Effect of alkalinity and pressure levels on methane concentration in biogas generated from carbohydrate wastewater

The Biogas from biogas production system from cassava starch wastewater. It mostly consists of methane (CH₄) about 50-60% and carbon dioxide (CO₂) about 30-40%. At present, there is a problem in the use of biogas. Because the biogas has an unstable concentration of methane below 50%. The use of biogas as a renewable energy in the industrial factory should have a concentration of methane not less than 55%.

Therefore, this research has an interesting to study the suitable value of alkalinity for biogas production system from cassava starch wastewater. Moreover, study to determine the appropriate pressure for the solubility of carbon dioxide in water to increase the alkalinity value of the biogas production system. According to Henry's law, the solubility of a gas increases with increasing pressure. The result of the reaction is carbonate that increasing of alkalinity value to the biogas production system. The increasing of alkalinity value keeps the biogas production system stable as well as to reduce carbon dioxide in biogas that results in a higher concentration of methane. In addition, to stabilize the methane concentration resulting in the biogas using obtained high efficiency.