Carbon dioxide removal from biogas through pressure swing adsorption – A review

Abstract

Biogas is considered a future energy, alternative to natural gas due to its high methane content. Different substrate feedstock determines the composition of the produced raw biogases. Upgrading or purifying the raw biogas by removing carbon dioxide and thereby increasing its methane content to produce high purity biomethane is mandatory before delivering for natural gas substitute. At present, the pressure swing adsorption (PSA) plays a vital role in biogas upgrading along with water scrubbing, chemical absorption, and membrane permeation. In PSA, the core system lies in the adsorbent choice, which determine the effectiveness of separation by measuring the adsorbent's adsorptive capacity and selectivity. In fact, the PSA system itself is bound for many configurations that require optimization for better tuning the system. As such, it is imperative to comprehend the parameters affecting the PSA performance, thus optimizing them to achieve the objective functions. The optimization through the design of experiment techniques provides realistic statistical information and is among the simplest PSA optimization strategies. Owing to the attractiveness of PSA in many gas separation applications from historical and practical evidences, it is expected that this technology will become more competitive for biogas upgrading.