摘要
甲缩醛是一种重要的化工原料,是由甲醇和甲醛反应生成,由于甲缩醛和甲醇存在共沸,普通精馏难以提纯至99%以上,需采用特殊精馏加以分离。N,N-二甲基甲酰胺(DMF)是一种高沸点的含氮类有机溶剂,通过氢键与甲醇形成络合物降低甲醇的挥发度,提高甲缩醛对甲醇的相对挥发度,从而使甲缩醛和甲醇较易分离。本文利用化工流程模拟软件Aspen Plus采用萃取精馏,以DMF为萃取剂,对甲缩醛生产中的产品精制进行了模拟计算,详细分析了萃取精馏塔理论板数、进料位置、溶剂比和回流比对产品浓度的影响,结果表明,最优工艺方案为:理论板数30,甲缩醛进料位置23,萃取剂进料位置4,溶剂比1.0,回流比1.8,塔顶产品甲缩醛含量达到99.9%,为分离过程的优化操作和设计提供依据。
The methylal is an important chemical material, which is reacted by methanol and formaldehyde. Ordinary distillation is difficult to be purified to more than 99%, because methylal and methanol can form azeotrope. SO they require the use of special distillation to be separated. N,N-dimethyl formamide （DMF） is a high boiling point of nitrogen-containing organic solvent, which reduces the volatility of methanol through hydrogen bonds with methanol to form complexes. Accordingly it improves methylal the relative volatility of methanol accordingly, which make methylal and methanol easier separation. In this paper, the process simulation software, Aspen Plus was used to simulate the extractive distillation in the process of methylal purification, and DMF was used as extractive agent. The influence of theory stage, feed location, ratio of extractive agent and reflux ratio on the methylal purification were detailed analyzed. The results showed the optimal condition： the number of theory plates is 30, the DMF feed location was at 4# plate, the methylal feed location was at 23# plate, the ratio of extractive agent was 1.0, reflux ratio was 1.8, the concentration of methylal caught reach 99,9 % at the top of tower. The results caught be provided for the design and operation of the purifying methylal in its industrial production.
出处
《计算机与应用化学》
CAS
CSCD
北大核心
2012年第11期1343-1346,共4页
Computers and Applied Chemistry
基金
福建省教育厅资助项目(JB11139)
