Abstract
The epichlorohydrin (ECH) were prepared by the method of dichloropropanol (DCH) saponified with Ca(OH)2, while using Ca(OH)2 as reactant, it could bring out some disadvantages, such as equipment jam and environment pollution. In this research, NaOH had been used as the alkali instead of Ca(OH)2 to react with the DCH to resolve the above questions. Firstly, the reaction kinetics of DCH saponification and ECH hydrolysis under NaOH circumstances were obtained by the experiments. Secondly, based on the obtained reaction kinetics and the appropriate thermodynamics, the mathematic models of DCH saponification processes under Ca(OH)2 and NaOH circumstances were built respectively. Thirdly, with comparison and analysis of the two cases, the operation parameters of DCH saponified in NaOH case had been optimized and gained the appropriate operation parameters. The results showed that, in the NaOH case the reaction speed of DCH saponification and ECH hydrolysis were more quickly compared to Ca(OH)2 case. So, if taking the NaOH instead of Ca(OH)2 as alkali, the residence time of reactants must been considered in order to reduce the ECH hydrolysis. Compared to Ca(OH)2 case, the optimum operating condition in NaOH case were modified. The results showed that in the feasible conditions, using NaOH instead of Ca(OH)2 as alkali in the saponification process could be achieved. And more, the CODs (Chemical Oxygen Demands) in wastewater was not yet increase, while the yield of ECH increased from 96.21 % (in case of Ca(OH)2) to 98.44 % (in case of NaOH).
