Category: Nonghua: 2980 Source: Green World No.65438 +00
Abstract: Biomass energy is energy stored in biomass and used as a carrier. Biomass energy is an important renewable energy, and all countries in the world regard the development of new energy sources such as biomass energy as the priority choice for energy development. The development of biomass energy in China has entered a substantive stage, and the biomass resources can reach 300 million tons by 20 10. Developing biomass energy is very feasible and necessary for optimizing rural energy structure. The technical problems and energy efficiency of developing biomass energy are also discussed.
Keywords: new energy; Biomass; Biomass energy; renewable energy
China Library Classification Number: tk6 Document Identification Number: A Document Number:1005-569X (2009)10-0031-02.
1 quotation
In modern society, human beings consume a lot of coal, oil and natural gas every day, and these energy sources are non-renewable. Therefore, the huge demand for energy and the serious shortage of supply have formed a sharp contradiction and become a huge obstacle to the development of human society. Developing new energy has become a major issue that people are generally concerned about. The development of new energy sources such as wind energy, solar energy, nuclear energy and biomass energy, as well as the research and development of energy-saving and environmental protection technologies, have become the main direction of energy development for governments all over the world. Based on the basic national conditions of China, the development of biomass energy has broad prospects.
2 About biomass new energy
As the name implies, biomass refers to all animals, plants and microorganisms, and is a variety of life forms through photosynthesis.
Renewable energy is an important energy resource, and the development and utilization of renewable energy has the following important significance:
1. Developing and utilizing renewable energy is the basic requirement for implementing Scientific Outlook on Development, building a resource-saving society and realizing sustainable development. Adequate, safe and clean energy supply is the basic guarantee for economic development and social progress. China has a large population, low per capita energy consumption level, and great pressure on the growth of energy demand. The contradiction between energy supply and economic development is very prominent. To fundamentally solve the energy problem in China, continuously meet the needs of economic and social development, protect the environment and realize sustainable development, besides vigorously improving energy efficiency, accelerating the development and utilization of renewable energy is an important strategic choice, and it is also the basic requirement for implementing Scientific Outlook on Development and building a resource-saving society.
2. The development and utilization of renewable energy is an important measure to protect the environment and cope with climate change. At present, the environmental pollution problem in China is outstanding and the ecosystem is fragile. The extensive exploitation and use of fossil energy has a great impact on the environment, especially the high proportion of coal in China's energy consumption structure, and the rapid growth of carbon dioxide emissions has a great impact on climate change. Renewable energy is clean and environmentally friendly, and the development and utilization process does not increase greenhouse gas emissions. The development and utilization of renewable energy plays a very important role in optimizing energy structure, protecting environment, reducing greenhouse gases and coping with climate change.
3, the development and utilization of renewable energy is an important measure to build a new socialist countryside. At present, rural areas are the weakest areas in China's economic and social development, and the energy infrastructure is backward. There are still about 1. 1.5 million people without electricity in China, and many rural domestic energy sources are still mainly provided by the traditional way of inefficient direct combustion of biomass such as straw and firewood. Rural areas are rich in renewable energy. Accelerating the development and utilization of renewable energy can, on the one hand, solve the problems of power supply in remote areas and rural residents' living energy consumption according to local conditions; on the other hand, it can transform rural biomass resources into commercial energy, make renewable energy a characteristic industry in rural areas, effectively extend the agricultural industrial chain, improve agricultural efficiency, increase farmers' income, improve the rural environment and promote the sustainable development of rural economy and society.
4. The development and utilization of renewable energy is an important choice to open up new economic growth points, promote economic transformation and expand employment. Renewable energy resources are widely distributed, and all regions have certain conditions for the development and utilization of renewable energy. The development and utilization of renewable energy mainly uses local natural resources and human resources, which is of great significance to promoting regional economic development. At the same time, renewable energy is also a high-tech and emerging industry. The rapid development of renewable energy has become a new economic growth point, which can effectively promote the development of equipment manufacturing and other related industries, and is of great significance to adjusting industrial structure, promoting the transformation of economic growth mode, expanding employment and promoting sustainable economic and social development.
At present, the international oil price has soared again and again, and the major energy consuming countries have suffered greatly, so the development of renewable energy has become a concern of many countries.
