What are Biofuels?

Biofuel refers to solid, liquid or gas fuel composed or extracted from biomass, which can replace gasoline and diesel made from petroleum. It is an important direction for the development and utilization of renewable energy. The so-called biomass refers to various organisms produced through photosynthesis using the atmosphere, water, and land, that is, all living organic matter that can grow. It includes plants, animals, and microorganisms. Unlike traditional fuels such as petroleum, coal, and nuclear energy, these emerging fuels are renewable fuels.

Chinese name: Biofuels

Broadly: Solid fuel consisting of or extracted from biomass
Substitute: Gasoline and diesel made from petroleum

Introduction to Biofuels

Biofuels broadly refer to solid, liquid or gaseous fuels composed or transformed by living organisms. It is an important direction for the development and utilization of renewable energy, has good storability and transportability, and can provide a liquid fuel that can replace petroleum. Biofuels in the narrow sense only refers to liquid biofuels, mainly including fuel ethanol, biodiesel and aviation biofuels.

Since the 1970s, due to the impact of traditional energy prices, environmental protection and global climate change, countries around the world have increasingly paid attention to the development of biofuels. In particular, Brazil, the United States, and the European Union are actively developing biofuel technologies. At present, the United States and Brazil are the world's first and second biofuel producers, respectively. At the end of the 20th century, China began to promote fuel ethanol for the purpose of digesting aging grains and finding new ways for high-yielding corn. At present, in order to promote the healthy development of the biofuel industry, the focus of research and development in China is mainly on bio-liquid fuel technologies using cassava, sweet sorghum and other starchy or sugary non-grain crops and lignocellulose as raw materials. ^[1]

Biofuels Overview

Biofuel refers to the fuel ethanol, biodiesel, and aviation biofuel produced through biological resources. It can replace gasoline and diesel made from petroleum. It is an important direction for the development and utilization of renewable energy. Affected by the world's petroleum resources, prices, environmental protection and global climate change, since the 1970s, many countries have increasingly paid attention to the development of biofuels and achieved significant results. China's biofuel development has also made great achievements, especially the production of fuel ethanol based on grains, which has initially formed a scale.

The latest research results of American scientists show that as the two most widely used biofuels, biodiesel and ethanol fuels, although superior to fossil fuels, cannot meet the energy needs of society. Researchers have found that even if all the corn and soybeans grown in the United States are used to produce bioenergy, they can only meet 12% of the society's gasoline demand and 6% of diesel demand, respectively. And corn and soybeans must first meet food, feed, and other economic needs, and they are not likely to be used to produce biofuels. Biofuels are not very promising, because the source is that agriculture is a highly water-consuming industry. Agriculture consumes up to 70% of water every year. All this is just to save non-renewable energy-the use of oil or coal. However, it did not take into account that the amount of water, electricity, and oil consumed by bioenergy in the production process and transportation process is also huge. The development and utilization of bioenergy can be said to be a stupid act of demolishing the east wall and filling the west wall.

Biofuel Advantage

Biofuel diversity

1. Diversified biofuels in raw materials can use crop straws, forestry processing residues, livestock and poultry manure, organic wastewater waste from the food processing industry, urban waste, and low-quality land for planting a variety of energy plants.

2. Diversity of products; Energy products include liquid bioethanol and diesel, solid prototypes and molded fuels, and gaseous biogas. It can replace oil, coal and natural gas, as well as heat and power generation.

Biofuel material properties

Like petroleum and coal, it can produce various materials such as plastics, fibers, and chemical raw materials, forming a huge biochemical production system. This is impossible for other renewable and new energy sources.

Biofuel recyclability and environmental protection

Biofuels are products produced during the detoxification and recycling of organic wastes from agriculture, forestry, and urban and rural areas. All living materials of biofuels can enter the biological cycle of the earth, and even the released carbon dioxide will be reabsorbed by plants. Participate in the Earth's cycle and achieve zero emissions. Material sustainability and resource recyclability are a modern advanced production model.

1. Recyclability; the carrier of biomass energy is organic matter, so this energy exists in the form of physical objects, and it is the only renewable energy that can be stored and transported. And it is the most widely distributed, not limited by weather and natural conditions, as long as there is biomass wherever there is life.

2. Environmental protection; from a chemical point of view, the composition of biomass is a CH compound, which is similar to conventional fossil fuels such as petroleum and coal. Because coal and petroleum are converted from biomass over a long period of time, biomass is the ancestor of fossil fuels and is known as green coal for immediate use.

Inhibition of biofuels on crude oil prices

Biofuels will increase the number of "crude oil" producing countries from the current 20 to 200. By independently producing fuel, the price of imported oil will be suppressed, and the cost of imported oil will be reduced, so that more funds can be used to improve people's lives. Resolving the food crisis.

Biofuel drive

Biofuels can expand the field of agricultural production, drive rural economic development, and increase farmers' income; it can also promote the development of manufacturing, construction, and automotive industries. The development of biofuels in China, etc., can also promote agricultural industrialization and the development of small and medium-sized towns, and narrow the gap between workers and peasants, which has important political, economic and social significance.

Biofuel use

The time to use biofuels is now mature. Biofuels are widely used in Brazil. At first, sugarcane was used to produce ethanol, and ethanol was used as a fuel for use. In other countries, it was from other sources, such as corn and sorghum.

