Techno-economic assessment of CO ₂ capture at steam methane reforming facilities using commercially available technology

Abstract

This study aimed to identify the optimal techno-economic configuration of CO ₂ capture at steam methane reforming facilities using currently available technologies by means of process simulations. Results indicate that the optimal system is CO ₂ capture with ADIP-X located between the water-gas shift and pressure swing adsorption units. Process simulations of this system configuration showed a CO ₂ emission reduction of 60% at 41€/t CO ₂ avoidance. This is at the lower end of the range reported in open literature for CO ₂ capture at refineries (26-82€/t CO ₂) and below the avoidance costs for CO ₂ capture at natural gas-fired power plants (44-93€/t CO ₂). CO ₂ avoidance costs are dominated by the natural gas consumption, responsible for up to 66% of total costs. Using imported steam and electricity can reduce CO ₂ avoidance costs by 45%. Addition of small amounts of piperazine to aqueous MDEA solutions results in up to 70% smaller absorbers or 10% lower reboiler heat duty. Optimising the whole capture process instead of individual units resulted in lower piperazine concentrations than the common industrial practice (3mass% vs. 5mass%). Finally, keeping the solvent rate constant when operating the capture unit below its design load resulted in a lower specific energy for CO ₂ capture than when the solvent rate was downscaled with the syngas flow.