Process for treating stack gases

A process for removing gaseous and particulate pollutants from stack gases including oxides of nitrogen and mercury vapor comprising the steps of:

• passing the stack gases through a defined substantially horizontally extending flow path having a substantially unrestricted cross-sectional flow area throughout the length thereof to avoid any substantial pressure drop;
• spraying into the flow path at least a liquid reagent including an oxidizing agent selected from the class consisting of acid-alkali metal dichromate and permanganate ion for contact with the stack gases therein and thereby effecting by said reagent removal of pollutants, including oxides of nitrogen and mercury vapor, from the stack gases passing therethrough;
• and
• discharging to discharge means pollutant laden liquid impinging on the sidewalls of said flow path by washing said discharging pollutant laden liquid into said discharge means by subsequently impinging liquid droplets.

A process of wet scrubbing stack gases, wherein the steps comprise:

• passing the stack gases through a scrubbing zone consisting of a substantially horizontally extending flow path having a substantially unrestricted cross-sectional flow area throughout the length of said flow path to avoid any substantial pressure drop in said scrubbing zone;
• spraying a liquid reagent across said scrubbing zone and substantially perpendicular to said path of flow to substantially cover the cross-sectional flow area of said path with liquid spray droplets at least at one stage along the length thereof whereby pollutants contained within said stack gases are removed therefrom by said spray droplets;
• washing the pollutants laden liquid in said scrubbing zone with subsequently emitted liquid spray to cause the pollutant laden liquid to move to the bottom of said scrubbing zone;
• and
• discharging the pollutant laden liquid from said scrubbing zone which has been washed to the bottom thereof.