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

1、<p>　　Separation of acetonitrile-ethyl acetate by extractive</p><p>　　distillation with mixed solvent</p><p>　　Li Chunli1, Zong Lili2 and Fang Jing</p><p>　　School of Chemical

2、Engineering, Hebei University of Technology, Tianjin, 30013</p><p>　　E-mail:lichunli_hebut@126.com, Tel: +86-022-60202246</p><p><b>　　Abstract</b></p><p>　　Computer-aide

3、d molecular design (CAMD) approach was bring in this work for selecting extractive solvents. The separation of acetonitrile-ethyl acetate Azeotropic system was carried out through a batch extractive distillation processe

4、s with N,N-dimethylformamide(DMF), glycol(EG) and DMF-EG mixture as solvents separately. The effects of different operating conditions were studied, solvents, ratio of mixed solvent, solvent flow rate and reflux ratio we

5、re all included. It was found that the mixed so</p><p>　　and EG ); when the solvent flow rate and reflux ratio increased, the separation effect of mixed solvent improved; under the conditions that solvent fl

6、ow rate was 20 mL/min, reflux ratio was 2, quality fraction of ethyl acetate in the top product could reach 99.62%.</p><p><b>　　Keywords</b></p><p>　　Separation; Batch extractive dis

7、tillation; Mixed solvents; Acetonitrile; Ethyl acetate</p><p>　　1.Introduction</p><p>　　Acetonitrile and ethyl acetate are widely used in chemical and pharmaceutical industries as chemical raw m

8、aterials and good organic solvent[1]. But the two form azeotrope, ethyl acetate hold 77% and the other 23% is acetonitrile(mass fraction), common distillation method can not make any effect. Therefore, some companies hav

9、e to treat them as waste, this not only cause seriously waste of resources and economy, but also pollute the environment. At present, Di Jiandong[2]of Tianjin university has </p><p>　　commercialized over the

10、 conventional distillation which may also be feasible but with substantial column investment. However, due to the problem of selectivity and solubility are often inconsistent in single solvent, limit its application and

11、development. Mixed solvents guarantee high selectivity, and improved solubility at the same time through the combination of main solvent and vice solvent[7]. In recent years, mixed solvents are applied more and more in e

12、xtractive distillation[8-11] .</p><p>　　This paper is devoted to the study of the separation of the mixture acetonitrile– ethyl acetate by using extractive batch distillation which extractive solvent is mixe

13、d solvents. First, the selection of an adequate extractive solvent is presented based on the computer aided molecular design of solvents for separation processes combining group contribution methods with graph principle.

14、 Later, results of several laboratory batch tests are presented serving for determination of the most effective s</p><p>　　2. Entrainer selection for the separation of acetonitrile– ethyl acetate mixture<

15、/p><p>　　The extractive distillation is generally applied to the separation of close-boiling mixtures, which by conventional distillation is difficult to separate. The design and optimization of extractive dist

16、illation is more complex than that of the conventional distillation when considering the selection of suitable solvent to enhance the separation. In the extractive distillation, the selection of a suitable solvent is fun

17、damental to ensure an effective and economical design. Currently, the solvent s</p><p>　　the basic physical and thermal properties. The basic molecular library is formed by using several limited rules of bas

18、ic physical properties. In the stage of solvent screening, the molecules in the basic molecular library are used directly. The candidate solvent molecules are obtained by using the solvent constraint and the appropriate

19、solvent molecules can be determined by using the refined calculation or checking property library.</p><p>　　According to the above method, we got some candidate solvents through the graph principle and group

20、 contribution method combined with computer-aided molecular design. After cautiously selected we obtained DMF and EG as solvents which are the most appropriate for the separation of acetonitrile– ethyl acetate.</p>

21、<p>　　3.Experiment supplies of the extractive distillation</p><p>　　3.1Materials</p><p>　　The component mass fraction of acetonitrile– ethyl acetate raw material is 0.77/0.23 (ethyl</p