Although using food as fuel is not new-Rudolf Düssel used a peanut oil as a fuel to drive cars a century ago-but the idea suddenly became very practical. Oil prices are getting higher and food prices are so low that politicians and many managers are rethinking the issue. Fully combustible, renewable biofuels are widely used in Europe. It can ease the supply of oil in the United States and help to stabilize the agricultural economy in the United States. However, it has brought irreversible changes to the natural environment in the United States. Resources have been overexploited and used. Short-sighted humans only consider themselves and their The recent generation has not considered how to survive with his grandson.

Difficulties in biofuel production

Biofuel crops are decomposed by biomass or burned into farmland, resulting in decades or even centuries of life.

Biofuels can compensate the carbon emissions. In order to produce biomass fuel, many lands have been converted to agricultural land, especially the development of new agricultural land will destroy the ecology. The heavy use of biomass fuels has also led to rising food prices and threatened the survival of the poor.

Pollution, carbon dioxide emissions, and the use of water resources and fertilizers for the production and transportation of biomass fuels. Local production and use of biofuels can reduce these problems, but even in local production, biofuels may not be environmentally worthwhile. Some studies have shown that some already produced bioethanol is not economically worth- For example, the energy needed to make corn alcohol will exceed the energy that corn alcohol can provide.

Tung oil trees can be used to produce biomass fuels, but some people still think that the following situations must be avoided: some third world farmers use the land originally used for food crops to grow energy crops; even if the energy crops themselves are not edible It can also be planted in inedible areas, but there is still the danger of reducing food production.

The use of waste cooking oil to produce biodiesel does not occupy food sources, and is considered to be a biofuel that is really worth promoting at present, but the waste oil contains many useless substances, which will increase production problems.

Prospects for the development of biofuels

Biofuels don't even have a bad smell. Users report that the biodiesel, which uses soybean as raw material, emits a bit of fume after burning. Experts say that even if food prices rise, if the United States prioritizes the development of biofuels to curb global warming, it may have a bright future. In fact, the production process of biofuels is more costly than any other industry because Large-scale planting of the same type of plants will cause insect pests, which in turn will cause humans to use pesticides, which will enter the water source, and the human water source will be contaminated, which is equivalent to chronic suicide. A comfortable and free modern life cannot last for ten years without bringing great changes to human life.

Maize farmers have been urged ever since people started using gasoline blends in the 1970s

Biofuels People use ethanol more as gasoline fuel. In addition to being used as livestock feed and for export, the production of biofuels has now become the third largest use of corn, and as a result, the diversity of agricultural cultivation has been replaced by standardized high yields, which directly results in the loss of species diversity.

The ethanol production industry used corn as a raw material last year, and a total of 1.6 billion gallons of ethanol were produced, and the scale of production is still expanding, which also means that the consumption of water resources is increasing.

Government subsidies for biofuels

Government subsidies have also promoted the development of biofuels. The USDA subsidizes ethanol producers by $ 150 million annually to increase the use of biofuels such as ethanol and biodiesel. At least five states are considering tax incentives to further encourage the use of biodiesel.

Encouraged by the above policy, the production of biodiesel increased sharply-from 500,000 gallons in 1999 to 5 million gallons in 2000. It is estimated that the USDA's incentives alone can increase biodiesel production by an additional 36.5 million gallons. State and federal governments in the United States have established many incentives and laws regarding the use of biofuels. Washington State alone has four incentive programs and 13 laws. According to the Energy Policy Act of 1992, B100 and B20 or B10, B5, and other bio-diesel blends are qualified alternative fuels. Most states provide tax exemptions and deductions for the use of biofuels. Other countries, especially Europe, offer similar incentives to encourage the use of bio-based products such as biofuels.

These numbers are still not comparable to 56 billion gallons of diesel output per year. But advocates of biofuel production say,

Biofuel laboratory If the oil industry, as announced by the Bush administration, is forced to switch to low-sulfur diesel before 2006, soybean oil may become the main lubricant used with biofuels. In fact, lubricants provide another promising market for food. Researchers have developed similarly cheaper and more environmentally friendly alternatives from grains, replacing petroleum products as lubricants for semi-trailer hooks, rails and chain saws.

Such projects will help inject funding into America's long-lost agriculture. According to the Renewable Fuels Association, ethanol production alone can increase farmers' income by $ 4.5 billion annually.

Biofuel fuel division

(Using ASTM D6866 test standard)

ASTM D6866 uses radiocarbon dating technology. Biomass contains carbon 14 and fossil materials no longer retain this weakly radioactive carbon isotope. Measuring the concentration of carbon 14 in an ethanol sample will indicate whether the ethanol is produced from renewable or fossil materials. It is expected that in some cases a mixture of bioethanol and synthetic ethanol will also be present.

Using ASTM D6866 to detect "biobased content" in carbon dioxide emissions is similar to the principle of carbon dating, but does not use it to calculate age. This detection method is performed by comparing the relative amount of radiocarbon (C14) in an unknown sample with a standard for radiocarbon content in the modern atmosphere. The results are reported as percentages in "pMC". If the tested material is a mixture of contemporary materials and fossil materials (without radiocarbon), then the pMC value is directly the percentage content of the bio-based material.

In the United States, ASTM D6866 will quantitatively determine the proportion of bioethanol for a sample containing two types of ethanol to give an appropriate tax credit. Similarly, ASTM D6866 is suitable for testing bulk gasoline with different bioethanol concentrations. The test will show the content of renewable materials in the entire liquid. However, it must be determined that the gasoline is sufficiently mixed so that the very small samples used can represent the entire storage tank, which is always an important concern for bulk material testing.

