biodiesel grew from 0.11 billion liters in 2004 to 2.6 billion in 2008, showing its greatest increase with a slight decrease in 2009 with 2.1 billion liters. In South America, Argentina and Brazil have increased their biodiesel production, using soy and palm oil, respectively, with Brazil reaching 1.6 billion liters in 2009. 13
In recent years, bioethanol production in the European Union has been led mainly by France, Germany, and Spain. These countries have used raw materials such as wheat, corn, and sugar beet. Although bioethanol production has increased, its rate of growth has slowed due to declining demand and competition from imports, especially from the United States. Biodiesel has maintained its position as the dominant biofuel in Europe, driven by strong demand for diesel in the transportation sector. However, since 2012, its growth has slowed as a result of changes in regulations, falling oil prices, and competition from imports from Argentina and Indonesia. Despite these challenges, Germany, France, and Spain have continued to be the main producers of biodiesel, using mainly rapeseed oil, although in recent years there has been an increase in the use of recycled oils and palm oil.15In general terms, despite the sustained growth of the biofuels industry up to 2020, recent trends indicate significant expansion in emerging markets and certain challenges in developed regions. Global demand for biofuels is estimated to increase steadily by 2045, with projections of between 257 and 500 billion liters per year by 2030. However, production in the US and the European Union is not on track to meet the sustainable development goals for 2030, due to a lower biofuel blending rate, increased vehicle efficiency, and a preference for drop-in biofuels.16
In contrast, Brazil and India have shown a trend of continuous growth. Brazil, which had already reached record figures in ethanol and biodiesel production in 2019, continues to expand its biodiesel mandate, increasing from 11% to 15% in recent years. India has accelerated its bioethanol production capacity, expanded the raw material base and introduced subsidies to encourage production. In addition, China and the countries of Southeast Asia have promoted the mixing of bioethanol with fossil fuels by 10%, strengthening their market share. 16Total liquid biofuel production is expected to range between 3,280 and 4,350 billion liters in 2035, with notable growth driven by the increase in the vehicle fleet, transportation demand, and the search for alternative fuels. However, stability in the supply chain remains a key challenge, as logistics and storage costs can represent up to 35% of the total cost in some supply chains. 16
2.2 Profitability and Production Costs of Biofuels
The economic profitability of biofuel production is conditioned by various factors, including the local environment, the business model adopted, and the type of feedstock used. 17Feedstock production involves a variety of processes, levels of intensity and efficiency, as well as different land uses, all within varying socio-economic contexts18. To assess the impact of biofuel feedstock production, key factors such as the type of biofuel, the feedstock, soil characteristics, climate, agricultural management system and socioeconomic conditions, such as labor and land costs, employment rates, land availability and land ownership, are considered. 17,19
Biofuel production is centered on two main categories: first and second generation. First-generation biofuels, which represent the vast majority of current production, are derived from food crops such as cereals, grains, sugar cane, and oilseeds. In developing countries, common feedstocks include sugar cane and palm oil. On the other hand, second-generation biofuels, also known as “next-generation” biofuels, use lignocellulosic raw materials, such as agricultural and forestry residues, and specific energy crops such as vegetative pastures and short-rotation forests. Although they currently represent a smaller fraction of total production, second-generation biofuels are considered more promising due to their potential to use non-food raw materials and reduce competition with food production. 4 5 The selection of raw materials is a critical factor for the profitability of biofuels. Cassava and oil palm, for example, can generate high returns with NPVs of up to US$16,000 and US$7,000/ha, respectively. However, crops such as jatropha present greater uncertainty, 17since their profitability depends to a large extent on the variability in labor costs and yields.17,18 Regarding production costs, first-generation biofuels have shown a downward trend, with estimated values between 10 and 35 US$/GJ in 2020, compared to 20-30 US$/GJ for fossil fuels. Argentina and Malaysia stand out as having the lowest production costs for soybean biodiesel (10–14 US$/GJ) and palm biodiesel (8–23 US$/GJ). However, the production cost of certain biofuels, such as those derived from cassava and Jatropha, can exceed 100 US$/GJ if labor costs increase. 18
