Temperature swing adsorption cycle with recovered gas injection

Abstract

A novel TSA cycle with recovered gas injection (RGI) is proposed, which aims to reduce the energy requirement in the gas purification process. Unlike traditional dual-column TSA cycles, the novel cycle comprises three adsorption columns, each equipped with a main bed and an auxiliary bed. Positioned between the main and auxiliary beds, an injection port is designed to introduce the recovered tail gas. In the RGI step, the tail gas is recycled and injected into the auxiliary bed for regeneration, ensuring the full utilization and consumption of residual heat, thereby achieving zero heat emission in principle. Since the tail gas is injected into the auxiliary bed, the new cycle avoids contact between the tail gas and the unused bed while utilizing the residual heat. To ascertain the quantitative heat emission of the new cycle, a case study focusing on the air purification unit of a large-scale air separation unit is studied by simulations. Consequently, simulation results of the adsorption column have been obtained, and comparisons between the new and traditional cycles have been conducted. The unit energy consumption of the new cycle was reduced by 24.5 % compared to the traditional one.