甲醇_甲缩醛_甲醛_水四元系的汽液平衡
甲醇_甲缩醛_甲醛_水四元系的汽液平衡_(1)
收稿日期:1998-11-26基金项目:江西省自然科学基金资助项目(982004)第18卷 第1期1999年3月南昌水专学报Journal of Nanchang College of Water Conservancy and Hydroelectric Power Vol.18 No.1Mar.1999文章编号:1006-4869(1999)-01-0005-03甲醇-甲缩醛-甲醛-水四元系的汽液平衡(Ⅱ)邱祖民1,倪柳芳2,章国荣3,刘建华4(11南昌大学 化工系,江西 南昌 330029;21上饶地区工业学校,江西 上饶 334000;31南吉化学工业公司,江西 南昌 330077;41深圳市燃气工程监理有限公司,广东 深圳 518001)摘 要:本文推算了甲醛液相组成为10%和20%时的甲醇-甲缩醛-甲醛-水四元系汽液平衡,给出了X F =10%、X F =20%时的等Y W 、Y M 和等温图1关键词:汽液平衡;热力学模型;甲醇;甲醛;甲缩醛中图分类号:O64214 文献标识码:A0 引 言文献〔1〕建立了甲醇-甲缩醛-甲醛-水四元系的汽液平衡热力学模型,文献〔2〕进一步研究了该四元系的汽液平衡,文献〔3〕验证了该模型的准确性,本文旨在预测该四元系在X F 为10%和20%时的汽液平衡行为,供工程研究及设计时参考11 热力学模型〔1〕针对以往含甲醛多元系热力学模型的不足,需考虑甲醛的溶剂化反应,因而模型复杂,计算工作量大,且由于甲醛溶剂化反应的平衡常数很缺乏,需作某些假设或进行近似计算1实际上,由于甲醛与活性组分间的溶剂化反应,使得单体甲醛甚少,生成难挥发的甲醛水合物或甲醛聚合物,这在宏观上表现为影响了甲醛的饱和蒸汽压,使其远远偏离真实的甲醛饱和蒸汽压,而表现为虚拟的饱和蒸汽压1因此只要拟合出甲醛在活性溶剂中的虚拟饱和蒸汽压,即可对含甲醛多元系在虚拟组分上进行计算,可不必考虑其溶液中的真实组分,也不必考虑甲醛的溶剂化反应,因而模型易建易算,详细的描述参阅文献〔1〕1相平衡方程P S i f S i X i exp 〔V L mi (P -P S i )/R/T 〕r i =P Y i f iP S ′F f S F X F exp 〔V L mF (P -P S ′F )/R/T 〕r F =P Y F f F 式中P S ′F =P c F exp (4.5+4.5/T r -11.91/T 2r )甲醇-甲缩醛-甲醛-水四元系所含二元系的Wilson 模型参数如附表所示1附表 二元系的Wilson 模型参数表系统水-甲醇甲缩醛-水水-甲醛甲醇-甲缩醛甲醇-甲醛甲醛-甲缩醛参数225.3 444.1629.1 2271.70.5 875-65.9 903.8-345 0.23050 7152 模型预测用该模型推算了甲醛液相组成为10%和20%时的甲醇-甲缩醛-甲醛-水四元系汽液平衡,推测结果分别示于图1～图61图1 X F =10%时的甲缩醛-甲醇-甲醛-水四元系VL E 等温图 1-44.2℃;2-4415℃;3-46℃; 4-55℃;5-65℃ 图2 X F =10%时的甲缩醛-甲醇-甲醛-水四元系VL E 等Y W 图 1-2%;2-5%;3-7%;4-8%;5-9%; 6-10%;7-20%图3 X F =10%时的甲缩醛-甲醇-甲醛-水四元系VL E 等Y M 图 1-10%;2-20%;3-30%;4-40%;5-50%; 6-60%;7-70% 图4 X F =20%时的甲缩醛-甲醇-甲醛-水四元系VL E 等Y M 图 1-47℃;2-48℃;3-49℃;4-50℃; 5-55℃;6-7215℃ 6南昌水专学报1999年第1期图5 X F =20%时的甲缩醛-甲醇-甲醛-水四元系VL E 等Y W 图 1-2%;2-5%;3-7%;4-815%; 5-10%;6-20% 图6 X F =20%时的甲缩醛-甲醇-甲醛-水四元系VL E 等Y M 图 1-5%;2-10%;3-20%;4-30%; 5-40%;6-50% 3 结 论本文推算了甲醛液相组成为10%和20%时的甲醇-甲缩醛-甲醛-水四元系汽液平衡,给出了X F =10%、X F =20%时的等Y W 、Y M 和等温图,可供工程研究及设计时参考1〔参考文献〕1 邱祖民,骆赞椿,胡英1甲缩醛-甲醇-甲醛-水四元系的汽液平衡〔J 〕1高校化学工程学报,1998,12(1):61.2 邱祖民,骆赞椿,胡英1甲缩醛-甲醇-甲醛-水四元系的汽液平衡(Ⅰ)〔J 〕1南昌大学学报,1998,20(4).3 邱祖民,柳雪芳,倪柳芳等1甲醇-甲缩醛-甲醛-水四元系的汽液平衡〔J 〕1南昌水专学报,1998,17(3):10.V apor Liquid Equilibria of theMethanol -Methylal -Formaldehyde -W ater System(Ⅱ)Q IU Zu -min 1,N I Liu -fang 2,ZHAN G Guo -rong 3,L IU Jian -hua 4 (1.Department of Chemical Engineering ,Nanchang University ,Nanchang 330029China ;2.Shangrao Supervisory Office of Technicality ,Shangrao 334000China ;3.PPG Nanchang Chemical Industry Ltd.,Nanchang 330077China ;4.Shen Zhen G as Engineering Supervision Company ,Shenzhen ,518001China )Abstract :The vapor -liquid equilibria (VL E )of the methanol -methylal -formaldehyde -water system was predicted ,and the isothermal figures ,the isograms of Y W and Y M were depicted at X F =10%and 20%in this paper.K ey w ords :VL E ;Thermodynamic model ;methanol ;formaldehyde ;methylal 7第1期邱祖民:甲醇-甲缩醛-甲醛-水四元系的汽液平衡(Ⅱ)。
甲醇水汽液平衡
ropt 1.01670 1.01772 1.02178 1.02687 1.03195 1.03703 1.04212 R/Rmin 1.000 1.001 1.005 1.01 1.015 1.02 1.025年总费用1344560.33 1329387.811318482.11314831.5% 2.37% 1.22% 0.39% 0.07% 0.06% 0.08% 0.11% ropt 1.04720 1.05228 1.05533 1.05737 1.06754 1.07770 1.08787 R/Rmin 1.03 1.035 1.038 1.04 1.05 1.06 1.07年总费用% 0.25% 0.36% 0.42% 0.46% 0.77% 1.05% 1.41% ropt 1.09804 1.10820 1.11837 1.22004 1.32171 1.42338 1.52505 R/Rmin 1.08 1.09 1.1 1.2 1.3 1.4 1.5年总费用% 1.73% 2.06% 2.67% 6.57% 10.67% 14.94% 19.25% ropt 1.62672 1.72839 1.83006 1.93173 2.0334 0 0R/Rmin 1.6 1.7 1.8 1.9 2 0 0年总费用1557936.51607201.2% 36.56% 41.37% 46.48% 51.27% 56.16% 31.05% 35.19%附录二甲醇—水汽液平衡数据(摩尔组成)t x y t x y100.00 0.00 0.000 75.30 0.40 0.729 96.40 0.02 0.134 73.10 0.50 0.779 93.50 0.04 0.234 71.20 0.60 0.825 91.20 0.06 0.304 69.30 0.70 0.870 89.30 0.08 0.365 67.60 0.80 0.915 87.70 0.10 0.418 66.00 0.90 0.958 84.40 0.15 0.517 65.00 0.95 0.979 81.70 0.20 0.579 64.50 1.00 1.000 78.00 0.30 0.665附录一甲醇—水系统的主要物理性质附录三优化设计程序源代码优化程序'定义全局变量Dim J1#, J2#, J3#, J4#, JJ#Dim N#, R#, Ropt#Dim lilunbanshu#, jinliaoweizhi%, tajing#, chukouwendu#, chuanremianji#, zongtagao#, tiliuduanbanshu#, jinliuduanbanshu#Dim XF#, F#, q#, XD#, D#, td#, rD#, po#, u#, Rmin#, t1#, Cw#, Cp#, SI#, HETP#Dim Co#, HA#, f1#, f2#, a#, b#, FL#, θ#, ρ#, bo#, Fc#'优化所需参数Public Sub Form_Load()XF = 0.3151: F = 402.34: q = 1XD = 0.982: D = 128.97: td = 64.93: rD = 35373.48: po = 101.3u = 5.4464: Rmin = 1.0167t1 = 20: Cw = 0.0002: Cp = 4.1875: Co = 0.03: cpa = 15674.4HETP = 0.462: HA = 6f1 = 1: f2 = 6.5: a = 487: b = 0.72: SI = 3.73FL = 6.22: θ= 7200: ρ= 7860: bo = 0.005: Fc = 0.125Text1.Text = 402.34Text2.Text = 0.3151Text3.Text = 128.97Text4.Text = 0.982Text5.Text = 35373.48Text6.Text = 64.93Text7.Text = 1Text8.Text = 1.0167Text9.Text = 7200Text10.Text = 3.73Text11.Text = 0.125Text12.Text = 6.22Text13.Text = 0.005Text14.Text = 7860Text15.Text = 5.4464Text16.Text = 0.462Text17.Text = 6Text18.Text = 15674.4Text19.Text = 0.0002Text20.Text = 4.1875Text21.Text = 20Text22.Text = 2000Text23.Text = 1Text24.Text = 6.5Text25.Text = 487Text26.Text = 0.72Text27.Text = 0.03Text28.Text = 1.01Text29.Text = 2Text30.Text = 0.0001Text31.Text = " "Text32.Text = " "Text33.Text = " "Text34.Text = " "Text35.Text = " "Text36.Text = " "Text37.Text = " "Text38.Text = " "Text39.Text = " "Text40.Text = " "Text41.Text = " "Text42.Text = " "Text43.Text = " "Text44.Text = " "Text45.Text = " "Text46.Text = " "Text47.Text = " "End Sub'主程序Private Sub Command1_Click() '菲波拿契法求RoptDim Aa#, Bb#, W#(1 To 50), i%, K%, N#, M%, R1#, R2#, ε# Dim JJ1#, JJ2#Aa = 1.01 * Rmin: Bb = 2 * Rmin '搜索区间[Aa,Bb]W(1) = 1: W(2) = 2: W(3) = 3: i = 1: ε= 0.0001Do While W(i + 2) <= ((Bb - Aa) / ε)i = i + 1W(i + 2) = W(i) + W(i + 1)LoopR1 = Aa + (Bb - Aa) * W(i) / W(i + 2): JJ1 = j(R1)N = i + 2: K = 1: M = 0Do While K <> N - 1If M = 0 ThenR2 = Aa + (Bb - Aa) * W(N - K) / W(N - K + 1)JJ2 = j(R2)ElseR1 = Aa + (Bb - Aa) * W(N - K - 1) / W(N - K + 1)JJ1 = j(R1)End IfIf JJ1 < JJ2 ThenBb = R2: R2 = R1: JJ2 = JJ1: M = 1ElseAa = R1: R1 = R2: JJ1 = JJ2: M = 0End IfK = K + 1LoopR = (Aa + Bb) / 2Ropt = RJJ = j(R)Text31.Text = RoptText32.Text = RminText45.Text = Ropt / RminText33.Text = lilunbanshuText34.Text = zongtagaoText40.Text = J1Text41.Text = J2Text42.Text = J3Text43.Text = J4Text44.Text = JJText37.Text = tajingText38.Text = chukouwenduText39.Text = chuanremianjiText46.Text = Ropt * DText47.Text = (Ropt + 1) * DText35.Text = tiliuduanbanshu * HETPText36.Text = jinliuduanbanshu * HETPEnd Sub'J函数Public Function j(R#) As DoubleCall jjj1(R#, J1#)Call jjj2(R#, J2#)Call jjj3(R#, J3#)Call jjj4(R#, J4#)j = J1 + J2 + J3 + J4End Function'求J1Public Sub jjj1(R#, J1#)Dim DT#, H#, Ws#, CH#Call tabanshu(R#, N#)DT = Sqr((R + 1) * D * 22.4 / (3600 * 0.785 * u) * (273 + td) / 273 * 101.3 / po)H = N * HETP + HAWs = 3.14 * DT * (H + 0.8116 * DT) * bo * ρ'ρ为碳钢的密度CH = FL * Exp(6.95 + 0.1808 * Log(Ws) + 0.02468 * (Log(Ws)) ^ 2 + 0.0158 * H / DT)J1 = SI * (Fc + 0.06) * CHtajing = DTzongtagao = HEnd Sub'求J2Public Sub jjj2(R#, J2#)Dim xx1#, xx0#, CD#, ff#, df#, t2#, AD#, KD#KD = 2000: xx1 = 70Do '牛顿迭代法求冷却水最佳出口温度t2xx0 = xx1CD = 1.3 * SI * a * b * f1 * f2 * Fc * ((R + 1) * D * rD / (td - t1)) ^ (b - 1) / KD ^ bff = -Cw * θ/ Cp + CD * ((xx0 - 1) / xx0 / Log(xx0)) ^ (1 - b) * (xx0 - 1 - Log(xx0))df = CD * ((xx0 - 1) / xx0 / Log(xx0)) ^ (2 - b) * ((b - 1) * (xx0 - 1 - Log(xx0)) ^ 2 / (xx0 - 1) ^ 2 + Log(xx0))xx1 = xx0 - ff / dfLoop Until Abs(xx1 - xx0) < 0.000001t2 = td - (td - t1) / xx1 't2optchukouwendu = t2AD = (R + 1) * D * rD * Log((td - t1) / (td - t2)) / KD / (t2 - t1) '传热面积chuanremianji = ADJ2 = Cw * θ* (R + 1) * D * rD / Cp / (t2 - t1) + 1.3 * SI * Fc * f1 * f2 * a * AD ^ bEnd Sub'求J3Public Sub jjj3(R#, J3#)Dim Z#, Cz#Cz = 0.03Z = ((R + 1) * D - (1 - q) * F) * 18J3 = Z * Cz * θEnd Sub'求J4Public Sub jjj4(R#, J4#)Dim ho#, cpa!, HETP!cpa = 15674.4: HETP = 0.462Call tabanshu(R#, N#)ho = N * HETPDT = Sqr((R + 1) * D * 22.4 / (3600 * 0.785 * u) * (273 + td) / 273 * 101.3 / po)J4 = 3.14 / 4 * DT ^ 2 * ho * cpa * FcEnd Sub'塔板数的计算Public Sub tabanshu(R#, N#)Dim ye#, XW#Dim X!(100), Y!(100), xx!