It hardly needs repeating the merits of sour gas, particularly in the domain of power generation. The region’s gas reserves are predominantly sour in nature, requiring that the hydrogen sulphide (H2S) content be removed to make the gas sweet enough to be used chiefly for producing electricity, among other usage benefits.
But the entire process of segregating the H2S and CO2 content from sour gas to make it ready for use, as also to produce sulphur, may not be as simple as it seems. “Sour gas is produced from a reservoir with the help of standard drilling completion technology,” Peter D Clark, senior research advisor at Canada-based Alberta Sulphur Research Ltd, who has been involved with the sour gas and sulphur sector in Abu Dhabi since 1995, said. “There are some differences in the terms of metallurgy used, because sour gas which contains H2S and CO2 can potentially cause corrosion. But basically the technology is the same for any gas production from a reservoir.”
“The key difference is that the H2S and CO2 needs to be separated,” Clark said. “The H2S must be separated because it is extremely toxic; you can only have a very small residual amount of H2S. The CO2 must also be removed because it affects the value of the gas. So that is the key difference in terms of standard processing of sour gas.”
He continued: “Then the H2S is converted into elementary sulphur in what we usually refer to as the modified cloud process, which is a very complex technology from both an engineering and chemistry viewpoint. But of course it is well established worldwide and is now operating in industrial processes. The net product of that is obviously sulphur and the other product is methane, which is in turn used for power generation. So the key process is to separate the H2S from the CO2 and converting the H2S into CH4 (methane),” which is the key component in power generation.
Effective equipment plays as important a role as technology in the treatment of sour gas to produce sulphur. Players involved, from operators to EPC contractors, are always seeking products that will aid them in not just implementing the process technology but also efficiently manage costs in an otherwise cost-intensive function of sour gas treatment.
German valves manufacturer OHL, which has been in existence for about 120 years, has been supplying valves for sour gas applications in Europe and Canada since 45 years, and more recently also began catering to the Middle East. “So wherever there is sour gas, we try to be there in that market with our special products,” Wolfgang Röhrig, general manager at OHL, told this magazine.
Effective equipment plays as important a role as technology in the treatment of sour gas to produce sulphur. Players involved, from operators to EPC contractors, are always seeking products that will aid them in not just implementing the process technology but also efficiently manage costs in an otherwise cost-intensive function of sour gas treatment.
German valves manufacturer OHL, which has been in existence for about 120 years, has been supplying valves for sour gas applications in Europe and Canada since 45 years, and more recently also began catering to the Middle East. “So wherever there is sour gas, we try to be there in that market with our special products,” Wolfgang Röhrig, general manager at OHL, told this magazine. “We have been associated with the Habshan project (operated by ADNOC) for 25 years. The valves are running there since 1994, when we supplied the first valve. We didn’t even have to supply spare parts for our products to Habshan, and that I think speaks for our quality and work attitude.”
Röhrig describes OHL as a niche company producing special valves for the oil and gas industry and having expertise in sour gas application. However, he does mention that standard equipment may not always be effective for sour gas operations and as a key supplier to the sector it entails that they constantly ‘reinvent the wheel’.
“We have modified our technology for valve manufacturing and always improve the technique related to the quality of the gas here. The development was not always connected to the region here, but with certain projects that we had in China and the Middle East or in North Africa or also in Canada,” Röhrig said. “So it is a question about the quality of the gas more than the market in the region. What you need to do is to improve your design to secure safe operations of the valve. So you need to be able to offer long-term service. Normally we don’t have a problem to offer such warranties.”
