화학공학소재연구정보센터
Industrial & Engineering Chemistry Research, Vol.48, No.1, 361-372, 2009
Development of Biomass Charcoal Combustion Heater for Household Utilization
In the present work a prototype powdered biomass charcoal fired heater with a heat output of 6 kW is designed and developed so that a new powdered charcoal market can be initiated to enhance greenhouse gas (GHG) reduction through massive biomass utilization. The combustion heater was designed based on the concept of charcoal combustion in a thin bed cross-flow (TBCF) mode, where a very thin uniform bed of charcoal is fixed by air flow on the wall of a cylindrical chamber with an air-penetrable wall. The distinct advantage of using such a thin bed cross-flow is low fuel inventory and good air-fuel contact, resulting in fast startup/ shutdown and low CO emissions in the exhaust gases. Fundamental data for realizing such a combustion heater are presented, and the performance characterization of the thus manufactured heater is investigated. The combustion heater was characterized for charcoal prepared from Japanese oak (Quercus serrata) and from several waste biomass sources, such as a pruned apple branch and charcoal formed from spent coffee waste and soybean fiber. For wood charcoal the heater's thermal efficiency was about 65-86%, and for waste biomass charcoal species it was found to be in the range of 60-81 %. When the combustion heater was operated at the stable combustion mode, the CO concentration in the exhaust after the flue gas passed through catalyst was less than 5 ppm.