Performance evaluation of a L-valve feeder for biomass powder in a circulating fluidized bed reactor

Abstract

The use of biomass is considered an excellent alternative for sustainable power production plants, for example, in process such as pyrolisis, gasification and combustion. Nevertheless, a common problem in operation of thermoelectric reactors is to ensure a stable, efficient and economic feeding of the particulate materials into the reactor. The solid feeding can be particularly limiting in the case of biomass particles, since these powders have unusual characteristics in terms of size distribution, composition and shape when compared to conventional materials. In this project, the performance of a non-mechanical L-valve with biomass particles will be analyzed for feeding biomass in a Circulating Pneumatic Bed. The powders tested will be the sawdust (with three different size distributions) and coffee grounds (two humidities). Tests will be performed by varying the type of biomass, the average diameter and humidity of the powders, aeration and transport flow rate. The influence of the powders properties on parameters such as solids flow rate, L-valve and CPB pressure drops, as well as on feed stability will be verified. The valve performance will be related to the physical characteristics and flowability parameters of each material. The collected data will be used to validate correlations and models available on the literature to describe the flow of solids through the L-valve. (AU)