Biomass pellet fuel is mostly a block-packed environmentally friendly new energy produced by processing stem-shaped crops. Its diameter is generally 6-8 cm, its length is 4-5 times its diameter, and the crushing rate is less than 1.5%-2.0%. The water content is less than 10%~15%, the ash content is less than 1.5%, the sulfur content and chlorine content are less than 0.07%, and the nitrogen content is less than 0.5%. If additives are used, they should be agricultural and forestry products, and the type and quantity used should be indicated. The EU standard does not provide specific values for the calorific value of biomass fuels, but requires sellers to mark them. The Swedish standard requires that the calorific value of biomass fuel should generally be above 16.9 MJ.
Biomass solid fuel is mainly carbon, and also contains hydrogen, oxygen, nitrogen and inorganic components such as potassium, sodium, calcium, silicon, etc., which are related to the nature of raw materials.
Different fuels produce different calorific values. For example, the calorific value of wood pellets: 4300-4800 kcal/kg, and the calorific value of corn stalk pellets: 3500-3800 kcal/kg. After compression, it is relatively resistant to burning. Is the fuel? Smoke is determined by the manufacturing process of the combustion equipment. The manufacturing process of the combustion equipment is reasonable, the combustion is sufficient, and there is basically no smoke. On the contrary, it will emit smoke. The straw can be cut into 1cm lengths to produce pellets, the density can reach 1.1, no special formula is needed.
Does burning biomass fuel increase greenhouse gases?
Because biomass fuel consumes CO2 in the production process, it just offsets the CO2 generated in the combustion process. For fossil fuels, it is a little different. Although the production process also needs to consume CO2 and generate O2, the O2 generated by it is in a long period of time. Over the years it has become part of the Earth's atmospheric environment to which humans and other modern organisms have adapted. If these fossil fuels are mined and burned today, the atmosphere is bound to return to ancient times.
In addition, the CO2 produced by burning fossil fuels is not easy to be removed by artificial methods. Some people propose to eliminate CO2 through the photosynthesis of forests and grasslands after reducing emissions. In practice, this is not feasible, because photosynthesis absorbs CO2 to generate O2 and After carbohydrates, although a part of CO2 is consumed, the same amount of CO2 is generated with respiration or combustion. Therefore, this method cannot remove excess CO2, unless a part of the carbohydrates are artificially buried in the ground and isolated from the air.
The emission of pollutants from biomass fuel combustion is mainly a small amount of air pollutants and solid wastes that can be comprehensively utilized. Coal is currently banned all over the country, so this is a prerequisite for the popularity of biomass pellets.
Biomass fuel has high cellulose content, about 70%; sulfur content is much lower than coal; high fuel density, easy to store and transport; many product shapes and specifications, wide application range; calorific value is comparable to medium coal, and combustion speed is faster than coal It is more than 11% faster, with sufficient combustion, less black smoke, low ash content, and environmental protection and hygiene; in addition, after adopting a matching desulfurization and dust removal device, there are fewer types of air pollutant emissions and low concentration.
The solid waste of biomass fuel boiler combustion is mainly ash after combustion, which can be recycled as potash fertilizer and comprehensive utilization of resources.