Optimization Of The Production Process Of Folic Acid

Folic acid is an essential vitamin for animals during their growth process,whose demand is rising.But there exist some problems in the production process of folic acid,such as unstable product quality and larger quantity of waste water discharge,which perplex the manufacturers.In order to solve above problems,synthesis and purification of crude folic acid and recycling of waste waster of refining process were studied.Optimal operation conditions of folic acid synthesis and refining process as well as measures of waste water recycling were put forward.Crude folic acid was synthesized through N-(P-aminobenzoyl)-L-glutamic acid,1,1,3-Trichloroacetone,6-hydroxy-2,4,5-triaminopyrimidine sulfate hydrate.The single factor experiments were done to investigate the effects of temperature,dosage of 1,1,3-trichloroacetone and sodium metabisulfite,reaction time,reaction pH on the yield of folic acid.And proper process conditions were obtained:temperature 40 ?,reaction time 6h,reaction pH value 3-3.5,n(N-(P-aminobenzoyl)-L-glutamic acid):n(6-hydroxy-2,4,5-triaminopyrimidine sulfate hydrate):n(1,1,3-Trichloroacetone):n(sodium metabisulfite)=1:1.31:2.92:0.82.The yield of folic acid was 56%.Compared with original progress,dosage of 1,1,3-trichloroacetone and reaction time was decreased 5%and 1h,respectively.In purification process of crude folic acid,the effect of dosage and kinds of acids,dosage of water,kinds of alkalis,dosage of activated carbon,initial and end crystallization temperature on purity and yield of folic acid were discussed.The samples were analyzed by HPLC.In acid refining process,the optimal refining process conditions were obtained:v(30%sulfuric acid):v(water)=1:4,concentration of crystal solution was 0.16g/mL.temperature of alkali refining was 90?,salt-forming agent was sodium hydroxide,addition of activated carbon was 2.7%(on the basis of crude folic acid),m(water):m(crude folic acid)=12.2:1,end crystallization temperature was 50?.The purity and total yield of folic acid could stably reached 98%and 88%,respectively.Feasibility of waste water of refining process recycling was discussed.The results showed that the waste water of acid refining could not be recycled as process water.However,by further treatment,barium sulfate could be prepared by sodium sulfate of waste water and barium sulfite.The Na2S contained waste water could further be used for removing SO2 contained vent gas.The desulfurization product,sodium sulfate,can be reused.The waste water of alkali refining process could be reused four times after treated.Reducing discharge of waste water and resources reusing could be realized.