Biofuel political relations

Agricultural organizations with political influence in developed countries, on the one hand, have put on a posture that attaches great importance to biofuels, but on the other hand, they are unceremoniously sticking to the protection barriers to protect their own interests. "They are waving the moral banner of passion for environmental protection in one hand, and the other hand is looking for a lot of subsidy funds," said Doralil of the Biofuels Consulting Center.

Biofuel food famine

Experts from the Food and Agriculture Organization of the United Nations warned on January 23, 2008 that the world s eagerness to develop and use biofuels is causing rising prices of corn and other food crops, which may further worsen water shortages and may cause poor people to lose their support Land for survival.

In March of the same year, the above-mentioned comments made by the United Nations Special Rapporteur on the Right to Food, Ziegler, at the United Nations Headquarters in New York aimed to draw attention to this issue. He pointed out that this kind of ill-considered and rushing to use corn and sucrose to convert biofuels would lead to disaster. He said the current practice of converting arable land into biofuels was a crime against humanity. He called for a five-year ban on the practice. He believes that during these five years, technological advances could use agricultural waste, such as corn cobs and banana leaves, instead of using grains and fruits to make fuel.

Currently, biofuel production continues to increase, in part because people are eager to find fuels that can replace oil and cause less damage to the environment. The United States is trying to reduce its dependence on oil supplies in politically volatile areas, but this trend has caused food prices to skyrocket as American farmers abandon wheat and soybeans and switch to corn for ethanol production. The International Monetary Fund has also warned that increasing global cereal production for biofuels could have serious implications for world poverty.

Biofuel other information

Biofuel crimes against humanity

Regional Bioenergy in Bangkok

Biofuel vehicle At the forum, FAO expert Reagan Suzuki acknowledged that bioenergy is indeed more beneficial to environmental protection than traditional fossil energy, and it can promote energy security in many countries and regions. But she also pointed out that these advantages must be weighed against the disadvantages of bioenergy.

Suzuki pointed out that many countries and regions are changing the use of millions of hectares of land, specializing in the cultivation of palm, sugar cane and other food crops that can produce biofuels. Biofuels have also become the hottest topic in the media, but large-scale production of biofuels The wide range of social and environmental issues that have arisen have been left behind.

The biggest concern is "grazing with the land", Suzuki warned that large-scale replanting of biofuel plants has caused rising corn prices in the United States and Mexico and could lead to food shortages in developing countries.

In 2007, 25% of the corn harvest in the United States became ethanol fuel, but on the other hand, a report by FAO at the end of 2007 stated that the world is experiencing "unprecedented" food, influenced by factors such as the conversion of large amounts of food to biofuels. crisis. Some UN officials consider the use of food to produce fuel as a "crime against humanity."

Biofuels are expensive

Suzuki said that because biofuels require a lot of water, China and India will suffer even more severe water shortages if they proceed blindly. According to the latest results of the water resources evaluation released by the Ministry of Water Resources of China in November 2007, according to the current normal needs and no over-exploitation of groundwater, China's water shortage in normal years is nearly 40 billion cubic meters.

Meanwhile, Suzuki said that forests in Indonesia and Malaysia are in danger of expanding palm plantations. "For tropical and subtropical countries, growing biofuels has a clear competitive advantage, but often also in these countries, forest and resource protection systems are fragile," she said.

The forecast report released by CGIAR on the 23rd is in line with Suzuki's statement. This report uses independently developed computer models to predict the additional water and land needed to produce biofuels from crops such as corn, wheat, and sugarcane by 2030 based on biofuel production plans and population growth trends in countries such as India. The results show that India will need about 30 billion tons of additional water. Other major agricultural nations also face large water supply shortages.

PK Biofuel Biofuel PK Food Production

"Energy is not extinguished, cars are always moving, and everything is reborn." This is a beautiful dream inspired by the heat of biofuels around the world. But with the new round of rising global agricultural product prices, many people have doubts about this beautiful dream, and ca nt help asking Will more people eat enough food or let more people drive cars?

Tracing back to the source, after focusing on the causes, development, and solutions of a series of problems such as "biofuel fever" and "developing biofuels endangering food production", the mania returned to rationality. Only by rationally treating the heat of biofuels can we get out of the "PK" competition of biofuels and food production.

Biofuels affect global commodity markets

The widespread use of biofuels to delay global warming has had an important impact on the global commodity market, the chairman of the Chicago Mercantile Exchange said last week.

Craig Donohue, the executive of the world's largest financial transaction, also said that the recent rapid increase in crude oil and wheat prices has had an important impact on commodity markets. "This is a brand new commodity market. As more and more companies use ethanol as their energy base, we are seeing a significant convergence between soft commodities (agricultural products) and energy." He did so when he visited Tokyo. Tell the reporter.

The International Monetary Organization warned this week: "Global reliance on cereals as an energy base will raise food prices in poor countries and bring 'serious implication'."

According to the International Monetary Organization, the United States has surpassed Brazil to become the world's largest ethanol producer in 2005, and the EU is the largest biodiesel producer.

China and India also plan to accelerate the production of biofuels due to the energy demand caused by rapid economic growth. Experts point out that this will accelerate water and food shortages.

Donohue pointed out that the rise of the two major energy demand countries in Asia has had a significant impact on world commodity markets.

"We see huge changes in the production, import and export of commodities due to the economic growth of India and China, which has also had an important impact on the supply and demand of commodities," he said.

