Key Publications and Presentations:
CO2REMOVAL FROM NATURAL GAS
Problem
CO2 is found in natural gas in many locations and must be removed to meet specifications before the gas can be delivered to the pipeline. Availability of a simple process technology that can be applied in remote, unattended, or offshore situations is highly desirable. Ease of operation, quick start-up, and high on-stream factors are needed in addition to competitive capital and operating costs.
Amine systems are used frequently but are complex and have high capital, operating, and installation costs; a relatively high fuel cost and potential environmental issues.
Membrane Solution
MTR’s membrane based systems provide a simple, low-cost, compact solution for reducing CO2 content in natural gas. These novel membranes have a unique polymer chemistry that is far superior to conventional membranes in withstanding the various components in natural gas. The membranes require minimal gas pretreatment and offer very high efficiency separation, with more than 95% hydrocarbon recovery achievable.
These membranes are used for achieving pipeline CO2 specifications of 4 mol% or less or for bulk CO2removal. Due to the high fluxes of these membranes and efficient module packaging, using MTR’s membrane process minimizes required deck space and weight in offshore installations.
MTR has commercialized several different types of membranes based on both glassy and rubbery membrane materials under different trade names. MTR customizes the overall separation solution using these commercial membranes in order to achieve optimal performance in the field and meet client requirements.
Benefits
- CO2 content reduced to required specifications (<2 mol% or optimal levels)
- Limited pretreatment required due to robust membrane chemistry
- Unique process design to maximize total hydrocarbon recovery
- High-efficiency packaging minimizes space and weight, making the units ideal for offshore applications
- Easy, low-cost installations. In many cases, single skid systems can installed in hours.
- Robust, proven membrane performance at high CO2 contents
- No regular maintenance, no moving parts, and designed for remote unmanned operation
- High on-stream times maximize revenues
MTR supplied CO2 removal system operating at a Texas gas well
System Performance
- Feed Rate: < 1 MMscfd to > 300 MMscfd
- Feed CO2 Content: > 40 mol% to < 5 mol%
- Product CO2 Content: to < 2 mol%
- Hydrocarbon Recovery: > 95% +
Frequently asked questions
What are the methods for CO2 removal from natural gas?
The primary methods for CO2 removal from natural gas include amine absorption (chemical solvent scrubbing), membrane separation, pressure swing adsorption (PSA), and cryogenic separation. Amine systems are widely used but are complex and have high capital and operating costs along with potential environmental concerns. Membrane based systems, such as those offered by MTR, provide a simpler, lower cost, and more compact alternative that requires minimal pretreatment and can achieve more than 95 percent hydrocarbon recovery.
What are the latest technologies for CO2 capture in natural gas plants?
The latest technologies for CO2 capture in natural gas plants include advanced polymeric membrane systems, hybrid membrane amine processes, and next generation solvents with lower energy requirements. MTR membrane systems use proprietary polymer chemistry that is resistant to natural gas contaminants, requires no moving parts or regular maintenance, and is suitable for remote and unmanned operation. These membrane units can handle feed CO2 content from less than 5 mol percent to over 40 mol percent and reduce CO2 to below 2 mol percent pipeline specifications.
What is the impact of CO2 on natural gas quality and pipeline specifications?
CO2 in natural gas reduces heating value, causes corrosion in pipelines and equipment, and can form dry ice at low temperatures, creating blockages in processing facilities. Pipeline specifications typically require CO2 content to be below 2 to 4 mol percent before the gas can be transported and sold. Removing CO2 to meet these specifications is essential for safe and efficient gas transmission and for maintaining the commercial value of the natural gas product.
What are the common methods used for CO2 removal from natural gas?
The most common methods for CO2 removal from natural gas include amine absorption using solvents such as MEA, DEA, or MDEA, membrane separation, physical solvent processes such as Selexol or Rectisol, and pressure swing adsorption. Amine absorption has been the industry standard for decades, but membrane based systems are gaining market share due to their simplicity, compact footprint, lower installation costs, and suitability for remote or offshore locations.
What are the advantages of membrane based CO2 removal?
Membrane based CO2 removal offers several advantages over traditional amine systems. No chemical solvents or consumables are required, the systems have no moving parts and require minimal maintenance, and they are compact enough for offshore platforms where space and weight are limited. MTR membrane systems can be installed as single skid units, achieve more than 95 percent hydrocarbon recovery, and are designed for remote unmanned operation. They also avoid environmental issues associated with solvent disposal and regeneration energy costs.
