異丙醇-水-堿/乙二醇物系常壓汽液平衡數據的測定

石油化PETROCHEMICAL TECHNOLOGY2006年第35卷第5期異丙醇一水一堿/乙二醇物系常壓汽液平衡數據的測定曾妮,張頌紅,姚克儉(浙江工業(yè)大學(xué)化學(xué)工程與材料學(xué)院綠色化學(xué)合成技術(shù)國家重點(diǎn)實(shí)驗室培育基地浙江杭州310032)[摘要]在常壓下,用循環(huán)式汽液平衡釜測定了異丙醇一水-氫氧化鉀(氫氧化鈉或醋酸鉀)/乙二醇物系的汽液平衡數據,其中氧化鉀(氫氧化鈉或醋酸鉀)/乙二醇作為復合溶劑,v(復合溶劑):(異丙醇一水)分別為0.5:1,1;1,2:1。實(shí)驗結果表明氫氧化鉀(氫氧化鈉)/乙二醇復合溶劑可消除異丙醇-水的共沸點(diǎn)并顯著(zhù)提高異丙醇-水的相對揮發(fā)度;當脫除復合溶劑后液相異丙醇的摩爾分數小于80%時(shí),氫氧化鉀(氫氧化鈉)/乙二醇復合溶劑對異丙醇一水的分離效果優(yōu)于醋酸鉀/乙二醇復合溶劑。用 Wilson模型對實(shí)驗數據進(jìn)行關(guān)聯(lián)汽相組分的平均偏差小于0.02。[關(guān)鍵詞]異丙醇;乙二醇;氫氧化鉀;氫氧化鈉;醋酸鉀;復合溶劑;汽液平衡[文章編號]1000-8144(2006)05-0448-04[中圖分類(lèi)號]TQ013.1[文獻標識碼]AVapor-Liquid Equilibrium of Isopropanol-Water-Alkali/Glycol Systemat Atmospheric PressureZeng Ni, Zhang Songhong, Yao KejianState Key Laboratory Breeding Base of Green Chemistry Synthesis Technology, College ofChemical Engineering and Materials Science, Zhejiang University of Technology, Hangzhou Zhejiang 310032, China)[Abstract Vapor-liquid equilibrium( VLE )of isopropanol-water-alkali/glycol system was measuredat atmospheric pressure. The alkali referred to potassium hydroxide or sodium hydroxide or potassiumacetate In the above system, glycol containing potassium hydroxide or sodium hydroxide or potassiumacetate formed a composite solvent. The volume ratios of composite solvent to isopropanol-water were0.5: 1, 1: 1 and 2: 1, respectively. Thermodynamic consistency for experimental data of isopropanolwater system was confirmed by means of Herington method. Azeotropic point of isopropanol-watercould be eliminated by adding composite glycol solvent containing potassium hydroxide or sodiumhydroxide. When mole fraction of isopropanol in liquid phase was less than 80% after removal ofcomposite glycol solvent from the system, the increase of relative volatility of isopropanol-water bycomposite glycol solvent containing potassium hydroxide or sodium hydroxide was obviously largerthan that of containing potassium acetate. vle data were correlated with Wilson model. Results showedthat average deviation of vapor-phase composition was less than 0. 