Today, the research on renewable energy is in the ascendant all over the world. One reason is that the energy crisis is approaching. According to the coal mining speed in 2003, China can still mine coal for more than 80 years, while China has the largest coal reserves in the world. In less than forty years, the oil in the Gulf of Mexico will also run out. Let's imagine what we humans will do if this day comes.
Therefore, no matter which country is aiming at this direction, it hopes to get a technological breakthrough, so as to get rid of the passive situation before the real crisis comes. Gain the dominance of the world. This is a question of national strategy. A western political elder put it well, "the energy science and technology in 2 1 century will greatly change the world political structure and geopolitics."
The significance of renewable energy goes far beyond this, and it will also change people's ideas. Renewable energy is a generous gift from nature, which can greatly get rid of the limitation of resources, thus reducing the competition for resources and bringing peace to the world. There is inexhaustible rain and wind here. And from then on, we can get rid of the environmental problems brought by human development industry. No matter how it is described, its importance cannot be overemphasized. What it brings to mankind is not only a way of life, but also a new ideological revolution.
At present, the breakthrough of renewable energy is wind power generation. Our country started early, and now it is backward. You can read my "Reasons for the Backward Wind Power Generation in China". At present, the single-unit capacity of wind turbines in China is not large, while the single-unit capacity of wind turbines in Germany has reached 5000 kilowatts, while that in foreign countries has reached 7500 kilowatts. More than one generation behind. In the past two years, all wind turbines in China have been imported from abroad. At present, the cost of power generation is higher than that of thermal power, and it depends on state financial subsidies to survive. Even so, it will take ten years to fully recover the cost. In other words, we have been working for foreign devils for the past ten years. Be a foreign slave.
In addition to wind power generation, biomass power generation is also in the ascendant, mainly burning biomass directly, such as straw power generation. At present, Guodian Group has many small thermoelectric units with good benefits. Its power generation mode is similar to traditional thermal power generation, using chain furnace. There are not many technological innovations. The other is mainly biogas power generation, which uses bacterial fermentation to produce biogas, which drives the gas turbine after combustion, with high power generation efficiency. But the cost is high, and a fermentation container alone needs a lot of investment. Moreover, the fermentation efficiency is not so high, so it is best to use semi-fermented raw materials, such as cow dung. Some farms in China have built small power plants, but the technology is mainly imported, and the patent for the use of photobacteria is also a big expense. Taineng power generation has also developed rapidly in China in recent years. The power generation efficiency of monocrystalline silicon and polycrystalline silicon is expected to increase to more than 20% in a short time. However, although the price of solar panels has dropped rapidly, the cost of power generation is more than five times that of thermal power, and there is still a long way to go before it can be put into commercial operation.
The biggest disadvantage of the above-mentioned power generation mode is that it can not become the main unit in the power system, can not meet the large-scale power consumption, and has poor stability. For example, wind power generation, although China is rich in wind power resources, due to the instability of wind power generation, after power flow calculation, its electricity consumption can only account for about 10% of the total power generation. If there are too many units, it will affect the stable operation of the whole power grid, because wind power is uncontrollable. However, other forms of generator sets have relatively small power generation, which is difficult to meet the demand.
In addition, there is tidal power generation. The installed capacity of the world's largest tidal power station has reached more than 200,000 kilowatts, which is already considerable. Considering the coastal conditions of China, the energy density is not large. The highest tides are in the coastal areas of Zhejiang and Guangdong. The tidal range in the highest area is about 8.5 meters. In addition, it is necessary to build seawalls, which is quite complicated and difficult. Both the maintenance of the dam and the seawater corrosion protection of the machine need a lot of money. Regardless of the cost, it is difficult to choose the dam site. At present, China Oceanic Administration has made an investigation report on seawater energy, and thinks that there are about10 million kilowatts of tidal power stations that can be developed in China at present. Then such a little electricity is far from meeting the demand.
China's energy policy, previously written in textbooks, is: "Vigorously develop hydropower, moderately develop nuclear power, and control the development of thermal power." Mainly shut down small thermal power units. Thermoelectricity is an exception. The actual situation of China power grid is that thermal power generation accounts for 80% and hydropower accounts for 20%. The rest is nuclear power, not a fraction. Other power generation methods can be basically ignored. Although I don't know the recent policy, vigorously developing nuclear power is definitely on the agenda. Because the development of small hydropower in China is not bad, there will not be many hydropower resources available for development. Thermal power is increasingly developing to large units and large capacity. At present, the largest fire generating set that has been put into operation is 6,543.8+0,000 kilowatts.
