Thermoeconomical analysis of CO_2 removal from the Corex export gas and its integration with the blast-furnace assembly and metallurgical combined heat and power (CHP) plant

摘要

The paper presents the possibility of integration of the Corex process, blast furnace, CO_2 removal installation and metallurgical combined heat and power (CHP) plant. Such an integration has significant advantages from the technical and environmental points of view. As the Corex export gas (after CO_2 removal) is a highly valuable reducing agent it is proposed to use it as a reducing gas injected to the thermal reserve zone of the blast-furnace process. Such an application leads first of all to a saving of coke. Besides the reduction of the consumption of coke, also the consumption of blast, high-purity oxygen, the amount and lower heating value (LHV) of blast-furnace gas as well as many other parameters are changed. CO_2 separation is realized by physical absorption, which has been chosen and analysed as the most appropriate technology in similar applications. Higher LHV of the Corex gas obtained by CO_2 removal provides the possibility of its utilization in the gas-and-steam CHP plant. Such a possibility has been also tested by means of energy and economical analyses.