Determination of water flow rate for the optimal biogas purification using water scrubbing technology at ambient temperature (23 0C)

Biogas has been proven to be a sustainable substitute for fossil fuel-based energy systems. It comprises mainly of CH4, CO2, H2S, and water vapour. Biogas purification is crucial for making the gas suitable for various applications in the renewable energy sector. Water scrubbing has been widely used for enriching the methane percentage. Determining the optimal water flow rate in biogas scrubbing is crucial for enhancing methane content and reducing carbon dioxide and hydrogen sulfide impurities. Various studies have identified specific water flow rates that maximize efficiency in different scrubbing systems. This study focused on determining the water flow rate (WFR) required for the optimal biogas purification using water scrubbing technology. The study applied Response Surface Methodology (RSM), specifically Central Composite Design (CCD) in the design of the experiment (DoE) to optimize the water flow rate (WFR). WFR was varied at the rates of 3.5, 4.0, 4.5, 5.0, and 5.5 litres per hour (l/hr). The study used Design Expert software version 13 in the analysis of results. This study found that the highest methane enrichment of 91.45% was attained at the WFR of 5.0 litres per hour.