Future prospects for biomass power generation

　　1. Status of biomass energy resources in my country

my country has abundant biomass energy resources, and if all use it, it can provide 66.6% of the country's power generation. Based on the 50% biomass energy collection and utilization rate, my country's biomass resources can be converted into energy every year, with a potential of about 500 million tons of standard coal in the near future, and can reach more than 1 billion tons of standard coal in the long term. If various energy forests are added to the barren mountains and slopes, the resource potential is more than 1.5 billion tons of standard coal.

Our country is the most populous country in the world, and the national economic development faces dual pressures from resources and environment. Judging from the per capita fossil energy resources, coal resources are only 60% of the world average, oil is only 10% of the world average, and natural gas is only 5%. From the perspective of energy production and consumption, my country has now become the second largest energy producer and the second largest energy consumer in the world. The environmental pollution caused by the mass production and use of fossil energy has become very serious. Experts believe that with the development of the economy and the improvement of people's living standards, my country's energy demand will grow rapidly, and the contradiction between energy, environment and economy will also become more prominent. Therefore, it is imperative to increase the adjustment of energy structure and accelerate the development of renewable energy.

my country's crop sowing area is about 1.5 billion mu, with an annual output of about 700 million tons of material. Except for some as papermaking raw materials and animal husbandry feed, the remaining part can be used as fuel. The waste of agricultural product processing, including rice husks, sugarcane bagasse and cottonseed husks, is about 200 million tons. my country's forest area is 175 million hectares. Every year, through normal shrub stubble rejuvenation, forest cultivation and inter-cutting, pruning, collection and harvesting, material making, processing residues, etc., the biological mass can be obtained. my country's livestock and poultry breeding industry emits about 1.8 billion tons of manure, the actual total discharge of sewage is about 20 billion tons, and it can produce about 50 billion m3 of biogas; industrial enterprises emit about 2.5 billion m3 of organic wastewater and waste slag annually, and it can produce about 10 billion m3 of biogas.

　 2 units selection and form

There are four forms of power generation in biomass.

Biomass Direct Combustion Power Generation Biomass Direct Combustion Power Generation Technology refers to the use of the thermal energy burned by biomass to convert it into steam for power generation. In principle, it is no different from coal-fired thermal power generation. The principle is to convert the chemical energy stored in biomass into the internal energy of high-temperature and high-pressure steam through combustion in a specific steam boiler, then convert it into the kinetic energy of the rotor through a steam turbine, and finally convert it into clean and efficient electrical energy through a generator. Direct combustion power generation is to directly burn biomass in a boiler, and produce steam to drive the steam turbine and generator to generate electricity. Key technologies for direct combustion of biomass power generation include biomass raw material pretreatment, boiler anti-corrosion, boiler raw material applicability and fuel efficiency, steam turbine efficiency and other technologies.

Biomass gasification power generation Biomass gasification power generation technology converts biomass into combustible gas and then uses combustible gas to generate electricity. The principle is to convert the chemical energy stored in biomass into combustible gases by combustion in a specific gasifier, and then convert it into clean and efficient electrical energy through the gas generator power generation system. Biomass gasification power generation technology refers to the conversion of biomass into gas fuel in a gasification furnace, and after purification, it is directly entered into a gas engine to generate electricity or directly enters a fuel cell to generate electricity. One of the key technologies for gasification power generation is gas purification. The gasified gas contains certain impurities, including ash, coke and tar. The impurities need to be removed through a purification system to ensure the normal operation of the power generation equipment.

Biogas power generation technology is a biogas utilization technology that has emerged with the continuous development of comprehensive utilization of biogas. It uses biogas on the engine and is equipped with a comprehensive power generation device to generate electricity and heat energy. It is an important way to effectively utilize biogas. Biogas power generation is a biogas utilization technology that emerged with the continuous development of biogas comprehensive utilization technology. Its main principle is to use biogas driven generator sets to generate electricity by anaerobic fermentation of a large amount of organic waste in industry, agriculture or urban life. The equipment used for biogas power generation is mainly internal combustion engines, which are generally transformed from diesel units or natural gas units. Biogas is mostly generated in sewage treatment plants, landfills, wineries, food processing plants, breeding plants, etc.

