(816e) Comparison of Various Carbon Capture Technologies to Reduce CO2 Emissions From a Cement Plant

Substantial reductions of global CO₂ emissions by at least 50% are required by 2050 according to Intergovernmental Panel on Climate Change [1]. While CO₂ reduction technologies have been mostly developed for the purpose of carbon capture from the power generation industry, it is important to extend this to the cement industry in order to achieve the CO₂ capture target projected over the next 40 years. The cement industry accounts for over 2 billion tonnes of CO₂ emitted per year [2,3]. Only marginal reductions in CO₂ emissions can be achieved through improving the energy efficiency of the cement manufacture process. Significant reductions can be obtained only if a carbon capture unit is integrated in a cement plant given that around 60% of CO₂ emission comes from the calcination of the raw material.

Both post-combustion and oxy-firing would be deemed appropriate for carbon capture from cement works. To compare the different configurations full process flowsheets have been developed and simulated in Unisim Design Suite from Honeywell. The process considered is based on the reference case from the IEA [4] and includes the main raw material decomposition and clinkerization reactions. The base case simulation was then modified to integrate three different post-combustion capture processes: amine-scrubbing; calcium looping process; and membrane-based capture units. Furthermore, an advanced configuration of Ca-looping process has been investigated where the energy intensive air separation unit was replaced with a chemical looping combustion (CLC) cycle.  Each case has been optimised to minimise its energy consumption and compared in terms of CAPEX/OPEX and its resulting CO₂ avoided cost at the same capture rate. 

[1] Intergovernmental Panel on Climate Change (IPCC) (2007b). Metz, Bert. Davidson, Ogunlade. Bosch, Peter. Dave, Rutu. Meyer, Leo (Eds.). Climate Change 2007: Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA.

[2] CW Group Global Cement Volume Forecast Report, 2012.

[3] IEA Carbon Emission Reductions up to 2050. In Cement Technology Roadmap 2009; International Energy Agency: Paris, 2009.

[4] IEA CO₂ Capture in the Cement Industry, July 2008/3, 2008.