EFFICIENT AND RELIABLE COAL FEEDING SYSTEM FOR ENTRAINED FLOW GASIFICATION

摘要

The type of fuel feeding system is of substantial importance for entrained flow gasification of coal and other feedstock. Currently there are two options commercially available: Slurry feeding and dry feeding (pneumatic dense flow). The dry feeding system enables higher cold gas efficiency and carbon conversion. It also permits higher fuel flexibility with the possibility to gasify low rank coals. However, certain design parameters must be met to ensure proper operation at high availability. Since coal is a natural product which varies in composition, a good design needs to take experimental data into account, along with simulation results and empirical data. For that purpose Siemens operates a coal feeding test rig with a capacity of up to 300 t/d under commercial scale conditions. This plant is currently used to test different coals, coal specific instrumentation and to validate simulation models. The article presents results of the test program regarding lock hopper cycles, coal mass flow monitoring and testing of alternative feedstock like biomass. together with lab scale tests and results gained from gasification testing in the adjacent test plant this provides a solid, basis for proper design and reliable operation of dry coal feeding systems.