Exhaust treatment system having membrane module for water removal

An exhaust after-treatment system for treating an exhaust produced by an engine, the exhaust after-treatment system comprising:

• an exhaust passage;
• at least one catalytic exhaust after-treatment component in communication with the exhaust passage for treating the exhaust;
• a membrane vessel that receives a portion of the exhaust therein at a location positioned upstream from the catalytic exhaust after-treatment component;
• and
• a bypass passage in communication with the exhaust passage that receives the portion of the exhaust,
• wherein the membrane vessel is positioned within the bypass passage, and
• the membrane vessel includes a molecular membrane that separates at least one constituent from the portion of the exhaust to provide a permeate gas that is enriched with the constituent removed from the portion of the exhaust, and produces a retentate gas that is depleted of the constituent, which facilitates the treating of the exhaust by the catalytic exhaust after-treatment component wherein the constituent includes water.