(100), i%, n1#td = 64.93: F = 402.34: XD = 0.982: XF = 0.3151: ηd = 0.999: D = 128.97: Rmin = 1.0167V = (R + 1) * D: W = F + V - D: XW = (F * XF - D * XD) / Wi = 1: Y(1) = 0.982: X(1) = 0.9702DoIf X(i) > XF ThenY(i + 1) = R * X(i) / (R + 1) + XD / (R + 1)n1 = i + 1 + (X(i) - XF) / (X(i) - X(i + 1))ElseY(i + 1) = W * (X(i) - XW) / VIf X(i) < XW Then Exit DoEnd Ifi = i + 1xx(i) = (Y(i) / (3.3874 * (1 - Y(i)))) ^ (1 / 0.7977)X(i) = xx(i) / (1 + xx(i))LoopN = i - 1 + (X(i - 1) - XW) / (X(i - 1) - X(i))lilunbanshu = Ntiliuduanbanshu = n1jinliuduanbanshu = N - n1End Sub调整ROPT程序：'定义全局变量Dim J1#, J2#, J3#, J4#, JJ#Dim N#, R#, Ropt#Dim lilunbanshu#, jinliaoweizhi%, tajing#, chukouwendu#, chuanremianji#, zongtagao#, tiliuduanbanshu#, jinliuduanbanshu#Dim XF#, F#, q#, XD#, D#, td#, rD#, po#, u#, Rmin#, t1#, Cw#, Cp#, SI#, HETP#Dim Co#, HA#, f1#, f2#, a#, b#, FL#, θ#, ρ#, bo#, Fc#'优化所需参数Public Sub Form_Load()XF = 0.3151: F = 402.34: q = 1XD = 0.982: D = 128.97: td = 64.93: rD = 35373.48: po = 101.3u = 5.4464: Rmin = 1.0167t1 = 20: Cw = 0.0002: Cp = 4.1875: Co = 0.03: cpa = 15674.4HETP = 0.462: HA = 6f1 = 1: f2 = 6.5: a = 487: b = 0.72: SI = 3.73FL = 6.22: θ= 7200: ρ= 7860: bo = 0.005: Fc = 0.125Text1.Text = 402.34 Text2.Text = 0.3151 Text3.Text = 128.97 Text4.Text = 0.982 Text5.Text = 35373.48 Text6.Text = 64.93 Text7.Text = 1Text8.Text = 1.0167 Text9.Text = 7200 Text10.Text = 3.73 Text11.Text = 0.125 Text12.Text = 6.22 Text13.Text = 0.005 Text14.Text = 7860 Text15.Text = 5.4464 Text16.Text = 0.462 Text17.Text = 6Text18.Text = 15674.4 Text19.Text = 0.0002 Text20.Text = 4.1875 Text21.Text = 20 Text22.Text = 2000 Text23.Text = 1Text24.Text = 6.5 Text25.Text = 487 Text26.Text = 0.72 Text27.Text = 0.03 Text28.Text = 1.01 Text29.Text = 2Text30.Text = 0.0001 Text31.Text = " " Text32.Text = " " Text33.Text = " " Text34.Text = " " Text35.Text = " " Text36.Text = " " Text37.Text = " " Text38.Text = " " Text39.Text = " " Text40.Text = " " Text41.Text = " " Text42.Text = " " Text43.Text = " " Text44.Text = " "Text45.Text = " "Text46.Text = " "Text47.Text = " "End Sub'主程序Private Sub Command1_Click() '菲波拿契法求Ropt R = Text31.TextRopt = RJJ = j(R)Text32.Text = RminText45.Text = Ropt / RminText33.Text = lilunbanshuText34.Text = zongtagaoText40.Text = J1Text41.Text = J2Text42.Text = J3Text43.Text = J4Text44.Text = JJText37.Text = tajingText38.Text = chukouwenduText39.Text = chuanremianjiText46.Text = Ropt * DText47.Text = (Ropt + 1) * DText35.Text = tiliuduanbanshu * HETPText36.Text = jinliuduanbanshu * HETPEnd Sub'J函数Public Function j(R#) As DoubleCall jjj1(R#, J1#)Call jjj2(R#, J2#)Call jjj3(R#, J3#)Call jjj4(R#, J4#)j = J1 + J2 + J3 + J4End Function'求J1Public Sub jjj1(R#, J1#)Dim DT#, H#, Ws#, CH#Call tabanshu(R#, N#)DT = Sqr((R + 1) * D * 22.4 / (3600 * 0.785 * u) * (273 + td) / 273 * 101.3 / po)If DT < 1 ThenDT = Int(DT * 10 + 1) / 10ElseDT = Int(DT * 5 + 1) * 0.2End IfH = N * HETP + HAWs = 3.14 * DT * (H + 0.8116 * DT) * bo * ρ'ρ为碳钢的密度CH = FL * Exp(6.95 + 0.1808 * Log(Ws) + 0.02468 * (Log(Ws)) ^ 2 + 0.0158 * H / DT)J1 = SI * (Fc + 0.06) * CHtajing = DTzongtagao = HEnd Sub'求J2Public Sub jjj2(R#, J2#)Dim xx1#, xx0#, CD#, ff#, df#, t2#, AD#, KD#KD = 2000: xx1 = 70Do '牛顿迭代法求冷却水最佳出口温度t2xx0 = xx1CD = 1.3 * SI * a * b * f1 * f2 * Fc * ((R + 1) * D * rD / (td - t1)) ^ (b - 1) / KD ^ bff = -Cw * θ/ Cp + CD * ((xx0 - 1) / xx0 / Log(xx0)) ^ (1 - b) * (xx0 - 1 - Log(xx0))df = CD * ((xx0 - 1) / xx0 / Log(xx0)) ^ (2 - b) * ((b - 1) * (xx0 - 1 - Log(xx0)) ^ 2 / (xx0 - 1) ^ 2 + Log(xx0))xx1 = xx0 - ff / dfLoop Until Abs(xx1 - xx0) < 0.000001t2 = td - (td - t1) / xx1 't2optchukouwendu = t2AD = (R + 1) * D * rD * Log((td - t1) / (td - t2)) / KD / (t2 - t1) '传热面积chuanremianji = ADJ2 = Cw * θ* (R + 1) * D * rD / Cp / (t2 - t1) + 1.3 * SI * Fc * f1 * f2 * a * AD ^ bEnd Sub'求J3Public Sub jjj3(R#, J3#)Dim Z#, Cz#Cz = 0.03Z = ((R + 1) * D - (1 - q) * F) * 18J3 = Z * Cz * θEnd Sub'求J4Public Sub jjj4(R#, J4#)Dim ho#, cpa!, HETP!cpa = 15674.4: HETP = 0.462Call tabanshu(R#, N#)ho = N * HETPDT = Sqr((R + 1) * D * 22.4 / (3600 * 0.785 * u) * (273 + td) / 273 * 101.3 / po)J4 = 3.14 / 4 * DT ^ 2 * ho * cpa * FcEnd Sub'塔板数的计算Public Sub tabanshu(R#, N#)Dim ye#, XW#Dim X!(100), Y!(100), xx!(100), i%, n1#td = 64.93: F = 402.34: XD = 0.982: XF = 0.3151: ηd = 0.999: D = 128.97: Rmin = 1.0167 V = (R + 1) * D: W = F + V - D: XW = (F * XF - D * XD) / Wi = 1: Y(1) = 0.982: X(1) = 0.9702DoIf X(i) > XF ThenY(i + 1) = R * X(i) / (R + 1) + XD / (R + 1)n1 = i + 1 + (X(i) - XF) / (X(i) - X(i + 1))ElseY(i + 1) = W * (X(i) - XW) / VIf X(i) < XW Then Exit DoEnd Ifi = i + 1xx(i) = (Y(i) / (3.3874 * (1 - Y(i)))) ^ (1 / 0.7977) X(i) = xx(i) / (1 + xx(i))LoopN = i - 1 + (X(i - 1) - XW) / (X(i - 1) - X(i))lilunbanshu = Ntiliuduanbanshu = n1jinliuduanbanshu = N - n1End Sub目录1 前言------------------------------------------------------------------------------------------------12 方案论证2.1 精馏塔类型----------------------------------------------------------------------------------1 2.2 精馏压力-------------------------------------------------------------------------------------1 2.3 进料方式-------------------------------------------------------------------------------------1 2.4 填料类型-------------------------------------------------------------------------------------2 2.5 加热方式-------------------------------------------------------------------------------------22.6 塔材料类型----------------------------------------------------------------------------------23 数学模型的建立3.1 精馏塔塔体年投资折旧费及维修费用-------------------------------------------------3 3.2 冷凝器年运转费用-------------------------------------------------------------------------4 3.3 直接蒸汽加热费用-------------------------------------------------------------------------53.4 填料年折旧费-------------------------------------------------- --54 数学模型的求解4.1 数学模型决策变量分析-------------------------------------------------------------------5 4.2 主要工艺参数的求解----------------------------------------------------------------------54.2.1 塔径的计算-----------------------------------------------------------------------------54.2.2 塔板数的计算-------------------------------------------------------------------------64.2.2.1 相平衡关系的表示--------------------------------------------------------------64.2.2.2 N的计算--------------------------------------------------------------------------64.2.3 冷凝器年运转费用的计算------------------ ----------------------- ----------------74.2.3.1 冷却水用量及冷凝器传热面积的计算- -------------------------------------74.2.3.2 冷凝器冷却水最佳出口温度的确定-----------------------------------------74.2.4 直接加热蒸气费用的计算----------------------------------------------------------8 4.3 数学模型的求解------------------------------------------------------- --------------------84.3.1 单变量最优化方法--------------------------------------------- ----------------------84.3.2 优化设计程序框图-------------------------------------------- -----------------------84.3.2.1 函数调用关系--------------------------------------------------------------------95 优化设计计算5.1 数据预处理---------------------------------------------------------------------------------105.1.1 进塔物料的计算----------------------------------------------------------------------105.1.2 塔顶蒸气温度的计算----------------------------------------------------------------105.1.3 等板高度的计算----------------------------------------------------------------------10Ⅰ5.1.4 产品汽化潜热的计算----------------------------------------------------------------115.1.5 最小回流比的确定-------------------------------------------------------------------115.1.6 填料单价的计算----------------------------------------------------------------------115.2. 