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Alexandr I Valdman

Alexandr P Khardin

Boris Nikolaevich Gorbunov

Stanislav V Sukhanov

Vyacheslav K Rykov

A method of producing acrolein comprising evaporating acetaldehyde and formaldehyde in the presence of diphenyl-N-nitrosamine taken in an amount of from 0.1 to 3 wt. %. The resultant vapors of said aldehydes are fed for aldol condensation which occurs in a gaseous phase on a catalyst, viz., coarsely porous silica gel promoted by 10 to 12 wt. % sodium silicate at a temperature of from 270.degree. to 300.degree. C. in the presence of diphenyl-N-nitrosamine taken in a quantity of from 0.1 to 3 wt. %. The resultant gas mixture formed at the stage of aldol condensation, containing acrolein, acetaldehyde, formaldehyde and water is cooled to obtain a condensate. Said condensate is subjected to rectification in order to isolate a mixture of acrolein with acetaldehyde and water, and an aqueous formaldehyde solution. Said aqueous formaldehyde solution is concentrated and returned to the aforesaid evaporation stage. Said mixture of acrolein with acetaldehyde and water is subjected to rectification in the presence of diphenyl-N-nitrosamine taken in an amount of from 0.1 to 3 wt. % in order to isolate the end product alongside with acetaldehyde containing from 0.2 to 1.5 wt. % acrolein and returned to the aforesaid evaporation stage. The proposed method makes it possible to avoid completely resinification at the stage of evaporation of aldehydes, to run aldol condensation of acetaldehyde with formaldehyde at a continuous discharge of resins as they form, to carry out rectification of a mixture of acrolein with acetaldehyde and water continuously as well as to substantially increase the purity of the acrolein produced (the acrolein content in the distillate being within 91 to 93 percent).

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Volzhsky, Volgogradskoi oblasti, undefined

Alexandr I Valdman