Nitrogen Removal From Natural Gas
Problem
Natural gas can be transported by pipeline only if it contains less than a specified amount of nitrogen. In general, gas containing more than 6% nitrogen must be treated to remove the nitrogen.
Membrane Solution
MTR’s membrane system produces pipeline-quality or pipeline-acceptable gas and a nitrogen-rich fuel from raw natural gas. The proprietary membranes are significantly more permeable to methane, ethane, and other hydrocarbons than to nitrogen. Gas containing 8% to 15% nitrogen is compressed and passed across a first set of membrane modules. The permeate, which contains 4% nitrogen, is sent to the pipeline; the nitrogen-rich residue gas is passed to a second set of membrane modules. These modules produce a residue gas containing 50% nitrogen and a nitrogen-depleted permeate containing 10% to 20% nitrogen. The residue gas is used as fuel; the permeate is mixed with the incoming feed gas for further recovery.
Benefits
Standardized skid designs are used for N2 removal applications
- Nitrogen content reduced to pipeline specification (3% or higher)
- Heavy hydrocarbons captured in the product gas
- Easy, low-cost installation; system can be installed in hours
- Membrane unit requires no maintenance; robust long-lasting membranes
- System is easily moved from one location to another
System Performance
- Feed rate: 0.4 to > 100 MMscfd
- Feed N2 content: 4% to 50%
- Target N2% or BTU value
- Product gas pressure: 35 to 350 psia
- Product BTU recovery: 90%+
- Heavy hydrocarbon recovery : >95%