Testing of an Innovative Installation for Alternative Fuel Low-temperature Gasification Prior to Co-firing in Power Boilers

The paper presents results of the investigation of an innovative biomass and alternative fuel low-temperature gasification method before co-firing in industrial or power plant boilers. Gasification process takes place with use of flue gas as a gasifying agent with recirculation of resulting gas (syngas) to the boiler's combustion chamber. Industrial-size rotary gasification reactor using flue gas as a gasifying agent has been designed and successfully built in Marcel power plant in Radlin town, Poland. The construction of the reactor allows the use of a wide range of alternative fuels (biomass, industrial waste and municipal waste). The paper presents the results of the reactor tests using coniferous wood pellets as a fuel. The flue gas from coal and coke-oven gas co-firing were used as the gasifying agent. The measuring system ensures online measurements of syngas composition: CO, CO₂, H₂, CH₄. As a result of presented gasification process a syngas with combustible components has been obtained and recirculated to the boiler's combustion chamber. Before running industrial-size installation, laboratory tests were carried out to determine usability of selected fuels to gasification process. Tests were conducted in a laboratory stand, equipped with a gasification reactor designed and constructed specifically for this purpose. The experimental stand enables the weight loss of a sample and syngas composition to be recorded. The aim of the laboratory research was to determine the usability of selected alternative fuel for indirect co-firing in power boilers and to build a knowledge base for industrial-size process.