PROCESS AND BIOFILTER SYSTEM FOR H2S REMOVAL FROM A H2S CONTAMINATED ENERGY PRODUCTION GAS STREAM CONTAINING METHANE AND USE OF SUCH A BIOFILTER SYSTEM

摘要

The invention relates to a process and a biofilter system (10) for removing H2S from a H2S contaminated energy production gas stream containing methane. The aqueous biofilter system comprises a biofilter (6) having biofilter support material constituting a biofilter bed supporting a humidified biofilm having microorganisms that are capable of oxidizing H2S. The process comprises the steps of contacting the H2S contaminated energy production gas stream with the microorganisms of the humidified biofilm, and oxidation of at least part of the H2S in the H2S contaminated energy production gas stream by the microorganisms, resulting in a H2S depleted energy production gas stream, wherein the process further comprises the step of adding an aqueous nitrate solution to the H2S contaminated energy production gas stream prior to being contacted with the microorganisms, enabling the microorganisms to oxidize the H2S under anoxic conditions. The invention furthermore relates to the use of such a biofilter system (10) in the removal of H2S from a H2S contaminated energy production gas stream containing methane.