Biogas Enrichment & Compression
A variety of processes are available for enrichment i.e. removing CO2, H2S and water vapour. Commonly CO2 removal processes also remove H2S. One of the easiest and cheapest methods involves is the use of pressurized water as an absorbent liquid. In this method, the biogas is pressurized and fed to the bottom of a scrubber column where water is sprayed from the top. In counter-currently operated absorption process, the carbon dioxide and hydrogen sulfide present in the biogas is absorbed in down going water and methane goes up and collected in vessel. However, water requirement in this process is high but it is the simplest method of removing impurities from biogas
Enriched biogas is made moisture free by passing it through filters after that it is compressed upto 200 bar pressure using a three stage gas compressor. Compressed gas is stored in high-pressure steel cylinders as used for CNG.
Besides this technology, ZEOLITE MOLECULAR SIEVES technology can also used for the purification. The advantages of this technology is as follows.
• Enrichment of raw – biogas through high grade imported ZMS sieves.
• Impurities of H2S & CO2 are adsorbed & vented.
• Process for storage & enrichment of vented CO2 under progress.
• 95 – 97% content of CH4 assured, with balance CO2.
• No water required, negligible power consumption.
• Ideal for industrial application.
• For use in big cattle dairy farms, food processing industry, sugar industry, distilleries, chemical plants, hotels, railway stations, airports, municipal waists, and sewage treatment plant.
Thanks and regards.
Pramod Hati