Dealing With H2S in Heavy Oil Thermal Projects

摘要

There is an abundance of natural gas being discovered andrnproduced that is slightly sour. According to a US Department of thernEnvironment (DOE) survey that includes Canada, about 80% ofrncurrent and new gas has a hydrogen sulphide (H2S) concentration ofrn1% or less. Of course, this must be treated to remove the H2S to meetrnsales gas specifications. For small scale (less than 50 – 100 kg) andrnlarge scale (greater than 20 tonne/d) of equivalent sulphur, currentrntechnologies appear reasonable. Conversely, for intermediate rangern(0.1 – 20 tonne/d) equivalent sulphur, current technology has provenrnto have high capital and/or operating costs and some processes arerndifficult to operate. Therefore, there is a need for an intermediaternscale (0.1 to 20 tonne/d) process with lower capital and operating costrnthan those currently available. The applications of such a processrnrange from the removal of H2S from acid gas at low pressurernproduced from the amine process to high pressure raw sour gas.rnThere are additional challenges from sour gas associated with heavyrnoil thermal projects in that it is at low pressure and containsrnsubstantial C7 +. The elemental sulphur produced should be of salesrngrade quality such that the handling of the product can fit into thernexisting sulphur infrastructure and sold into existing markets.rnOtherwise, disposal of the product becomes costly and in some casesrnbecomes another environmental problem.rnIn answer to this need, Xergy Processing Inc. has developed a gasrnphase direct oxidation process for the above applications as well asrntreating heavy oil off-gas, fuel gas, power generation gas. Thernprocess has relatively low capital and operating costs and is easy tornoperate, with no equipment that is unfamiliar to the petroleumrnindustry. Conversion to sulphur depends on the processrnconfiguration and pressure but ranges from 80% to 99.9+% based onrnlab and field data.