Novel technologies lor low-quality natural gas purification

Novel low-temperature technologies have been recently studied for CO2 removal from low-quality natural gas or biogas. The aim of this work is to compare the performances of a low-temperature distillation process with those of other two processes, respectively based on physical absorption and a combination of both, depending on the CO2 content varied between 10 and 70 mol%. Each process has been simulated, with attention to energy-saving issues, using Aspen HYSYS® V9.0 and Aspen Plus® V9.0. This study points out that novel technologies based on low-temperature distillation are the best option for CO2 separation from low-quality natural gas or biogas and that, by combining a bulk CO2 removal by low-temperature distillation with a finishing step by physical absorption, it is possible to reduce the energy consumptions of the separation achieved by physical absorption only. These outcomes suggest the importance of further investigating novel low-temperature and hybrid CO2 removal technologies.