Biomass Energy [Study on the Development and Application of Biomass Energy in Rural Areas of China]

China is rich in rural biomass resources and vast in land. How to use cheap biomass resources, rely on existing science and technology according to local conditions, partially replace fossil energy with clean energy or alleviate the shortage of fossil energy, reduce the environmental pollution caused by direct burning of straw and livestock manure in rural areas, study biomass energy suitable for rural development and utilization, and make farmers profit from waste utilization, so as to obtain a new industry that can be operated for a long time, are the key issues discussed in this paper.

Biomass energy; Biomass energy; Rural areas; develop

First, the status quo of rural biomass energy utilization in China

The cultivated land area in China is 65.438+83.7 million mu, and the saline-alkali land is about 65.438+48.7 million mu. Farmers are the real owners and cultivators of the land. For many years, free-style farming has been practiced in rural areas of China. What to plant and how much to plant depend on farmers. There is no overall arrangement for cultivating raw materials such as castor, sweet sorghum, cassava, jatropha curcas, palm and perilla, and the pattern of agricultural industrialization has not yet been formed, and some uncultivated land has not been rationally utilized, so there is great potential for developing biomass energy in rural areas; Over the years, the government of China has strongly advocated that on the basis of meeting the urban residents' rations, idle land should be excavated, non-grain biomass combustible raw materials should be planted on a large scale, and land resources should be rationally arranged according to the specific conditions in rural areas, so as to take the road of sustainable development with high efficiency, low carbon and environmental protection. Through hard work, we have achieved initial results. China has established many demonstration bases for the production of non-grain biomass fuel raw materials from south to north, which has accelerated the progress of agricultural structure adjustment; The traditional energy conversion form in rural areas of China is direct burning of straw crops for heating and cooking. This extremely backward energy utilization mode with high pollution and low heat has caused waste of resources and serious environmental pollution. At present, there are many non-grain substances suitable for the development of rural biomass energy in China, which can be divided into solid fuel, liquid fuel and gas fuel according to the characteristics and transformation methods of biomass.

Second, solid biomass fuel.

Solid biomass fuel refers to combustible substances such as crop straw, firewood, trees and chaff. The annual output of crops in China can reach 700 million tons of straw alone, 84 million tons of agricultural processing residues such as rice husk and bagasse, and 654.38+58 million tons of firewood and forestry processing wastes. Among the exploitable biomass resources, the planting and development potential of energy crops is huge. 40% of crop straw is used as feed, fertilizer and industrial raw materials, and 60% can be used for energy development and utilization, which is equivalent to about 2654.38+ 1 100 million tons of standard coal. Fuelwood is also an important biomass resource, with 40% of forest residues available, equivalent to about 300 million tons of standard coal; A large number of agricultural by-product residues and wastes contain huge biomass energy, which opens up an important way for the utilization of biomass energy.

At present, we use a new technology to dehumidify and remove impurities from straw and rice husk, and compress them into briquettes, rods and particles at a certain temperature and pressure. The transportation and storage capacity of straw are improved, the combustion performance of straw is improved, and the utilization efficiency is improved. In rural areas of China where biomass resources are relatively concentrated, local materials can be used to reduce the cost. Using small biomass power generation facilities to generate electricity by burning straw and filling sawdust can not only realize waste utilization, but also reduce environmental pollution during power generation. In addition, the existing rural power plants adopt the mixed combustion of sawdust and crop straw with coal as a practical technology, which improves the utilization rate of agricultural and forestry wastes, reduces the air pollution caused by pure coal combustion, and reduces people's dependence on fossil energy. China has initially formed a certain scale in the production and application of straw solid molding, mainly using sawdust, straw, rice husk and shrubs as raw materials to meet the energy consumption of rural residents, agricultural machinery and power generation. In recent years, the state has issued a series of policies to support enterprises engaged in straw briquette processing in rural areas, especially to encourage the construction of small biomass power plants in rural areas. At present, the general biomass direct combustion power generation technology is relatively simple and easy to master, which is suitable for rural development. China technicians have developed small-scale biomass power generation equipment suitable for villages and towns, taking rice husk and straw as raw materials, taking the road of developing rural power plants according to local conditions, and making contributions to rural energy conservation and emission reduction.

