二十五万吨二甲醚及甲醇精馏系统设计论文21170.docx

摘 要二甲醚（DME）具有一系列优良的物化性质，可以用于制药、染料和制冷剂等，此外，二甲醚作为一种新型的清洁能源，市场前景非常乐观。所以对二甲醚生产工艺的研究非常有意义。 本文在文献资料的基础上选用甲醇气相脱水法制取二甲醚，所得产品为粗二甲醚。二甲醚的分离是一个三组分的分离，所以本设计采用两个简单精馏塔，即一个二甲醚精馏塔和一个甲醇精馏塔来将三种物质分离。为了节约原料和减少成本，对二甲醚精馏塔塔底馏分中的甲醇进行回收提纯，继而将分离得到的甲醇气化得到气化甲醇，重新应用到生产流程中，使工艺流程更加合理化。二甲醚精馏系统中残留甲醇的纯度比较低，是含有水的双组份系统，会对反应的收率产生很大的影响，不能直接用于原料使用。故本文在二甲醚精馏塔的基础上对其产生的尾气进行再精馏，以充分提纯其中的甲醇。文中对二甲醚精馏系统全流程进行了物料和能量衡算，并对甲醇精馏塔进行了工艺设计计算，主要包括塔径、筛板塔尺寸、塔高以及除沫器、吊柱等附件的设计与选型。关键词：二甲醚 甲醇 精馏 工艺设计AbstractDimethyl ether（DME），which has many excellent physical and chemical properties for manufacturing pharmacy，dye，pesticide and refrigerant and so on，is widely used as raw materials。As a novel clean fuel，DME has a very promising future for developments。So，it is magnificent to study on the process of producing DME。Based on the literature summarize，the paper chooses methanol gas phase dehydration to make DME，and the product is called thick DME。Separation of DME is a separation of three components of the multi-component. Therefore, this design uses two simple distillation column, one of DME and one of methanol recovery. In order to save the material costs as much as possible, purifying the methanol in the DME ditillation bottoms fraction，and then the isolated methanol gasification gasified methanol, re-applied to the production process, so that process could be rationalized.The remaining methanol of DME distillation system is relatively low purity，which is a two-component system containing water，so it will have a huge impact on the yield，and it can not be used for feedstock directly.Therefor re- distillation the mixture generated by the DME distillation column in this article，and purify its methanol fully. The whole process of the material and energy balance of the DME distillation system has been introduced in this test，and the process design calculations of the methanol distillation was also carried out .Which including the design of diameter and higher of tower,sieve clumn dimensions,davit and other accessories selection.Keywords