Biofuels Thailand's biofuels lead

Facing the fluctuations of international crude oil prices, how to deal with the economic and social problems that may be caused by the rise in crude oil prices has become the focus of attention of all countries. At a recent energy seminar held in Bangkok, Thailand, many experts believed that the use of renewable biofuels as an alternative could ease the dependence of many countries on fossil fuels such as crude oil. Each year, Thailand spends about $ 10 billion on imported crude oil.

The production and full utilization of bio-blended fuels was the subject of discussion at this conference. Among them, the method proposed by Brazilian experts to mix ethanol with gasoline or diesel to make fuel is the most interesting.

Ethanol is also known as alcohol. The cost of producing ethanol is not high, and the raw materials are convenient and readily available. Starch or sugar plants can produce a large amount of ethanol after fermentation and distillation. Tests show that the new fuel made from ethanol and gasoline or diesel is not only environmentally friendly, but also can greatly reduce people's demand for crude oil.

In addition, another advantage of using new hybrid fuels is adapting to the conditions of Asia and Latin America. Countries in these regions are mostly agricultural producers, and ethanol can be extracted from some high-yielding crops, such as sugar cane and corn. Brazil is a large sugar producing country. At present, it has the world's largest ethanol processing base. It can process about 13 billion liters of ethanol with sugar each year. It is one of the major exporters of industrial ethanol. Thailand currently does not have a base for ethanol production. Thai Prime Minister Thaksin said he has decided to send experts to study the scheme and hopes to implement it as soon as possible.

Biofuel biofuel development is in full swing worldwide

With the depletion of traditional fossil energy (coal, petroleum, etc.) and the increasing environmental pollution facing humankind, countries around the world are actively seeking to develop renewable energy. Bioenergy, especially biofuels, has attracted wide interest from large automobile consuming countries and agricultural countries because it can use a wide range of agricultural waste as raw materials for production and can directly replace fuel for vehicles. Brazil, the United States, the European Union, etc., have been at the forefront of the world in the field of bioenergy development, providing many valuable experiences.

Fuel agriculture provides the possibility for large-scale promotion of high-tech methods such as genetic modification, and can provide sufficient raw materials for increasingly important biofuels. Compared with grains, oils, vegetables and forage plants for human and animal consumption, the advantages of developing fuel plants are outstanding. First, there is no concern about human health with genetically modified plants. Second, in addition to considering environmental impacts, large pesticide residues can be tolerated. Third, many fuel plants have the characteristics of tolerance to drought and drought.

Brazil is the world's largest producer of biofuels (mainly sugarcane, ethanol), and it has begun its biofuels program as early as the 1970s. Brazil's cheap biofuel feedstock has stimulated renewable energy production, and hybrid vehicle sales have doubled. Brazil's domestic consumption and export demand have led to a rapid increase in biofuel production, and total output in 2010 is expected to increase from 18 billion liters in 2005 to 26 billion liters.

The United States is the world's second-largest producer of renewable fuels. It began research and development in the 1980s, and by 2004 it had reached 12.9 billion liters. The new energy bill passed in 2005 will focus on the development of renewable fuels, stipulating that the use of renewable fuels in the United States in 2012 will reach 28.4 billion liters, which is twice the current level.

Two biofuel directives passed by the European Commission in 2003 pushed the EU to develop ethanol fuel and biodiesel production. In 2004, the EU produced 526 million litres of ethanol and 2.2 billion litres of biodiesel. The directive requires that by 2010, the use of renewable fuels for vehicle fuels should reach 5.75%. Fuels containing bioethanol or biodiesel are exempt from fuel tax.

Biofuels Brazil builds bioenergy nation

Brazil's renewable energy accounted for 44.7% of the country's energy, while the global average was only 13.3%. Renewable energy in Brazil is mainly ethanol and hydropower. The proportion of ethanol is increasing.

According to data released by the Brazilian Ministry of Minerals and Energy, sugarcane energy accounted for 13.9% of the 218.6 million tons of oil equivalent energy produced in the country in 2005. At present, bioenergy has become the third largest energy source in Brazil. It is estimated that by 2010, half of the more than 100 sugarcane ethanol distillation plants currently under construction will be put into operation. By then, bioenergy will surpass hydropower and electric power and will become Brazil's second largest energy source.

Brazilian sugar cane orchard

Since 1973, Brazil's bioenergy production has increased by 744.4%, from 3.6 million tons of oil equivalent to 30.4 million tons of oil equivalent, with an average annual growth rate of 21.3%. Brazil has great potential for the development of ethanol fuel. Currently, sugarcane planting area is 5.9 million hectares and ethanol production is 18 billion liters. Sugarcane planting area is expected to double in the next 10 years. Brazil has developed new early-maturing sugarcane varieties through genetic technology, prolonged the sugarcane harvesting period, thereby increasing the utilization rate of equipment in the distillation plant, and the start-up period has been increased from six to seven months each year to 10 months.

Given that Brazil is the only country in the world that can produce ethanol at low cost, developed countries have expressed strong interest in participating in ethanol development in Brazil. Japan International Cooperation Bank will provide more than 600 million US dollars to finance Brazil's sugarcane ethanol production. Through cooperation with Japan, Brazil's annual ethanol output can increase by 3 billion liters. A Dutch company and a Brazilian company have jointly established an investment fund of 50 million euros, which will reach 500 million euros in the next three years to finance the development of bioenergy projects such as sugar cane ethanol in Brazil.

