Influence of biomass raw materials on char combustion duration of highly densified single cylindrical briquette

Abstract

It is known that char combustion duration is almost proportional to the product of the inverse square of the specific surface area and the fixed carbon content of the briquette. It is suggested that the proportional constant Cc can be correlated with the mass percentage of the ash content in the biomass raw materials. However, the individual influence of cellulose, hemicellulose and ash content on the char combustion durations, and thus on Cc, have not been clarified yet. In the present study, to investigate the effects of holocellulose content, cellulose (hemicellulose) content in holocellulose, and ash content in raw materials on Cc in detail, briquettes made of artificial raw materials adding cellulose, hemicellulose powder or cypress ash to cypress were burned in the hot air flow. It was found that char combustion duration for briquettes manufactured from artificially formulated raw materials is also proportional to the product of the inverse square of the specific surface area and the fixed carbon content of the briquette. It was seen that there was little dependence of holocellulose content and cellulose content in holocellulose on 1/Cc. It was confirmed that increasing the ash content decreased 1/Cc, and the dependence decreased as the ash content increased.