Fuel retrofitting possibilities in pulverised brown coal power plants towards reduction of CO_2 emissions

摘要

The thesis intends to assess the potential of two different brown coal substitution concepts as possible options to reduce CO_2 emissions in existing pulverised brown coal power plants. The substitution of brown coal by Solid Recovered Fuels (SRF) is examined as first concept. The second concept regarded is the integration of a lignite pre-drying system in an existing steam cycle and the substitution of raw brown coal by pre-dried brown coal. SRF co-firing is demonstrated in a 600 MWe pulverised brown coal boiler in Germany, while pre-dried brown coal co-firing is demonstrated in a 75 MWth pulverised lignite boiler in Greece. Specific environmental, technological and economic parameters are used for the evaluation according to a multi-criteria analysis approach. The analysis tools adopted include experimental measurement activities in the industrial and semi industrial scale, 3D numerical simulations (CFD), thermodynamic calculations of power plant steam cycles and financial calculations.