Second-generation biofuels have higher costs, although with potential for long-term reduction. By 2020, their costs were estimated at between US$17 and US$26/GJ, with projections of US$14 to US$23/GJ by 2030. One of the most critical factors in its viability is the optimization of the conversion process, which represents between 35-65% of the total cost. In addition, efficiency in biomass logistics is essential to reduce costs, since storage and transportation can represent up to 35% of the total cost in some supply chains. Another key aspect of the competitiveness of biofuels is the fluctuation of the price of oil, which directly affects their profitability. 18
3 Ecological Performance
Biofuels derived from biomass have captured global attention due to their potential to address multiple environmental challenges, especially climate change, and to boost rural economies. This advance in biofuel production is considered crucial to achieve a transition towards a global low-carbon energy supply, in line with the Sustainable Development Goals (SDGs). 19,20 Biofuels, presented as a more ecological alternative to fossil fuels due to their lower environmental impact, show a variability in their capacity to reduce emissions. First-generation biofuels, such as corn or sugarcane ethanol, manage to reduce carbon dioxide emissions by 40-50% compared to conventional gasoline. However, subsequent generations, which use lignocellulosic waste and microalgae, can achieve reductions of up to 80%, as well as avoiding competition with food production. It has been shown that the cultivation of microalgae for biofuels can capture large amounts of carbon dioxide, which contributes to the fight against climate change.21
In terms of ecological performance in 2015, its use contributed to the reduction of approximately 589.3 million tons of CO₂ worldwide, consolidating itself as a fundamental strategy in the transition towards cleaner energy sources. In the United States, the production of 15.7 billion gallons of bioethanol in 2019 has facilitated compliance with the requirement to mix 10% with gasoline, which has reduced greenhouse gas emissions from transportation. In Europe, biodiesel derived from rapeseed, palm, and soy oils and used cooking oil makes up 75% of the biofuel market, allowing for the partial substitution of fossil fuels and reducing their environmental impact. Furthermore, improvements in the genetic engineering of energy crops and advances in biomass fermentation have optimized the efficiency of biofuel production, which has allowed for a greater reduction in carbon emissions and strengthened its role in the fight against climate change. Biofuels are expected to continue to play an important role in reducing carbon emissions, with the potential to replace up to 27% of fossil fuels in transportation by 2050. 22
Despite these benefits, the production of biofuels has significant negative impacts. The conversion of land for first-generation biofuels is a significant cause of deforestation, especially in tropical areas, resulting in loss of biodiversity and increased carbon emissions due to changes in land use. In addition, the production of corn ethanol requires a high consumption of water, which affects the availability of water resources. Although third-generation biofuels avoid competition with food, harvesting and extracting microalgae biomass is costly and energy-intensive.23
3.1 Impact on biodiversity
In terms of biodiversity loss, the adverse effects of biofuels are manifested at multiple levels. At the genetic level, the introduction of genetically modified energy crops poses risks of contamination and displacement of native species. At the species level, the expansion of monocultures for biofuels has caused habitat fragmentation and invasion of exotic species, resulting in the decline of local populations. In tropical regions, the conversion of forests into palm oil and sugar cane plantations has been a major cause of deforestation, seriously affecting biodiversity in ecosystems such as the Amazon and Southeast Asia.23,24
