Steam Production Options for CO2 Capture at a Cement Plant in Norway

Abstract

Norcem cement plant, Brevik has the potential to use waste heat to power an amine based CO2 capture plant. Dimensioning the CO2 capture plant according to available waste heat has the possibility to capture around 30 % of the total CO2 emitted from the cement plant. To achieve a higher CO2 capture rate (around 90%), there is a need for extra steam/energy for the capture plant. This work analyses three steam production options i.e., coal fired boiler, natural gas fired boiler, biomass fired boiler. A proposed steam recycle network is simulated in Aspen Hysys v8.6. The results from the simulation provides the input for equipment dimensioning and subsequently in cost estimation. Steam production based on natural gas is calculated to be more economical than steam production based on coal or biomass. Natural gas has the highest boiler efficiency and it also give the lowest amount of CO2 in the flue gas. Although coal has the cheapest fuel cost, it is not the cheapest steam production option. Besides, it gives the second highest amount of CO2 in the flue gas. Other factors that do not go in favor of selecting a coal fired boiler is the pretreatment of coal, the ash handling system and post-treatment of flue gases. Biomass boilers give the highest steam cost that is mainly due to the higher purchase cost of biomass (wood pellets), but an advantage is that the CO2 present in the flue gas is neutral. A cheaper biomass option as a fuel may be an alternative.

Keywords: Coal/gas/biomass boiler, Cement plant, Cost estimation, CO2 capture, GHGT-14