Membrane module to remove gaseous substances from a gas stream

A process to remove undesirable gaseous substances from a gas stream comprising the steps:

• (a) flowing the gas stream containing the undesirable gaseous substances adjacent a membrane pocket wherein the membrane pocket includes a chamber containing a mixture selected from the group consisting of a reaction liquid and a suspension of micro-organisms and a membrane that encloses said chamber, wherein the membrane is a liquidproof material of hydrophobic microporous expanded polytetrafluoroethylene, wherein the mixture is suitable to react with the undesirable gaseous substances;
• (b) permeating the gas stream through the membrane;
• and
• (c) interacting the undesirable gaseous substances with the mixture so as to remove the undesirable gaseous substances from the gas stream and cause the gas stream to be purified.

An assembly for use in flue gas purification comprising a plurality of membrane modules arranged and connected within a housing wherein each membrane module comprises:

• (a) a plurality of planar membrane pocket assemblies stacked on top of one another so as to be parallel to the direction of flow of the gas stream, wherein each assembly further comprises:
• (i) a flat circumferential frame having two parallel surfaces, wherein the frame determines the outer contours of each assembly, said frame containing a supply bore and a drainage bore;
• (ii) a gas permeable liquidproof membrane that covers both parallel surfaces of the frame so as to form a pocket in said frame;
• and
• (iii) a mixture selected from the group consisting of a reaction liquid and a suspension of micro-organisms located within the pocket, wherein the mixture enters the pocket through the supply bore and exits from the pocket through the drainage bore;
• (b) a plurality of spacers wherein spacers are located between two adjacent pocket assemblies so that a spacer is at each side of the housing to form a minimum distance between adjacent assemblies through which the gas stream flows;
• (c) a supply channel that extends to all membrane pocket assemblies and spacers, said supply channel providing the mixture to all pocket assemblies via the supply bore;
• (d) a drainage channel that extends to all membrane pocket assemblies and spacers, said drainage channel accessible to the drainage bore of each pocket assembly so that the mixture is drained through said channel;
• (e) a top plate that covers the plurality of assemblies, said top plate further including the supply channel that extends through the assemblies;
• and
• (f) a floor plate that goes under the plurality of assemblies;
• said floor plate further including the drainage channel that extends through the assemblies.