Optimization of Pressure Swing Absorber (PSA) Geometry to Achieve Highest Methane Purity from the Egyptian Biogas Using Aspen HYSYS Simulation

In Egypt, it is easy to obtain large amount of biogas from different available sources such as sewage, agricultural and livestock waste. It is important to purify the biogas from its acidic components (CO₂ and H₂S) before pumping it into the domestic natural gas network to meet the standards of these networks. In addition, the purifying process is required in case of using the very high purity methane in sophisticated devices such as X-Ray metal analyzer that requires pure methane for the purpose of alloys analyzing process. This article is aimed to purify the biogas from CO₂& H₂S gases, which are the main reasons of the acidic compounds formation. Moreover, the purifying process increases the biogas calorific value. In order to design an optimized biogas treatment cycle; numerical simulation was performed using Aspen HYSYS software. The results show that the optimum absorber dimensions are 1.7 m tray diameter, 1.4 m3 tray volume and 0.5 m tray spacing when the biogas enters the absorber at a temperature of 43 ^OC, a pressure of 25 bars, a flow rate of 13 m3/hour and Diethanolamine (DEA) concentration of 0.3.