Natural Gas Processing with Membranes:  An Overview

Abstract

Every year, the world uses close to 100 trillion scf (standard cubic feet) of natural gas. All of this gas requires treatment before it enters the pipeline, making natural gas processing by far the largest market for industrial gas separation processes and equipment. Of this huge market, membranes have less than a 5% share, but this is changing; membrane-based removal of natural gas contaminants is growing faster than any other segment of the membrane gas separation business. This paper gives an overview of the membrane technology in current use for natural gas treatment and outlines the future prospects.

Gas permeation and physical aging properties of iptycene diamine-based microporous polyimides

“…Some advantages of membrane-based gas separation over conventional technologies, such as cryogenic distillation, adsorption and absorption include: simple modular design, cost effectiveness and small footprint, which is important for offshore natural gas processing operations [2,3]. Ideal polymers for gas separation membranes should have the following properties: (i) high permeability, (ii) high selectivity, (iii) good chemical resistance and (iv) stable long-term separation properties.…”

“…Triptycene is the simplest iptycene and frequently used in polymer building units due to its unique rigid and contorted structure with phenyl rings attached to the [2,2,2] bicyclooctatriene bridgehead system. Triptycene, as shown in Figure 1a, has three phenyl rings bound by a single hinge, which provides a high energy barrier to molecular twisting or deformation which keeps the angle between aromatic rings at 120 o .…”

Mixed gas sorption in glassy polymeric membranes: II. CO2/CH4 mixtures in a polymer of intrinsic microporosity (PIM-1)

“…in natural gas and biogas processing, has been under the attention of membrane scientists. [1][2][3][4] Membrane technology may be more advantageous than conventional absorption of acid gases in basic solvents, and pressure swing adsorption (PSA), for small-to-medium scale separations and those not requiring stringent product purity. In particular, it is highly desirable to explore membrane materials which can selectively remove CO 2 from gas mixtures, thereby maintaining CH 4 at or near feed pressure to avoid gas recompression.…”

“…In particular, it is highly desirable to explore membrane materials which can selectively remove CO 2 from gas mixtures, thereby maintaining CH 4 at or near feed pressure to avoid gas recompression. [1,2] The performance of a polymeric membrane for gas separation is expressed by its gas permeability and gas pair selectivity, which must be considered together with other important factors such as chemical and mechanical resistance. [5] The determination of permeability and selectivity of membrane materials in conditions as close as possible to the real operating conditions is essential for the design of membrane separation processes of gaseous mixtures and to identify the most appropriate range of conditions, and also to understand the fundamental mechanisms governing the transport processes.…”

Elucidation on the Effect of Operating Temperature to the Transport Properties of Polymeric Membrane Using Molecular Simulation Tool

“…Before supplying to users all over the world, the natural gas has to be treated by removing all unwanted residual gases, e.g. acid gases (CO 2 ), inert gases (N 2 ) and oxidizers (O 2 ), prior to entering the pipeline to obtain highly concentrated methane (CH 4 ) that constitutes to its actual heating value [3,4]. Polymeric membranes play a pivotal role in gas separation applied in industrial application attributed to their various advantages, such as occupying a relatively smaller footprint, chemical free, cost effective, high process flexibility, simplicity and high energy efficiency [5].…”