塔径的计算---------------------------------------------------------------------------------13 5.3 填料层高度的计算-------------------------------------------------------------------------13 5.4 精馏塔塔体年投资折旧费及维修费用的计算-----------------------------------------13 5.5 冷凝器年运转费用的计算----------------------------------------------------------------145.5.1 冷凝器冷却水最佳出口温度的确定----------------------------------------------145.5.2 冷却水用量及冷凝器传热面积的计算-------------------------------------------145.5.3 精馏塔塔体年投资折旧费及维修费用的计算----------------------------------15 5.6 再沸器年运转费用的计算----------------------------------------------------------------15 5.7 填料年折旧费用的计算-------------------------------------------------------------------15 5.8 汽液负荷-------------------------------------------------------------------------------------155.8.1 气相负荷-------------------------------------------------------------------------------155.8.2 液相负荷-------------------------------------------------------------------------------155.9 年总费用与回流比的关系--------------------------------------------------------------156 填料塔水力学性能校核6.1 泛点率校核--------------------------------------------------------------------------------- 17 6.2 径比校核-------------------------------------------------------------------------------------17 6.3 喷淋密度校核-------------------------------------------------------------------------------176.4 填料塔压降----------------------------------------------------------------------------------177 附属设备的设计与选型7.1 塔顶冷凝器--------------------------------------------------------------------------------- 187.1.1 冷凝器传热量-------------------------------------------------------------------------187.1.2 冷凝器传热推动力-------------------------------------------------------------------187.1.3 初估冷凝器传热面积----------------------------------------------------------------197.1.4 冷凝器传热系数的校核-------------------------------------------------------------197.1.5 冷凝器传热面积的校核-------------------------------------------------------------227.1.6 冷凝器壳程、管程流动阻力-------------------------------------------------------22 7.2 接管选型------------------------------------------------------------------------------------ 247.2.1 进料口接管的选型-------------------------------------------------------------------247.2.2 冷却水接管的选型-------------------------------------------------------------------257.2.3 塔顶蒸气接管选型------------------------------------------------------------------ 25Ⅱ7.2.4 塔顶产品接管选型-------------------------------------------------------------------257.2.5 塔底产品接管选型-------------------------------------------------------------------267.2.6 塔顶产品回流接管选型-------------------------------------------------------------267.2.7 塔底加热蒸气接管选型------------------------------------------------------------- 26 7.3 冷却水输送泵7.3.1 塔高的计算---------------------------------------------------------------------------277.3.2 冷却水输送泵选型------------------------------------------------------------------27 7.4 填料支承结构-------------------------------------------------------------------------------28 7.5 液体分布装置-------------------------------------------------------------------------------287.7 液体收集再分布装置----------------------------------------------------------------------298 设计结果汇总------------------------------------------------------------------------------------299 设计心得------------------------------------------------------------------------------------------31 参考文献---------------------------------------------------------------------------------------------- 31 附录一甲醇和水部分物性参数-----------------------------------------------------------------32 附录二甲醇—水汽液平衡数据（摩尔组成）-------------------------------------------------33 附录三优化设计程序源代码--------------------------------------------------------------------34化工原理课程设计学生姓名：黄圣楠学号：081000115专业班级：10级生工（1）班____指导教师：张星___2013年1月24日。
甲醇 乙醇 水 汽液平衡
This article was downloaded by: [Dalhousie University]On: 15 January 2013, At: 07:11Publisher: Taylor & FrancisInforma Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House, 37-41 Mortimer Street, London W1T 3JH, UKPhysics and Chemistry of Liquids: AnInternational JournalPublication details, including instructions for authors andsubscription information:/loi/gpch20Phase equilibria of binary mixturescontaining methyl acetate, water,methanol or ethanol at 101.3 k PaV.H. Álvarez a , S. Mattedi b , M. Iglesias c , R. Gonzalez-Olmos c &J.M. Resa da Chemical Engineering School, State University of Campinas, P.O.Box 6066, Campinas-SP 13081-970, Brazilb Chemical Engineering Department, Polytechnic School, FederalUniversity of Bahia, Rua Aristides Novis, 2 Federação, 40210-630Salvador-BA, Brazilc PF&PT Research T eam, Department of Chemical Engineering,T echnical High School of Engineering, University of Santiago deCompostela, Rúa Lope Gómez de Marzoa, 15782 Santiago deCompostela, Españad Departamento de Ingeniería Química, Universidad del PaísVasco, Apartado 450, 01006 Vitoria, EspañaVersion of record first published: 27 Jan 2011.PLEASE SCROLL DOWN FOR ARTICLEsources. The publisher shall not be liable for any loss, actions, claims, proceedings,demand, or costs or damages whatsoever or howsoever caused arising directly or indirectly in connection with or arising out of the use of this material.D o w n l o a d e d b y [D a l h o u s i e U n i v e r s i t y ] a t 07:11 15 J a n u a r y 2013Physics and Chemistry of Liquids Vol.49,No.1,January 2011,52–71Phase equilibria of binary mixtures containing methyl acetate,water,methanol or ethanol at 101.3kPaV.H.Alvarez a ,S.Mattedi b *,M.Iglesias c ,R.Gonzalez-Olmos c and J.M.Resa d aChemical Engineering School,State University of Campinas,P.O.Box 6066,Campinas-SP 13081-970,Brazil;b Chemical Engineering Department,Polytechnic School,Federal University of Bahia,Rua Aristides Novis,2Federac ¸a ˜o,40210-630Salvador-BA,Brazil;cPF&PT Research Team,Department of Chemical Engineering,Technical High School of Engineering,University of Santiago de Compostela,Ru´a Lope Go ´mez de Marzoa,15782Santiago de Compostela,Espan ˜a;dDepartamento de Ingenierı´aQuı´m ica,Universidad del Paı´s Vasco,Apartado 450,01006Vitoria,Espan ˜a(Received 3April 2009;final version received 1May 2009)Isobaric vapor–liquid equilibria data at 101.3kPa were reported for the binary mixtures (methyl acetate þ(water or methanol or ethanol),methanol þ(water or ethanol)and (ethanol þwater)).The experimental data were tested for thermodynamic consistency by means of the Wisniak method and were demonstrated to be consistent.The experimental data were correlated using Wilson,NRTL and UNIQUAC models for the activity coefficients and predicted using the UNIFAC and PSRK equation of state for testing theirs capability.The results show that the obtained data for the studied binary systems are more reliable than other published data.Keywords:phase equilibria;associating binary mixture;correlation,modelling errors1.IntroductionThermodynamic measurements and phase equilibria of ethanol,water and the different flavour components (alcohols,aldehydes and acetates,so-called congeners)in distillated alcoholic beverages are of practical interest to the food industry since industrial procedures applied are closely related to their temperature and pressure dependence in order to obtain a high quality final product.In the last few years,published studies have highlighted a clear need for accurate information about these types of mixtures,in order to develop and optimise industrial techniques.Despite the considerable effort invested in the field of thermodynamic properties,a great scarcity of data is observed in the available literature for mixtures of components present in commercial distillated alcoholic beverages.Such properties are strongly dependent on hydrogen bond potency of hydroxyl or polar groups,chain length,isomeric structures and molecular package.After decades of study,there is still much room for improvement in our ability to understand the behavior of these systems and add accurate data to the available literature.Simulation and optimisation are not used in*Corresponding author.Email:silvana@ufba.brISSN 0031–9104print/ISSN 1029–0451online ß2011Taylor &FrancisDOI:10.1080/00319100903012403D o w n l o a d e d b y [D a l h o u s i e U n i v e r s i t y ] a t 07:11 15 J a n u a r y 2013the right manner in this matter,with an overestimation of equipment size or high energy-consuming conditions being usually applied due to inaccurate calculations.The difficulties of simulation in these types of processes,as well as possible errors derived from that,have been commented upon previously [1].As a continuation of