Modeling, Simulation, and Optimization of Postcombustion CO₂ Capture for Variable Feed Concentration and Flow Rate. 1. Chemical Absorption and Membrane Processes

This is the authors' abstract. We don't add key points for this paper.

Studies on leading technologies for industrial CO 2 capture are performed. Each technology includes flue gas dehydration, capture of at least 90% of CO 2 from the feed, and compression to almost pure CO 2 for sequestration at 150 bar. This paper presents the modeling, simulation, optimization, and energy integration of a monoethanolamine (MEA)-based chemical absorption process and a multistage membrane process over a range of feed compositions (1–70% CO 2, 5.5–15% H 2 O, 5.5% O 2, and the balance N 2 ) and flow rates (0.1, 1, 5, and 10 kmol/s). A superstructure of process alternatives is developed to select the optimum dehydration strategy for the feed to each process. A rigorous simulation-based optimization model is proposed to determine the minimum annualized cost of the MEA-absorption process. The MEA-absorption process is energy integrated through heat exchanger network optimization. A novel mathematical model is developed for the optimization of multistage and multicomponent separation of CO 2 using membranes, which can be also used for a range of membrane-based gas separation applications. The results showing the optimum investment, operating, and total costs provide a quantitative approach toward technology comparison and scaling up the absorption- and membrane-based CO 2 capture from various CO 2 emitting industries. Explicit expressions for the investment and operating costs of each alternative postcombustion CO 2 capture process as functions of feed flow rate and CO 2 composition are also developed for the first time. This may assist the decision-makers in selecting the cost-appropriate technology for comprehensive carbon management by taking the diverse emission scenarios into consideration.