At the level of ecosystems as a whole, the establishment of biofuel crops over large areas has simplified natural landscapes, reducing ecological resilience and increasing vulnerability to pests and diseases. Studies have shown that the conversion of rainforests and grasslands into biofuel plantations can release between 17 and 420 times more CO₂ than these biofuels can offset annually by replacing fossil fuels. Furthermore, the use of forest biomass for biofuels can compromise crucial ecosystem services, such as carbon capture, soil retention, and the provision of wildlife habitat.23,24To mitigate these impacts, various strategies have been suggested, such as using degraded land instead of primary forests for biofuel crops, adopting sustainable agricultural practices and promoting third-generation biofuels, such as those derived from algae. However, the economic viability and scalability of these solutions present significant challenges. Environmental organizations have warned that, without proper management, the expansion of biofuels could cause more harm than good in terms of biodiversity conservation and water availability.23
3.2 Impact on water resources
The production of biofuels raises serious concerns about water management due to the high consumption and resulting pollution. For example, the production of ethanol from corn in the United States can require between 10 and 17 liters of water for each liter of ethanol, while biodiesel from microalgae, without recycling of fresh water, could consume up to 3,726 liters per kilogram. In China, it is estimated that biofuel production could consume between 32 and 72 km³ of water annually by 2020, an amount comparable to the flow of the Yellow River. In addition, the intensive use of fertilizers and pesticides in biofuel crops can contaminate groundwater and surface water sources, contributing to the eutrophication of water bodies.23,25
3.3 Biofuel renewability
The renewable quality of biofuels is intrinsically linked to fossil energy consumption throughout their life cycle, which encompasses everything from the production and transportation of biomass to its conversion into fuel. Studies on the amount of fossil energy required in the production of biofuels show a wide variation. For example, the ratio of fossil energy used to energy generated (FER) for Jatropha biodiesel fluctuates between 1.4 and 8.0, while for soybean biodiesel it has been calculated at 1.97, and for sugarcane bioethanol, it can reach up to 9.4. However, some research has cast doubt on this renewability, arguing that, in certain cases, the fossil energy consumed in the production of biofuels can exceed the energy obtained. This occurs, for example, with corn ethanol in some contexts, where the non-renewable energy cost can be up to 1.7 times greater than the energy produced.23
3.4 Biofuel cleanliness
The controversy over the neutrality of biofuels in terms of greenhouse gas emissions persists. Although it is argued that, in theory, these fuels reduce net carbon dioxide emissions due to the prior capture of carbon by plants, the reality is more complex. For example, first-generation biofuels can reduce greenhouse gas emissions by 78%, and second-generation biofuels by up to 94%, compared to fossil fuels. However, when considering the entire life cycle, from cultivation to distribution, the balance of emissions may not be so favorable.23 In addition, biofuel production can generate significant indirect emissions. In China, the cultivation of corn for ethanol produces 11.61 kg of carbon dioxide equivalent per kilogram of bioethanol, a figure 5.99 times greater than the emissions from gasoline combustion. A large part of these emissions are due to the use of fertilizers and wastewater treatment. Likewise, changing the use of soil for energy crops can release large amounts of carbon stored in the soil, counteracting the climatic benefits. Biodiesel, meanwhile, has been criticized for its high emission of nitrogen oxides, which can increase by up to 70% compared to conventional diesel, contributing to smog formation and air pollution.23
4 Social Impact
The rise of biofuels represents a new stage in human civilization that witnessed the shift from traditional coal fuels to petroleum, and then to renewable sources of energy that carry with them opportunities, challenges and economic, social, environmental and humanitarian repercussions.26 Social impact refers to the effects that biofuels have on society. It includes factors such as food security, sustainability, and land use change. These are key to understanding the impacts of both the use and production of it. Biofuels have both positive and negative social impacts. On the positive side:
4.1 Positive Social Impacts of Biofuels
4.1.1 Energy Security and Fossil Fuel Reduction
It helps reduce dependence on fossil fuels by providing them as an alternative source of energy production. Fossil fuels are chemically similar to diesel, making it possible to use biodiesel without having to modify engines. Choosing biodiesel over fossil fuels reduces greenhouse gas emissions. But it does not eliminate emissions. 27
One of the most popular examples of biodiesel is Hydrotreated Vegetable Oil (HVO). This innovative biofuel is a promising alternative to diesel. HVO is produced by hydrotreating vegetable oil, a process that exposes hydrotreated organic materials to high temperatures and pressures to form a hydrocarbon fuel. As the chemical composition is similar to diesel, HVO can be used without blending or modifications to your vehicle, making it an easy and environmentally friendly alternative to fossil fuels.27