Brazil started to promote "ethanol-gasoline" dual-fuel vehicles 5 years ago, also known as flexible fuel vehicles. Under the situation of high oil prices, the use of ethanol fuel has increasingly shown a price advantage. In 2005, the average price of ethanol in Brazil was 53% of gasoline, which resulted in significant savings for consumers. Bi-fuel vehicles are becoming increasingly popular and demand is strong. About two-thirds of the new vehicles currently leaving the country are dual-fuel vehicles. Brazil currently has 1.3 million dual-fuel vehicles, and is accumulating at a rate of 100,000 new vehicles per month. According to the Brazilian National Association of Automated Vehicle Manufacturers, sales of dual-fuel vehicles increased by more than 70% in 2005, and their sales exceeded gasoline vehicles for the first time. It is estimated that in 2006, the share of dual fuel vehicles in the new car market will reach 70%.

Brazil also implements a biodiesel plan, that is, adding 2% of biodiesel to ready-made diesel. The government stipulates that this measure will be implemented compulsorily by 2008, and the proportion will be expanded to 5% by 2013. In view of the rising oil prices and the rapid progress of more than a dozen biodiesel plants under construction, the government has begun to study the possibility of achieving these goals ahead of time.

It is said that Brazil has developed a new mixed fuel with 10% vegetable oil added to diesel and plans to officially start production in 2007. The technical innovation of this new fuel is to add vegetable oil to diesel oil during the crude oil refining process, and the new process ensures that the sulfur content in the finished fuel is greatly reduced. Therefore, it is not only cheaper than conventional diesel, but also less polluting. The new biodiesel has excellent texture, so that all diesel vehicles can use this new fuel without any modification.

U.S. bullish on biofuels

In a State of the Union address issued early this year, US President Bush called for a 20% reduction in US oil consumption within 10 years. One way is to replace renewable energy sources, such as biofuels, with 15% of the oil consumed by automobiles, while reducing the other 5% of oil consumption by improving fuel efficiency. The 20% fuel savings are equivalent to 75% of the current US oil imports from the Middle East.

Bush suggested that by 2017, the output of ethanol and other renewable vehicle fuels be increased by nearly five times, reaching 132.475 billion liters per year, which is equivalent to nearly nine times the United States' ethanol fuel production in 2005.

Since ethanol is the primary feedstock for ethanol fuel, the proposal will have a huge impact on US agriculture. According to the American Renewable Fuels Association, ethanol is a huge economic engine in the agricultural states of the United States, and it will generate good returns. The ethanol industry helped create 153,000 jobs in 2005, increasing household income in the US agricultural region by $ 5.7 billion.

The United States produced 6,056 million liters of ethanol in 2000, and reached 15.14 billion liters in 2005. In 2000, 6% of US corn production was used for ethanol production, and in 2006 this proportion may increase to 20%. The chief economist of the United States Department of Agriculture said that fuel ethanol has now become the third largest industry in corn use in the United States. As the world's largest corn exporter, US corn exports account for 70% of global exports. In 2006, the use of corn by the US ethanol industry may exceed its exports for the first time.

Of course, some people are skeptical of biofuels. To produce 132.65 billion liters of ethanol, 40 million acres of land need to be dedicated to planting corn, and a large number of ethanol production facilities need to be built. The most important thing is that the current cost of ethanol production is very expensive. According to the USDA's estimation, if the government subsidy is cancelled, the cost per liter of ethanol is about 0.92 US dollars, which is twice as much as gasoline.

As of now, there are more than 5 million E85 (burnable 85% ethanol fuel) ethanol fuel vehicles in the United States.

Ethanol fuel car

Fuel ethanol is made from corn and biodiesel is made from soybeans. In addition, American researchers are developing fuels from weeds. Bush mentioned Willow Branch in his State of the Union address. Switchgrass is a ubiquitous wild plant on the American continent. It has thick grass stalks that can grow up to 3 meters tall. Compared with corn and soybeans, switchgrass is more likely to become a long-term fuel source in the United States.

Researchers at the University of Oklahoma in the United States are trying to develop a method for making ethanol from switchgrass. Specifically, it cuts switchgrass, heats it, and sprays carbon monoxide, carbon dioxide, and hydrogen produced into a bioreactor. The gas becomes ethanol. Another method is to extract sugar from cellulose of switchgrass, and then use sugar to make fuel. The current problem is mainly high costs.

The University of Oklahoma has cultivated several high-yielding switchgrass. "The seeds of switchgrass are valuable to wildlife, especially birds, so they are also good for the environment. Switchgrass is easier to grow than other perennial grasses, and in wasteland where corn and other crops cannot be grown," said school professor Telia Ferro. In fact, switchgrass can grow, and with minimal fertilizer and water, switchgrass can produce a high yield. "

The United States has vast land for switchgrass. If switchgrass could become a source of alternative fuels, this new fuel would be inexhaustible. ^[2]

Biofuels EU promotes bioenergy development

In May 2003, the European Union passed a directive to promote the use of biofuels in transportation. According to this directive, by the end of 2005, the use of biofuels in the EU should reach 2% of the fuel market and 5.75% by the end of 2010. By 2020, 20% of fuels used for transportation will be new fuels.

