Biomass refers to organic matter derived from animals, plants, and microorganisms other than fossil fuels. Biomass has a wide range of sources and a wide variety of species, including animals, plants, microorganisms, and all organic matter excreted and metabolized by these organisms. The development and utilization of biomass energy is to convert biomass energy into heat or electricity that people need. There are basically two ways to obtain biomass: one is the recycling of organic waste, and the other is the cultivation of agricultural and forestry crops that are a source of biomass. Specifically:
(1) Timber, forest industrial waste and short-term deforestation;
(2) Crops and wastes;
(3) Oil plants and sugar plants;
(4) Urban and industrial organic waste;
(5) Human and animal feces.
In addition, certain photosynthetic microorganisms can also form useful biomass.
Biomass power generation is a power generation technology that uses the heat generated by the direct combustion of biomass or the combustion of biomass after conversion into a certain fuel. There are many ways to convert biomass energy into heat energy, mainly including:
(1) Direct combustion. The direct oxidation process of organic matter generates a large amount of heat energy.
(2) Extract biogas. Organic substances are fermented by microorganisms under anaerobic conditions to produce combustible gas, mainly methane. After desulfurization and other cleaning treatments, the biogas can be directly burned as combustible gas to obtain heat energy.
(3) Extract ethanol and methanol. Plant cellulose is processed by a certain process to produce liquid fuels with high calorific value such as ethanol or methanol, and heat energy is generated when the fuel is burned.
(4) Biomass gasification. Combustible biomass undergoes drying, dry distillation, pyrolysis, redox and other processes under high temperature conditions to produce a mixed gas with a large amount of combustible gas, and obtain heat energy through combustion.
The process of biomass power generation can be roughly divided into two stages: The first stage is to collect a variety of usable biological materials, and through certain procedures of processing, transform them into fuels that can be burned efficiently; the second stage is to burn the generated fuels to directly or indirectly generate power.
Features of biomass power generation:
(1) Decentralized construction and local utilization. Compared with conventional power generation methods and other renewable energy power generation such as wind power, biomass energy is more suitable for decentralized construction and nearby utilization. Biomass is closer to the place of human life. It does not need external fuel and long-distance power transmission. It can meet the demand of human electricity nearby. It is especially suitable for agricultural and pastoral areas and mountainous areas with scattered living, sparsely populated, and small electricity load.
(2) It has a technical foundation and is easy to construct. The organizational structure of biomass is similar to that of conventional fossil fuels, and its utilization is similar to that of fossil fuels, so it can learn from conventional energy utilization technologies.
(3) Less carbon emissions. Compared with fossil fuels, carbon emissions are low; compared with renewable energy power generation methods such as wind power and photovoltaic power generation, biomass power generation still produces carbon emissions, but it is much less than that of conventional thermal power plants.
(4) Turn waste into treasure and be more environmentally friendly. Biomass power generation can not only produce less environmental pollution, but also realize waste utilization, solve the problem of waste and garbage disposal, and play a role in purifying the environment.
For other types of distributed power sources, such as wind power generation, fuel cells and micro gas turbines, please refer to the previous article.