02Keywords] isopropanol; glycol; potassium hydroxide; sodium hydroxide; potassium acetatecomposite solvent; vapor-liquid equilibrium異丙醇是一種重要的有機化工原料和有機溶著(zhù)提高異丙醇-水的相對揮發(fā)度,并可有效地減少劑,廣泛應用于油漆、油墨、農藥、合成樹(shù)脂、醫藥等萃取劑的用量3。鮑靜等對異丙醇-水-含方面2。常壓下異丙醇與水形成共沸物,共沸點(diǎn)鹽/堿復合溶劑物系的汽液平衡進(jìn)行了研究,研究溫度為80.31℃,共沸組分中異丙醇的質(zhì)量分數為結果表明,在溶劑已加鹽的基礎上再加入適量的堿87.4%。因此,用一般的精餾方法難以獲得高純度的異丙醇,需要采用特殊精餾或其他分離方法。[收稿日期]2005-12-28;[修改稿日期]2006-01-24。人們對加鹽萃取精餾分離異丙醇-水物系進(jìn)作者簡(jiǎn)介]曾妮(198-),女,廣西省桂林市人,碩士生。聯(lián)系人行了許多研究,結果表明,在萃取劑中加入鹽可顯姚克儉電話(huà)0571-88020706,電郵 aoki@ zjut. edu.cm第5期曾妮等.異丙醇-水-堿/乙二醇物系常壓汽液平衡數據的測定可進(jìn)一步提高異丙醇-水的相對揮發(fā)度。林軍1.3實(shí)驗方法等對加堿萃取精餾制無(wú)水乙醇進(jìn)行了初步探討首先配制氫氧化鉀/乙二醇、氫氧化鈉/乙二醇通過(guò)加堿萃取精餾可有效分離乙醇和水,但加堿萃醋酸鉀/乙二醇復合溶劑,在乙二醇中加堿或鹽的量取精餾制取無(wú)水異丙醇的過(guò)程尚未進(jìn)行深入的為0.15g/mL。按V(復合溶劑):V(異丙醇-水)研究。(溶劑比)為0.5:1,1:1,2:1的比例配制溶液,將本工作在常壓下,以氫氧化鉀(氫氧化鈉或醋溶液加入到汽液平衡釜中并加熱至沸騰。用校正后酸鉀)乙二醇為復合溶劑,測定了異丙醇-水-復的溫度計(精度為0.1℃)測量沸騰室頂部的溫度,合溶劑物系的汽液平衡數據。當溫度不再變化時(shí)視系統達到平衡狀態(tài),保持平衡狀態(tài)1h以上,用微量取樣針取樣,進(jìn)行分析。1實(shí)驗部分1.4分析方法11試劑采用日本島津公司生產(chǎn)的GC-14B型氣相色異丙醇和乙二醇:均為分析純經(jīng)色譜分析無(wú)雜譜儀對試樣進(jìn)行分析,色譜數據采用浙江大學(xué)生產(chǎn)質(zhì)峰;氫氧化鉀氫氧化鈉醋酸鉀:均為分析純使的2010型色譜數據工作站處理。色譜分析條件為:用時(shí)進(jìn)行脫水處理;水為去離子水。填充柱 Porpark-Q,中3mm×3m,熱導檢測器,柱12實(shí)驗儀器與熱力學(xué)一致性檢驗溫200℃,進(jìn)樣溫度220℃,檢測器溫度220℃,載采用天津大學(xué)生產(chǎn)的CE-2型循環(huán)式汽液平氣為H2,采用校正面積歸一化法定量。衡釜測量汽液平衡數據。為了檢驗實(shí)驗數據的可靠性,首先測定了常壓下異丙醇-水二組分物系的汽2結果與討論液平衡數據,測定結果與文獻[10]值一致,用2.1汽液平衡數據Herington法對異丙醇-水二組分物系的汽液平衡在常壓下,測定了溶劑比分別為0.5:1,1:1數據進(jìn)行熱力學(xué)一致性檢驗,結果符合熱力學(xué)2:1時(shí)的異丙醇-水-復合溶劑物系的汽液平衡數致性。據,實(shí)驗結果見(jiàn)表1~3表1異丙醇(1)-水(2)-氫氧化鉀/乙二醇(3)物系的汽液平衡數據Table 1 Vapor-liquid equilibrium data of isopropanol(1)-water(2)potassium hydroxide/ glycol( composite solvent)(3)v( Composite solvent): V(Isopropanol +H,o)0.5:1(I)l:1(Ⅱ)2:1(Ⅲ)T/KT/KyI361.60.8860.863372.3361.30.8080.8860.7650.901371.60.902360.90.7010.871371.20.556359.80.5180.7550.0.833371,10.368359.70.2160.718360.40.1840.6000.2220.677373.00.1610.525376.2364.30.0730.4470.119377,70.493368,40.0840.5140.417x 1: Mole fraction of isopropanol in liquid phase when composite solvent had been eliminated; y1 mole fraction of isopropanol in vapor phase whencomposite solvent had been eliminated2.2討論小于80%時(shí),氫氧化鉀(氫氧化鈉)乙二醇復合溶加入復合溶劑能使異丙醇-水物系的異丙醇劑對提高異丙醇-水的相對揮發(fā)度的效果優(yōu)于醋汽相組成大于共沸組成,說(shuō)明異丙醇-水的共沸點(diǎn)酸鉀/乙二醇復合溶劑。