4.1.2 Job Creation and Economic Development
Biofuels create jobs and stimulate economic development, especially in rural areas where raw materials are grown. For example, on February 5, 2025, it was announced that there was a new Biofuel facility in Texas, USA. It will create 200 permanent jobs in Newton County. The $2.8 billion project will convert raw wood into sustainable aviation fuel. The facility is an important step in boosting the region’s renewable energy sector and providing jobs for the local community.28
4.1.3 Reduction of Greenhouse Gas Emissions
Biofuels play an important role in reducing greenhouse gas emissions, mitigating the negative effects of climate change. 2 Biofuels burn cleaner than gasoline, resulting in fewer greenhouse gas emissions, and are fully biodegradable, unlike some fuel additives Such as toxic chemicals or synthetic additives that are chemically processed and cannot be degraded.29
4.1.4 Local Economic Growth
Improving local economic development: Local ownership of plants is key to the success of rural development through biofuels, ensuring that investments and revenues stay in the local community and support sustainable development. Small biofuel projects owned by local farmers can have significant economic benefits for the community, creating new jobs as mentioned above, increasing local income and revitalizing the local economy. As a practical example, in Minnesota, government policies have helped local farmers set up ethanol plants owned by the farmers themselves and local landowners, significantly increasing local returns. Studies show that these projects increased the GDP of local communities by 56% compared to plants owned by outside companies.30
4.2 Negative Social Impacts of Biofuels
While biofuels have positive social impacts on the one hand, they also have negative social impacts on the other. The potential impact on food security caused by changing the use of agricultural land solely for growing crops for biofuel production and increasing competition for water and fertile land has serious social consequences such as conflicts, wars and inequality driven violence. Another major concern is the potential displacement of farmers and indigenous communities on these lands, who will have difficulty adapting to the changes caused by fossil fuel production.31
As a result, a global assessment of the environmental and social impacts of biofuel production concluded that its results may cause unforeseen negative impacts on both people and the environment. 32 Now, these include:
4.2.1 Conversion of agricultural land for biofuel production
Due to the agricultural land use change and the process of growing crops and refining biofuels, crop-based biofuels do not appear to be an effective tool for climate change. Growing corn and soybean crops for biofuels, for example, reduces land that could be used more effectively to combat climate change or provide societal benefits. land set aside for biofuels could produce food instead. or it could be used to restore forests or grasslands.The Midwest’s agricultural landscape is dominated by corn and soybeans. These crops are grown on 75% of arable land; it is estimated that between one-third and three-quarters of these crops are used in the biofuel industry. 32
4.2.2 Concerns have been raised about the actual carbon benefits of using biofuels
Biofuel production consumes a significant amount of energy from fossil sources, contributing to a significant carbon footprint due to activities such as fertilization and harvesting that promote the growth of crops used in production, such as corn, sugarcane, and soybeans.
4.2.3 Gas emissions during the combustion of biofuels in engines and power systems
Although biofuels are considered a more sustainable source of energy than fossil fuels, their use is not without emissions. These residual emissions may include carbon dioxide (CO2) and other gases that are released during the combustion of biofuels in engines or power systems. Thus, even after the biofuel is used, there is still an environmental impact due to the production and use of the fuel.33
4.2.4 Biofuel production can consume a significant amount of energy from fossil sources for several reasons
| Intensive agriculture |
| Transportation and storage |
Growing crops used for biofuels, such as corn or sugarcane, requires the use of heavy machinery and irrigation, processes that often rely on fossil fuels such as diesel.
| Crop processing |
The process of converting agricultural crops into biofuels (such as ethanol or biodiesel) requires large amounts of energy, which often comes from fossil sources.
