Modified Ionex Change Resin Catalyze The Synthesis Of Methyl Acetate

Methyl acetate is a kind of important industrial raw materials, traditional crafts usually use concentrated sulfuric acid as catalyst, but it was eliminated because of its significantly drawbacks. With the development of green chemistry, solid catalyst is widely noted, especially cation exchange resin. But on the one hand, the catalyze speed is too slow, on the other hand, it often loses its activity because of the ion exchange between the hydrogen ion on the resin and the metal ion which comes from industry. By using metal ions to modify the resin, it not only can improve its catalytic activity, but also can overcome the restrictions on industrial application.On this paper, we have selected acetic acid and methanol as raw materials, used modified ion exchange resin as catalyst, aimed at acetic acid conversion rate, we researched a series of factors which influence the esterification reaction. Details are as follows:1. Select the appropriate cationic exchange resin. Choose several different types of resins for esterification reaction under the same conditions, select the resin with the highest acetic acid conversion rate.2. Select the appropriate metal ions to modification with. We choose several kinds of metal ions to load and use them for the esterification reaction, select the metal ion with the highest acetic acid conversion rate.3. Optimization of load conditions. Metal ion concentration, load time and load temperature which influence the catalytic effect are respectively considered.4. Optimization of reaction conditions. We make the modified resin under optimized conditions above and consider reaction conditions such as the ratio of acid and alcohol, time, temperature and catalyst dosage.5. Experimental results are as follows:When the resin loads tetravalent tin, the catalytic effect is best and it is better than the unloaded one. Via orthogonal experiment, the optimum loading condition as follows:temperature is50℃; reaction time is3hours; load concentration is0.05mol per litre. The optimized reaction conditions are as follows:the mole ratio of acid and alcohol is1:1.3; reaction time is2.5h; temperature is60℃; dosage of catalyst is as much as20percent mass of acetic acid. Under conditions, the conversion can reach88.48percent, what’s more, the catalytic effect is still good after reusing five times.