Thermochemical behaviour of empty fruit bunches and oil palm shell waste in a circulating fluidized-bed combustor (CFBC)

Circulating fluidized-bed (CFB) technology is considered to be one of the most suitable techniques to thermally convert fuels into useful energy. However, practical experience is available for only a limited number of fuels and conditions. This paper describes the results from a bench-scale circulating fluidized-bed combustor (CFBC), installed at SIRIM Berhad, Shah Alam, for gasification and combustion of different biomass materials. The purpose of the tests was to investigate the suitability of the selected fuels for energy production using CFBC while taking care of the flue gas emissions. The experiments gave sufficient information on the main process and flue gas characteristics. The measurements for temperatures and emissions were done for four different biomass samples of empty fruit bunch (EFB) of palm shell and palm shell waste powders of 210-300, 425 and 600 microns. The concentrations of CO, NOx and CO2 in the flue gas were measured continuously. The combustion performances were evaluated by varying the primary gas flow through the CFBC tubular furnace to identify the optimum operating conditions for the CFBC. The NOx content was from 20-164 ppm while the CO emissions were high for some operating conditions