Introduction
Biogas is a natural process between microorganism and discarded organic waste (Biomass) , such as food, agricultural waste, may be sewage by conversion of biomass through digester to clean disposal of organic waste, produce fertilizer and energy from renewable natural gas.
Biogas is composed mostly of methane (CH4) and carbon dioxide (CO2). The methane content vary from 40%–60%, with CO2 making up most of the remainder along with small amounts of water vapor and other gases.
Biogas can be burned directly as a fuel or treated to remove CO2 and other gases for use like natural gas. Anaerobic decomposition of biomass occurs when anaerobic bacteria—bacteria that live without the presence of free oxygen—eat and break down, or digest biomass and produce biogas. The material remaining after anaerobic digestion is complete is called digestive, which is rich in nutrients and can be used as a fertilizer.
Bio-Digester Process
Before start the process, the waste received will be segregated plastic and grass will be sent to the suitable process and the organic waste will be sent to shredder system then will be mix with wastewater 80:20 %
Startup need 25-30 days then the operation will be continuous production, Temperature must be 20-37 C and each digester capacity is 1.5 m3 volume, may add more as needed
Production Stages
- Liquefaction – Organic matter is degraded to basic structure, Protein, Glycerin, Fatty Acid and Amylose
- Acid Production – Also called the acidogenesis, Simple organic matters are converted into H2 and CO2
- Acetate Production- Short-chain fatty acids are metabolized into acetate, carbon dioxide, and hydrogen.
- Methane Production – In this process, acetic acid, H2, CO2, are converted into CH4.
Each digester can produce by product- fertilizer and up to 1000L of biogas daily, the biogas will be sent to the biogas generator to produce power up to 7kwh, this power can be utilized to run the main office electrical equipment.
- Biogas is generated by the activity of anaerobic bacteria.
- Biogas is comprised of about 60% of methane, 40% of carbon dioxide, and small amount of hydrogen sulfide, nitrogen, and hydrogen.
- The heating value of biogas is about 60% of natural gas and about 25% of propane.