22、><p>　　acetate/acetonitrile). The purity of DMF is 0.995 (mass fraction).The purity of EG is 0.995 (mass fraction).</p><p>　　3.2Equipment</p><p>　　Batch experiments were carried out in

23、 a small laboratory column to evaluate the feasibility of the new solvent. The glass column has a total height of 1.8 m and an internal diameter of 30mm. It is packed with stainless steel θ-rings of 3 mm × 3 mm. The

24、 total packed height is about 1.5m. The bottom is a 1500 ml flask with opening. The solvent is feed to the column from the top section. The flow rate is controlled by a rotameter. The reflux ratio is provided at the top

25、of the column by a solenoid </p><p>　　4.Results and discussion</p><p>　　In order to illustrate the effect of the new solvent to acetonitrile– ethyl acetate ,we do some experience to investigate

26、the technological parameters, and receive optimized operation conditions.</p><p>　　4.1Effects of different solvent</p><p>　　The effects of different solvent on the concentration of ethyl acetate

27、 in the top product were showed in Fig.2. To do this, some conditions were maintained: solvent flow rate was 15mL/min, solvent ratio(mass ratio of solvent to the product)was 4.0，reflux ratio was 1,n(DMF)：n(EG)=1:1 in the

28、 mixed solvent(DMF:N,N-dimethyformamide；EG: ethylene glycol).Fig.2 shows that the three solvents all has the function of increase the concentration of ethyl acetate in the top product, Destroy the azeotropic co</p>

29、<p>　　4.2Effects of mixed solvents with different ratio</p><p>　　The effects of mixed solvent with different ratio on the concentration of ethyl acetate in the top product are showed in Fig.3.</p&g

30、t;<p>　　Similarly, to do this, some conditions were maintained: solvent flow rate was 15mL/min, solvent ratio(mass ratio of solvent to the product)was 4.0，reflux ratio was 1.We can see from Fig.3 that while the th

31、e 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

32、 is 98.3104%.When the content of DMF in mixed solvent lower than 30%,the ma</p><p>　　the effect of the mixed solvent was weakened. According to these data, we think the mixed solvent that DMF/EG= 3/7 was the

33、 best.</p><p>　　4.3Effects of solvent flow rate</p><p>　　The effects of solvent flow rate on the concentration of ethyl acetate in the top product are showed in Fig.4.</p><p>　　In t

34、he 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 t

35、op 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 opera

36、tion time, energy needed in the tower bottom increase, i</p><p>　　5.Conclusion</p><p>　　We got DMF and EG as candidate solvents for acetonitrile– ethyl acetate separation through the graph princ

37、iple and group contribution method combined with computer-aided molecular design. The effect of the solvent was illustrated by experiment. From the result we can see that mixed solvent DMF-EG has a lot of advantage than

38、single DMF or EG solvent. Through the experiments we obtained the optimized operation parameters: the ratio of mixed solvent DMF/EG=3/7,flow rate of the mixed solvent was 20 </p><p>　　References</p>&

39、lt;p>　　[1] Cheng Nenglin. Solvents handbook[M]. Beijing: Chemical Engineering Press.2002.</p><p>　　[2] Di Jiandong. Study on separation of acetonitrile and ethyl acetate mixture by batch</p><p&

40、gt;　　azeotropic distillation[D].Tianjin. Tianjin University,2006.</p><p>　　[3] Ma Wenchan, Sun Jianjie. Study on separation of acetonitrile and ethyl acetate mixture by extractive distillation. Application C

41、hemical. 2010,39(5):781-782.</p><p>　　[4] R. Van Kaam, I. Rodríguez-Donis, V. Gerbaud. Heterogeneous extractive batch distillation of chloroform–methanol–water: Feasibility and experiments. Chemical Eng

42、ineering Science. 2008,63(1):78-94</p><p>　　[5] Jing FANG, Chunli LI, Honghai WANG, Lijun SUN. A Quasi-steady-state Model for Numerical Simulation of Batch Extractive Distillation Original Research Article.

