Definition of biomass Biomass energy in a broad sense includes all solar energy transformed and fixed by photosynthesis of plants. Biomass as a carrier of biomass energy has many definitions. The U.S. Department of Energy (DOE) defines biomass as the organic matter derived from plants and animals. Types of biomass: Biomass generally used for energy conversion can be divided into four categories: wood residues (covering all materials derived from wood and wood products, mainly including: firewood, charcoal, waste wood and forest residues), agricultural waste Materials (all wastes) are related to planting and crop processing.

For example: rice husk, rice straw and animal manure, energy crops (crops dedicated to energy production, such as sugar cane stems and cassava) and municipal solid waste (MSW). Detailed description of biomass boiler Biomass fuel characteristics: According to the biomass pellet standards of Sweden and the European Union, biomass pellets should have the following characteristics.

The diameter is usually 8 mm, and the length is 4 to 5 times the diameter; damage rate ≤ 1.5% to 2.0%; dry basis moisture content ≤ 10% to 15%; ash content ≤ 1.5%; sulfur content and chlorine content ≤ 0.07%, nitrogen Content ≤0.5%; Calorific value: EU does not clearly require, Sweden requires ≥16.9MJ. Utilization and transformation of biomass: There are three main ways of using biomass for transformation: thermochemical method, biochemical method and extraction method.

Thermochemical method refers to the conversion technology that converts biomass into other forms of energy at high temperature. It mainly includes four methods of direct combustion (the direct combustion of biomass to directly release heat); gasification (the process of partially oxidizing biomass and converting it into gaseous fuel with the participation of gaseous media such as oxygen, air or steam.