Combustion characterization of producer gas from biomass gasification.

Abstract

In the present work, premixed flames from the combustion of producer gas have been analyzed. Two different compositions have been tested, corresponding to air and steam gasification processes (the latter leading to a better quality gas due to its higher CO and H2 concentration and its lower N2 content). The main objectives of the work have been the determination of the flame stability region (placed between the flashback and the blowoff limits) for each producer gas composition, as well as the study of the OH and CH radicals. The combustion experimental tests have been carried out by using an atmospheric burner and a chemiluminescence camera. The results obtained show that producer gas coming from biomass entrained-flow steam gasification seems to be more adequate to be used in combustion systems, since it provides a larger flame stability region, and its blowoff limit for a given relative producer gas/air ratio is higher (which enable to obtained more power). From the study of CH and OH radicals, it can be deduced that it is possible to reduce the nitrogen oxides emissions up to 18.6 and 15.2 % with producer gas from steam gasification and air gasification respectively by using lean mixtures (while keeping the flame stability).