After harvesting, crops must be transported, processed in industrial facilities, and then stored. This requires extensive transportation using trucks and vehicles that run on fossil fuels, which increases the consumption of fossil energy.33
In furtherance of creating an imbalance in worldwide agricultural diversity, the exploitation of land for energy crops and the conversion of agricultural fields that grow food crops for human or animal consumption into fields to produce biofuels likewise deforests many forests and natural reserves, increases erosion rates, and uses a significant amount of fresh water. for example, some studies estimate that it takes 5,000 liters of water to produce one liter of biofuel, and 13 liters of ethanol requires, for example, 231 kilograms of corn.26
5 Political and Legal Aspects
After the oil crisis in the 1970s, which limited availability and increased the cost of fuel, many countries began searching for energy stability and sources of energy. Biofuels were found to be an attractive alternative for several reasons, including their similarity to fossil fuels in terms of chemistry and secondly, their beneficial aspects in terms of economics and some social benefits as mentioned above. 34 On the Second hand, in order to reduce economic costs, ensure food security or cause a net increase in total net greenhouse gas emissions, there is increasing pressure in the United States and the European Union to reform policies that support biofuels. Initially, a cap on the expansion of first-generation biofuels, as proposed by the U.S. Environmental Protection Agency (EPA) and the European Union (EU).35
5.1 Forms of policies to support biofuel:
5.1.1. Some are “top-down” implemented at a national or regional level and affecting all producers and consumers. One such option is to set a national target, where policymakers declare their intention to reach a certain level of production in transportation fuels. This policy puts the focus on governments, which are responsible for creating a supportive environment for industrial expansion. The Renewable Fuel Standard sets mandatory legal levels for the incorporation of biofuels into fuels.Another popular option is to exempt biofuels from national excise taxes, which reduces production costs and increases potential profits, and can be seen as an industry subsidy.
Others can be “bottom-up” policies that affect only some participants in the biofuels market. One such option is direct government funding of capital projects to increase capacity or modernize distribution networks. In addition, increased use of biofuels in government or corporate vehicle fleets can be targeted.
In some countries, multiple policies have been implemented to support biofuel development, making it difficult to determine the effectiveness of each policy separately.36
5.2 Stages of developments in biofuel policy and production overtime
5.2.1 Global Treaties (2005-2010)
It was during this period that the world witnessed the signing of the Kyoto Protocol, an international treaty that extended the United Nations Framework Convention on Climate Change (UNFCCC), committing countries to reduce greenhouse gas emissions. The Kyoto Protocol was adopted in December 1997, and in February 2005 it entered into force. By 2008, 183 countries had ratified the agreement. Signatories to the convention then began allocating investments and legislation to support the development of biofuels, which became part of their efforts to reduce greenhouse gas emissions.37
5.2.2 Expansion of production and utilization (2010-2015)
Then, from 2010 to 2015, biofuel production and use increased significantly, especially in the transportation sector. In 2009, global ethanol production amounted to about 74 billion liters, with the United States accounting for 54% (about 40 billion liters) and Brazil 34% (about 25 billion liters). Biodiesel production in the European Union exceeded 10 billion liters in the same year, accounting for 57% of global production.38
5.2.3 Environmental Criticism and Challenges (2015-2020)
