Abstract
The aim of this study is to assess the load modulation capability of a pilot plant open top downdraft gasifier using standard wood pellet. The input gasifying agent, which is air, can be split into primary air (from the top) and into secondary air, where the remaining required air is fed directly into the reduction zone of the reactor through a nozzle. The novelty of this research reside in the investigation of the effect of the supplied secondary air flow rate at different loads, with the aim to improve the load modulation capabilities by means of controlling the air distribution and achieving the higher possible conversion efficiency with varying amounts of producer gas power production. The gasifier was tested at different loads. The equivalence ratio (ER) is related to the mass flow rate of secondary air, thus by increasing the secondary air the equivalence ratio increases as well. The results confirm that it is possible to have high gas conversion at different loads using the mass flow rate of secondary air as a control parameter for the management of the equivalence ratio into the reactor.