Purification of biogas

Abstract

The present invention is a biogas purification system, which uses a novel method for the complete removal of traces of hydrogen sulfide and water vapors as well as the removal of more than 90% of carbon dioxide from biogas. The said system comprises of an apparatus which is connected with Digester (source of Biogas to be purified), started with Chamber 1 (Cl), vessel (V) containing solution (mixture of mono ethanol amine and di ethanol amine) and Chamber 2 (C2). These all three stages are connected through pipes in series. This sequence provides the sorbents present in each stage a strong environment to react with desired impurity. A Positive displacement compressor is in downstream which is connected with apparatus on its inlet and with storage tank on its outlet. The vessel (V) has three "control valve loaded" pipe connections at the bottom for Gas entrance, emerging entrance pipe (if return valve chokes) and drain pipe, respectively. The vessel also has a loading pipe for solution (mixture of mono ethanol amine and di ethanol amine), a pressure gauge a safety valve and an outlet pipe (for C02 while recovering it with simultaneous regeneration of chemical mixture) at the top thereof. The internal surface of said apparatus used in the said system including that of the connecting pipes is PVC coated whereas the material of external construction is SS 316. The whole apparatus has the same metallic assembly which fixes all stages on the same plate. It could be a fixed apparatus or mobile apparatus. Any option can be used according to requirements.