During the period from 2015 to 2020, environmental challenges and criticisms, as mentioned earlier, related to the production of biofuels have emerged. Especially about its impact on food security and biodiversity. The reports noted that the land use associated with biofuel production has sparked debate about the best use of arable land, its impact on global food prices, and the sustainability of production practices.39
5.2.4 Switching to second-generation biofuels (2020-present)
From 2020 to the present, the biofuel industry is shifting towards the second generation, which we mentioned above. With a focus on developing different technologies to produce biofuels from non-food materials, such as agricultural waste, to minimize the negative impacts associated with the first generation. Second-generation biofuels (known as advanced biofuels) are produced from non-food biomass, such as lignocellulosic materials (woody crops, agricultural residues and waste) and algae. These feedstocks do not compete with food crops, promoting environmental sustainability. 40
5.3 The global legal aspects of biofuels:
5.3.2 The Paris Agreement (2015)
The agreement aims to minimize global warming by reducing greenhouse gas emissions. The agreement urges countries to use renewable energies (including biofuels) to achieve carbon emission reduction goals, while emphasizing the environmental sustainability of biofuel technologies. 41
5.3.3 International standards (ISO)
For example, (ISO 13065) defines sustainability principles related to biofuels, including assessing the environmental and social impact of biofuels on the environment and local communities. It ensures that biofuels are produced in a sustainable manner. This includes minimizing their impact on food security and biodiversity.42
5.3.4 The Renewable Energy Directive (RED II)
The Renewable Energy Directive (RED II) is part of the EU’s energy strategy and sets specific targets to increase the use of renewable energy sources, including biofuels, in all sectors including transportation. The directive commits EU countries to produce 10% of renewable fuels in the transport sector by 2020 with the aim of increasing the share to 14% by 2030 in the transport sector, which is part of the EU’s commitment to meet the Renewable Energy Targets 2030. It also promotes the use of second-generation biofuels.43
5.3.5 Policies to support biofuels in developed and developing countries
Incentives and financing. For example, countries such as Brazil, the United States and the European Union offer financial incentives to manufacturers and projects that produce tradable biofuels. In Brazil, the PROALCOOL program offers subsidies to facilities that produce ethanol from sugar cane.44
References
1 in Biodiesel: A Realistic Fuel Alternative for Diesel Engines (ed Ayhan Demirbas) 111-119 (Springer London, 2008).
2 Agarwal, S. & Kumar, A. in Biofuels: Greenhouse Gas Mitigation and Global Warming: Next Generation Biofuels and Role of Biotechnology (eds Ashwani Kumar, Shinjiro Ogita, & Yuan-Yeu Yau) 17-45 (Springer India, 2018).
3 Demirbas, A. Biofuels securing the planet’s future energy needs. Energy Conversion and Management 50, 2239-2249 (2009). https://doi.org:https://doi.org/10.1016/j.enconman.2009.05.010
4 Saladini, F., Patrizi, N., Pulselli, F. M., Marchettini, N. & Bastianoni, S. Guidelines for emergy evaluation of first, second and third generation biofuels. Renewable and Sustainable Energy Reviews 66, 221-227 (2016). https://doi.org:https://doi.org/10.1016/j.rser.2016.07.073
5 Jeon, K.-W. et al. Review on the production of renewable biofuel: Solvent-free deoxygenation. Renewable and Sustainable Energy Reviews 195, 114325 (2024). https://doi.org:https://doi.org/10.1016/j.rser.2024.114325
6 Harish K. Jeswani, A. C. a. A. A. Environmental sustainability of biofuels: a review. Proceedings of the Royal Society A 476, 20200351 (2020). https://doi.org:https://doi.org/10.1098/rspa.2020.0351
7 Häggström, C., Rova, U., Brandberg, T. & Hodge, D. B. in Biorefineries (eds Nasib Qureshi, David B. Hodge, & Alain A. Vertès) 161-187 (Elsevier, 2014).
