Abstract: Distribution of pollution reducing agents within an effluent at the effective temperature window for effective gas phase reaction is greatly improved. A two-phase mixture having fine droplets of liquid, e.g. a NO.sub.x reducing agent such as aqueous solutions of urea or ammonia, dispersed in a gaseous component, such as air, is injected into the effluent an sonic velocity to achieve a distribution of particles of sizes effective to uniformly reduce NO.sub.x within the zone of effective temperature while not producing a significant level of droplets so large that they survive beyond the temperature zone.

Abstract: The present invention relates to a process for the use of a urea hydrolysate for nitrogen oxides reductions. More particularly, the process involves forming a urea hydrolysate and introducing the hydrolysate into a combustion effluent under conditions effective for the reduction of nitrogen oxides.

Abstract: A process for removing hydrogen sulphide and sulphur dioxide from a Claus reaction tail gas comprises separating the tail gas into two partial streams, conducting the first partial stream through a first catalyst bed charged with sulphur while at a temperature above the sulphur dew point, separating out the discharged sulphur from the first partial stream by condensation, combining the first partial stream freed from sulphur with the second partial stream, and passing the combined gas stream through a second catalyst bed already freed from sulphur while at a temperature below the sulphur dew point. When the second catalyst bed becomes charged with sulphur and the first catalyst bed becomes free of sulphur, the flow of gas through the beds is reversed.

Abstract: A process is provided for the production of hydrogen and sulphur from a gas containing hydrogen sulphide. Such a process comprises passing the gas through a cracking zone at a temperature of from about 850.degree. C. to 1600.degree. C., cooling the cracked gas to a temperature of from about 110.degree. C. to 150.degree. C., and separating the condensed elemental sulphur. The uncracked hydrogen sulphide is separated and returned to the cracking zone; the remaining gas is withdrawn as hydrogen-rich gas.