Abstract
To increase the co-firing ratio of biomass in existing pulverized coal-fired power plants, biomass should be pulverized to obtain a particle size suitable for combustion. However, evaluation of the particle size distribution of each coal and biomass mixture via traditional fuel analysis is difficult. Because coal does not contain neutral sugars, the particle size distribution of biomass in the mixture can be estimated based on its neutral sugar content. The current study was conducted to evaluate the effect of biomass carbonization on the grinding process via neutral sugar analysis. Mixtures of coal and carbonized pine chips with three different degrees of carbonization were prepared and ground using a Hardgrove grindability index mill. In the pulverized mixtures of low carbonized biomass and coal, the biomass content at all particle size ranges was nearly the same as that of the input feedstock. As the degree of biomass carbonization increased, the biomass content in the mixture of large particle sizes was decreased, whereas it was increased in the mixture of small particle sizes. The current study indicated that particle size distribution of coal and biomass in the pulverized mixture depends on the degree of carbonization of biomass.
Highlights
Co-firing of biomass is conducted in pulverized coal-fired power plants to reduce CO2 emissions
In existing pulverized coal-fired power plants, the maximum achievable co-firing ratio is limited by the design of the coal mill and grindability of the biomass fuel
Biomass cofiring requires the efficient operation of coal-fired power plants leading to the pulverization of coal and biomass to sizes corresponding to the combustibility of each of these entities
Summary
Co-firing of biomass is conducted in pulverized coal-fired power plants to reduce CO2 emissions. In existing pulverized coal-fired power plants, the maximum achievable co-firing ratio is limited by the design of the coal mill and grindability of the biomass fuel. Because biomass is more difficult to pulverize than coal using a roller mill,[1] a high ratio of biomass in the feedstock remains unpulverized. In most cases, co-firing of the biomass in pulverized coal-fired power plants is only possible up to a maximum mass percent. The calorific value per weight of the biomass is increased, water repellency is improved, and grindability is markedly improved.[1,3,8−10] In pulverized coal-fired power plants, the particle size of the pulverized mixture is an important parameter affecting combustion efficiency, unburned ash content, and combustion stability.[11,12] biomass cofiring requires the efficient operation of coal-fired power plants leading to the pulverization of coal and biomass to sizes corresponding to the combustibility of each of these entities
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