previous work related to alcoholic beverages [2–4],this work is part of a research project whose objective is to measure thermodynamic properties and vapour–liquid equilibrium (VLE)data for different systems involved in most distillation processes to benefit subsequent studies of modelling and simulation.In this work,the VLE at 101.3kPa was determined for binary systems:methyl acetate þwater,methyl acetate þmethanol,methyl acetate þethanol,methanol þwater,methanol þethanol and ethanol þwater.These mixtures also have some special characteristics.The concentration of the solute in the vapor phase is small and shows molecular association.Thermodynamic consistency was achieved to validate the new experimental data.In this way,data obtained have lower deviations when compared with previously published data;thereby,the information of available literature was improvement.The –’approximation was used to fit the experimental data and obtain the UNIFAC Dortmund model [5],which was used for VLE prediction.Also,the predictive Soave–Redlich–Kwong (PSRK)model proposed by Holderbaum and Gmehling [6]was used in the ’–’approximation.2.Experimental sectionAll chemicals were Lichrosolv quality (Merck Farma y Quımica S.A.).The pure components were recently acquired and kept in an inert argon atmosphere after the bottles were opened.The materials were degassed ultrasonically and dried over molecular sieves Type 4A or 3A,1/16in.Chromatographic (GLC)analysis gave purities of 0.998for methyl acetate,methanol and ethanol,with maximum water contents of 6.8Â10À3, 1.5Â10À2and 2.2Â10À2mass%(Metrohm 737KF coulometer),respectively.Water was millipore quality with organic total mass 55ppb and resistivity of 18.2M cm.The densities and refractive indices at 298.15K,as well as normal boiling points,were within recommended values and are shown in Table 1.Table 1.Observed physical properties of pure compounds and literature data (densities ( ),refractive indices (n D )at 298.15K,and normal boiling points (T b )).Mw (kg kmol À1)(kg m À3)n DT b (K)Obs.Lit.Obs.Lit.Obs.Lit.Methyl acetate 74.080a 0.926740.9273b 1.35850 1.3589b 329.82330.4a 0.9279c 1.3614c 330.09d Water 18.015a 0.99700.99705c 1.33250 1.33250c 373.15373.15a Methanol 32.042a 0.786650.78664b 1.32645 1.32652b 337.86337.7a 0.78664c 1.32652c 337.85d Ethanol46.069a0.785020.78509b 1.359221.35941b 352.07351.4a 0.78504c1.35941c351.44dNote:a See [7];b See [8];c See [9];d See [10].Physics and Chemistry of Liquids 53D o w n l o a d e d b y [D a l h o u s i e U n i v e r s i t y ] a t 07:11 15 J a n u a r y 2013The system used to measure VLE data was a dynamic recirculating apparatusdescribed previously [11,12].The equilibrium temperature was measured with a digital platinum 100resistance thermometer with an accuracy of Æ0.1K.For the pressure measurement,a digital manometer regulator (Divatronic DT1model),manufactured by Leybold with an accuracy of Æ0.1kPa,was used.Both vapour and liquid phase compositions for the systems were determined by measurements of physical properties (density and refractive index)and application of mathematical correlations,published earlier by the authors [13–16].The accuracy of the composition measurements on each phase was estimated as better than Æ0.001in molar fraction for each mixture.The VLE experimental data at 101.3kPa of the studied binary systems are compiled in Table 2.Table 2.Observed vapour-liquid equilibrium data for different binary systems.x 1y 1T (K)1 2 1 2 s 1 s 2Methyl acetate (1)þwater (2)0.0020.14095.6423.732 1.0090.9790.9910.9350.9930.0050.29590.3923.206 1.2260.9780.9920.9410.9940.0140.57777.8121.348 2.0150.9770.9950.9550.9960.0220.68271.2719.808 2.6560.9770.9970.9610.9970.0290.73966.9018.413 3.2160.9770.9990.9650.9970.0420.79461.9016.207 4.0320.977 1.0010.9690.9980.7120.83557.45 1.158 4.9640.978 1.0030.9720.9980.8000.86156.99 1.080 5.0790.978 1.0040.9730.9980.8730.89456.67 1.041 5.1640.979 1.0060.9730.9980.8730.89556.67 1.041 5.1640.979 1.0060.9730.9980.9300.93356.54 1.024 5.2070.981 1.0080.9730.9980.9910.98956.621.0205.2030.983 1.0110.9730.998Methyl acetate (1)þmethanol (2)0.0090.02764.00 2.417 1.0090.9750.9830.9670.9830.0540.14561.90 2.259 1.0960.9750.9830.9690.9840.0740.18661.14 2.194 1.1300.9750.9830.9690.9840.1030.24060.12 2.101 1.1770.9740.9830.9700.9850.1040.24260.09 2.097 1.1780.9740.9830.9700.9850.1210.26959.58 2.048 1.2030.9740.9830.9710.9850.1230.27259.52 2.042 1.2060.9740.9830.9710.9850.1450.30658.88 1.978 1.2380.9740.9840.9710.9860.1480.30958.82 1.971 1.2410.9740.9840.9710.9860.1650.33258.39 1.924 1.2630.9750.9840.9720.9860.1990.37357.63 1.834 1.3040.9750.9850.9720.9860.2160.39157.30 1.794 1.3220.9750.9850.9720.9860.2660.43856.45 1.680 1.3700.9750.9860.9730.9870.2950.46256.05 1.621 1.3930.9760.9860.9730.9870.3270.48655.65 1.558 1.4170.9760.9870.9730.9870.3540.50555.36 1.509 1.4350.9760.9880.9740.9870.3710.51655.19 1.480 1.4460.9760.9880.9740.9870.4190.54554.80 1.406 1.4710.9770.9890.9740.9870.4400.55754.65 1.375 1.4800.9770.9890.9740.9870.4850.58254.37 1.3151.4990.9780.9900.9740.988(Continued )54V.H.A´lvarez et al.D o w n l o a d e d b y [D a l h o u s i e U n i v e r s i t y ] a t 07:11 15 J a n u a r y 2013Table 2.Continued.x 1y 1T (K) 1 2 1 2 s 1 s 20.5190.59954.21 1.274 1.5100.9780.9900.9740.9880.5370.60954.13 1.254 1.5160.9780.9910.9750.9880.6320.65853.87 1.164 1.5350.9790.9930.9750.9880.6360.66053.86 1.160 1.5360.9790.9930.9750.9880.6730.68053.83 1.132 1.5390.9800.9930.9750.9880.6960.69353.83 1.116 1.5400.9800.9940.9750.9880.7190.70753.84 1.102 1.5400.9810.9950.9750.9880.7420.72153.87 1.089 1.5390.9810.9950.9750.9880.7950.75754.02 1.063 1.5320.9830.9970.9750.9880.8850.83754.65 1.035 1.4980.986 1.0010.9740.9870.9240.88155.12 1.030 1.4730.988 1.0030.9740.9870.9810.96556.191.029 1.4160.992 1.0080.9730.987Methyl acetate (1)þethanol (2)0.0110.05076.972.541 1.0110.9790.9790.9560.9800.0390.16574.47 2.420 1.1160.9780.9780.9580.9810.0890.31070.97 2.231 1.2870.9790.9790.9610.9830.1210.37869.19 2.121 1.3850.9790.9800.9630.9840.1740.46566.77 1.955 1.5350.9800.9810.9650.9850.2570.55864.02 1.734 1.7290.9820.9830.9670.9870.2670.56663.75 1.711 1.7490.9820.9830.9670.9870.2920.58763.11 1.653 1.7990.9820.9840.9680.9870.3160.60562.58 1.604 1.8420.9830.9840.9680.9870.3250.61162.39 1.585 1.8580.9830.9840.9680.9870.3360.61962.17 1.563 1.8760.9830.9850.9690.9870.3690.63961.55 1.502 1.9280.9840.9850.9690.9880.3740.64261.46 1.493 1.9360.9840.9850.9690.9880.4370.67660.48 1.392 2.0240.9850.9870.9700.9880.5340.72259.28 1.266 2.1380.9860.9880.9710.9890.5510.73059.10 1.248 2.1560.9860.9890.9710.9890.5760.74058.85 1.223 2.1810.9870.9890.9710.9890.6360.76758.30 1.169 2.2380.9880.9900.9720.9890.6370.76758.29 1.168 2.2390.9880.9900.9720.9890.6610.77858.09 1.150 2.2600.9880.9910.9720.9890.6920.79257.84 1.128 2.2870.9890.9910.9720.9890.6990.79657.79 1.124 2.2920.9890.9920.9720.9890.7520.82157.42 1.094 2.3340.9900.9930.9720.9890.7600.82557.37 1.089 2.3400.9900.9930.9720.9890.7650.82857.34 1.087 2.3430.9910.9930.9720.9890.7680.83057.32 1.085 2.3450.9910.9930.9720.9890.8080.85157.09 1.069 2.3730.9920.9940.9720.9900.8160.85657.04 1.066 2.3790.9920.9950.9730.9900.8610.88456.84 1.052 2.4040.9930.9960.9730.9900.8620.88456.83 1.052 2.4050.9930.9960.9730.9900.8820.89856.75 1.047 2.4160.9940.9970.9730.9900.9240.93056.64 1.040 2.4330.9960.9990.9730.990Methanol (1)þwater (2)0.00010.00199.65 2.425 1.0130.9860.9920.9560.9920.0010.00999.46 2.384 1.0190.9860.9920.9560.9920.0100.07597.79 2.313 1.0820.9850.9920.9580.9920.0640.32190.812.0171.4000.9850.9930.9640.994(Continued )Physics and Chemistry of Liquids55D o w n l o a d e d b y [D a l h o u s i e U n i v e r s i t y ] a t 07:11 15 J a n u a r y 2013Table 2.Continued.x 1y 1T (K) 1 2 1 2 s 1 s 20.1030.42587.38 1.8511.5960.9850.9940.9670.9940.2170.59681.04 1.5162.0520.9860.9960.9720.9950.3060.67277.93 1.355 2.3310.9870.9970.9740.9960.3160.67977.62 1.340 2.3610.9870.9980.9750.9960.3830.72275.80 1.256 2.5470.9880.9990.9760.9960.4430.75774.35 1.198 2.7080.988 