Abstract: This patent describes technology for generating ammonia from urea. The method is based on the hydrolysis of an aqueous solution of urea and/or biuret by heating under pressure to form a mixture of ammonia, carbon dioxide and water. The gas mixtures produced are useful for supplying ammonia at controlled pressure and rate of flow for many industrial applications without the risks and hazards associated with the transportation and on-site storage of ammonia, thereby providing a significant safety advantage over present industrial practice.

Abstract: This patent describes technology for generating ammonia from urea. The method is based on the hydrolysis of an aqueous solution of urea and/or biuret by heating under pressure to form a mixture of ammonia, carbon dioxide and water. The gas mixtures produced are useful for supplying ammonia at controlled pressure and rate of flow for many industrial applications without the risks and hazards associated with the transportation and on-site storage of ammonia, thereby providing a significant safety advantage over present industrial practice.

Abstract: A process to provide a pressurized gas stream useful for removing nitrogen oxides from a combustion gas stream by hydrolyzing urea in aqueous solution in a closed reactor to evolve gaseous ammonia at a rate essentially balanced to the amount required from the combustion gas stream. The improvement resides in maintaining the pressure in the reactor within a preselected range when the demand for ammonia for external use suddenly drops by cooling the solution within the hydrolysis reactor by heat exchange either within or external to the reactor in response to rapid changes in demand for ammonia required to remove said nitrogen oxides.

Abstract: This patent describes technology for generating ammonia from urea. The method is based on the hydrolysis of an aqueous solution of urea and/or biuret by heating under pressure to form a mixture of ammonia, carbon dioxide and water. The gas mixtures produced are useful for supplying ammonia at controlled pressure and rate of flow for many industrial applications without the risks and hazards associated with the transportation and on-site storage of ammonia, thereby providing a significant safety advantage over present industrial practice.

Abstract: This patent describes technology for generating ammonia from urea. The method is based on the hydrolysis of an aqueous solution of urea and/or biuret by heating under pressure to form a mixture of ammonia, carbon dioxide and water. The gas mixtures produced are useful for supplying ammonia at controlled pressure and rate of flow for many industrial applications without the risks and hazards associated with the transportation and on-site storage of ammonia, thereby providing a significant safety advantage over present industrial practice.

Abstract: Apparatus and a method are disclosed for reducing sulfate contained within a flowable material to hydrogen sulfide by the use of two stages of reaction. The flowable material is deoxygenated and then introduced into a first reactor which contains a sulfate reducing bacteria such as a Desulfovibrio or Desulfotomoculum. Hydrogen sulfide is removed from the first reactor and the remaining portion of the flowable material is subjected to a separating action to produce a supernatant component and a sludge component. The sludge component is reintroduced to the first reactor which is generally devoid of packing or support and the supernatant is introduced into a second reactor which is preferably in the nature of a supported film reactor. Mixed products including carbonate may be removed from the first reactor. The second reactor also contains anaerobic sulfate reducing bacteria. Hydrogen sulfide, low sulfate water and carbonates may be withdrawn from the second reactor.

Abstract: Systems for desulfurization of a flue gas containing fly ash including formation of a dry powder in a spray dryer absorber resulting from reaction of an alkaline aqueous feed and the flue gas. The dry powder is collected and a specifically selected fraction is recycled to a feed preparation subsystem for inclusion in the aqueous feed. Selective recycle is based on physical or chemical properties and, for example, large diameter and dense particles provide enhanced reagent utilization compared to smaller and less dense particles.