Systems and methods for removing gaseous pollutants from a gas stream

A method for removing gaseous pollutants from a gas, the method comprising:

• (a) flowing a gas stream comprising gaseous pollutants into a horizontally disposed housing via a waste gas inlet, the horizontally disposed housing comprising the waste gas inlet at one end, a treated gas outlet at an opposite end, a liquid inlet manifold proximal the waste gas inlet and a demister proximal the treated gas outlet, wherein the horizontally disposed housing is substantially free of flow deflection members between the liquid inlet manifold and the demister, thereby defining a substantially unrestricted gas-liquid contacting zone between the liquid inlet manifold and the demister;
• (b) passing the gas stream through the substantially unrestricted gas-liquid contacting zone;
• (c) spraying, concomitant to the passing step, a scrubbing liquor through the substantially unrestricted gas-liquid contacting zone and co-current to the flow of the gas stream, thereby contacting the gas stream with the scrubbing liquor;
• (d) removing at least some of the gaseous pollutants from the gas stream during the contacting;
• (i) wherein the gaseous pollutants comprise at least one of (i) one or more halogenated hydrogen compounds, and (ii) volatile organic compounds;
• and
• (e) operating, during the flowing, passing, spraying and removing steps, the horizontal duct scrubbing system at an L/G ratio of less than 20.