The large-scale promotion of bioenergy is of great significance to the German energy strategy. At present, bioenergy accounts for more than 60% of the German renewable energy market. Sources of bioenergy include energy plants, wood, biogas, biodegradable household waste, and industrial waste. While promoting the large-scale commercial application of "first-generation bioenergy", Germany is also stepping up the development of a more economical and environmentally-friendly "second-generation bioenergy". The new generation of bioenergy technology will directly use agricultural straw, wood, sawdust, and animal manure as energy raw materials to effectively solve the ecological problems existing in the development of bioenergy, with lower production costs, higher energy conversion efficiency and higher quality.

Biofuels are good renewable energy

"Second-generation bioenergy" no longer competes with land for food and edible oil. The recycling of agricultural wastes ensures the sustainable development of bioenergy, and solves the problem that the current biofuel production process consumes more energy. New technology is still in its infancy, and there is still a long way to go before large-scale industrial production, but its development potential is huge. For example, in Germany, 40 million tons of agricultural straw are discarded on the spot due to unavailability, which is equivalent to 4 million tons of biodiesel or 14% of German annual diesel demand.

Since 2003, the French government has adopted a series of measures to promote the development of bioenergy and encourage the use of bioenergy. In 2003, France used 320,000 hectares for the cultivation of biofuel raw materials; that year, the output of biofuel was 410,000 tons, of which 80% was biodiesel. The government plans that by 2010, the area of farmland used for the cultivation of biofuel raw materials will reach 2 million hectares.

Britain built the EU's largest biodiesel plant in 2004, with an annual output of 250,000 tons. Biofuels plans to produce 750,000 tons of biodiesel annually. The University of Leeds has developed a new technology for producing hydrogen using sunflower seed oil. The purity of the obtained hydrogen is as high as 90%, which can provide efficient and clean hydrogen products for automotive and household fuel cells. The UK also uses plants such as sugar beet to produce biobutanol, which is mixed with traditional gasoline and sold at gas stations.

Current status of biofuels abroad

Currently, biofuels are mainly used to replace fossil fuels as transportation fuels, such as ethanol for gasoline, and biodiesel for petroleum-based diesel. In the context of gradual decline in fossil fuel reserves and increasingly severe environmental protection, biofuels are highly valued by governments. The European Commission actively promotes the development of biofuels, setting a target of 8% of total transportation fuel consumption in 2015. In the United States, biofuels are compulsorily added to transportation fuels through legal means. The specific proportion is to add 2% biodiesel to diesel and 5% ethanol to gasoline. According to statistics from the survey, on August 16, 2011, the White House announced a plan totaling $ 510 million, which was jointly invested by the Department of Agriculture, the Department of Energy, and the Navy to promote the development of the US biofuel industry. From 2006, the British government requires that energy companies producing transportation fuels must have 3% of their raw materials come from renewable resources, and the proportion will increase year by year. According to the International Energy Agency (IEA), the global daily output of biofuels in 2010 was 1.822 million barrels, which fell to 1.818 million barrels in 2011.

Biofuel biodiesel

As part of their strategy to address climate change, governments in Western Europe and North America have mandated that more biofuel components be added to gasoline and diesel over the next 15 years. The revised EU Fuel Quality Law stipulates that the content of renewable ethanol in EU gasoline will double from 5% to 10%, and EU countries will sell this gasoline named E10 at gas stations.

World demand for biodiesel is expected to increase from 6.9 million tons in 2006 to 44.8 million tons in 2010. By 2010, Asia is expected to surpass North America, Central and Eastern Europe and become the world's second largest biodiesel production region after Western Europe. The global biodiesel industry has shown rapid growth. From 2000 to 2005, the average annual growth rate of production capacity, output and consumption was about 32%. By 2008, the growth rate of production capacity and demand is even faster, with annual average growth rates of 115% and 101. % Or even higher. The global biodiesel production model will also change from 2005 to 2010. In 2005, biodiesel production in Western Europe accounted for 75% of the global total output, and it will be reduced to less than 40% in 2010, mainly due to output growth in other regions led by Asia. Accelerating, Asia will likely become the second largest biodiesel production region, followed by North America. From the perspective of consumption, Germany accounted for 61% of global consumption in 2005. Other consumer countries mainly include France, the United States, Italy, and Brazil. The total consumption accounted for only 11% of global consumption. In 2010, the United States may become the world's largest biodiesel market, accounting for 18% of global consumption. New large consumer markets will appear in China and India, and the total consumption of other countries will account for 44% of global consumption. The source of biofuels has become an important issue for sustainable development of biofuels.

Southeast Asia is emerging as a major biodiesel production base, and it is expected to become the world's leading supply region by 2010. Southeast Asian governments and companies have invested heavily in the development of the biodiesel industry, with biodiesel plants under construction all over the country, which will therefore become the main supplier of biodiesel in Western Europe and North America in the future. Palm tung oil is one of the richest natural resources in Southeast Asia and will become the main raw material for the development of the biodiesel industry in the region.85%

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In China, ethanol gasoline blended with 10% ethanol has become an important target of China's energy substitution strategy, but the competition for grain and food products and ethanol fuel is also becoming increasingly fierce. Professional research institutions predict that during the "Eleventh Five-Year Plan" period, China s corn shortfall will be around 3.5 million tons, which will change from a net exporter of corn to a net importer, and the snap-up of grain sources by processing companies will inevitably skyrocket the price of corn. In addition, unlike other countries, China's corn is non-GMO, which is very suitable for human and livestock consumption. It is obviously used for the production of ethanol fuel.

(2) Opposition has gradually risen, and some studies suggest that ethanol fuel has exacerbated environmental pollution.