1.0000.9770.9960.4440.75774.32 1.197 2.7120.988 1.0000.9770.9960.5320.80272.44 1.133 2.9390.989 1.0010.9780.9970.6320.84770.52 1.0843.1950.990 1.0020.9790.9970.6760.86769.73 1.068 3.3070.991 1.0030.9800.9970.6890.87269.49 1.064 3.3430.991 1.0030.9800.9970.6960.87569.37 1.062 3.3600.991 1.0030.9800.9970.7680.90668.12 1.044 3.5520.992 1.0040.9810.9970.7700.90668.11 1.043 3.5530.992 1.0040.9810.9970.8270.93067.16 1.034 3.7080.992 1.0050.9810.9970.8960.95866.05 1.026 3.8980.993 1.0060.9820.9970.9140.96665.75 1.025 3.9520.993 1.0070.9820.9970.9330.97365.46 1.0244.0040.993 1.0070.9820.9970.9370.97565.40 1.024 4.0150.993 1.0070.9820.9970.9720.98964.86 1.023 4.1150.994 1.0080.9830.9970.9770.99164.78 1.023 4.1300.994 1.0080.9830.9970.9770.99164.771.023 4.1320.994 1.0080.9830.997Methanol (1)þethanol (2)0.0180.03477.71 1.152 1.0060.9850.9790.9750.9790.0960.16776.08 1.139 1.0730.9860.9790.9760.9800.1710.27774.65 1.127 1.1360.9870.9790.9770.9810.1790.28974.49 1.126 1.1430.9870.9790.9770.9810.1820.29374.44 1.125 1.1450.9870.9790.9770.9810.2460.37673.31 1.115 1.1990.9880.9800.9780.9820.2750.41172.83 1.110 1.2230.9890.9800.9780.9820.2870.42672.62 1.108 1.2340.9890.9800.9780.9820.2940.43472.51 1.107 1.2390.9890.9800.9780.9820.3120.45572.22 1.104 1.2540.9900.9810.9780.9820.3260.46972.01 1.102 1.2650.9900.9810.9780.9830.4000.54770.90 1.090 1.3250.9910.9820.9790.9830.4230.56970.57 1.087 1.3440.9920.9820.9790.9830.4420.58770.31 1.084 1.3590.9920.9830.9790.9830.4590.60270.09 1.081 1.3710.9930.9830.9800.9840.5340.66769.12 1.070 1.4290.9950.9840.9800.9840.5690.69668.69 1.065 1.4560.9950.9850.9800.9840.5800.70568.56 1.063 1.4640.9960.9850.9800.9840.5980.71968.35 1.061 1.4780.9960.9850.9810.9850.5990.72068.34 1.060 1.4780.9960.9850.9810.9850.6820.78267.42 1.050 1.5390.9980.9870.9810.9850.7260.81366.98 1.044 1.5690.9990.9880.9810.9850.7610.83866.63 1.041 1.593 1.0000.9890.9820.9850.7630.83966.61 1.041 1.595 1.0000.9890.9820.9850.8760.91665.57 1.032 1.671 1.0040.9910.9820.9860.9410.95965.041.030 1.712 1.0060.9930.9820.986Ethanol (1)þwater (2)0.0150.17095.99 5.8380.9740.9810.9910.9650.9930.0320.27692.695.1331.0990.9800.9920.9680.993(Continued )56V.H.A´lvarez et al.D o w n l o a d e d b y [D a l h o u s i e U n i v e r s i t y ] a t 07:11 15 J a n u a r y 20133.Data treatment3.1.VLE consistency dataPhase equilibrium data should be tested in order to assure and guarantee an acceptable quality and reliability of VLE data.Available literature offers different procedures to test the thermodynamic consistency of a set of data for isothermal or isobaric condition.The thermodynamic consistency of the measured VLE data have been tested with the Wisniak method [17]to reject possible inconsistent equilibrium points from the experimental determined collection.According to this test,two experimental points (a)and (b)are thermodynamically consistent when:D 5D maxð1ÞTable 2.Continued.x 1y 1T (K) 1 2 1 2 s 1 s 20.0460.33690.68 4.624 1.1860.9800.9920.9690.9940.0680.39888.50 3.978 1.2880.9800.9920.9710.9940.0790.42087.72 3.717 1.3280.9800.9920.9720.9940.1190.47385.80 2.991 1.4300.9790.9930.9730.9950.1630.50884.54 2.454 1.5030.9790.9930.9740.9950.1900.52483.99 2.215 1.5360.9790.9940.9750.9950.2060.53283.72 2.094 1.5530.9790.9940.9750.9950.2320.54483.33 1.933 1.5770.9790.9940.9750.9950.2360.54683.27 1.908 1.5810.9790.9940.9750.9950.2390.54783.23 1.896 1.5840.9790.9940.9750.9950.2810.56582.70 1.698 1.6180.9790.9940.9760.9950.2860.56782.64 1.675 1.6220.9790.9940.9760.9950.2910.56982.59 1.658 1.6250.9790.9940.9760.9950.3030.57482.45 1.614 1.6340.9790.9950.9760.9950.3440.59082.01 1.486 1.6630.9790.9950.9760.9950.3670.59981.79 1.427 1.6780.9790.9950.9760.9950.3800.60581.66 1.396 1.6870.9790.9950.9760.9950.3920.61081.55 1.371 1.6950.9790.9950.9760.9950.3970.61281.50 1.360 1.6980.9790.9950.9770.9950.4100.61781.38 1.336 1.7070.9790.9950.9770.9950.4120.61881.36 1.332 1.7080.9790.9950.9770.9950.4810.64880.76 1.224 1.7510.9800.9960.9770.9950.5270.66980.40 1.171 1.7770.9800.9960.9770.9950.6170.71579.77 1.094 1.8250.9800.9980.9780.9960.6880.75479.36 1.053 1.8570.9810.9990.9780.9960.7220.77579.19 1.037 1.8710.9810.9990.9780.9960.7570.79779.04 1.023 1.8840.982 1.0000.9780.9960.8510.86278.770.997 1.9090.983 1.0020.9780.9960.8980.89978.720.988 1.9150.984 1.0030.9780.9960.9080.90878.720.987 1.9160.984 1.0040.9780.9960.9310.92878.730.984 1.9160.984 1.0040.9780.9960.9440.94178.750.983 1.9160.985 1.0050.9780.9960.9470.94378.750.983 1.9160.985 1.0050.9780.9960.9670.96378.790.9821.9140.9851.0060.9780.996x 1,Liquid-phase mole fraction;y 1,vapour-phase mole fraction;T ,boiling temperature; 1and2,activity coefficients; 1and 2,fugacity coefficients; s 1and s2,fugacity coefficients at saturation at 101.3kPaPhysics and Chemistry of Liquids57D o w n l o a d e d b y [D a l h o u s i e U n i v e r s i t y ] a t 07:11 15 J a n u a r y 2013where D max is the maximum deviation with a value of 3,D is the local deviation,which is expressed as:D ¼100L ÀW L þW,ð2Þwhere L and W are each side temperature function integrals on liquid compositionfor the Wisniak test [13].The correlations for heat of vapourisation (J kmol À1)and density liquid (kmol m À3)used are:D vap H ¼A 1ÀT r ðÞðB þCT r þDT 2r Þð3Þ ¼AB 1þð1ÀT =C ÞDðÞ,ð4Þwhere,T is the temperature in K,T r is the reduced temperature and the constants A ,B ,C and D are shown in Table 3.The physical properties used were taken from Diadem Public v1.2[10],and the activity coefficients were calculated as shown in the next section.Table 4shows the values for the integrals L and W calculated for the thermodynamic consistent test and the values for the deviation D .Also,this table shows that the condition D 5D max satisfies all systems.Therefore,the thermo-dynamic consistency of the binary VLE data reported in this work is confirmed.Table 3.Coefficients for heat of vapourisation and density liquid,Equations (3)and (4).Compound D T (K)A B C D Ethanol 159–514a557890000.3124500159–514b 1.62880.274695140.23178Methanol 175–512a 504510000.3359400175–512b 2.32670.27073512.50.24713Methyl acetate 175–506a 449200000.368500175–506b 1.130.2593506.550.2764Water273–647a 520530000.31990À0.2120.25795300–380b,c5.77830.3124462.25450.05977aInterval for heat vapourisation,b interval for liquid density,c calculated from [14].Table 4.Results of the thermodynamic consistency test;L,W and D are variables defined in Equation (2).System (1)þ(2)L W D Methyl acetate þwater 19.8420.30 1.15Methyl acetate þmethanol 5.10 5.00 1.05Methyl acetate þethanol 6.59 6.81 1.61Methanol þwater 7.527.560.30Methanol þethanol 1.48 1.470.18Ethanol þwater7.217.260.3758V.H.A´lvarez et al.D o w n l o a d e d b y [D a l h o u s i e U n i v e r s i t y ] a t 07:11 15 J a n u a r y 20133.2.Equilibrium equation and activity coefficientsThe activity coefficients ( i )of the components were calculated from the following equation:i ¼y i Èi Px i P o i,ð5Þwere x i and y i are the liquid and vapor mole fractions in equilibrium,Èi is the vaporphase correction factor,P is the total pressure and P o i is the vapour pressure of pure component i .These vapour pressures were calculated from the Antoine equation:log P ¼A i ÀB ii,ð6Þwhere,P is the vapor pressure in mmHg,T is temperature in C and the constants A i.,B i and C i are reported in Table 5.The value constants for the pure compounds were obtained in literature by Riddick et al .