Researching On The Production Proess Of Sodium Citrate By Chromatography Extraction In The Mother Liquor Of Calcium Hydrogen Citrate

Sodium citrate is one of the important products of citric acid salt,widely used in various fields.At present the method of fixed bed ion exchange is mostly used to produce sodium citrate at home and abroad.However,the process has some flaws such as low extraction rate,bad quality,no industrialization etc.Based on this,Firstly,the experimental studying on the selection of the resin and single column shows that the optimizing parameters for the chromatography extraction are these:?.The resin should be SQD815.?.The static exchange capacity after 80 cycles of citric acid should be 0.928(g·g-1 dry basis)with a 12.54%decrease scale.III.The activated carbon compounds of eluent perform better when it is 2.55.It is identified that the positive and negative feed way adsorption resins for citric acid had no significant effect,while feed flow rate 3.0 cm·min-1,the washing water from1600mL to 1800mL,elution temperature 80?,recycled resin in 4.0%NaOH,are optimum technological conditions for the mother liquor of calcium hydrogen citrate chromatographic separation.Secondly,according to the test results,the application of L100-139 chromatography apparatus in the follow study of production process of sodium citrate by chromatography extraction in the mother liquor of calcium hydrogen citrate is deceided.I.After studying on the influence of the column connection between the active carbon decoloring column and cation exchange resincolumn,on the effect of calcium hydrogen for liquor pretreatment,the results show that the coarse decoloring-main cation column-secondary anion column-refining decoloring process,getting rid of iron at 80°Cwith the linear velocity of 1.0 cm·min-1 of the feed,decoloration at 60?under the linear velocity of 1.0 cm·min-1 feed are the best method.II.We study the influence of the configuration mode of the chromatographic separation system on the separation effects,the results show that the system configuration in figure 3,the residence time of 1500 s,the adsorption velocity 4-5cm·min-1,purification area velocity 3-4cm·min-1,elution velocity of 4-5 cm min-1 separation effect are better.III.Acidization of Sodium citric mother liquor and the influence of recycled waste from continuous cation-cation exchange instead of hydrochloric acid on the final yield is studied,the results show that the continuous cation-cation exchange regeneration waste liquid can not directly replace hydrochloric acid.With acidizing fluid dilute to 3 times,the cationic content which is converted into monovalent cation concentration is not more than 0.358mol·L-1.with the proportion of 0.65%acidizing fluid added to the citric acid have no effect on the yield of neutralization,while the extraction yield increased by 32.26%,economic benefit of which is ?1.6933 million/year.Finally,according to the results of pilot study verifies the industrialization and economic benefit analysis.The industrialization results show that the production process of sodium citrate by chromatography extraction in the mother solution of calcium hydrogen citrate is feasible.Extraction yield is 96.4%,and saving the economic benefit of about ?1.25 million,the product quality conforms to the national standard BP2003.GB2008.FCC-IV.USP35.This paper presents the new process of sodium citrate by continuous ion exchange chromatography extraction technique with "the mother liquor of calcium hydrogen citrate "as raw material.Which solves the problem of the mother liquor recycling,Which reduces production cost,Which improves the economic benefit.It has reference significance for production of citric acid and sodium citrate enterprises at the same time.