Abstract: Purge gas removed from a first synthesis loop for conversion of synthesis gas to ammonia over an iron based synthesis catalyst is converted to ammonia over a more active synthesis catalyst in a second synthesis loop.

Abstract: A process for production of ammonia wherein stoichiometrically hydrogen-lean synthesis gas is reacted over a highly active synthesis catalyst.

Abstract: Ammonia synthesis gas having excess nitrogen is produced in a reactor-exchanger primary reformer followed by an autothermal secondary reformer wherein process air for the latter is preheated by heat exchange with gas turbine exhaust and the primary reformer is heated by synthesis gas from the secondary reformer.

Abstract: Sulfur-containing compounds, particularly sulfur dioxide, are removed from stack gas streams by wet scrubbing the gases wherein an alkaline earth metal sulfate and/or sulfite are formed. Example processes are lime/limestone and Double Alkali scrubbing processes. These processes produce sludge material containing primarily the alkaline earth metal sulfate which is disposed of only with significant difficulty. An improvement is described herein whereby the aqueous sludge is reduced in contact with sufficient coal to produce the corresponding sulfide and effluent gases from the reduction step having a sufficient heating value to be used to dry the mixture of sludge and coal prior to the reducing step. The alkaline earth metal carbonate and elemental sulfur are recovered from the sulfide.

Abstract: This process provides for the oxidation of calcium sulfite produced from wet scrubbing sulfur oxides to gypsum in an aqueous medium containing magnesium sulfate. The process renders scrubber sludge filterable for further manufacturing use or disposal without use of acidic streams.