Process Optimization Of Guaiacol Sythesized By Diazotization-Hydrolyzation Process

Guaiacol is being widely utilized as an intermediate in fine chemical industry. It is an important raw material in pharmaceutical industry and in compound perfume production. Guaiacol is also frequently used in agriculture. Hence, it was significant to optimize the original mthyl catechol production process and provide technical foundation for the design, costruction and operation of the future3000t/a guaiacol production process in the Vanillin Factory of Jilin Petrochemical Company, China National Petroleum Corporation.Diazotization-hydrolyzation process is a frequently-used method for the production of guaiacol. In this process, guaiacol generated by the diazotization-hydrolyzation process is exempt from isomers, which is benefit for the purification of the product.With the purpose to optimize the production process of guaiacol through diazotization-hydrolyzation process, the diazotization, hydrolyzation and the guaiacol-water separation unit were studied, respectively. First, methods for realizing successive reaction and the optimal conditions and material mixture ratio for successive reaction were investigated. Second, the influences of hydrolyzation temperature, feeding duration and dilution degree of diazotization solution, dosage amount of catalyzer and addition of CUSO4sulution on the yield of guaiacol were investigated in the hydrolyzation process. Finally, in guaiacol-water separation process, the effects of extraction temperature, the flow rate of turbine extracting tower, the adsorption temperature and time on the separation efficiency of guaiacol and water through extraction and adsorption tests. The efficiency of turbine extracting tower in guaiacol and water separation was also analyzed.Results from the diazotization process optimization study showed that before diazotization, the temperature of the mixture of o-aminoanisole and H2SO4should be controlled below32℃, the temperature of the raw material system should be retained between5to10℃. After dosage, the reaction temperature should be regulated below15℃. In addition, a tube reactor was designed for the successive proceeding of diazotization and the retention time for the raw material in this reactor was at least4min. The hydrolyzation optimization research revealed that when the hydrolyzation temperature was105℃, the diazotization was double diluted, the dosage time was one hour, the CUSO4was35%(m/m) of the total hydrolyzation solution, the highest yield was acquired with an average of86.27%. The guaiacol and water separation process optimization process demonstrated that the turbine extraction technology was totally suitable for the separation of guaiacol and water. The highest extraction efficiency (99%) was acquired when the extraction temperature was55℃, the rotation speed was160～180rpm and the feeding flow rate was100-130L/h. The residual COD in the process wastewater was only2500mg/L.The optimized diazotization-hydrolyzation process has a promising perspective for the production of guaiacol. The adoption of this process could resolve the raw material source for the vanillin production in the Vanillin Factory of Jilin Petrochemical Company. Results obtained in this research provide scientific guidance for further industrialization, yield enhancement and cost reduction.