Biogas is a clean and renewable energy source due to its high methane content. However, direct use is not feasible because of the presence of corrosive and toxic components such as methane (50–70%), carbon dioxide (30–50%), and hydrogen sulfide (300–2000 ppm). Therefore, biogas must be purified and upgraded to reach natural gas quality.

Common upgrading technologies include cryogenic separation, membrane purification, pressurized water scrubbing, chemical (amine) scrubbing, and pressure swing adsorption. Among these, water scrubbing stands out for its simplicity and low operational cost. In this method, unwanted gases such as CO₂ and H₂S are dissolved in water and removed from the gas phase. The resulting gas, with over 90% methane content, is called biomethane.