Abstract: Anhydrous liquid sulfur dioxide is recovered from environmentally unsuitable vapor or liquid streams comprising water, sulfur dioxide and carbon dioxide. The vapor streams are fed into an absorption zone and contacted with a lean liquid water stream. A resulting sulfur dioxide rich water stream is passed into a first fractionation column utilized in part as the stripper column which produces the lean water stream. A sidecut stream removed above the feed point is passed into a second fractionation column, and the overhead vapor of the first column is subjected to two stages of partial condensation to aid carbon dioxide rejection. Anhydrous sulfur dioxide is removed as a liquid sidecut of the second column, and the net overhead vapor of the second column is preferably passed into the overhead system of the first column after a partial condensation.

Abstract: Benzene is admixed and reacted continuously with a mixed acid containing 3-7.5% nitric acid, 58.5-66.5% sulfuric acid, and 28-37% water under pressure sufficient to maintain benzene in liquid state until complete conversion of nitric acid is achieved to provide mononitrobenzene containing less than 500 ppm dinitrobenzene.

Abstract: An aqueous urea solution is concentrated to a substantially water-free molten urea by conducting successively a first step of concentrating said aqueous urea solution under the conditions forming a urea slurry and a second step of concentrating said urea slurry under conditions forming a substantially water-free molten urea free from crystalline urea.

Abstract: An overall process for the separation of ethyl fluoride from a propane stream containing same is provided wherein said propane stream is extractively distilled using HF, as the extractive solvent producing a first mixture consisting essentially of propane and HF and a second mixture consisting essentially of ethylfluoride and HF, and wherein this second mixture is then mixed with water followed by phase separation.

Abstract: Aqueous solutions and suspensions of solid particles, even those containing less than one percent of organic materials, may be combusted with air, oxygen, or their mixtures in a process which provides for preheating in countercurrent batches of the raw original liquid by either open (direct contact) or closed (heat transfer surface) condensation of steam generated by multiple flash evaporations which cool earlier batches of hot liquid after the wet combustion. Excess heat may often be withdrawn from the process for power generation or other use as high pressure steam, with or without combustion gases and other non-condensibles. No pumps are necessary, liquid batches are pressurized by steam generated in the flash evaporations for which only one pressure vessel is required instead of the many in the continuous processes.