43、Chinese Journal of Chemical Engineering.</p><p>　　2010,18(1): 43-47</p><p>　　[6] Estela Lladosa, Juan B. Montón, MaCruz Burguet. Separation of di-n-propyl ether and n-propyl alcohol by extr

44、active distillation and pressure-swing distillation: Computer simulation and economic optimization. Chemical Engineering and Processing: Process Intensification. 2011,50(11-12):1266-1274</p><p>　　[7] Lee F M

45、, Brown R E. Extractive distillation of hydrocarbon mixture employing mixed solvent[P]. US:4 954</p><p>　　224,1990-09-04.</p><p>　　[8] Paul Langston, Nidal Hilal, Stephen Shingfield, Simon Webb.

46、 Simulation and optimisation of extractive distillation with water as solvent. Chemical Engineering and Processing: Process Intensification.</p><p>　　2005,44(3):345-351</p><p>　　[9] Li Chunli, S

47、un Jingjing, Lv Jianhua. Study on mixed solvent for separating ethanol and water by using batch extractive distillation. Chemical Engineering China.2011,39(10):29-33</p><p>　　[10] Li Chunli,Li Lijie,Fang Jin

48、g. Separation of ethyl acetate-ethanol by batch extractive</p><p>　　distillation with mixed solvent. Petrochemical Technology.2010,39(11):1232-1235</p><p>　　[11] Gu zhenggui, Zhi Huizhen，Ma Zhen

49、gfei. Study on composite extractive distillation of</p><p>　　ethyl acetate-ethanol-water. Comput Appl Chem,2005,22(6):466-468</p><p>　　[12] Lang P,Lelks Z, Moszkowicz P.Batch Extractive Distilla

50、tion: The Process and the</p><p>　　Operational Policies. Chemical Engineering Science,1998,53(7):1331-1348.</p><p>　　www.bisheziliao.com</p><p><b>　　中文翻譯：</b></p>

51、<p>　　用混合溶劑萃取精餾分離乙腈-乙酸乙酯</p><p><b>　　摘要</b></p><p>　　計(jì)算機(jī)輔助分子設(shè)計(jì)（CAMD）方法是把在這項(xiàng)工作中選擇萃取溶劑。乙腈-乙酸乙酯共沸體系的分離是通過一批進(jìn)行萃取精餾過程與N，N-二甲基甲酰胺（DMF），乙二醇（EG）和dmf-eg混合物溶劑分別。不同的操作條件的影響進(jìn)行了研究，溶劑，混合溶劑的配

52、比，</p><p>　　溶劑流量和回流比均包括。結(jié)果發(fā)現(xiàn)，混合溶劑dmf-eg表現(xiàn)出更好的分離效果比單一溶劑。混合溶劑的最佳比例為3:7（DMF質(zhì)量和EG）；當(dāng)溶劑流量和回流比的增加，混合溶劑的分離效果改進(jìn)的；的條件下，溶劑的流速為20毫升/分鐘，回流比為2，質(zhì)量分?jǐn)?shù)</p><p>　　在產(chǎn)品乙酸乙酯可以達(dá)到99.62%。</p><p><b>　　

53、關(guān)鍵詞</b></p><p>　　間歇萃取精餾分離；；混合溶劑；乙腈；乙酸乙酯</p><p><b>　　1引言</b></p><p>　　乙腈和乙酸乙酯廣泛應(yīng)用于化工、醫(yī)藥等行業(yè)為化工原料材料和良好的有機(jī)溶劑[ 1 ]。但兩種形成共沸物，乙酸乙酯持有77%和另23%是乙腈（質(zhì)量分?jǐn)?shù)），普通精餾方法不做任何的效果。因此，一些公

