Process for scrubbing ammonia from acid gases comprising ammonia and hydrogen sulfide

A process for removing ammonia from an acid gas comprising ammonia and hydrogen sulfide comprising:

• (a) contacting the acid gas with a strong acid, selected from the group consisting of sulfuric acid, phosphoric acid and nitric acid and with recycle solution at a pH less than 7, wherein recycle solution is a portion of the product ammonium salt solution, to produce a gas phase and an ammonium salt solution;
• (b) separating the gas phase from the solution;
• (c) feeding the solution from step (b) to an evaporator, to provide a gas phase and a concentrated ammonium salt solution;
• (d) feeding the concentrated ammonium salt solution to a steam stripper to remove residual hydrogen sulfide, water and hydrocarbons, if present, wherein steam provides driving force to remove said hydrogen sulfide, water and hydrocarbons from said concentrated salt solution to provide a purified concentrated ammonium salt solution and a gas component;
• and
• (e) contacting the purified ammonium salt solution exiting the stripper with a base to provide an ammonium salt solution having a pH between 6 and 8.

A process for removing ammonia from an acid gas comprising ammonia and hydrogen sulfide comprising:

• (a) contacting the acid gas with a strong acid, selected from the group consisting of sulfuric acid, phosphoric acid and nitric acid and with recycle solution at a pH less than 7, wherein recycle solution is a portion of the product ammonium salt solution, to produce a gas phase and an ammonium salt solution;
• (b) separating the gas phase from the solution;
• (c) feeding the solution from step (b) to an evaporator, to provide a gas phase and a concentrated ammonium salt solution;
• (d) feeding the concentrated ammonium salt solution to a gas stripper to remove residual hydrogen sulfide, water and hydrocarbons, if present, wherein carrier gas provides driving force to remove said hydrogen sulfide, water and hydrocarbons from said concentrated salt solution to provide a purified concentrated ammonium salt solution and a gas component;
• and
• (e) contacting the purified ammonium salt solution exiting the stripper with a base to provide an ammonium salt solution having a pH between 6 and 8.