The Utilization Of Waste Phosphoric Acid Produced In The Process Of Production Of Pharmaceutical Intermediates

The content of phosphate waste acid liquor generated in the production process of pharmaceutical intermediates is very high,the waste phosphoric acid with high concentration of pollutants,complex composition and poor biodegradability characteristics,biological toxicity,often need to be processed before discharge,thus not only requires a lot of processing costs,but also caused a lot of phosphorus resources waste.Therefore,how to reasonably and effectively deal with the waste acid is an important research topic of comprehensive utilization and environmental protection.The waste acid produced by pharmaceutical intermediates in the production process as the raw material,through carbonization method and ZSM-5 type molecular sieve adsorption of organic waste in phosphoric acid as adsorbent to purify the waste acid,in addition,also studied directly to the waste phosphoric acid as raw materials to prepare process route three polyphosphate sodium.The main work includes:Research of carbonization temperature and time on the treatment of waste acid;the molecular sieve adsorption temperature on the adsorption effect on the process of the dosage and frequency parameters such as adsorption time and molecular sieve,and discusses its adsorption behavior and the use of thermal regeneration regeneration temperature and regeneration time effect the regeneration efficiency of the molecular sieve;and to optimize the process conditions of preparing sodium tripolyphosphate by using waste phosphoric acid.The main conclusions are as follows:The content of organic matter in the spent phosphoric acid was significantly correlated with the carbonization time.The organic matter content during pyrolysis and carbonization decreased with the increase of carbonization temperature and the time of carbonization.The adsorption of organic waste phosphoric acid in ZSM-5 molecular sieve,Freundlich adsorption model,.Freundlich adsorption model with correlation coefficient higher than the Langmuir adsorption model can better express the adsorption of organic matter in line with the quasi two order kinetic equation model of adsorption process of.ZSM-5 molecular sieve adsorption than Langmuir model,the correlation coefficient of fitting(R~2)than a high,show that quasi two order kinetic equation can better describe the ZSM-5 molecular sieve adsorption process.The adsorption temperature is not conducive to the adsorption rate increased,the adsorption process is a physical adsorption process,after analysis,adsorption mainly occurs in the first 8 hours,so the adsorption time can refer to 8 h.when the amount is more than 20%,with the increase of amount of molecular sieve,adsorption capacity increase slowed,has almost reached the molecular sieve adsorption waste phosphoric acid solution containing organic substance in the upper limit When the zeolite is adsorbed five times,the molecular sieve can adsorb the organic matter in the waste phosphoric acid solution to 90%.The regeneration of molecular sieve using thermal regeneration method,when the molecular conditions of regeneration temperature is 500℃under the regeneration of the sieve,after regeneration adsorption performance is better than other regeneration temperature.When the regeneration temperature is 500℃,the regeneration time is 2~3 h,the regenerated molecular sieve can keep high adsorption performance in that.Has been basically completed the regenerative burning carbon,the adsorption properties of the molecular sieve has been recovered.The parameters of thermal regeneration:2 h.regeneration under 500℃.Using waste phosphoric acid process conditions for preparation of sodium tripolyphosphate,obtained the optimum conditions:in the neutralization time is 30 min~40 min,and the temperature is85 to 95℃,the pH value is 6.60~6.70,the amount of ethanol was 50%,the polymerization temperature is 420℃,polymerization time is 30 min~50 min.in the under the reaction conditions,can remove the system satisfying the sodium tripolyphosphate.This study provides some way for recycling of waste acid generated in the production process of pharmaceutical intermediates use,not only can solve the waste phosphoric acid caused by environmental pollution and other issues,but also can treat waste acid,waste,high economic and social benefits.