[9].The vapour phase correction factor is given by:Èi ¼ i sat i exp ÀV i ðP ÀP o iÞRT !,ð7Þwhere i is the fugacity coefficient of component i in the mixture, sat iis the fugacity coefficient at saturation condition and V i is the molar volume of component i in the liquid phase calculated using the correlation of the liquid density.Fugacity coefficients were calculated with PSRK model,where the expression proposed by Mathias and Copeman [18]is used to evaluate (T )in the PSRK model:ðT Þ¼1þc 1ð1ÀT 0:5r Þþc 2ð1ÀT 0:5r Þ2þc 3ð1ÀT 0:5r Þ3ÂÃ2for T r 51,ð8Þwhere,T r is the reduced temperature and T c is the critical temperature,while c 1,c 2and c 3are empirical parameters.These parameters for the pure compounds were calculated in this work and are shown in Table 5.The physical properties for the pure components used in the PSRK model were taken from [10]and shown in Table 6.The calculated fugacity and activity coefficients are shown in Table 2for all data points.Table 5.Antoine and Mathias and Copeman pound A i a B i a C i a D T (K)b C 1c c 2c C 3cEthanol 8.3221718.10237.52296.9–463.2 1.4125300.287222À1.496099Methanol7.8981474.08229.13292.0–461.3 1.433991À0.7681150.226212Methyl acetate 7.0651157.622219.724277.1–462.7 1.069537À0.759819 1.492479Water8.0121695.167230.41276.6–590.91.093544À0.6730560.699288aSee [19];b see [18];c calculated in this work.Physics and Chemistry of Liquids59D o w n l o a d e d b y [D a l h o u s i e U n i v e r s i t y ] a t 07:11 15 J a n u a r y 20133.3.Modelling –Correlation modelThe VLE data were correlated in the –’approximation,where the PSRK equation of state was used to evaluate the fugacity coefficients,as the thermodynamic model in a bubble-point calculation.The description of the models applied here (Wilson,NRTL,and UNIQUAC)is freely available in the literature [7]and hence it is not discussed here.In the ’approximation,the Wilson,NRTL and UNIQUAC models were used instead of the UNIFAC model to calculate the excess Gibbs energy in the PSRK model.Theoretically,the range for the parameters A ij (Wilson,NRTL and UNIQUAC)is defined as (À104,104)J mol À1.Since this is a very wide range based on physical considerations,it is extremely likely that it will contain the globally optimal parameter values.Renon and Prausnitz [18]explain that the range for ij with theoretical bases can have values from 0.2to 0.55.To evaluate these parameters,the regression was performed using a genetic algorithm code,implemented and fully explained in the study by Alvarez et al .[19],with the minimisation of the overall objective function (Q ).Q ¼X N j ¼1½y exp 1jÀy cal 1j = y2þX N j ¼1½T cal ÀT exp = T ÀÁ2,ð9Þwhere y is the accuracy in the vapour mole fraction (10À3), T is the accuracy in the temperature (10À1),N is the number of data sets,y i is the molar fraction of the component i and the superscript ‘exp’and ‘cal’are the experimental and calculated values,respectively.The fitting parameters of these models and deviations are shown Table 7,the relative percent deviations in temperature and vapour phase compositions are calculated by Valderrama and Alvarez [20]:D T j j %¼100N XN i ¼1T cali ÀT exp i T expi ð10ÞD y %¼100N X N i ¼1y cal i Ày exp i y exp i,ð11Þwhere N is the number of data sets,T is the temperature,y i is the vapour molarfraction of the component i and the superscript ‘exp’and ‘cal’are the experimental and calculated values,respectively.Also,this table shows that all models present similar deviations in temperature and concentration in vapour phase,with a slightly better performance of the UNIQUAC model.The modelling of VLE data areTable 6.Physical properties for components:T c,critical temperature;P c,critical pressure;!,acentric factor;and uniquac parameters r and q .Compound T c (K)P c (bar)!r q Ethanol 514.061.50.644 2.11 1.97Methanol512.581.00.566 1.43 1.43Methyl acetate 506.647.50.331 2.80 2.58Water647.1221.20.3450.921.4D o w n l o a d e d b y [D a l h o u s i e U n i v e r s i t y ] a t 07:11 15 J a n u a r y 2013presented in T Àx 1Ày 1diagrams shown in Figures 1–6.In Figure 7,comparisons between models desviations using Equation (11)are shown for all binary systems,it is easy to observe that UNIQUAC model has a good agreement between experimental and calculated composition vapor phase.Table 7.Correlation parameters for activity coefficients and average deviation for the studied systems.ModelA 12(KJ mol À1)A 21(KJ mol À1)j D T j %(K)j D y 1j %j D y 2j %Methyl acetate (1)þwater (2)Wilson3249.1878660.5650.27 2.9512.96NRTL ( 12¼0.415)3276.9667494.2400.050.73 2.36UNIQUAC c 2216.998959.0940.100.42 1.46UNIFAC ––0.060.75 2.08PSRK––0.39 3.25 6.52Methyl acetate (1)þmethanol (2)Wilson À75.0113815.6350.020.190.47NRTL ( 12¼0.534)1927.7051181.4910.020.190.50UNIQUAC c 2922.085À594.6130.020.220.43UNIFAC ––0.020.310.52PSRK ––0.16 2.63 1.86Methyl acetate (1)þethanol (2)Wilson 467.4572721.9650.020.230.95NRTL ( 12¼0.550)1772.0651504.5650.020.25 1.00UNIQUAC c1667.680À178.6690.030.36 1.03UNIFAC ––0.060.61 1.30PSRK ––0.23 1.93 2.24Methanol (1)þwater (2)Wilson 173.8432373.1030.040.54 3.87NRTL ( 12¼0.550)75.5062425.8120.04 1.01 3.08UNIQUAC c À1289.7642072.2820.050.35 2.12UNIFAC ––0.080.45 1.39PSRK ––0.070.530.77Methanol (1)þethanol (2)Wilson À309.2071565.2990.030.230.66NRTL ( 12¼0.200)4229.869À2822.0700.020.260.60UNIQUACc1412.023À763.4080.030.230.64UNIFAC ––0.020.380.97PSRK ––0.020.440.71Ethanol (1)+water (2)Wilson2083.97763953.53670.250.39 1.16NRTL ( 12¼0.550)734.705007.820.180.92 1.46UNIQUAC c À495.04021988.10910.210.75 1.58UNIFAC ––0.220.330.82PSRK ––0.09 1.84 2.46Mean Wilson 0.100.76 3.34NRTL0.060.56 1.50UNIQUAC 0.070.39 1.21UNIFAC 0.080.47 1.18PSRK0.161.772.43D o w n l o a d e d b y [D a l h o u s i e U n i v e r s i t y ] a t 07:11 15 J a n u a r y 2013Figure 1.T Àx 1Ày 1diagram for methyl acetate (1)þwater (2)at 101.3kPa:(.)experimentalliquid phase;( )experimental vapour phase;(—)UNIQUAC correlation;(---)UNIFACprediction.Figure 2.T Àx 1Ày 1diagram for methyl acetate (1)þmethanol (2)at 101.3kPa:(.)experimental liquid phase;( )experimental vapour phase;(—)UNIQUAC correlation;(---)UNIFAC prediction.D o w n l o a d e d b y [D a l h o u s i e U n i v e r s i t y ] a t 07:11 15 J a n u a r y 2013。
常压下甲醇-聚甲氧基二甲醚二元体系汽液平衡
常压下甲醇-聚甲氧基二甲醚二元体系汽液平衡王丰阳;梁欢欢;周彩荣【摘要】At 101.3 kPa constant pressure, the VLE data of methanol-DMM3 (polyoxymethylene dimethyl ethers with degree of polymerization of n, i.e., DMMn) system were determined by using an improved Rose still. Thermodynamic consistency of the obtained vapor liquid equilibrium data were examined. The results were satisfied with Gibbs-Duhenm’s thermodynamic consistency. The VLE data were correlated by Wilson, NRTL and UNIQUAC activity coefficient model by Aspen Plus v7.1. The objective function was optimized by the maximum likelihood method and the corresponding model parameters were returned. Compared with the experimental results, the average absolute deviations for temperature and the composition in the vapor phase were less than 0.65 K and 0.0065, respectively. This work provides the important engineering data for an engineering design and further study in the multicomponent system containing methanol and DMM3.%在101.3 kPa 恒定压力下，采用改进的Rose 汽液平衡釜测定了甲醇-DMM3（聚甲氧基二甲醚，聚合度为 n，即 DMMn）二元体系汽液平衡数据，并对汽液平衡数据进行热力学一致性检验，结果表明所测定数据符合Gibbs-Duhenm 的热力学一致性。
甲醇分离方法的研究进展
第1期杨振钰:甲醇分离方法的研究进展•101 +甲醇分离方法的研究进展杨振枉(中石化催化剂有限公司工程技术研究院，北京100029)摘要：甲醇的来源和应用都非常广泛，但是由于高浓甲醇在工业中难以获取，需要从混合物中分离出高浓甲醇。
目前分离甲醇混合物的方法有许多，包括萃取精馏法、膜分离法、共沸蒸馏法等，主要探讨各种含甲醇混合物的不同分离方法。
关键词：甲醇%水%分离中图分类号!T Q028文献标识码！A文章编号：1008-021X(2021)0卜0101-021甲醇的发展现状甲醇在实际化工生产过程中起着重要的作用。
在医药、染 料、合成纤维、塑料等有机工业中都是重要的化工原料[1]。
同时，甲醇也可以作为重要的原料用来制作敌百虫、甲基对磷酸、多菌灵等农药产品。
近些年来，甲醇汽油也是一个研究热点，甲醇俗称“木醇’’或“木精’’，甲醇主要是由煤经过汽化加氢而生成，性能与汽油 接近[2]。
甲醇汽油是一种新型的环保燃料，甲醇燃烧充分、热 能利用率高、耗量低、排放的颗粒物非常少，并且甲醇汽油较常 规汽油来说更便宜，来源范围更广。
总体来说，因甲醇有清洁、高效、节能等特点，甲醇汽油的相关研究被国家列为节能减排 的重点项目，各个省市也在积极推动甲醇汽油。
甲醇也可作为重要化工原料来生产甲醛、醋酸、乙二醇等，其中，30%~40%的甲醇用于生产甲醛。
甲醇一般是由合成气在 473~573 K、5~10 M P a的条件下合成[3]，此外，甲醇还可通过生 物质(如玉米、甘蔗、高粱和微藻)发酵生产。
因甲醇作为燃料使 用时，具有稳定性、清洁性和运输方便性，因此在国家战略和环保 政策的双重推动下，我国对甲醇的需求量预计将加快。
2甲醇-水体系的分离目前分离醇-水体系国内外研究的方法主要有膜分离法、共沸精馏法、分子筛吸附法和萃取精馏法。
这些方法具有操作 简单、投资少、分离能力强等优点，因而具有广泛的工业应用前景[4]。
于清野等人[5]研究了低温甲醇洗甲醇-水分离系统，对工 业实际生产过程进行模拟计算，在原工艺基础上进行改造优 化，使其达到甲醇-水分离塔所要达到的分离标准。
实验三 甲醇-水二元体系汽液相平衡数据测定
在稳定运行时对EC（平衡室）作物料衡算得：
}
（1）
又因沸点仪可视为封闭系统，故运行前后物料总量不变，所以，
}
（2）
由式（1）和（2）可推得：
（3）
（4）
式中，
：为回流比；
：为滞液量因子；
：为组分的平衡常数。
式（3）和（4）将可测量的非分析量与平衡浓度联系起来，即为沸
点仪在稳定运行时各浓度间函数关系式。
四、实验方法
1. 实验前的准备工作 (1) 试剂的提纯
按照实验要求预先清洗精馏所用的仪器并且充分干燥，待用。精馏 装置主要由电炉、电加热套、可调式变压器、三口烧瓶、精馏柱和分馏 头组成。从下往上依次接好实验仪器，接好循环冷却水。由三口烧瓶加 入待精馏物质，密封后接通电源开始加热。首先可适当提高加热功率， 三口烧瓶中加玻璃珠，待液体沸腾后再控制调压器缓慢加热，防止爆 沸。在收集的过程中，必须先去掉初馏分，再收集沸点恒定的中间馏 分，馏分经气相色谱检测无杂质峰。试剂的提纯是一项复杂、耗时的工