Three. Liquid biomass fuel

Biological liquid fuel refers to bioethanol and biodiesel. Biological liquid fuel, as a substitute for fossil energy oil, is an ideal choice among liquid fuels. Liquid biofuel comes from renewable energy, and its net greenhouse gas emission is almost zero, so it is an ideal sunrise industry. The production technology we developed with corn, sugarcane, beet, beans and edible oil as the raw materials of the first generation of biofuels has been eliminated. The production technology of non-grain biofuel with straw, chaff, sweet potato and castor as raw materials has been formed. These raw materials are taken from rural areas and used in rural areas, with low cost and can be produced on a large scale. If the products are surplus, they can be sold to urban residents in the form of commercial fuel to increase farmers' income. The second generation biofuel is made of agricultural wastes such as straw, chaff, jatropha curcas, sweet potato, perilla, flax, etc., which is recognized as having great potential to replace oil and has broad market development prospects.

Developing rural biomass energy economy in China according to local conditions. Among the non-food crops currently developed, sweet sorghum is one of the first choices, and 4.39 million hectares have been planted in northern provinces of China. Sweet sorghum is a kind of high-energy crop with drought resistance and salinity tolerance. It can harvest 0.3 tons of grain per mu, 5 tons of sugar-rich straw, 460-660 kilograms of sugar squeezed from straw, and straw powder residue can also be used for paper making. It is a high-yield and versatile crop. About 500 million mu of saline-alkali land in northern China 18 province is suitable for planting sweet sorghum and has the potential to produce 20 million tons of sweet sorghum fuel ethanol. At present, sweet sorghum uses solid fermentation to produce ethanol, that is, it takes only 40 hours to crush sorghum straw and ferment it into ethanol, so the commercial production of sweet sorghum fuel ethanol in rural areas of China is just around the corner; Oil plants such as Litsea cubeba, Cyperus esculentus, Camellia oleifera and Sapium sebiferum planted in Fujian are important suppliers of biomass fuel. These crops are developing in the direction of short, dense, abundant, early and pollution-free; Hubei Province will build 2 million mu of woody oil base at the end of the 11th Five-Year Plan, and plant demonstration gardens such as camellia oleifera and tung oil tree. Hainan Olive Coconut Demonstration Park has also been completed, with 686,000 mu of coconuts planted alone, with an annual output of 226 million coconuts, accounting for 99% of the national coconut output. Guangxi is the largest province of cassava production in China, with an annual output of 8 million tons and a planting area of more than 4 million mu, accounting for more than 60% of the country. Guangxi has 30 million mu of dry land and sloping land suitable for growing cassava, which is equivalent to producing 54 1 1,000 tons of fuel ethanol. Sugar and starch crops such as beet, Jerusalem artichoke, sugarcane and potato planted in rural areas of northern provinces are also raw materials for producing fuel ethanol in rural areas of China, and also have broad development prospects.

The lignocellulosic biomass being developed and put into production in China is the only predictable and sustainable resource in the world, which can provide material and fuel for human beings. The annual agricultural and forestry waste in China is about 65.438+0.5 billion tons. According to the calculation method of producing one ton of ethanol from four tons, there is a resource potential of producing 375 million tons of ethanol in rural areas of China. Butanol biofuel with high energy density is also being developed, which is another bright spot of developing biomass energy in rural areas. Bio-butanol is a high-energy fuel with four carbon atoms, which mainly comes from sugarcane, beet, cassava and fast-growing energy plant cellulose. The production process is similar to ethanol, which is an important chemical raw material and has a wide range of uses. In addition, biodiesel is another liquid biofuel besides ethanol and butanol, and its raw materials come from animal fat, waste oil from catering industry, crops and plants. In order to produce biodiesel, oil-bearing and woody oil crops such as cottonseed, flax, flax and rapeseed planted in the north and oil leaves, palm trees and jatropha curcas planted in the south are planted on a large scale without competing with grain and oil and affecting the supply of edible oil. At present, the production of biodiesel has been scaled up. Due to the need for a large number of raw materials, this industry has also brought many farmers new industries and income opportunities.