GASIFICATION TESTS WITH SEWAGE SLUDGE AND COAL/SEWAGE SLUDGE MIXTURES IN A PILOT SCALE, AIR BLOWN, SPOUTED BED GASIFIER

摘要

A series of tests have been done in a pilot scale air blown gasifier, to assess the performance of sewage sludge pellets and sewage sludge pellet/coal mixtures. The aim has been to compare the performances with that achieved with coal alone and to assess the suitability of the sewage containing fuel as a candidate fuel for the Air Blown Gasification Cycle (ABGC). The co-gasification of sewage sludge with coal raised both the CV of the fuel gas and the fuel conversion compared with values achieved with coal alone. The mixtures were operated under very similar conditions to those needed with coal and no adverse operational problems were encountered A lower fluidising velocity was needed with the neat pellets to enable a stable bed height to be achieved However, the conversion of the pellets to gas was very high and the fuel gas CV was higher than that achieved during the co-gasification tests. Overall, the results suggest that sewage based materials are suitable for use in the ABGC and that their use can improve the process performance.