数量级之间，若此时汽液平衡能够保持，我们称之为拟静态。对值不是
很大的体系，由于拟静态法是汽液回流比趋于零并能保持稳定沸点的循
环状态，所以从理论上说，拟静态是沸点仪测定汽液相平衡的最佳条
件。
三、实验装置
1. 设备装置 采用泵式沸点仪，在拟静态条件下，在101.325下测定了液相组成
与沸点的关系。压力控制采用二级自动控制系统，其压力波动不大于3 水柱。压力控制系统由恒压仪、电磁阀及继电器组成。大气压由福丁式 （Fortin）气压计测定，系统压力由U型压差计测出，U型压差计中装 水，计入水的密度校正。为了保证系统温度的稳定性，整个沸点仪用水
的特例。在动态法中，对于上式（3）中给定的，与的相对偏差非但不
化工热力学第五章作业讲解
第五章 例题一、填空题1. 指出下列物系的自由度数目，(1)水的三相点 0 ，(2)液体水与水蒸汽处于汽液平衡状态 1 ，(3)甲醇和水的二元汽液平衡状态 2 ，(4)戊醇和水的二元汽-液-液三相平衡状态 1 。
2. 说出下列汽液平衡关系适用的条件(1) l i v i f f ˆˆ= ______无限制条件__________； (2)i l i i v i x y ϕϕˆˆ= ______无限制条件____________； (3)i i s i i x P Py γ= _________低压条件下的非理想液相__________。
3. 丙酮(1)-甲醇(2)二元体系在98.66KPa 时，恒沸组成x 1=y 1=0.796，恒沸温度为327.6K ，已知此温度下的06.65,39.9521==s s P P kPa 则 van Laar 方程常数是A 12=______0.587_____，A 21=____0.717____(已知van Laar 方程为 221112212112x A x A x x A A RT G E+=)4. 在101.3kPa 下四氯化碳(1)-乙醇(2)体系的恒沸点是x 1=0.613和64.95℃，该温度下两组分的饱和蒸汽压分别是73.45和59.84kPa ，恒沸体系中液相的活度系数693.1,38.121==γγ。
1. 组成为x 1=0.2，x 2=0.8，温度为300K 的二元液体的泡点组成y 1的为(已知液相的3733,1866),/(75212121==+=s s E t P P n n n n G Pa) ___0.334____________。
2. 若用EOS ＋γ法来处理300K 时的甲烷（1）－正戊烷（2）体系的汽液平衡时，主要困难是MPa P s4.251=饱和蒸气压太高，不易简化；（ EOS+γ法对于高压体系需矫正）。
3. EOS 法则计算混合物的汽液平衡时，需要输入的主要物性数据是ij Ci Ci Ci k P T ,,,ω，通常如何得到相互作用参数的值？_从混合物的实验数据拟合得到。
甲醇—水,甲缩醛—甲醇和甲缩醛—水系统的汽液平衡
甲醇—水,甲缩醛—甲醇和甲缩醛—水系统的汽液平衡
邱祖民;骆赞椿
【期刊名称】《高校化学工程学报》
【年(卷),期】1994(008)002
【摘要】用泵式沸点仪测定了常压下甲醇－水、甲缩醛－甲醇、甲缩醛－水三个
二元系在不同液相组成时的沸点，并用间接法由ＴＰｘ推算了与之平衡的汽相组成。
用最小二乘法求出了三个二元系的液相活度系数模型参数，由模型参数推算的三个二元系的泡点与实验值能很好的吻合。
【总页数】5页(P106-110)
【作者】邱祖民;骆赞椿
【作者单位】不详;不详
【正文语种】中文
【中图分类】O642.42
【相关文献】
1.甲醇-甲缩醛-甲醛-水四元系的汽液平衡(Ⅱ) [J], 邱祖民;倪柳芳;章国荣;刘建华
2.甲缩醛—甲醇—甲醛—水四元系的汽液平衡 [J], 邱祖民;骆赞椿
3.甲缩醛—甲醇—水三元系的汽液平衡 [J], 邱祖民;骆赞椿
4.甲醇—甲缩醛—甲醛—水四元系的汽液平衡 [J], 邱祖民;柳雪芳
5.甲缩醛—甲醇—甲醛—水四元系的汽液平衡研究 [J], 邱谊民;倪柳芳
因版权原因，仅展示原文概要，查看原文内容请购买。
化工原理学习指导-第6章-蒸馏-计算题答案
化工原理学习指导 第6章 蒸馏 计算题答案6-31 某二元混合物蒸汽，其中轻、重组分的摩尔分数分别为0.75和0.25，在总压为300kPa 条件下被冷凝至40℃，所得的汽、液两相到达平衡。
求其汽相摩尔数和液相摩尔数之比。
轻、重组分在40℃时的蒸汽压分别为370kPa 和120kPa 。
解：两相中，720.01203701203000B0A 0B =--=--=p p p p x 888.0300720.03700A A =⨯===x p p p p y设汽相摩尔量为V ，液相摩尔量为L ，总量为F ，那么L V F +=Lx Vy Fx F +=由以上两式可得：217.075.0888.072.075.0F F =--=--=x y x x L V 事实上，汽液平衡体系中，两相的摩尔量比值服从杆杠定律。
6-32 苯和甲苯组成的理想溶液送入精馏塔中进行别离，进料状态为汽液共存，其两相组成分别如下：5077.0F =x ，7201.0F =y 。
用于计算苯和甲苯的蒸汽压方程如下：8.2201211031.6lg 0A +-=t p5.2191345080.6lg 0B +-=t p其中压强的单位为Pa ，温度的单位为℃。
试求：〔1〕该进料中两组份的相对挥发度为多少？〔2〕进料的压强和温度各是多少？〔提示：设进料温度为92℃〕 解：〔1〕混合物中两组分的相对挥发度：49.25077.015077.07201.017201.011F F F F=--=--=x x y y α 〔2〕设进料温度为92℃，那么16.28.220921211031.6lg 0A =+-=pkPa 38.1440A =p 762.15.219921345080.6lg 0B =+-=pkPa 83.570B =p由此求得体系的相对挥发度为：496.283.5738.144'0B0A ===p p α 其值与〔1〕中所求相对挥发度足够接近，故可认为进料温度为92℃。
化工热力学答案课后总习题答案详解
化工热力学答案课后总习题答案详解化工热力学答案_课后总习题答案详解第二章习题解答一、问答题：2-1为什么要研究流体的pVT关系？【参考答案】：流体p-V-T关系是化工热力学的基石，是化工过程开发和设计、安全操作和科学研究必不可少的基础数据。
（1）流体的PVT关系可以直接用于设计。
（2）利用可测的热力学性质（T，P，V等）计算不可测的热力学性质（H，S，G，等）。
只要有了p-V-T关系加上理想气体的idC，可以解决化p工热力学的大多数问题。
2-2在p-V图上指出超临界萃取技术所处的区域，以及该区域的特征；同时指出其它重要的点、线、面以及它们的特征。
【参考答案】：1）超临界流体区的特征是：T>T c、p>p c。
2）临界点C的数学特征：3）饱和液相线是不同压力下产生第一个气泡的那个点的连线；4）饱和汽相线是不同压力下产生第一个液滴点（或露点）那个点的连线。
5）过冷液体区的特征：给定压力下液体的温度低于该压力下的泡点温度。
6）过热蒸气区的特征：给定压力下蒸气的温度高于该压力下的露点温度。
7）汽液共存区：在此区域温度压力保持不变，只有体积在变化。
2-3 要满足什么条件，气体才能液化？【参考答案】：气体只有在低于T c 条件下才能被液化。
2-4 不同气体在相同温度压力下，偏离理想气体的程度是否相同？你认为哪些是决定偏离理想气体程度的最本质因素？【参考答案】：不同。
真实气体偏离理想气体程度不仅与T 、p 有关，而且与每个气体的临界特性有关，()()()()点在点在C V P C V P T T 0022==∂∂∂即最本质的因素是对比温度、对比压力以及偏心因子r T ，rP 和ω。
2-5 偏心因子的概念是什么？为什么要提出这个概念？它可以直接测量吗？【参考答案】：偏心因子ω为两个分子间的相互作用力偏离分子中心之间的作用力的程度。
其物理意义为：一般流体与球形非极性简单流体（氩，氪、氙）在形状和极性方面的偏心度。
汽液相平衡系统的分类
吸收章节
①原理不同 • 吸收是根据各组分溶解度不同进行分离的。 • 精馏利用组分间相对挥发度不同使组分分离。
物质传递的机理包括以下两种： ⑴分子扩散。 ⑵对流传质
与等分子反向扩散速率方程相比，单向扩散时多了一个因子
cM cBm
或
p pBm
，
cM cBm
p 1(
pBm
1)
,我们称之为漂流因子（数），它
目标函数 : yi xi 0
xi
Zi
1 v(ki
1)
1
yi
kiZi 1 v(ki 1)
1
F (v)
( yi
xi )
Zi (ki 1) 1 v(ki 1)
0
F (v) Z i (ki 1) 2
1 v(ki 1)2
F (v) vk1 vk F (v)
名词解释
①关键组分： 在设计或操作控制中，有一定分离要求， 且在塔顶、塔釜都有一定数量的组分称为关 键组分。 轻关键组分，指在塔釜液中该组分的浓度 有严格限制，并在进料液中比该组分轻的组 分及该组分的绝大部分应从塔顶采出 重关键组分， 塔顶 重 塔釜
i
ˆ Vi p
一、泡点计算 1、泡点计算与有关方程
已知 xi , P(T ) 求 yi ,T, 泡点温度，（P，泡点压力）
①相平衡关系： yi ki xi
②浓度总和式： yi ki xi 1
③相平衡常数关联式： ki f (T, P, xi , yi )
2、计算方法 ①平衡常数与组成无关的泡点计算
xa=x0 ya=y1
y1
1 2
x1
y2
x
y3
2
yN-1
N-1
xN-1 yN
甲醇水汽液平衡
ropt 1.01670 1.01772 1.02178 1.02687 1.03195 1.03703 1.04212 R/Rmin 1.000 1.001 1.005 1.01 1.015 1.02 1.025年总费用1344560.33 1329387.811318482.11314831.5% 2.37% 1.22% 0.39% 0.07% 0.06% 0.08% 0.11% ropt 1.04720 1.05228 1.05533 1.05737 1.06754 1.07770 1.08787 R/Rmin 1.03 1.035 1.038 1.04 1.05 1.06 1.07年总费用% 0.25% 0.36% 0.42% 0.46% 0.77% 1.05% 1.41% ropt 1.09804 1.10820 1.11837 1.22004 1.32171 1.42338 1.52505 R/Rmin 1.08 1.09 1.1 1.2 1.3 1.4 1.5年总费用% 1.73% 2.06% 2.67% 6.57% 10.67% 14.94% 19.25% ropt 1.62672 1.72839 1.83006 1.93173 2.0334 0 0R/Rmin 1.6 1.7 1.8 1.9 2 0 0年总费用1557936.51607201.2% 36.56% 41.37% 46.48% 51.27% 56.16% 31.05% 35.19%附录二甲醇—水汽液平衡数据(摩尔组成)t x y t x y100.00 0.00 0.000 75.30 0.40 0.729 96.40 0.02 0.134 73.10 0.50 0.779 93.50 0.04 0.234 71.20 0.60 0.825 91.20 0.06 0.304 69.30 0.70 0.870 89.30 0.08 0.365 67.60 0.80 0.915 87.70 0.10 0.418 66.00 0.90 0.958 84.40 0.15 0.517 65.00 0.95 0.979 81.70 0.20 0.579 64.50 1.00 1.000 78.00 0.30 0.665附录一甲醇—水系统的主要物理性质附录三优化设计程序源代码优化程序'定义全局变量Dim J1#, J2#, J3#, J4#, JJ#Dim N#, R#, Ropt#Dim lilunbanshu#, jinliaoweizhi%, tajing#, chukouwendu#, chuanremianji#, zongtagao#, tiliuduanbanshu#, jinliuduanbanshu#Dim XF#, F#, q#, XD#, D#, td#, rD#, po#, u#, Rmin#, t1#, Cw#, Cp#, SI#, HETP#Dim Co#, HA#, f1#, f2#, a#, b#, FL#, θ#, ρ#, bo#, Fc#'优化所需参数Public Sub Form_Load()XF = 0.3151: F = 402.34: q = 1XD = 0.982: D = 128.97: td = 64.93: rD = 35373.48: po = 101.3u = 5.4464: Rmin = 1.0167t1 = 20: Cw = 0.0002: Cp = 4.1875: Co = 0.03: cpa = 15674.4HETP = 0.462: HA = 6f1 = 1: f2 = 6.5: a = 487: b = 0.72: SI = 3.73FL = 6.22: θ= 7200: ρ= 7860: bo = 0.005: Fc = 0.125Text1.Text = 402.34Text2.Text = 0.3151Text3.Text = 128.97Text4.Text = 0.982Text5.Text = 35373.48Text6.Text = 64.93Text7.Text = 1Text8.Text = 1.0167Text9.Text = 7200Text10.Text = 3.73Text11.Text = 0.125Text12.Text = 6.22Text13.Text = 0.005Text14.Text = 7860Text15.Text = 5.4464Text16.Text = 0.462Text17.Text = 6Text18.Text = 15674.4Text19.Text = 0.0002Text20.Text = 4.1875Text21.Text = 20Text22.Text = 2000Text23.Text = 1Text24.Text = 6.5Text25.Text = 487Text26.Text = 0.72Text27.Text = 0.03Text28.Text = 1.01Text29.Text = 2Text30.Text = 0.0001Text31.Text = " "Text32.Text = " "Text33.Text = " "Text34.Text = " "Text35.Text = " "Text36.Text = " "Text37.Text = " "Text38.Text = " "Text39.Text = " "Text40.Text = " "Text41.Text = " "Text42.Text = " "Text43.Text = " "Text44.Text = " "Text45.Text = " "Text46.Text = " "Text47.Text = " "End Sub'主程序Private Sub Command1_Click() '菲波拿契法求RoptDim Aa#, Bb#, W#(1 To 50), i%, K%, N#, M%, R1#, R2#, ε# Dim JJ1#, JJ2#Aa = 1.01 * Rmin: Bb = 2 * Rmin '搜索区间[Aa,Bb]W(1) = 1: W(2) = 2: W(3) = 3: i = 1: ε= 0.0001Do While W(i + 2) <= ((Bb - Aa) / ε)i = i + 1W(i + 2) = W(i) + W(i + 1)LoopR1 = Aa + (Bb - Aa) * W(i) / W(i + 2): JJ1 = j(R1)N = i + 2: K = 1: M = 0Do While K <> N - 1If M = 0 ThenR2 = Aa + (Bb - Aa) * W(N - K) / W(N - K + 1)JJ2 = j(R2)ElseR1 = Aa + (Bb - Aa) * W(N - K - 1) / W(N - K + 1)JJ1 = j(R1)End IfIf JJ1 < JJ2 ThenBb = R2: R2 = R1: JJ2 = JJ1: M = 1ElseAa = R1: R1 = R2: JJ1 = JJ2: M = 0End IfK = K + 1LoopR = (Aa + Bb) / 2Ropt = RJJ = j(R)Text31.Text = RoptText32.Text = RminText45.Text = Ropt / RminText33.Text = lilunbanshuText34.Text = zongtagaoText40.Text = J1Text41.Text = J2Text42.Text = J3Text43.Text = J4Text44.Text = JJText37.Text = tajingText38.Text = chukouwenduText39.Text = chuanremianjiText46.Text = Ropt * DText47.Text = (Ropt + 1) * DText35.Text = tiliuduanbanshu * HETPText36.Text = jinliuduanbanshu * HETPEnd Sub'J函数Public Function j(R#) As DoubleCall jjj1(R#, J1#)Call jjj2(R#, J2#)Call jjj3(R#, J3#)Call jjj4(R#, J4#)j = J1 + J2 + J3 + J4End Function'求J1Public Sub jjj1(R#, J1#)Dim DT#, H#, Ws#, CH#Call tabanshu(R#, N#)DT = Sqr((R + 1) * D * 22.4 / (3600 * 0.785 * u) * (273 + td) / 273 * 101.3 / po)H = N * HETP + HAWs = 3.14 * DT * (H + 