H2S Removal From Natural Gas
Problem
H2S is found in natural gas in many locations, and this high H2S gas cannot be transported from the wellhead to pipelines without treatment. For remote or off-shore locations, H2S in the gas also causes problems in choosing equipment used to produce local power (gensets) or drives for compressors (gas engines and turbines). Low-cost simple equipment is desired to reduce H2S content to levels acceptable in fuel gas. Conventional scavengers and amine systems come with high operating and capital costs, and significant logistical and installation problems.
Membrane Solution
MTR’s membranes can provide a simple, low-cost, compact solution for reducing H2S in natural gas used as fuel. MTR’s membranes are significantly more permeable to H2S and CO2 than CH4, and will reduce the concentrations of these components from 5 mol% or higher to a few hundred ppm in most cases. The H2S-rich gas can be recycled back to the suction side of the pipeline compressor, resulting in safe operation and virtually no losses. These membranes not only remove the acid gases but also dehydrate the gas and significantly reduce the heavy hydrocarbon content, providing clean conditioned fuel gas. Heavy hydrocarbons recovered from the fuel gas and returned to the pipeline provide added value downstream as liquid products. Engine de-rating can be completely eliminated and maintenance is significantly reduced, resulting in greater on-stream time and higher profitability.
Benefits
Field testing H2S removal membranes
- H2S content reduced to required specifications (200-300 ppm or lower)
- Water and heavy hydrocarbons (C3+) removed simultaneously with H2S
- Easy, low-cost installations. In most cases, system installed in hours. Movable skid adjusts to changing needs.
- Robust, proven membrane performance at high H2S content
- No regular maintenance, no moving parts; designed for remote unmanned operation
- Eliminates engine de-rating - increased power generation or horse power, immediately increases profitability
- Recovery of heavy hydrocarbons from fuel gas to pipeline gas increases revenues and offers positive cash flow.
- Eliminates need for scavenger (high operating cost) and amine unit (high capital and operating cost)
System Performance
- Feed Rate: < 1 MMscfd to > 30 MMscfd
- Feed H2S Content: > 5 mol% to < 100 ppm
- Product Fuel: < 300 ppm down to < 50 ppm
- Product Gas Pressure: 30 to 1200 psia
- H2S Reduction: 90% +