84 results about "Hydroxyacetonitrile" patented technology

The invention relates to a preparation method of methyl-glycine diacetate tri-sodium, successively comprising the following steps of: preparation of hydroxy acetonitrile solution, preparation of iminodiacetonitrile solution, preparation of methyl-flycine nitrile diacetonitrile crystal, preparation of methyl-glycine diacetate tri-sodium (MGDA-3Na) and preparation of solid product MGDA-3Na. In the method, the yield of methyl-flycine nitrile diacetonitrile crystal is higher than 92%, the total yield of MGDA-3Na can reach more than 86%, the content of NTA (nitrilotriacetic acid) is less than 0.08%; and the equipment investment and energy consumption in the hydrocyanic acid refining process are saved on the premise that high yield and low toxic side product content are met, and the hydrocyanic acid refining process is not required, so that the production cost is reduced and the environment pollution is reduced.

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.