Cola and biomass co-combustion on fluidized bed: comparison of circulation and bubbling fluidized bed technologies

摘要

Fluidized bed is one of the most promising methods for combustion today. Its application to boilers is recognized primarily for its low sensitivity to fuel quality and its capacity to limits air pollution. This technology is being used all over the world for biomass as well as for coal combustion. Nevertheless, there are no results available on the joint utilization of these fuels.The main objective of the proposed paper is to demonstrate the technical feasibility of fluidized bed as a clean technology for the combustion of low grade coal/biomass blends.The utilization of biomass in blends with low grade coal is expected to improve the conversion of the fossil fuels due to the high volatile content of biomass, thus reducing the emissions of SO{sub}2 and NOx as well as the emissions of CO{sub}2 due to the renewable origin of the biomass.The raw materials used as fuels in the tests are different blends of the following materials:* Refuse coal with a heating value of 3658 Id/kg (LHV, db) and 79.63 % ash content.* Low grade coal: lignite with a heating value of 19952 jJ/kg (LHV, db), a sulphur content of 10.32 % (db) and 23.70 % ash content.* Biomass: Forestry wastes from wood cleaning whose heating value is 19555 kJ/kg (LHV, db)An absorbent, limestone, has been used for reducing sulphur emissions.Co-combustion tests, at the pilot plant level, have been carried out by using two fluidized bed technologies, circulating and bubbling.The object of this paper is to study, in an energy and emission point of view, the clean and efficient use of these resources. The paper collects, analyses and compares combustion test data.