Investigations On Absorption Technique For Biogas Purification

To develop a purification system for biogas using Sodium Hydroxide (NaOH) and Calcium Hydroxide [Ca(OH)2] solution was developed using bubble column absorption tower made from plastic bottle. Different bio-gases from 3 digesters (D1, D2, D3,) each with different feeds were used in the study. The experiment was done with five types of solutions which include: pure water, NaOH 0.625Mol, NaOH 0.9375mol, Ca(OH)2 0.625 mol and Ca(OH)2 0.9375 mol at a constant volume of 400 ml per run. The Biogas flow rate was set at 1.25 l/min and 3.33l/min while measuring the biogas composition before and after purification through Gas Analyzer. The effectiveness of the purification system was affected by biogas flow rate, type of solution used and its concentration as revealed by research findings. In addition, the results show that higher absorbent in bubble column leads to high CO2 absorption percentages as well as CH4 contents. This is because it can give a maximum methane ratio of 86.2% at a flow rate of biogas of about 1.25 l/min. DWSIM software model is given in this paper when it is being used to provide software analysis on the interaction between the gas molecules within the absorption column and dilute acid on the outlet gas temperature. The research findings demonstrated that the interaction between the molecules was affected by the gas flow rate, the absorbent flow rate and the absorbent pressure.