Integrated Simulation and Optimization for the Whole Chain of CCS

Abstract

Operation pressure of distillation column is one of the key variable for optimizing the required energy in a CCS process. It affects the steam drag point in power plant, the regeneration energy in capture process and the compression energy in liquefaction process. A new algorithm, which is less dependent on simulation, for determining optimal stripper pressure for CCS process using MEA as an absorbent is proposed based on the integrated simulation model. Total energy required is represented as a function of the pressure based on the equivalent work. The results show that the compression work can be reduced at high pressure while that for reboiler increases and the total energy can be represented as a decreasing function with the stripper pressure. The evaluated optimal pressure decreases as the terminal pressure increases, showing the crucial condition for determining operation pressure of stripper depends on the terminal pressure of liquefaction process. It is also shown that a general analytical solution for optimal pressure including both the capture and the liquefaction process cannot be made through differentiation based on Abel Ruffini theorem. The total energy required in the possible range of the pressure can be estimated directly using approximation with given input variables.