化工外文文獻(xiàn)翻譯--用混合溶劑萃取精餾分離乙腈-乙酸乙酯(編輯修改稿)
2025-06-26 15:22 本頁面
【文章內(nèi)容簡介】 e to investigate the technological parameters, and receive optimized operation conditions. of different solvent The effects of different solvent on the concentration of ethyl acetate in the top product were showed in . To do this, some conditions were maintained: solvent flow rate was 15mL/min, solvent ratio(mass ratio of solvent to the product)was ， reflux ratio was 1,n(DMF)： n(EG)=1:1 in the mixed solvent(DMF:N,Ndimethyformamide； EG: ethylene glycol). shows that the three solvents all has the function of increase the concentration of ethyl acetate in the top product, Destroy the azeotropic position. When the solvent is DMF or EG only, the concentration of ethyl acetate in the top product will be % and %, when use n(DMF)：n(EG)=1:1 as solvent, the concentration will increase to %,the effect obviously superior to the single solvent. This due to bination of the strong solubility of DMF and the efficient selectivity of EG. They plement and promote each other, so the mixed solvent reveals better effect on the concentration of ethyl acetate than single solvent. The relative volatility of acetonitrile– ethyl acetate was changed in a large extent ,so that the separation efficiency improved and the purity of product increased. of mixed solvents with different ratio The effects of mixed solvent with different ratio on the concentration of ethyl acetate in the top product are showed in . Similarly, to do this, some conditions were maintained: solvent flow rate was 15mL/min, solvent ratio(mass ratio of solvent to the product)was ， reflux ratio was can see from that while the the content of DMF in mixed solvent increase, the concentration of ethyl acetate in the top product increase first and then decrease, and when the content of DMF was 30%,the ethyl acetate own the highest concentration that is %.When the content of DMF in mixed solvent lower than 30%,the main solvent EG ensure the selectivity of the mixed solvent, but added of DMF improved the solubility of the mixed solvent, so show better effect. When the content of DMF in mixed solvent higher than 30%, the selectivity of EG decreased gradually, so the effect of the mixed solvent was weakened. According to these data, we think the mixed solvent that DMF/EG= 3/7 was the best. of solvent flow rate The effects of solvent flow rate on the concentration of ethyl acetate in the top product are showed in . In the above conditions that be optimized, we investigated the effect on the reflux ratio on the concentration of ethyl acetate in the top product. From the line chart we find that the concentration of ethyl acetate in the top product increase with the increase of reflux ratio, while the reflux ratio exceed 2,the purity of the product will almost constant. On the other hand, exceed reflux ratio will bring some problems, such as extend operation time, energy needed in the tower bottom increase, influence production efficiency and so on. So we should decrease the reflux ratio in the premise of quality assurance. In that case, we chose 2 as suitable reflux ratio. We got DMF and EG as candidate solvents for acetonitrile– ethyl acetate separation through the graph principle an
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