【摘要】 本文采用改进的遗传算法设计了醋酸甲酯-甲醇体系萃取精馏萃取剂,根据体系特征选取特定基团,采用子基团号直接替代基团的编码方案,设计出的分子以数字形式体现,简化传统遗传算法编码方式,提高算法运行效率。对操作算子中的选择算子,交叉算子进行了改进,避免了遗传算法自身缺陷。为了全面评价采用改进遗传算法设计的醋酸甲酯-甲醇体系萃取精馏萃取剂,本文建立了模糊综合评价的优化筛选方法,从选择性,溶解度,热容,粘度,相对分子量,沸点及毒性等方面对设计出的萃取剂进行综合评判,使评价结果更加可靠。设计结果表明:采用该设计方法设计的萃取剂如水,二甲亚砜,丙三醇和乙二醇等与工业生产上使用的萃取剂具有很好的一致性。且设计出的萃取剂水和丙三醇相对挥发度的预测值与文献报道值相对偏差分别为0.71%和6.35%。醋酸甲酯-甲醇体系萃取剂设计过程主要考虑分离效果方面的性能,在化工生产中还需要考虑萃取剂的可操作性和经济成本,对设计结果中的典型分子,采用模糊综合评价的方法对其进行优劣判断。筛选评价结果显示从醋酸甲酯-甲醇体系萃取精馏分离效果、可操作性和经济性综合考虑,水,二甲亚砜,丙三醇,乙二醇及十一烷是效果较好的萃取剂。设计和筛选结果表明本文研究方法具有较好的可靠性和应用价值。更多还原

【Abstract】 A novel method based on computer optimization design method for designing extractants for methyl acetate-methanol system was presented.It was composed of the modified genetic algorithm and computer optimization screening method.In order to greatly enhance the algorithm performing efficiency,a new encoding scheme was developed.Groups were represented by their own group numbers,and the molecular structure was described by string figures and "*".To prevent the random errors of selecting molecules and losing good solutions in generation reproduction,a cross generatent elitist selection operator and dislocation crossover operator had been comprised.For the methyl acetate-methanol system,water,dimethyl sulfoxide,propanetriol,glycol and so on were the better solvents.The average relative deviation between prediction values and experiments values reported in the literatures of relative deviation in water and propanetriol were 0.71% and 6.35%,respectively.In order to estimate the obtain extractants comprehensively,a model for the comprehensive judgement of extractants in which seven factors including selectivity(40%),solubility(20%),viscosity(10%),heat apacity(10%),boiling poin(8%),molecular weight(6%) and toxicity(6%) were considered.The screening results showed that water,dimethyl sulfoxide and propanetriol were the better solvents.The designing and screening results are similar as the literatures reported.The accuracy and reliability of the method have been verified.更多还原