Although we don't know much about nuclear power, and I personally don't know much about it, I don't think anyone wants to live next to an atomic bomb. This is the last resort. The leakage of Chernobyl nuclear power plant in the former Soviet Union still puzzles the world.
Since so many power generation modes have problems, is there no way out for energy problems? The answer is no, everything will be solved in the end. The lack of energy is actually relative. On the one hand, fuel prices are rising; On the other hand, with the progress of science, the price of renewable energy is declining. When the two are equal, investment will inevitably tilt towards the latter. A new era is coming. But to fully meet the power demand, except nuclear power, others can only be used as a supplement. But not as the main unit. This is the main problem we are facing. In other words, if nuclear power is not developed, is there any other way out? This is a problem.
At present, the dawn is the wave power generation and ocean current power generation in seawater. This is a better way to generate electricity. Not only national research institutions, but also private research institutions and individuals have been exploring. This exploration can even be traced back to 30 years ago, when a farmer in Fujian used a wave-powered boat to generate 7 kilowatts of electricity. Its large-scale experiment has only recently begun. Britain has invested a lot of money in this field. This country is small in territory and poor in resources, but it is surrounded by the sea and rich in ocean energy. In addition, it is the Japanese who study wave energy ahead.
There are thousands of mechanical designs that use waves all over the world, and hundreds of them have obtained patent certificates. Wave energy utilization is called "inventor's paradise".
The earliest invention patent of wave energy machinery was obtained by French father and son Gillard in 1799. From 1854- 1973 to 1 19, Britain registered 340 wave energy invention patents, and the United States registered 6 1. In France, you can find 600 descriptions of wave energy utilization technology.
In 1960s, Japan successfully developed a pneumatic wave power generation device used on the floating body of navigation lights. This device has been put into mass production, and the rated power of the product ranges from 60 watts to 500 watts. In addition to Japan's own use, products are also exported, becoming one of the few commercial wave energy equipment.
The power generation principle of this product is like an inverted water pump, which sucks in air through the reciprocating power of waves and pushes the turbine to generate electricity.
Japan's "Haiming" wave power generation test ship has achieved good results of annual power generation of 6.5438+0.9 million kWh, and realized small-scale power transmission from offshore floating wave power station to land. Japan has listed "Haiming" as the first choice for "power supply to outlying islands" and continues to study and improve it.
However, the attention of our government is obviously insufficient. Over the past 30 years, more than10 million has been invested in scientific research funds alone, which is enough for several cadres to buy several cars. Britain has invested billions of pounds in five years.
The advantages of wave power generation are obvious, that is, strong regularity and short periodic change of energy. If there is a large-scale energy storage device, (such as a reservoir) can generate electricity on a large scale as the main unit. If a breakthrough is made, it is entirely possible to replace thermal power.
In order for wave power generation to replace thermal power generation, energy storage is essential, and the cheapest way to store energy is the reservoir. Therefore, I personally think that the mode of land storage plus conventional hydro-generator set should be the research direction. That is, using the wave energy of seawater to lift water and send it to the reservoir built on the shore. There is no other reason, mainly because the reservoir is the most economical to store energy, and there is no need to build a dam like a conventional barrage reservoir. Because rivers change greatly with seasons, there are high water periods and low water periods. And the sea surface has hardly changed. Another reason is that it is very convenient to build a reservoir on the shore, without engineering difficulty, and the maintenance cost is much less than that of a barrage. The influence on seawater corrosion is also relatively small.
Examples of bioenergy: algae biofuels.
The goal of the United States is a new type of bioenergy based on algae.
Bioenergy accounts for the largest proportion of renewable energy in the United States, rising from 43% in 1998 to 53% in 2008. In May 2008, Congress passed a bill including accelerating the development of bioenergy, requiring that the consumption of fuel extracted from petroleum be reduced by 20% and replaced by biofuels after 10. This requires the production of 35 billion gallons of biofuels every year. Since 2004, the research and development of bioenergy in the United States has developed in the direction of extracting ethanol from corn, soybeans and other crops, which experts call the first generation bioenergy. But now many experts believe that the United States may skip the first generation of bioenergy represented by corn and soybeans and go straight to the new type of bioenergy represented by algae.
