Heat supply alternatives for CO2 capture in the process industry

Abstract

An economic analysis for post-combustion CO2 capture in a petrochemical industry has been performed. Previous studies have shown that the largest costs are related to the costs for energy supply. In this study we therefore focus on how heat can by supplied to the capture process in the most cost-efficient way. Five different heat supply options have been evaluated by using an energy market scenario tool together with a variation of the specific heat demand (reboiler duty). Three stand-alone options (natural gas combined cycle, natural gas boiler and biomass boiler) and two excess heat options (use of current excess heat and optimal use of excess heat) were analysed. For the stand-alone alternatives, the fuel consumption and co-generation of electricity are important. The best alternatives were the ones using excess heat. Considering that the process integration potential in the process industry generally is high and expecting high future CO2 charges, these options may become profitable. A quantification of the capture costs per CO2 avoided using excess heat shows costs in the range of 37–70€/t CO2, which are comparable to costs reported for oxy-fuel combustion in petrochemical industries as well as for post-combustion in the power sector.