這是由于氫氧化鉀(氫氧消失。加入氫氧化鉀(氫氧化鈉)/乙二醇復合溶化鈉)溶于乙二醇中形成溶堿萃取劑,其中一部分劑,均能使異丙醇-水的共沸點(diǎn)消失,相對揮發(fā)度堿與乙二醇發(fā)生可逆反應(以氫氧化鉀為例),如顯著(zhù)提高,且加入氫氧化鉀的效果優(yōu)于加人氫氧化式(1)鈉。當脫除復合溶劑后液相中異丙醇的摩爾分數C2HO, + KOHC,H,O,K+H,O450PETROCHEMICAL TECHNOLOGY2006年第35卷表2異丙醇(1)-水(2)-氫氧化鈉乙二醇(3)物系的汽液平衡數據Table 2 Vapor-liquid equilibrium data of isopropanol(1 )-water(2)-sodium bydroxide/ glycol( composite solvent)(3)v( Composite solvent): V( Isopropanol+H,O)0.5:1(Ⅳ)1:1(V)2:1(Ⅵ)T/KT/KT/K0.9270.897371.80.9030.7650.860362.80.829371.10.6820.6983710.5780.7650.434362.2359.60.1940.626362.3360.90000.774373.50.707375.00.1600.610376.50.0860.492364.40.1580.0420.3850.4160.0930.5550.3680.351368.7379.1表3異丙醇(1)-水(2)-醋酸鉀/乙二醇(3)物系的汽液平衡數據Table 3 Vapor-liquid equilibrium data of isopropanol( 1 )-water(2)-potassium acetate/glycol( composite solvent)(3)-y Composite solvent): V( Isopropanol +H,O)0.5:1(Ⅶ)1:1(Ⅷ)2:1(Ⅸ)T/K363.30.937366.80.8520.371.30.879362.8370.80.759361.20.6380.774366.30.802370.6360.3370.20.3000.4369.9360.30.5440.2890.6150.3061.50.245371.3363.40.0860.407372.20.4230.290368.0374.6式(1)中的乙二醇鉀起著(zhù)“載體”的作用,它與因此在堿和乙二醇的雙重作用下,異丙醇-水的相被分離物系中的水發(fā)生反應生成乙二醇和氫氧化對揮發(fā)度得到了較大的提高鉀,相當于乙二醇鉀將物系中的水不斷地帶出,而它2.3實(shí)驗數據的關(guān)聯(lián)本身不發(fā)生變化,只起著(zhù)遷移水分的載體作用。同將異丙醇(1)-水(2)-復合溶劑(3)作為擬時(shí)由于苛性堿是強電解質(zhì)在水溶液中可解離為離三組分物系,采用 Wilson模型分別對實(shí)驗數據子,產(chǎn)生離子電場(chǎng)。水分子和醇分子的極性和介電進(jìn)行關(guān)聯(lián),平均偏差用式(2)計算。Wlon模型參常數不同,在離子電場(chǎng)的作用下,極性強和介電常數數和關(guān)聯(lián)結果見(jiàn)表4。由表4可見(jiàn),汽相組分的平大的水分子就會(huì )較多地聚集在離子周?chē)?減小了水均偏差(△y1m)小于0.02。的活度系數,從而提高了異丙醇一水的相對揮發(fā)度而且,乙二醇與水形成氫鍵的能力比異丙醇與水強(2)表4 Wilson模型參數和汽相組分的平均偏差及異丙醇-水的相對揮發(fā)度Table 4 Wilson model parameters, average deviation of vapor component and relative volatility of isopropanol-water20.27120.6807-0.45670.22600.31590.83120.00602.0250.13660,40090.46070.99261.23030.00582.8080.00920.61730.4140.52301.60201.00680.01132.837Ⅳ0.19830.65270.13090.31480.64740.83590.20150.74830.24660.0092Ⅵ0.1614-0.12400.76191.32250.27740.0157Ⅶ0.6ll1-0.2573.7980-0.25630.01071.6340.13321.18520.61710.47651.28310.01332.1330.1554l.11720.04080.75570.477101232.141A: wilson model pararmeters; AyI m: average deviation of vapor component第5期曾妮等.