"Drilling wood to make fire" and "striking stones to take fire"... The use of fire is an important milestone in the development of human civilization, highlighting the survival wisdom of mankind in harsh environments. Fire cooking, lighting and heating, people use the flame to ignite the most common branches around, straw and other thermal energy, support their survival and development. In the long ancient society, branches and straws, which we call biomass energy today, are the earliest, most common and most important "classical" energy sources for human use.
In modern society, with the development and utilization of coal, oil, natural gas and other fossil energy, the dependence of human on biomass energy and the proportion of its use have been greatly reduced. However, the traditional industrialization, which is characterized by a large amount of fossil energy consumption, has brought about increasingly serious environmental problems. Human beings have made great efforts to develop and utilize various renewable energy sources to optimize and "green" the energy structure. It is in this context, as a "classical" energy, with "green", "environmentally friendly" and "renewable" characteristics of biomass energy, in the promotion of modern science and technology to re-glow vigorous vitality. Since the founding of New China, especially since the reform and opening up 40 years ago, China has made fruitful achievements in the field of biomass energy development and utilization. Today, in China's energy structure, biomass energy is on the road of revival with the momentum of steady and rapid development.
1. Green renewable energy with abundant quantity
Biomass can be divided into broad sense and narrow sense. In broad sense, biomass refers to all kinds of organisms produced by photosynthesis, such as atmosphere, water and land, that is, all living and growing organic substances are generally called biomass, including all plants, microorganisms, and animals and their growth that feed on plants and microorganisms. Waste produced. Representative biomass such as crops, crop waste, wood, wood waste and animal manure.
In a narrow sense, biomass mainly refers to lignocellulose, agricultural products processing waste, agricultural and forestry waste, livestock manure and waste in the process of agricultural and forestry production, except for grain and fruit.
Biomass is the carrier and the energy generated by biomass is biomass energy. Biomass energy is a form of energy stored in organisms by solar energy in the form of chemical energy, directly or indirectly derived from photosynthesis of plants.
It is estimated that the energy consumed by plants in photosynthesis accounts for 0.2% of the total solar radiation to the earth, although the proportion is very low, but the absolute value is astonishing, it can be said that biomass energy is an inexhaustible energy treasure house for mankind. The main sources include firewood, livestock manure, sugar crops, municipal waste and sewage, aquatic plants and so on.
Biomass energy has three major characteristics. First, renewability. Because it can be formed by photosynthesis of plants, biomass energy, like wind energy and solar energy, is a renewable energy source of continuous production to ensure sustainable use. The two is green environmental protection. On the one hand, because the content of sulfur and nitrogen in biomass is very low, harmful gases will not be produced during combustion; on the other hand, the amount of carbon dioxide released by biomass combustion is equivalent to the amount of carbon dioxide needed for its growth, so the net emission of carbon dioxide to the atmosphere is close to zero, which will not aggravate the greenhouse effect. Three, they are widely distributed and abundant. According to biologists'estimates, the land produces 100 billion to 125 billion tons of biomass a year; the ocean produces 50 billion tons of biomass a year. The annual production of biomass energy far exceeds that of the world's total annual energy demand.
Large scale promotion of biogas to help build beautiful countryside
Biogas is a typical representative of biomass energy. Wang Fei, an engineer from the Planning and Design Institute of the Ministry of Agriculture and Rural Areas, said that biogas, as a convenient, clean and high-grade biomass energy, is a combustible gas produced by microbial fermentation of straw, feces, domestic sewage and other organic substances under certain moisture, temperature and anaerobic conditions. Because of its rich raw materials, simple technology, low cost, environmentally friendly characteristics and attracted great attention by the state.
The large-scale construction of rural household biogas began in the late 1950s. In 1979, the State Council approved the "Report on Several Problems in the Current Rural Biogas Construction" by the Ministry of Agriculture and other departments, which promoted the construction of rural biogas, and a wave of construction climax appeared in the early 1980s. Since then, to the beginning of this century, rural biogas construction has been developing steadily. By the end of 2000, there were nearly 8 million 500 thousand rural biogas in the whole country. In the past 2003-2015 years, with the investment from the central government, the development of rural biogas has entered a new stage of rapid development. By the end of 2015, nearly 42 million households were used for biogas production in China, benefiting 200 million of the population.
The great development of biogas has brought far-reaching influence to the construction of new countryside. Specifically, it includes 3 aspects.
First, it has enhanced the ability of rural energy security. The rural biogas has historically solved the problem of improving the cooking energy quality of more than 200 million people, and promoted the cleanliness and convenience of rural household energy consumption. The large-scale biogas project not only provides gas for the surrounding farmers, but also meets the demand of clean energy such as gas, heat and electricity in the farm. In 2015, China's annual production capacity of biogas reached 15.8 billion cubic meters, about 5% of the country's natural gas consumption. It can replace fossil fuels by about 11 million tons of standard coal every year. It has played a positive role in optimizing the country's energy structure and enhancing the country's energy security capability.
Two is to promote the transformation of agricultural development mode.