Optimal Flue Gas Treatment for Oxy-Combustion-Based Pulverized Coal Power Plants

Abstract

Oxy-combustion is recognized as the cleanest technology which uses coal as an energy source. Flue gas clean-up is essential for sustainable operation. In this work, the optimal selection of the flue gas treatment technologies in oxy-combustion power plants is determined. A two-stage procedure combining heuristics and mathematical programming is used to evaluate the technologies involved including the boiler, denitrification, electrostatic precipitation, sulfur dioxide removal, and carbon capture. For plant operation, the coal feed has to be selected. An extended blending problem is solved to evaluate the coal type to be purchased based on its cost and composition. The optimal flue gas processing consists of electrostatic precipitation, followed by dry SO2 removal, and CO2 purification using zeolites. No specific denitrification method is required due to the low concentration levels of NOx generated in oxy-combustion. This flowsheet is used to select one among a mixture of three different types of coal: national, imported, and crude coal tar. However, no mixture is recommended as crude coal tar was the one selected. Even though the processing costs are higher, it is outweighed by the lower cost of the raw material.