A number of studies around the world have shown that the ethanol fuel that has been advertised as green does not protect the environment as people wish, but has worsened environmental pollution. The results of research by atmospheric scientist Mark Jacobson of Stanford University and others show that ethanol fuel is more harmful to human and biological health than previously thought, and ethanol-fueled vehicles may cause more people to suffer or die. Respiratory diseases. If ethanol-fuelled vehicles replaced all cars and trucks, the number of people killed in the United States by air pollution would increase by 4%. The results of studies showing that ethanol fuels are not "green" but "black" are not alone. A team of biologists Burton Vaughn at Washington State University in the United States found through actual investigation that the production of ethanol caused another type of environmental pollution, reducing biodiversity and increasing soil erosion. In addition, even the use of non-food crop sugar cane to produce ethanol also consumes a lot of water. Each ton of sugar cane needs 3900 liters of water (3.9 tons of water), which adds to the burden on the environment.

(3) Low bioethanol production efficiency

At present, corn is widely used to produce bioethanol in the world, but the output efficiency is relatively low. Even the most technologically advanced plant with 100 kg of corn can only produce about 45 L of ethanol, and the energy consumed in the production of ethanol and growing corn and other raw material crops is equivalent to 80% of the energy produced by ethanol produced, and it also emits carbon dioxide. After systematic calculations, scientists have questioned the economics of biofuels.

Biofuels consume more energy in the production process than they can produce, and the production costs are higher than the petroleum fuels they replace. Energy costs include, first of all, the fertilizers needed to grow the crops, as well as the water, steam, and electricity needed to convert them. Economic costs include labor, herbicides, irrigation and machinery, and fertilizers. The lower energy density of ethanol compared to gasoline also increases transportation costs and reduces engine efficiency. The energy and economic deficits of corn, switchgrass, lignocellulose, soybean, and sunflower oil and other biofuel feedstock plants are similar. All plants require carbon dioxide to grow and are released again when they are used as fuel or converted to other fuels for combustion. In this sense, the impact of biomass on carbon absorption and emissions is neutral. However, this does not take into account the energy consumption during cultivation, fertilization, pesticide application, transportation, drying, and conversion to usable fuel. Among them, chemical fertilizer is the main aspect of energy consumption. The Haber-Bosch process for industrial nitrogen fixation to produce ammonia requires a lot of energy. Approximately 31 million BTUs of energy per ton of ammonia. If the raw material is not natural gas but coal, Other oxidation processes require 41 million BTUs of energy per ton of ammonia. The energy consumed in the production of phosphate fertilizer and potash fertilizer is much lower (mainly in mechanical mining, crushing, drying and other links). Chemical fertilizers account for 45% and 24% of the energy consumed in the production of bioethanol and biodiesel, respectively. In the production process of biodiesel, a transesterification reaction with methanol is required, and this also accounts for 35% of the energy consumed.

Prospects for biofuels

China is drafting a medium- and long-term development goal for bioenergy to replace petroleum. By 2020, the scale of biofuel production will reach 20 million tons, of which 15 million tons of bioethanol and 5 million tons of biodiesel. If it goes well, it will reach 30 million tons by 2020. China imported 140 million tons of oil in 2006, and is expected to import 200 million tons in 2010 and 300 million tons in 2020. This will be able to control China s foreign dependence on oil below 50% by 2020 and improve China s energy security. China is rich in biofuels, with 1 billion tons of straw and forestry cutting and processing residues, 500 million tons of standard coal, 9 million hectares of woody oil forests and fuel carbon forests, and more than 30 oil tree species.

"Eleventh Five-Year Plan" China will invest 101 billion US dollars, and by 2020, bioenergy will account for 15% of transportation energy needs, or 12 million tons. China also plans to plant 13 million hectares of jatropha by 2010 and extract 6 million tons of biodiesel from it. The production standard for biodiesel (BD100) for diesel fuel blending was officially promulgated recently and implemented on May 1, 2007. This will definitely greatly promote the development of China's biofuel industry.

However, in order to avoid threats to food production, China's development of fuel ethanol is also changing from a food-based raw material route to non-grain. Of course, as a means of regulating food supply and demand surplus, corn fuel ethanol will still maintain a modest scale. From a broad perspective, grain can no longer be used as fuel for ethanol. Replacing oil with non-grain materials will be the long-term direction. China's rural labor force is abundant, and cellulose raw materials plants can be planted in the fields and corners, which is more suitable for development.

When the international oil price plunged in 2008 once broke through $ 40, the development prospects of fuel ethanol as one of the alternative energy sources are also worrying. However, fuel ethanol is clean and renewable, which can reduce carbon monoxide and hydrocarbon emissions in automobile exhaust. In the future, China's fuel ethanol industry will focus on reducing production costs and reducing government subsidies. To this end, formulate consumption control specifications for biofuel ethanol production processes and product quality and technical standards, and unify the fuel ethanol production consumption quota standards, including material consumption, water consumption, Energy consumption is a powerful way to reduce costs and increase efficiency. And the future development direction of China's fuel ethanol industry is how to achieve the scale of non-grain ethanol. Therefore, the key to determining the future development of fuel ethanol is cost and technology.

In the future, the Chinese government will continue to moderately develop the fuel ethanol industry. During the "Eleventh Five-Year Plan" period, the potential market size of China's fuel ethanol will expand dramatically. Judging from the production capacity of China's four fuel ethanol production enterprises, it is far from meeting the domestic demand for fuel ethanol in the future, and the expansion of fuel ethanol plant capacity is inevitable. Therefore, it is planned that by the end of the "11th Five-Year Plan" period, the proportion of domestic ethanol gasoline consumption in the national gasoline consumption will rise to more than 50%, which means that China's fuel ethanol capacity and output will have a qualitative leap then.

