Thermal Analysis Of Biomass And Tannery Sludge Blended Briquette Fuel

The fossil energy exhaustion and environmental pollution are two crucial problems which are blocking people’s future development. To develop a clean and sustainable energy has become the worldwide energy strategic development orientation. Therefore, more and more attention has been paid to biomass energy which is clean and CO2neutral. However, with the characteristics of low volume energy density and slag formation, biomass is not available for a large scale application. Co-firing and biomass briquette are two important technologies of biomass application. A growing number of tannery sludge is engendered during production and daily life, which need to be disposed. Combustion is the most effective way of tannery sludge treatment, which not only eliminates organics in sludge, but also makes them quantity-reducing and harmless.This work chose three straw biomass which are wheat-straw, corn-straw and corn-cob, briquetting them blending with tannery sludge, and made thermal analysis of the blended briquette fuel. The research shows that the main mass loss of biomass happens during the volatile combustion, which is more than60%. There are two volatile combustion peaks during the tannery sludge combustion, and the maximum of combustion rate is the first one. Both biomass and tannery sludge have a good ignition characteristic. With the increase of biomass content, the TG and DTG curves move toward the low temperature section and the maximum of combustion rate grows. It greatly improves the combustion characteristics of blended fuel that blending biomass into tannery sludge, and there will be a higher degree increase when the biomass content is more than60%. The tannery sludge effects greatly on the burnout temperature of blended briquette fuel. Therefore, for a more effective application in practice, the ratio of biomass in blended fuel should be higher than60%.To describe the combustion reaction mechanism, we divided the curve into three sections according to the DTG curve peaks, making n=0.5,1.0,1.5,2.0and got the results. The reaction orders of tannery sludge are0.5,1.5and1.0. The reaction orders of biomass are all2, and the blended fuels’ are the same to the tannery sludge.The combustion of blended fuel whose biomass ratio is80%under different heat rate shows that with the rise of heat rate, the TG curve moves towards high-temperature side, that maximum burning velocity rises up and that the general combustion characteristics are improved. With the rise of heat rate, the activation energy and frequency factor wasn’t monotonous, which means there a best combustion heat rate value exists. Compared to the powder fuel, the ignition temperature of briquette fuel is lower, the maximum of combustion rate is much higher, the burnout temperature is close to, and the combustion characteristic index is much higher. The activation energy and frequency factor of briquette fuel are lower than the powder fuel in the low temperature section and higher in the high temperature section. Therefore briquette fuel combusts more stably than the powder.