發(fā)布時間：2018-04-12 09:58

  本文選題：乙酰甲胺磷 + 乙酰精胺�。� 參考：《湘潭大學》2017年碩士論文

【摘要】：乙酰甲胺磷,CAS登記名稱為O,S-二甲基-N-乙�；虼柞０�,是一種新型的乙�；袡C磷殺蟲劑,具有廣譜高效、低毒低殘留、持效期長、抗藥性好等優(yōu)點,相信在未來的農藥市場上一定會取代甲胺磷成為大噸位品種而大放異彩。但是目前乙酰甲胺磷的生產,還是存在著反應收率低,后處理分離不徹底,會產生大量難以處理的有機磷廢水,以及操作過程復雜,生產成本高等缺點。因此,對乙酰甲胺磷的合成工藝進行優(yōu)化改進并對其酰化反應液中副產物的分離及回收利用,不僅具有重要的經(jīng)濟價值,更具有節(jié)約自然資源,減少環(huán)境污染,利于使用推廣等社會價值。本論文針對乙酰甲胺磷生產工藝上的缺點,進行了詳細的優(yōu)化和改進。首先,在甲胺磷的異構化階段,提出利用結晶和萃取來分離溶液中剩余10%左右未反應完全的原料精胺,以提高溶液中甲胺磷純度和下一步�；磻x擇性。其次,在乙酰甲胺磷反應液的后處理分離步驟,針對具有腐蝕性的乙酸,采取減壓蒸餾的方法,在壓力-0.08MPa,溫度55℃的條件下減壓蒸餾1小時可以分離回收58%的乙酸,剩余的乙酰甲胺磷過飽和溶液則在適宜條件下繼續(xù)結晶可以得到總收率65.83%,質量分數(shù)98.53%的乙酰甲胺磷晶體。再次,對乙酰甲胺磷反應液進行了萃取分離實驗,通過有機溶劑萃取來分離�；磻褐幸阴＞泛鸵宜�。實驗篩選甲苯作為萃取劑,在萃取溶劑與反應液質量配比1.25:1,萃取溫度45℃,萃取時間60min、靜止時間90min的最優(yōu)化條件下,乙酰精胺和乙酸與乙酰甲胺磷的分離系數(shù)大于1,能夠被有效地萃取分離。同時為了增強萃取傳質分離效果,開展了多級逆流萃取實驗,實驗結果表明當萃取級數(shù)為5時,乙酰精胺和乙酸分別能達到97.63%和98.77%的萃取率,分液后的萃取相和萃余相經(jīng)過繼續(xù)結晶,可以分別得到高純度的乙酰精胺晶體和乙酰甲胺磷晶體。最后,對不同原料來源的乙酰精胺異構化反應進行了研究,以硫酸二甲酯為催化劑,加入原液質量分數(shù)10%~12%或18%不等的催化劑,反應3~4小時,得到的乙酰甲胺磷反應液最大收率為55%,選擇性可以大于100%,為分離回收的乙酰精胺合理利用提供了依據(jù)。
[Abstract]:Cas is a new type of acetylated organophosphorus insecticide, which has the advantages of broad spectrum efficiency, low toxicity and low residue, long duration of efficacy and good resistance to insecticides, and is a new type of acetylated organophosphorus insecticide.It is believed that methamidophos will be replaced by methamidophos as a large tonnage variety in the future pesticide market.However, at present, the production of acephate still has some shortcomings, such as low yield of reaction, incomplete separation after treatment, large amount of organic phosphorus wastewater which is difficult to treat, complex operation process, high production cost and so on.Therefore, the optimization and improvement of the synthetic process of acetamidophos and the separation and recovery of by-products from acylation reaction solution not only have important economic value, but also save natural resources and reduce environmental pollution.It is beneficial to use and popularize social value.In this paper, the shortcomings of acephate production process were optimized and improved in detail.Firstly, in the isomerization stage of methamidophos, it is proposed that the remaining 10% or so unreacted spermine can be separated by crystallization and extraction in order to improve the purity of methamidophos in the solution and the selectivity of acylation reaction in the next step.Secondly, in the post-treatment and separation step of acephate reaction liquid, for the corrosive acetic acid, the method of vacuum distillation was adopted. Under the pressure of -0.08 MPA, the temperature of 55 鈩，

本文編號：1739254