Biogas is a combustible gas produced by decomposing and converting organic matter under anaerobic conditions and belongs to the category of biomass energy. The main component is methane carbon dioxide, of which the methane content is about 50% to 70%, the carbon dioxide content is 30% to 40% (volume ratio), and a small amount of hydrogen sulfide, nitrogen, oxygen, hydrogen and other gases, accounting for about 10% to 20% of the total content. Methane burns in the air with fire, converts to carbon dioxide and water, and releases energy. Biogas fermentation, also known as anaerobic digestion, anaerobic fermentation or methane fermentation, refers to the complex biochemical process in which organic matter is catalysis and metabolism by a wide variety of microorganisms with different functions under certain moisture, temperature and anaerobic conditions, and finally forms mixed gases such as methane and carbon dioxide (biogas).

Biomass mixed combustion power generation refers to the application of biomass raw materials in coal-fired power plants and the use of two raw materials for power generation. The principle is to burn biomass and coal together in the boiler to convert the internal energy of high-temperature and high-pressure steam, then convert it into the kinetic energy of the rotor through the steam turbine, and finally convert the electric energy through the generator. The biomass and coal mixed combustion technology can be divided into two forms: direct mixing and gasification utilization. Biomass can also be mixed with coal as fuel to generate electricity, which is called biomass mixed combustion power generation technology. There are two main ways to mix combustion. One is that biomass is directly mixed with coal and then put into combustion. This method has high requirements for fuel treatment and combustion equipment, and not all coal-fired power plants can adopt it; the other is that gas produced by biomass gasification is mixed with coal. The combustion in this mixed combustion system, and the steam generated is sent to the turbine generator set together.

(1) Abide by the principle of "using heat to determine electricity, cogeneration of heat and power". Since the city's industrial and heating thermal load is large, based on the characteristics of the heat load and from the perspective of ensuring investment efficiency, the installation plan should be determined based on meeting the near-term thermal load demand and combining the city's long-term thermal load scale and power load demand planning, and ultimately achieve the purpose of cogeneration of heat and power and centralized heating.

(2) In order to ensure the safety and reliability of heating, the capacity and number of units should be made reasonable as much as possible to avoid excessive impact on heating when the largest unit is shut down.

(3) In order to improve the efficiency of the thermal power plant, the main equipment should use higher initial parameters.

　 3 Future prospects for biomass power generation

With the continuous intensification of competition in the biomass power generation industry, mergers and acquisitions and integration and capital operations among large biomass power generation companies are becoming increasingly frequent. Excellent domestic biomass power generation companies are paying more and more attention to the research on the industry market, especially in-depth research on the changes in the development environment of the enterprise and the trend of customer demand. Because of this, a large number of excellent domestic biomass power generation companies have risen rapidly and have gradually become leaders in the biomass power generation industry!

At the same time, developing biomass power generation and implementing coal substitution can significantly reduce carbon dioxide and sulfur dioxide emissions and generate huge environmental benefits. Compared with traditional fossil fuels, biomass energy is a clean fuel, and carbon dioxide emissions after combustion belong to the carbon cycle in nature and do not form pollution. It is estimated that operating a 25,000 kW biomass generator set can reduce carbon dioxide emissions by about 100,000 t/a compared with the same type of thermal power unit. The "In-depth Research and Investment Strategic Planning Analysis Report of China's Biomass Energy Power Generation Industry from 2013 to 2017" predicts that by 2025, biomass energy power generation will dominate in renewable energy. In the future, using biomass renewable energy to generate power has become one of the important ways to solve energy shortages.

　 4 Summary

Fully and effective utilization of the biomass resources of agricultural and forestry waste and provide stable power and heat load supply is the most important core of biomass power generation projects. Therefore, it is particularly important to choose mature and reliable installation plans that are reasonable, energy-saving and environmentally friendly, economical and applicable, to maximize the safety and reliability of the project after completion, and to obtain the best economic and social benefits through reasonable investment. Taking the Cameroon SUDCAM biomass power generation project designed by Shandong Electric Power Engineering Consulting Institute Co., Ltd. as an example, based on the power load and heating load requirements of the project, the installation plan that is most suitable for this project is obtained through technical and economic comparison of different installation plans.