Biofuel energy efficiency

In the past 5 years, the planting area of the Swedish willow clone energy forest has been increasing, which is mainly related to the promotion of the willow tree as a crop by the Swedish Farmers Trade Association and various other institutions. At the same time, the government's subsidy system also provides necessary conditions for the large-scale promotion of willow energy forests. At present, there are about 11,000 hm of willow energy forests in southern and central Sweden, of which 2,000 hm were planted in 1994 and planned to be 5,000 hm in 1995. The average biomass production per hectare of these energy forests is 10 to 12 tons per year, which is equivalent to 25 to 30 m of wood or 4 to 5 m of fuel oil, which is about 25-30 barrels of crude oil. If bamboo willow is used as the analysis object, the average biomass production per hectare per year can reach 37.8t under the conditions of ultra-high density (1.5 million plants / hm) and ultra-short-term rotation (rotation period 1-2 years). The above is equivalent to 94.5m of wood or 15.12m of fuel oil, which is about 94 barrels of crude oil. Affected by the current global financial turmoil, international crude oil prices have plummeted. Based on the current average price of US $ 43 / barrel after the fall, the annual output value per hectare is US $ 4042, equivalent to approximately RMB 27,500 (exchange rate 6.8). For example, if the biomass produced is used for power generation, the energy consumption per unit of electricity is calculated at 1.37 kg / kwh of the domestic power generation efficiency of domestic direct-fired generating units. These energy forests can generate 27560 kwh per hectare per year. Calculated based on 1.05kg / kwh of raw material consumption per unit of electricity, 36,000kwh can be generated per hectare per year. The electricity price is calculated at 0.5 yuan / kwh, and the annual output value is 13,780 yuan per hectare.

Future outlook for biofuels

China's policy support in biofuels is relatively late. In recent years, with the government's attention, biofuel technology has rapidly improved, and market competition has become increasingly fierce. By the end of 2010, the annual utilization of biomass solid molding fuel in China was about 500,000 tons, the annual utilization of non-grain raw material fuel ethanol increased by 200,000 tons, and the annual output of biodiesel was about 500,000 tons. According to the "Renewable Energy Medium- and Long-Term Development Plan" and the "Eleventh Five-Year Plan" for Renewable Energy Development, the country's "11th Five-Year Plan" for the development of biomass energy is: by 2010, the year of biomass solid molding fuel The utilization reached 1 million tons, the annual utilization of non-grain feedstock fuel ethanol increased by 2 million tons, and the annual utilization of biodiesel reached 200,000 tons. It can be seen that the scale of China's biofuel development is far from the previous plan. The biomass solid fuel has only completed 1/2, and the non-grain fuel ethanol has only completed about 10% of the established target. In general, the use of biomass energy in China during the "Eleventh Five-Year Plan" period has been "tiger-headed", the main reason is that the national industrial support policy has not kept up. As of mid-April 2012, the "Twelfth Five-Year Plan" for renewable energy development has been submitted to the State Council, but has not yet been officially released. The "Planning" has preliminarily determined that the annual utilization of biofuel ethanol in China will reach 5 million tons in 2015, which has more than doubled compared to the "11th Five-Year Plan"; the annual utilization of biodiesel is 1 million tons.

In order not to repeat the same mistakes during the "Twelfth Five-Year Plan" period, China's relevant departments are actively formulating countermeasures. According to the "Renewable Energy Medium and Long-Term Development Plan", by 2020, China's annual utilization of biodiesel will reach 2 million tons, and the annual utilization of biofuel ethanol will reach 10 million tons. Due to the limited nature of fossil energy, the development of new energy sources has risen to the energy strategy of various countries. At present, the recoverable period of global crude oil is about 46 years, while the recoverable period of oil in China is only 15.62 years. The development of alternative energy is an effective way to solve the problem of China's energy shortage. Although due to the shortage of raw materials and high prices, China's current capacity utilization rate of biodiesel is relatively low, and some companies are in the state of partial or even complete production suspension. The situation of heating first and then cooling down will no longer occur, and the biodiesel industry will certainly have long-term development.

Problems with biofuels

Large-scale use may also bring the risk of major impacts on agriculture and ecology. The consequence of the infiltration of energy crops into the natural landscape will obviously lead to habitat destruction and fragmentation, which will directly lead to the loss of biodiversity. The use of unsustainable agricultural practices in the cultivation and management of biomass (such as excessive use of fertilizers may cause soil loss or compaction) can further result in the loss of biodiversity.

Biofuel farmland

The area of land available for energy biomass cultivation is limited, and energy biomass cultivation may compete with existing agricultural land. The UN's report on "Sustainable Energy: A Framework for Decision Makers" states that the production of biofuels will affect adequate food supply by occupying land and other required resources, and those crops that produce biofuels often require the best land, Water and chemical fertilizers.

Biofuel food production

Jatropha (also known as tung oil tree) can be used to produce biofuels. These crops can be grown in wastelands that are not suitable for the growth of food crops, require little fertilization, and their seeds are not edible, which has less impact on food production. However, some scientists believe that farmers in some third world countries use the land that was originally used to produce food crops to grow energy crops, and their development is at risk of reducing food production.