異丙醇一水一堿/乙二醇物系常壓汽液平衡數據的測定451異丙醇-水-復合溶劑物系的汽液平衡數據的鈉或醋酸鉀)/乙二醇物系在常壓下的汽液平衡數據。實(shí)驗值與 Wilson模型關(guān)聯(lián)值的比較見(jiàn)圖1。由圖1(2)在異丙醇-水中加入氫氧化鉀(氫氧化可見(jiàn),實(shí)驗值與關(guān)聯(lián)值基本吻合。復合溶劑對異丙鈉)/乙二醇復合溶劑,均能使異丙醇-水的共沸點(diǎn)醇-水的相對揮發(fā)度影響的實(shí)驗結果見(jiàn)表4。由表消失,異丙醇-水的相對揮發(fā)度顯著(zhù)提高,且加入氫4可見(jiàn),氫氧化鉀/乙二醇能使異丙醇-水的相對揮氧化鉀的效果優(yōu)于加入氫氧化鈉。當脫除復合溶劑發(fā)度顯著(zhù)提高,且效果優(yōu)于氫氧化鈉/乙二醇和醋酸后液相異丙醇的摩爾分數小于80%時(shí),氫氧化鉀鉀/乙二醇。(氫氧化鈉)/乙二醇復合溶劑對提高異丙醇-水的相對揮發(fā)度的效果優(yōu)于醋酸鉀/乙二醇復合溶劑。(3)用 Wilson模型以擬異丙醇一水-堿/乙二醇三組分物系對實(shí)驗數據進(jìn)行關(guān)聯(lián),汽相組分的平均偏差Δy1m<0.02,取得了較好的結果,可用于工程計算符號說(shuō)明泡點(diǎn)溫度,K液相摩爾分數汽相摩爾分數V( Composite solvent): V(Isopropanol+H,O)=0. 5: 1Wilson模型參數汽相組分的平均偏差下角標實(shí)驗值計算值1楊曉勇,沈健,袁興東等.介孔分子篩負載磷鎢酸酸式銫鹽催化合成十一碳烯異丙酯石油化工,2004,3(12):1155-11592崔小明.異丙醇的生產(chǎn)應用及市場(chǎng)分析.四川化工與腐蝕控制,2005,5(3):32-37V( Composite solvent): V(Isopropanol+H,O)=1:I3許文友,袁希鋼用氟化鉀水溶液從制藥廢液中回收異丙醇的工藝研究.上海環(huán)境科學(xué),2002,21(10):630~6324武文良,張雅明,王延儒等異丙醇一水-乙酸鉀物系汽液平衡數據的測定及關(guān)聯(lián)石油化工,1997,26(9):610-6135 Polka H M, Gemhling J. Effect of Calcium Nitrate on the Vapor-Liquid Equilibria of Ethanol Water and 2-Propanol Water. JChem Eng Data, 1994, 39: 621-6246吳健康,羅大忱乙醇-異丙醇-水三元物系汽液平衡鹽效應華東化工學(xué)院學(xué)報,1990,16(5):505-5097雷志剛,周榮琪,葉堅強等加鹽反應萃取精餾分離醇水溶液.化學(xué)工業(yè)與工程,2001,18(5):290-294v(Composite solvent): V(Isopropanol+H2 O)=2: I8鮑靜,張雅明,金鑫異丙醇一水一含鹽復合物系汽液平衡.高校圖1異丙醇(1)-水(2)-復合溶劑(3)物系的汽液平衡曲線(xiàn)化學(xué)工程學(xué)報,2005,19(2):258-2629林軍,顧正桂加堿萃取精餾制無(wú)水乙醇化學(xué)研究與應用,2004Fig 3 Vapor-liquid equilibrium curves for systems ofisopropanol(1)-water(2)-composite solvent (3)J0 Gmehiling J, Onken U. Vapor-Liquid Equilibrium Data Collection.Potassium hydroxide exp i o Sodium hydroxide expiA Potassium acetate exp:- wilson modelAqueous-Organic System Vol 1, Part 1, Germany: DECHEMA1977.3343結論11陳鐘秀,顧飛燕,胡望塑明等.化工熱力學(xué),北京:化學(xué)工業(yè)出版社01.9397(1)實(shí)驗測定了異丙醇一水-氫氧化鉀(氫氧化(編輯李治泉)