Technoeconomic Feasibility Study of Cement Plants as Reference Facilities for Centralized CO2 Capture in Industrial Sites

Abstract

The proposed concept connects industrial sites with significant heat demands (self-produced in natural gas or coal-fired boilers) with a cement plant through the implementation of a calcium looping carbon capture system which uses the kiln furnace as calciner for both the cement and the capture plant. This new concept includes a carbonator reactor fed by CaO from the cement plant in each one of the industry sites to capture the CO2 content of their own flue gas. After carbonation reaction, the exhaust sorbent is transported back to the cement plant for regeneration in the kiln furnace. The aim of this project is to carry out a techno-economic feasibility study of the integration proposed. An introduction about the state of the art of the technologies involved, with particular regard to Ca-looping and to Oxy-fuel combustion in cement manufacturing, is presented to establish the context of the study. In order to analyse various operation conditions of the proposed CO2 capture system, different levels of integration are described. The three studied scenarios are (i) the integration of the coal-fired industrial boiler and the cement plant, (ii) the integration of the natural gas-fired industrial boiler and the cement plant and (iii) the integration of both industrial boilers and the cement plant. An economic study is carried out to assess the feasibility of the centralized carbon capture system. The assumptions of carbon tax equal to 30 €/tCO2 and CaO cost of 20 €/tCaO were considered in the economic analysis. Under these conditions there are room for economic feasibility of both, the small industries and the cement plant as saving are obtained when the scenarios are integrated. It must be pointed out that the economic feasibility of the proposed concept will strongly depend on the policies of emissions taxation.