Combined Flue Gas Cleanup Process for Simultaneous Removal of SOx, NOx, and CO2—A Techno-Economic Analysis

Abstract

Flue gas cleanup often requires the removal of SOx, NOx, and CO2 in separate units before being emitted into the atmosphere. This stepwise treatment process incurs significant cost and energy penalty to the electricity production. A combined adsorption process based on pressure swing adsorption (PSA) by which these impurities are removed is envisioned as an efficient means of flue gas cleanup that can be applied relatively easily. In this study, the technological and economic feasibilities of a combined separation process in which SOx, NOx, and CO2 are simultaneously removed from flue gas streams are assessed. Capital and operating costs are estimated based on sizing the equipment items and utilities needed, and the potentials for increased energy efficiency are determined in relation to the required PSA performance. The energy saving potential for the adoption of 2-bed and 4-bed PSA cycles is compared with conventional FGD, SCR, and amine scrubbing units needed to clean up flue gas in a stepwise fashion....