Energy Analysis of CO2 Removal in a CHP Plant Fired With Corex Export Gas

The Corex process is a more environmental-friendly method of pig iron production than the blast-furnace process. Additionally, this technology is accompanied by production of a fuel gas with a LHV twice as high as blast-furnace gas. Corex gas may be a useful fuel in a metallurgical CHP plant including a combined gas-and-steam cycle. The utilization of Corex gas contributes also to a decrease of CO2 emissions, which is an advantage from the viewpoint of the greenhouse effect. Moreover removing CO2 from the gas before its consumption can allow a further reduction of greenhouse issues. The paper considers the application of two methods of CO2 removal, namely “physical absorption (Selexol solvent)” and “cryogenic gas separation”. The effect of CO2 removal on the operation of CHP plants has been investigated. The removal of CO2 affects first of all the quality of fuel gas in comparison with the raw Corex gas. However, the CO2 -removal installation is characterized by a considerable power consumption. Thus the net power and the efficiency of the CHP plant are reduced. Comparing the two considered methods of CO2 removal the cryogenic separation method requires more input energy, but in some cases liquefied CO2 may be an attractive agent. The paper contains the results of a quantitative analysis of the application of these two CO2 -removal methods in the Corex technology and their effect on the exploitation characteristics of CHP plants fired with Corex gas.Copyright © 2004 by ASME