Coal Based Power Plants Using Oxy-Combustion for CO2 Capture: Pressurized Coal Combustion to Reduce Capture Penalty

Abstract

The goal of this paper is to design and study a new variation of an oxy-combustion coal based power plant with CO2 capture that employs a pressurized coal combustor. The concept is compared with an atmospheric pressure oxy-combustion power plant (baseline case). Such analyses would provide us with information regarding potential heat integration and improvement opportunities of oxy-combustion coal based power plants. The power cycle presented in this paper has a gross electric power output of 792 MW for the baseline case and 796 MW for the pressurized case. The auxiliary power consumption is reduced from 228.5 MW in the baseline case to 215.3 MW in the pressurized case. This results in a net LHV efficiency improvement of 1.7 percentage points over the baseline case. The improvements achieved in the pressurized case are due to reduced power consumption in the CO2 compression and enhanced heat recovery in the acid condenser, despite additional oxygen compression power consumption. In both the cases, over 90 % of the produced CO2 is captured and compressed to 110 bar after removal of volatiles.