54、司要把他們當(dāng)作廢物，這不僅造成嚴(yán)重的資源浪費(fèi)和經(jīng)濟(jì)，而且還污染環(huán)境。目前，翟建[ 2 ]天津大學(xué)實(shí)現(xiàn)了分離乙腈-乙酸乙酯由異質(zhì)批次共沸蒸餾醋，但收到的產(chǎn)品以這種方式具有較低的純度，但高能耗。根據(jù)溶解在乙腈和乙酸乙酯的差異水，馬汶川[ 3 ]采用液-液萃取使用水作為萃取劑的方法分離乙腈-乙酸乙酯，乙酸乙酯產(chǎn)品可以達(dá)到98.5%，但與乙腈混合豐富的水，所以乙腈的回收是很困難的。據(jù)我們所知，沒有了乙腈萃取精餾分離乙酸乙酯。近年來，應(yīng)用萃取精餾

55、[4-6]對(duì)近沸點(diǎn)混合物的分離已被廣泛接受商業(yè)化在傳統(tǒng)的蒸餾，也可能是可行的但有大量的柱投資。然而，由于對(duì)選擇性與溶解性問題往往是在單一溶劑不一致，限制了它的應(yīng)用與發(fā)展?；旌先軇┲校ＷC高選擇性，和改進(jìn)的溶解度在同時(shí)通過主溶劑、副溶劑[ 7 ]的組合。近年來，混合溶劑萃取精餾過程[8-11]越來越多的應(yīng)用。</p><p>　　本文用乙腈的混合物–乙酸乙酯的分離研究間歇萃取精餾，萃取溶劑的混合溶劑。首先，一個(gè)適當(dāng)

56、的選擇溶劑萃取是基于溶劑的計(jì)算機(jī)輔助分子設(shè)計(jì)分離了流程圖原理相結(jié)合的基團(tuán)貢獻(xiàn)法。后來，幾個(gè)實(shí)驗(yàn)室分批結(jié)果測(cè)試是為最有效的溶劑的測(cè)定。最后，主要經(jīng)營(yíng)</p><p>　　萃取精餾的工藝參數(shù)進(jìn)行了優(yōu)化。</p><p>　　2．乙腈的–乙酸乙酯混合物分離夾帶劑的選擇萃取精餾是普遍適用于近沸點(diǎn)混合物的分離，由傳統(tǒng)的精餾分離困難。與萃取精餾優(yōu)化設(shè)計(jì)比較比常規(guī)蒸餾時(shí)考慮合適的溶劑，提高選擇的復(fù)雜分離

57、。在萃取精餾，合適的溶劑的選擇是根本保證有效和經(jīng)濟(jì)的設(shè)計(jì)。目前，溶劑的選擇可以借助有效的處理計(jì)算機(jī)輔助分子設(shè)計(jì)（CAMD）的方法。</p><p>　　候選作為萃取溶劑的圖原理與基團(tuán)貢獻(xiàn)方法的選擇結(jié)合計(jì)算機(jī)輔助分子設(shè)計(jì)。首先，基于改UNIFAC法，功能組分和預(yù)先選定的系統(tǒng)根據(jù)一定的規(guī)則，然后自動(dòng)結(jié)合組用圖算法完成?；鶊F(tuán)貢獻(xiàn)的方法被用來獲得基本物理性能和熱性能。基本的分子庫是通過使用幾個(gè)有限的規(guī)則的形成基本物理性能

58、。在溶劑篩選階段，用于基本的分子庫的分子直接。采用溶劑約束和相應(yīng)的得到候選溶劑分子溶劑分子可以通過精確的計(jì)算和校驗(yàn)性能庫確定。根據(jù)上述方法，我們得到了一些候選溶劑通過圖的原則和組貢獻(xiàn)法結(jié)合計(jì)算機(jī)輔助分子設(shè)計(jì)。經(jīng)過慎重選擇我們得到的如DMF和溶劑是最合適的用于乙腈–乙酸乙酯的分離。</p><p>　　3的萃取精餾實(shí)驗(yàn)用品</p><p><b>　　3.1材料</b>

