Effects of pyrolysis temperature and feedstock type on particulate matter emission characteristics during biochar combustion

Aiming to reduce the emission of particulate matter (PM) during biomass combustion, we investigated the effects of pyrolysis temperature and feedstock type on the chemical properties of biochar and PM emission characteristics during subsequent combustion. Wood- and manure-based char samples were prepared at pyrolysis temperatures ranging from 200 to 500 °C and combusted in a laboratory-scale tube furnace at 850 °C. Due to the removal of volatile matter (VM), the total PM emission factor (EF) of the wood char decreased with increasing pyrolysis temperature, becoming negligible with pyrolysis at temperatures over 400 °C. For manure char, although pyrolysis removed VM and reduced the total PM EF from 12.5 ± 2.7 to 5.8 ± 2.9 mg/g-fuel, the high ash content precluded any effect on the emission of ash-derived PM. The occurrence of ash-derived PM resulted from release of Na, Mg, K, and Ca and was enhanced at higher combustion temperatures. We demonstrated that the pyrolysis of low-ash biomass effectively reduces the risk of PM emission. However, the efficacy of thermal treatment of high-ash biomass is limited but might be improved with further treatment, such as ash removal

Biobriquettes-an Alternative Fuel for Sustainable Development

Raw coal is still burnt as fuel in many developing countries. These also have a lot of waste biomass, which finds limited use or used inefficiently. Besides pollution from coal and biomass combustion, they always face problems during transportation and storage because they are susceptible to moisture. Biobriquettes are composite fuel prepared from a mixture of biomass and coal in a roller press briquetting machine. They consist of different proportions of biomass (up to 30%) and coal or lignite (up to 70%). Introduction of lime based desulfurizing agents (DSA) such as CaCO and Ca (OH) into the briquettes can reduce the SO emissions by 80-90%, thus minimizing the pollution coming 3 2 2 from coal combustion. Some fuel and combustion properties of these briquettes were studied. The briquette fuels have better physico-mechanical properties and combustion properties in comparison to coal/lignite. The ignitio