8 Pandey, S., Narayanan, I., Selvaraj, R., Varadavenkatesan, T. & Vinayagam, R. Biodiesel production from microalgae: A comprehensive review on influential factors, transesterification processes, and challenges. Fuel 367, 131547 (2024). https://doi.org:https://doi.org/10.1016/j.fuel.2024.131547
9 Mingxin Guo , W. S., Jeremy Buhain Bioenergy and biofuels: History, status, and perspective. Renewable and Sustainable Energy Reviews 42, 712–725 (2015). https://doi.org:10.1016/j.rser.2014.10.013
10 Ayadi, M., Sarma, S. J., Pachapur, V. L., Brar, S. K. & Cheikh, R. B. in Green Fuels Technology: Biofuels (eds Carlos Ricardo Soccol, Satinder Kaur Brar, Craig Faulds, & Luiz Pereira Ramos) 1-14 (Springer International Publishing, 2016).
11 Demirbas, A. Biofuels sources, biofuel policy, biofuel economy and global biofuel projections. Energy Conversion and Management 49, 2106-2116 (2008). https://doi.org:https://doi.org/10.1016/j.enconman.2008.02.020
12 Dong, J. et al. High-efficiency conversion of corn bran to ethanol at 150 L scale. Bioresource Technology 408, 131216 (2024). https://doi.org:https://doi.org/10.1016/j.biortech.2024.131216
13 Timilsina, G. R. & Shrestha, A. How much hope should we have for biofuels? Energy 36, 2055-2069 (2011). https://doi.org:https://doi.org/10.1016/j.energy.2010.08.023
14 Ma, F. & Hanna, M. A. Biodiesel production: a review1Journal Series #12109, Agricultural Research Division, Institute of Agriculture and Natural Resources, University of Nebraska–Lincoln.1. Bioresource Technology 70, 1-15 (1999). https://doi.org:https://doi.org/10.1016/S0960-8524(99)00025-5
15 Kapustová, Z., Kapusta, J., Boháčiková, A. & Bielik, P. Development status in EU biofuels market. Visegrad Journal on Bioeconomy and Sustainable Development 9, 67-71 (2020).
16 Sandesh, K. & Ujwal, P. Trends and perspectives of liquid biofuel – Process and industrial viability. Energy Conversion and Management: X 10, 100075 (2021). https://doi.org:https://doi.org/10.1016/j.ecmx.2020.100075
17 J. Eijck, E. S., & A. Faaij. The economic performance of jatropha, cassava and eucalyptus production systems for energy in an east african smallholder setting. GCB Bioenergy 4, 828-845 (2012). https://doi.org:https://doi.org/10.1111/j.1757-1707.2012.01179.x
18 van Eijck, J., Batidzirai, B. & Faaij, A. Current and future economic performance of first and second generation biofuels in developing countries. Applied Energy 135, 115-141 (2014). https://doi.org:https://doi.org/10.1016/j.apenergy.2014.08.015
19 Prasad, S. et al. Review on biofuel production: Sustainable development scenario, environment, and climate change perspectives − A sustainable approach. Journal of Environmental Chemical Engineering 12, 111996 (2024). https://doi.org:https://doi.org/10.1016/j.jece.2024.111996
20 Khan, N. F. & Rehman, I. U. in Environmental Sustainability of Biofuels (eds Khalid Rehman Hakeem, Suhaib A. Bandh, Fayaz A. Malla, & Mohammad Aneesul Mehmood) 87-97 (Elsevier, 2023).
21 Nazari, M. T., Mazutti, J., Basso, L. G., Colla, L. M. & Brandli, L. Biofuels and their connections with the sustainable development goals: a bibliometric and systematic review. Environment, Development and Sustainability 23, 11139-11156 (2021). https://doi.org:10.1007/s10668-020-01110-4
22 Liu, Y. et al. Biofuels for a sustainable future. Cell 184, 1636-1647 (2021). https://doi.org:10.1016/j.cell.2021.01.052
23 Ji, X. & Long, X. A review of the ecological and socioeconomic effects of biofuel and energy policy recommendations. Renewable and Sustainable Energy Reviews 61, 41-52 (2016). https://doi.org:https://doi.org/10.1016/j.rser.2016.03.026
24 Tudge, S. J., Purvis, A. & De Palma, A. The impacts of biofuel crops on local biodiversity: a global synthesis. Biodiversity and Conservation 30, 2863-2883 (2021). https://doi.org:10.1007/s10531-021-02232-5
25 Drabik, D. & Venus, T. J. in Competition for Water Resources (eds Jadwiga R. Ziolkowska & Jeffrey M. Peterson) 144-159 (Elsevier, 2017).