59、</p><p>　　乙腈–乙酸乙酯原料成分的質(zhì)量分?jǐn)?shù)為0.77/0.23（乙基醋酸乙烯/乙腈）。DMF純度為0.995（質(zhì)量分?jǐn)?shù)）。EG的純度為0.995（質(zhì)量分?jǐn)?shù)）。</p><p><b>　　3.2設(shè)備</b></p><p>　　批實(shí)驗(yàn)是在一個(gè)小的實(shí)驗(yàn)室柱評(píng)價(jià)新的可行性進(jìn)行了溶劑。玻璃柱總高度1.8米，內(nèi)部直徑30mm。這是擠滿了不銹

60、鋼θ- 3毫米3毫米×環(huán)。總的填料高度約150萬。底部是一個(gè)1500毫升瓶與開放。溶劑是飼料從上節(jié)柱。的流量由流量計(jì)控制?；亓鞅仁峭ㄟ^電磁閥柱的頂部設(shè)有。示意圖顯示在圖1。</p><p><b>　　4．結(jié)果與討論</b></p><p>　　為了說明新的溶劑效應(yīng)對(duì)乙腈–乙酸乙酯，我們做的一些經(jīng)驗(yàn)研究了工藝參數(shù)，得到優(yōu)化的操作條件。不同的溶劑4.1effe

61、cts在不同溶劑中的頂級(jí)產(chǎn)品乙酸乙酯的濃度的影響表現(xiàn)在圖2。</p><p>　　為此，一些條件下保持：溶劑流速為15ml/min，溶劑比（質(zhì)量比溶劑對(duì)產(chǎn)品）為4，回流比為1，n（DMF）：n（EG）＝1:1的混合溶劑（DMF：N，N—二甲基甲酰胺；例如：乙二醇）。圖2顯示三溶劑都有增加的功能在產(chǎn)品乙酸乙酯濃度，破壞共沸組成。當(dāng)溶劑DMF或如只在頂級(jí)產(chǎn)品，乙酸乙酯的濃度是90.4%和93.9%，但當(dāng)使用N（DMF

62、）：n（EG）＝1:1作溶劑，濃度增加到97.7678%，效果明顯優(yōu)于單一溶劑。這是由于DMF的強(qiáng)溶解性組合和高效的選擇性他們相互補(bǔ)充、相互促進(jìn)，從而揭示了在混合溶劑的濃度的效果更好</p><p>　　乙酸乙酯比單一溶劑乙腈。–乙酸乙酯相對(duì)波動(dòng)是在一個(gè)大的改變程度，使分離效率提高，產(chǎn)品的純度提高。用不同比例的混合溶劑</p><p>　　4.2以不同配比對(duì)產(chǎn)品</p>&l

63、t;p>　　頂部的乙酸乙酯混合溶劑的濃度的影響顯示在圖3。同樣，要做到這一點(diǎn)，一定條件下保持：溶劑流速為15ml/min，溶劑比（質(zhì)量溶劑對(duì)產(chǎn)品比）為4，回流比為1。從中我們可以看到，在圖的內(nèi)容DMF混合溶劑中的頂級(jí)產(chǎn)品的增加，先增加后的乙酸乙酯的濃度</p><p>　　減少，當(dāng)DMF含量為30%，乙酸乙酯的濃度最高，是98.3104%。當(dāng)DMF混合溶劑中的含量低于30%，主要溶劑如保證混合溶劑的選擇性，

64、但增加了改進(jìn)的DMF混合溶劑的溶解度，從而表現(xiàn)出更好的的影響。當(dāng)含DMF混合溶劑中高于30%，乙二醇的選擇性逐漸下降，所以混合溶劑的作用減弱。根據(jù)這些數(shù)據(jù)，我們認(rèn)為DMF／乙二醇混合溶劑= 3 / 7是最好的。</p><p>　　4.3溶劑流量的影響</p><p>　　在塔頂產(chǎn)物乙酸乙酯濃度的溶劑流量的影響表現(xiàn)在圖4。</p><p>　　在

