84 results about "Hydroxyacetonitrile" patented technology

The invention discloses a preparation process of glycine, which comprises amination, alkaline hydrolysis, ammonia discharge acidification, decolorizing, concentration, desalting, crystallization and recrystallization steps, wherein in the amination step, hydroxyacetonitrile and ammonia water are mixed in a tubular reactor, and a reaction is undergone at the temperature of 50-100 DEG C under the pressure of 0.5-2.0 MPa for 4-10 minutes; and in the alkaline hydrolysis step, 30-50 percent of sodium hydroxide solution is added into an alkaline hydrolysis reactor in advance, an amination liquid is collected from an amination liquid outlet, a reaction is undergone at the temperature of 60-90 DEG C under the pressure of between -0.01 MPa and -0.09 MPa, and ammonia in a system is recovered simultaneously. In the process, the tubular reactor is taken as an amination reactor, so that the reaction temperature and pressure are raised, the reaction time is shortened, and raw material decomposition, pyrolytic polymerization of aminoacetonitrile and the generation of byproducts are reduced; alkaline hydrolysis is performed during the collection of the amination liquid, the concentration of an alkaline liquor and the alkaline hydrolysis temperature are raised simultaneously, and ammonia in the system is recovered under reduced pressure, so that the alkaline hydrolysis reaction is more complete, the speed is higher, and the generation of colored impurities is reduced; and a mother liquor circular utilizing mode is established, so that the treatment amount of waste mother liquor is reduced, the product yield is increased, and the production cost is reduced.