Purifying of Biogas Produced from Anaerobic Digestions Processes: An Economical Assessment

Abstract

Anaerobic digestions processes (ADPs) are promising renewable energy resource that convert solid wastes to energy. Such processes can replace conventional energy resources and prompt sustainability. The products of the ADPs composed mainly of CH4 and CO2., known as biogas., in addition to other impurities such as N2., and H2S. The product composition depends on the feed to the ADPs as well as the operational conditions. The economic value and feasibility of biogas can be enhanced by selecting suitable treatment and upgrading by separating CH4 from CO2. This study presents the development of cryogenic separation process (CSP) to produce two grades (95% and 98%) of CH4 and pure CO2. The CH4 can be used as valuable fuel., while the pure liquid CO2 could be used to produce added value products. Results revealed that the CSP has an excellent potential to generate high purity liquid CH4 and CO2 that can be stored or shipped easily without needing extra units. Hence., providing economic and environmental advantages. Moreover., the optimized CSP support the implementing biogas upgrading technology. Additionally., this study aims to provide a techno-economic analysis of the utilized cryogenic process through evaluating the efficiency and profitability of the process at varying conditions., that will smoothen the transition towards renewables. Net Present Value (NPV) is used to evaluate different sale scenarios assumed to be dedicated to Asian markets throughout the project's lifetime.