26 Al-Rajab, D. W. J. Biofuels and alternative energy sources. Middle East Newspaper (2018).
27 Greenly. Exploring Biofuels: Renewable Alternatives to Fossil Fuel, < https://greenly.earth/en-gb/blog/company-guide/exploring-biofuels-renewable-alternatives-to-fossil-fuel> (2024).
28 Matt Faye & editor, S. Biofuel facility will bring 200 permanent jobs to Newton County, <https://www.beaumontenterprise.com/jasper/article/land-purchase-finalized-2-8-billion-biofuel-20044729.php> (2025).
29 Energy, U. S. D. o. Biofuels & Greenhouse Gas Emissions: Myths versus Facts. 1 (2025).
30 Kleinschmit, J. Biofueling Rural Development: Making the Case for Linking Biofuel Production to Rural Revitalization. (Carsey Institute, University of New Hampshire, Durham, NH, Winter 2007).
31 Welch, D. The Social Impact of Biofuels: A Thought Leader’s Reflection, <https://greenexpeditions.org/2024/01/30/the-social-impact-of-biofuels-a-thought-leaders-reflection/#Introduction> (2024).
32 Environmental, t. I. C. o. A Global Assessment of the Environmental and Social Impacts Caused by the Production and Use of Biofuels. 44 ( IUCN (International Union for Conservation of Nature), Gland, Switzerland, 2014).
33 Prangon Chowdhury, N. A. M., Rahbaar Yeassin, Nahid-Ur-Rahman Chowdhury, Omar Farrok. Biomass to biofuel: Impacts and mitigation of environmental, health, and socioeconomic challenges. Energy Conversion and Management: X 25, 10 (2025).
34 M. Ayadi, S. J. S., Vinayak Pachapur, Satinder Kaur Brar. in Green Energy and Technology 3-4 (2016).
35 Elliott, K. A. in CGD Policy Paper 051, January 2015 1 (Center for Global Development, 2015).
36 Mabee, W. E. Policy Options to Support Biofuel Production. Adv Biochem Engin/Biotechnol 108, 2 (2007). https://doi.org:10.1007/10_2007_059
37 Wikipedia. Kyoto Protocol, <https://en.wikipedia.org/wiki/Kyoto_Protocol> (2025).
38 Joudeh, E. A. Renewable Energy and its Social and Economic Implications, <https://www.ajialpress.com/article/renewable-energy-and-its-social-and-economic-implications> (2012).
39 Rudolph, M. Sustainability Drives Global Biofuel Policy and Technology, <https://www.scsglobalservices.com/blog/sustainability-drives-global-biofuel-policy-and-technology> (2017).
40 contributors, W. Second-generation biofuels, <https://en.wikipedia.org/wiki/Second-generation_biofuels> (2024).
41 Change), U. U. N. F. C. o. C. The Paris Agreement, < https://unfccc.int/process-and-meetings/the-paris-agreement> (2021).
42 Standardization), I. I. O. f. (ISO (International Organization for Standardization)
2015).
43 Commission, E. Renewable Energy – Recast to 2030 (RED II), <https://joint-research-centre.ec.europa.eu/welcome-jec-website/reference-regulatory-framework/renewable-energy-recast-2030-red-ii_en> (2018).
44 Rosillo-Calle, F. & Cortez, L. A. B. Towards ProAlcool II—a review of the Brazilian bioethanol programme. Biomass and Bioenergy 14, 115-124 (1998). https://doi.org:https://doi.org/10.1016/S0961-9534(97)10020-4