Patent ID: 7258848

Claim:
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 a stripper to remove hydrogen sulfide, water, and hydrocarbons, if present in said acid gas to provide a purified concentrated ammonium salt solution and a gas component, wherein heat and driving force to remove said hydrogen sulfide, water, and hydrocarbons is supplied to said stripper by a reboiler, which circulates purified concentrated ammonium salt solution; and (d) 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.