Will thurmond, director of the research and development department of the National Algae Federation, said in response to a question from Xinhua News Agency that the research on extracting bio-crude oil from algae can be traced back to the oil crisis in the 1970s. After the crisis was lifted, the US government suspended research funding several times, and related projects failed to be implemented. In recent years, the soaring oil price has accelerated the research on algae, and now it has entered the final mature stage of research and development. According to the plan, multi-point demonstration projects will be started in 20 10, the first batch of government procurement contracts will be signed with the US military and government in 20 10, the first batch of commercial contracts will be signed in 20 12, and mass commercial production will be carried out in 20 13 to reduce the sales price. The U.S. military is most interested in developing algae resources, because its aircraft, ships, tanks, armored vehicles and other weapons are the "oil tigers" that consume the most diesel in the world. In 65438+February last year and 65438+1October this year, Air New Zealand, Continental Airlines and Japan Airlines successively successfully tested the biofuel extracted from mixed aviation gasoline and algae.
Thurmond believes that compared with the first generation of bioenergy, the new bioenergy has incomparable advantages: first, corn and soybeans can only be harvested on cultivated land; Algae can be cultivated in ditches, ponds, beaches and any barren land, thus saving a lot of valuable cultivated land. This is of great significance to countries like China and India, which have a large population and little arable land. Second, planting soybeans, European rape and palm on an acre of arable land (about six acres in China) can extract 50 gallons, 150 gallons and 650 gallons of fuel each year; On the other hand, cultivating algae on an acre of water can extract 10000 gallons of fuel a year, which are 200, 69 and 15 times of the former, respectively. This is because crops such as soybeans are only planted once a year due to seasonal influences. Algae are generally not affected by seasons, and their reproduction speed is very fast, and they can double in one day. There are more than 20 small enterprises that cultivate algae in the United States, and farmers there say, "Don't let China farmers master the technology of cultivating algae, or one billion China farmers will make money all over the world." Thirdly, algae need to absorb a lot of carbon in the air during photosynthesis, so it can purify the atmosphere and play an environmental protection role. Now American experts propose to build algae farms around coal-fired power plants and other enterprises with serious pollution emissions in order to achieve the goal of low or even zero emissions, which not only develops a green circular economy, but also increases new growth points.
In May last year, the US Congress approved the Bush administration to allocate 654.38 billion US dollars for research and development of biofuels. After Obama took office, despite the subprime mortgage crisis and severe economic recession in the United States, the new government resolutely allocated about $800 million in the economic stimulus plan to accelerate the research and development of biofuels. In the past three years, the U.S. Department of Energy, as a partner, has invested about $654.38+0 billion to support bioenergy research projects, with the goal of producing results by 2065.438+02. Some of these research funds have flowed into research and development projects related to algae. The U.S. government also stipulates that any refinery that mixes a certain proportion of biofuels into its refined oil can enjoy a reward of one dollar per gallon of refined oil. This led the European Commission to announce earlier this year that it would impose 29% anti-dumping duties and 47% countervailing duties on "American biofuels" sold to the European market within six months. American private investment in algae research and development projects is also very enthusiastic. Bill Gates of Microsoft invested $6,543.8 billion at a time. Many private investors think this is a profitable project. An interesting phenomenon is that the representatives of the world's major oil companies gathered in Houston are not opposed to or disgusted with the accelerated development of new bioenergy-algae in the United States, but have a strong interest. They never miss the opportunity to attend the next generation bioenergy seminar. They asked more questions at the meeting than the reporters. Most of the world-renowned oil companies they represent support or even invest in research and development projects of algae energy.
BarryCohen, president of the National Algae Federation, told reporters that the existing research results show that biodiesel, gasoline and even aviation gasoline can be extracted from algae, and algae residues can also generate electricity. In the near future, it is impossible for the United States to produce enough soybeans and corn to extract ethanol, and it is impossible for Europe to grow enough sunflowers and rapeseed to extract bio-crude oil. At present, biological refineries in the United States and Europe have excess refining capacity, and about half of the equipment has been idle for a long time because of a serious shortage of biological raw materials. This provides a godsend opportunity for algae, a new type of bioenergy. In the long run, diesel and gasoline extracted from algae may eventually provide fuel for all vehicles in the United States. If oil is black gold and seaweed is green diamond, the market prospect is very broad.