65、上述條件下，優(yōu)化，我們調(diào)查的影響，對(duì)塔頂產(chǎn)品濃度的乙酸乙酯回流比。從線圖，我們發(fā)現(xiàn)在回流比的增加，產(chǎn)品的頂部增加乙酸乙酯的濃度，而回流比超過2，產(chǎn)品純度的幾乎恒定的。另一方面，超過回流比會(huì)帶來一些問題，如延長(zhǎng)運(yùn)行時(shí)間，在塔的底部增加所需的能量，影響生產(chǎn)效率等。所以我們應(yīng)該減少在保證質(zhì)量的前提下，回流比。在這種情況下，我們選擇了2個(gè)合適的回流比。</p><p><b>　　5．結(jié)論</b>&

66、lt;/p><p>　　我們得到了DMF，如通過圖的原理與基團(tuán)貢獻(xiàn)法結(jié)合計(jì)算機(jī)輔助分子設(shè)計(jì)–乙酸乙酯分離的候選溶劑乙腈。通過實(shí)驗(yàn)說明了該溶劑的效果。從結(jié)果中我們可以看到，混合溶劑dmf-eg具有許多優(yōu)點(diǎn)，比單一溶劑DMF或如。通過我們得到了優(yōu)化的操作參數(shù)的實(shí)驗(yàn)：混合溶劑DMF／EG = 3 / 7的比例，混合溶劑的流速為20毫升/分鐘，回流比為2。</p><p>

67、;<b>　　參考文獻(xiàn)</b></p><p>　　【1】程能林。溶劑手冊(cè)[M].。北京：化學(xué)工程press.2002。</p><p>　　【2】翟建。通過批乙腈和乙酸乙酯的混合物的分離研究</p><p>　　共沸蒸餾的研究[D]。天津。天津大學(xué)2006。</p><p>　　【3】馬汶川，太陽簡(jiǎn)介。通過對(duì)萃取精餾分

68、離乙腈和乙酸乙酯混合物的研究。應(yīng)用化學(xué)。2010,39（5）：781-782。</p><p>　　[ 4 ] R. Van Kaam，即Rodríguez當(dāng)尼斯，瑞波節(jié)。異構(gòu)的間歇萃取精餾的氯仿甲醇水––：可行性和實(shí)驗(yàn)。化學(xué)工程科學(xué)。2008,63（1）：78-94</p><p>　　【5】京房，春麗李，王洪海，孫立軍。用于間歇萃取精餾的原始研究論文數(shù)值模擬的準(zhǔn)穩(wěn)態(tài)模型。中國(guó)

69、化學(xué)工程學(xué)報(bào)。</p><p>　　2010,18（1）：43-47</p><p>　　[ 6 ]愛斯特拉lladosa，胡安B. MontóN，Macruz布爾格特。采用萃取精餾法和變壓精餾分離二丙醚和正丙醇：計(jì)算機(jī)仿真和優(yōu)化經(jīng)濟(jì)?；瘜W(xué)工程與工藝：過程強(qiáng)化。2011,50（11）：1266-1274</p><p>　　【7】李F M，棕R E萃取精餾

70、采用混合溶劑的烴混合物的研究[J ]。美國(guó)：4954</p><p>　　2241990-09-04。</p><p>　　[ 8 ]保羅蘭斯頓，尼達(dá)爾希拉爾，史蒂芬shingfield，西蒙韋伯。仿真和優(yōu)化水萃取精餾溶劑?；瘜W(xué)工程與工藝：過程強(qiáng)化。</p><p>　　2005,44（3）：345-351</p><p>　　[ 9 ]李春

71、利，孫菁菁，LV建華。利用間歇萃取精餾分離乙醇和水的混合溶劑的研究。中國(guó)化學(xué)工程。2011,39（10）：29-33.</p><p>　　[ 10 ]李春利，李麗潔，方靜。通過間歇萃取分離乙酸乙酯-乙醇</p><p>　　混合溶劑蒸餾。石化技術(shù)。2010,39（11）：1232-1235</p><p>　　【11】顧正規(guī)，智惠貞，馬正飛。復(fù)合萃取精餾的研究&l