Biogas to CNG plant

Biogas is an energy-rich gas produced by anaerobic decomposition of biomass. It is produced from waste / bio-mass sources like agriculture residue, cattle dung, sugarcane press mud, municipal solid waste, sewage treatment plant waste, etc.

Biogas, a renewable fuel, constitutes mainly of methane (~60%), carbon dioxide (~40%), and traces of hydrogen sulfide. It can be burned directly as a fuel or purified & upgraded by removing carbon dioxide (CO2), hydrogen sulfide (H2S) and compressed to make Compressed Bio-Gas (CBG). The CBG has methane content of more than 90%, which is similar to the commercially available natural gas in composition and energy potential.

WHY DO WE PURIFY BIOGAS

Biogas is a carbon-neutral source of renewable energy that may be produced by anaerobic digestion of any Biomass. In addition to methane, biogas contains carbon dioxide and other ubiquitous impurities such as water vapor and hydrogen sulfide. Hence, biogas purification, to produce biomethane, is required prior to using it as transportation fuel or injecting it into natural gas grid or using it for Industrial purposes.

HOW WE PURIFY BIOGAS

General Scheme

Process

Raw Biogas coming from the storage comprise of many contaminants like H2S , Water Vapors, Sysloxenes , VOCs and small qty of N2 or even O2

The water is supplied from the top of the column while the raw biogas is allowed to pass from the bottom to top. Ammonia and H2S trapped in the water and CH4 with CO2 and some traces of other gases along with moisture leave at the top of the water scrubber. After water scrubbing the gas passes through Chemical Scrubber where further H2S is trapped in iron flakes.

After Chemical Scrubber process, the gas is made to pass through customized Biogas Dehumidifier where gas is cooled down to 8-10 Deg C and moisture is condensed and removed in cyclonic moisture separator which is automatically discharged through auto drain valve.

Now the outgoing low temperature gas is passed through economizer / reheater to reduce the inlet Biogas temperature to reduce load on chiller and also outgoing gaows is heated up to 30 Deg C for enhancing the RH of the Dehumidified gas so that no further condensation takes place due to expansion in Adsorber Towers. Next,

We are using Activated Carbon Filter to remove impurities like H2S, VOC & Siloxane etc., For further purification of Biogas, we use VPSA technology. This method is particularly used to remove CO2 present in cleaned and dehumidified biogas. The dry biogas (after moisture removal) enters at the bottom of the adsorption column filled with different grades of molecular Sieves, Activated Alumina/Silica Gel where CO2 is adsorbed and pure dry methane leaves from the top of the towers which is sent to a surge vessel for analysis. When one tower is in Adsorption process the other adsorber tower undergoes in Regeneration by depressurization process and vacuum with the help of a vacuum pump.

The exhaust gas mainly containing CO2 is released into the atmosphere at elevated height. After a preset timing the process is changed from one tower to another to keep producing the pure gas continuously. It is done through automatic changeover valves signaled through a PLC. Stored pure gas in surge vessel is analyzed for purity and sent to the final storage if minimum methane percentage is achieved.

WHY AIR-N-GAS

M/s AIR-N-GAS Process Technologies are pioneers in PSA/VPSA based gas separation technology manufacturing Biogas Purification Plants, N2 and O2 generation plants, Custom designed Biogas & Air Dehumidifiers, Industrial Dryer and filters since 2007 having its Corporate Office and Manufacturing units in Ahmedabad. M/s. AIR-N-GAS Process Technologies, is an ISO 9001 certified fully integrated engineering company having accreditations from TUV NORD, TUV SUD, Bureau Veritas and worked with consultants like SAIPEM. With more than 500 satisfied customers pan India and abroad which includes NTPC, ISRO, ONGC, RELIANCE, ADANI, PIRAMAL GROUP, ZYDUS ETC, M/s. AIR-N-GAS PROCESS TECHNOLOGIES, has carved its name among the top few in this technology. The CEO of M/s AIR-N-GAS PROCESS TECHNOLOGIESPVT. LTD., Mr. Shailesh Verma has rich hands-on experience of 30+ years in this technology, having worked with companies like INDCON and thereafter running his own manufacturing unit since 2007.

In 2012, M/s. AIR-N-GAS PROCESS TECHNOLOGIES, entered into a research agreement with SARDAR PATEL RENEWABLE ENERGY RESEARCH INSTITUTE (SPRERI) at Ananad – Gujarat thru which the institute agreed to jointly develop commercially scalable PSA/VPSA technology in the field of renewable energy and more particularly into CNG equivalent gas from Biogas using PSA/VPSA technology. Having jointly conducted various experiments for 5 years on upgradation of Methane using different adsorbent under Indian Conditions more specifically the pre-treatment of Biogas required for consistent purity of Methane and longer life of Molecular Sieve, we entered this market of Biogas purification with in-depth knowledge and elaborate data on different composition of Biogas and use of VPSA/PSA method for its purification.

WHY AIR-N-GAS

1. Proficient 4 stage pretreatment process for removal of contaminants like H2S, VOCs and Moisture etc
2. Complete Pretreatment System in SS 304, ensuring long life of the plant.
3. Moisture removal up to -60 Degree ADP ensured thru custom designed fully SS low pressure zero loss dehumidifier
4. Only world renowned and recognized CECA (Arkema) Molecular Sieves are used in PSA towers.
5. Proprietary, scientifically designed purge loss recovery system to ensure negligible losses of Methane.
6. Man Less Operations thru PLC with HMI. Provision for remote access to process control.
7. Clean Process with high Performance, stable and user-friendly operations.
8. Well researched design to ensure long life and trouble-free operations of the Plant