0.8116 * DT) * bo * ρ'ρ为碳钢的密度CH = FL * Exp(6.95 + 0.1808 * Log(Ws) + 0.02468 * (Log(Ws)) ^ 2 + 0.0158 * H / DT)J1 = SI * (Fc + 0.06) * CHtajing = DTzongtagao = HEnd Sub'求J2Public Sub jjj2(R#, J2#)Dim xx1#, xx0#, CD#, ff#, df#, t2#, AD#, KD#KD = 2000: xx1 = 70Do '牛顿迭代法求冷却水最佳出口温度t2xx0 = xx1CD = 1.3 * SI * a * b * f1 * f2 * Fc * ((R + 1) * D * rD / (td - t1)) ^ (b - 1) / KD ^ bff = -Cw * θ/ Cp + CD * ((xx0 - 1) / xx0 / Log(xx0)) ^ (1 - b) * (xx0 - 1 - Log(xx0))df = CD * ((xx0 - 1) / xx0 / Log(xx0)) ^ (2 - b) * ((b - 1) * (xx0 - 1 - Log(xx0)) ^ 2 / (xx0 - 1) ^ 2 + Log(xx0))xx1 = xx0 - ff / dfLoop Until Abs(xx1 - xx0) < 0.000001t2 = td - (td - t1) / xx1 't2optchukouwendu = t2AD = (R + 1) * D * rD * Log((td - t1) / (td - t2)) / KD / (t2 - t1) '传热面积chuanremianji = ADJ2 = Cw * θ* (R + 1) * D * rD / Cp / (t2 - t1) + 1.3 * SI * Fc * f1 * f2 * a * AD ^ bEnd Sub'求J3Public Sub jjj3(R#, J3#)Dim Z#, Cz#Cz = 0.03Z = ((R + 1) * D - (1 - q) * F) * 18J3 = Z * Cz * θEnd Sub'求J4Public Sub jjj4(R#, J4#)Dim ho#, cpa!, HETP!cpa = 15674.4: HETP = 0.462Call tabanshu(R#, N#)ho = N * HETPDT = Sqr((R + 1) * D * 22.4 / (3600 * 0.785 * u) * (273 + td) / 273 * 101.3 / po)J4 = 3.14 / 4 * DT ^ 2 * ho * cpa * FcEnd Sub'塔板数的计算Public Sub tabanshu(R#, N#)Dim ye#, XW#Dim X!(100), Y!(100), xx!(100), i%, n1#td = 64.93: F = 402.34: XD = 0.982: XF = 0.3151: ηd = 0.999: D = 128.97: Rmin = 1.0167V = (R + 1) * D: W = F + V - D: XW = (F * XF - D * XD) / Wi = 1: Y(1) = 0.982: X(1) = 0.9702DoIf X(i) > XF ThenY(i + 1) = R * X(i) / (R + 1) + XD / (R + 1)n1 = i + 1 + (X(i) - XF) / (X(i) - X(i + 1))ElseY(i + 1) = W * (X(i) - XW) / VIf X(i) < XW Then Exit DoEnd Ifi = i + 1xx(i) = (Y(i) / (3.3874 * (1 - Y(i)))) ^ (1 / 0.7977)X(i) = xx(i) / (1 + xx(i))LoopN = i - 1 + (X(i - 1) - XW) / (X(i - 1) - X(i))lilunbanshu = Ntiliuduanbanshu = n1jinliuduanbanshu = N - n1End Sub调整ROPT程序：'定义全局变量Dim J1#, J2#, J3#, J4#, JJ#Dim N#, R#, Ropt#Dim lilunbanshu#, jinliaoweizhi%, tajing#, chukouwendu#, chuanremianji#, zongtagao#, tiliuduanbanshu#, jinliuduanbanshu#Dim XF#, F#, q#, XD#, D#, td#, rD#, po#, u#, Rmin#, t1#, Cw#, Cp#, SI#, HETP#Dim Co#, HA#, f1#, f2#, a#, b#, FL#, θ#, ρ#, bo#, Fc#'优化所需参数Public Sub Form_Load()XF = 0.3151: F = 402.34: q = 1XD = 0.982: D = 128.97: td = 64.93: rD = 35373.48: po = 101.3u = 5.4464: Rmin = 1.0167t1 = 20: Cw = 0.0002: Cp = 4.1875: Co = 0.03: cpa = 15674.4HETP = 0.462: HA = 6f1 = 1: f2 = 6.5: a = 487: b = 0.72: SI = 3.73FL = 6.22: θ= 7200: ρ= 7860: bo = 0.005: Fc = 0.125Text1.Text = 402.34 Text2.Text = 0.3151 Text3.Text = 128.97 Text4.Text = 0.982 Text5.Text = 35373.48 Text6.Text = 64.93 Text7.Text = 1Text8.Text = 1.0167 Text9.Text = 7200 Text10.Text = 3.73 Text11.Text = 0.125 Text12.Text = 6.22 Text13.Text = 0.005 Text14.Text = 7860 Text15.Text = 5.4464 Text16.Text = 0.462 Text17.Text = 6Text18.Text = 15674.4 Text19.Text = 0.0002 Text20.Text = 4.1875 Text21.Text = 20 Text22.Text = 2000 Text23.Text = 1Text24.Text = 6.5 Text25.Text = 487 Text26.Text = 0.72 Text27.Text = 0.03 Text28.Text = 1.01 Text29.Text = 2Text30.Text = 0.0001 Text31.Text = " " Text32.Text = " " Text33.Text = " " Text34.Text = " " Text35.Text = " " Text36.Text = " " Text37.Text = " " Text38.Text = " " Text39.Text = " " Text40.Text = " " Text41.Text = " " Text42.Text = " " Text43.Text = " " Text44.Text = " "Text45.Text = " "Text46.Text = " "Text47.Text = " "End Sub'主程序Private Sub Command1_Click() '菲波拿契法求Ropt R = Text31.TextRopt = RJJ = j(R)Text32.Text = RminText45.Text = Ropt / RminText33.Text = lilunbanshuText34.Text = zongtagaoText40.Text = J1Text41.Text = J2Text42.Text = J3Text43.Text = J4Text44.Text = JJText37.Text = tajingText38.Text = chukouwenduText39.Text = chuanremianjiText46.Text = Ropt * DText47.Text = (Ropt + 1) * DText35.Text = tiliuduanbanshu * HETPText36.Text = jinliuduanbanshu * HETPEnd Sub'J函数Public Function j(R#) As DoubleCall jjj1(R#, J1#)Call jjj2(R#, J2#)Call jjj3(R#, J3#)Call jjj4(R#, J4#)j = J1 + J2 + J3 + J4End Function'求J1Public Sub jjj1(R#, J1#)Dim DT#, H#, Ws#, CH#Call tabanshu(R#, N#)DT = Sqr((R + 1) * D * 22.4 / (3600 * 0.785 * u) * (273 + td) / 273 * 101.3 / po)If DT < 1 ThenDT = Int(DT * 10 + 1) / 10ElseDT = Int(DT * 5 + 1) * 0.2End IfH = N * HETP + HAWs = 3.14 * DT * (H + 0.8116 * DT) * bo * ρ'ρ为碳钢的密度CH = FL * Exp(6.95 + 0.1808 * Log(Ws) + 0.02468 * (Log(Ws)) ^ 2 + 0.0158 * H / DT)J1 = SI * (Fc + 0.06) * CHtajing = DTzongtagao = HEnd Sub'求J2Public Sub jjj2(R#, J2#)Dim xx1#, xx0#, CD#, ff#, df#, t2#, AD#, KD#KD = 2000: xx1 = 70Do '牛顿迭代法求冷却水最佳出口温度t2xx0 = xx1CD = 1.3 * SI * a * b * f1 * f2 * Fc * ((R + 1) * D * rD / (td - t1)) ^ (b - 1) / KD ^ bff = -Cw * θ/ Cp + CD * ((xx0 - 1) / xx0 / Log(xx0)) ^ (1 - b) * (xx0 - 1 - Log(xx0))df = CD * ((xx0 - 1) / xx0 / Log(xx0)) ^ (2 - b) * ((b - 1) * (xx0 - 1 - Log(xx0)) ^ 2 / (xx0 - 1) ^ 2 + Log(xx0))xx1 = xx0 - ff / dfLoop Until Abs(xx1 - xx0) < 0.000001t2 = td - (td - t1) / xx1 't2optchukouwendu = t2AD = (R + 1) * D * rD * Log((td - t1) / (td - t2)) / KD / (t2 - t1) '传热面积chuanremianji = ADJ2 = Cw * θ* (R + 1) * D * rD / Cp / (t2 - t1) + 1.3 * SI * Fc * f1 * f2 * a * AD ^ bEnd Sub'求J3Public Sub jjj3(R#, J3#)Dim Z#, Cz#Cz = 0.03Z = ((R + 1) * D - (1 - q) * F) * 18J3 = Z * Cz * θEnd Sub'求J4Public Sub jjj4(R#, J4#)Dim ho#, cpa!, HETP!cpa = 15674.4: HETP = 0.462Call tabanshu(R#, N#)ho = N * HETPDT = Sqr((R + 1) * D * 22.4 / (3600 * 0.785 * u) * (273 + td) / 273 * 101.3 / po)J4 = 3.14 / 4 * DT ^ 2 * ho * cpa * FcEnd Sub'塔板数的计算Public Sub tabanshu(R#, N#)Dim ye#, XW#Dim X!(100), Y!(100), xx!(100), i%, n1#td = 64.93: F = 402.34: XD = 0.982: XF = 0.3151: ηd = 0.999: D = 128.97: Rmin = 1.0167 V = (R + 1) * D: W = F + V - D: XW = (F * XF - D * XD) / Wi = 1: Y(1) = 0.982: X(1) = 0.9702DoIf X(i) > XF ThenY(i + 1) = R * X(i) / (R + 1) + XD / (R + 1)n1 = i + 1 + (X(i) - XF) / (X(i) - X(i + 1))ElseY(i + 1) = W * (X(i) - XW) / VIf X(i) < XW Then Exit DoEnd Ifi = i + 1xx(i) = (Y(i) / (3.3874 * (1 - Y(i)))) ^ (1 / 0.7977) X(i) = xx(i) / (1 + xx(i))LoopN = i - 1 + (X(i - 1) - XW) / (X(i - 1) - X(i))lilunbanshu = Ntiliuduanbanshu = n1jinliuduanbanshu = N - n1End Sub目录1 前言------------------------------------------------------------------------------------------------12 方案论证2.1 精馏塔类型----------------------------------------------------------------------------------1 2.2 精馏压力-------------------------------------------------------------------------------------1 2.3 进料方式-------------------------------------------------------------------------------------1 2.4 填料类型-------------------------------------------------------------------------------------2 2.5 加热方式-------------------------------------------------------------------------------------22.6 塔材料类型----------------------------------------------------------------------------------23 数学模型的建立3.1 精馏塔塔体年投资折旧费及维修费用-------------------------------------------------3 3.2 冷凝器年运转费用-------------------------------------------------------------------------4 3.3 直接蒸汽加热费用-------------------------------------------------------------------------53.4 填料年折旧费-------------------------------------------------- --54 数学模型的求解4.1 数学模型决策变量分析-------------------------------------------------------------------5 4.2 主要工艺参数的求解----------------------------------------------------------------------54.2.1 塔径的计算-----------------------------------------------------------------------------54.2.2 塔板数的计算-------------------------------------------------------------------------64.2.2.1 相平衡关系的表示--------------------------------------------------------------64.2.2.2 N的计算--------------------------------------------------------------------------64.2.3 冷凝器年运转费用的计算------------------ ----------------------- ----------------74.2.3.1 冷却水用量及冷凝器传热面积的计算- -------------------------------------74.2.3.2 冷凝器冷却水最佳出口温度的确定-----------------------------------------74.2.4 直接加热蒸气费用的计算----------------------------------------------------------8 4.3 数学模型的求解------------------------------------------------------- --------------------84.3.1 单变量最优化方法--------------------------------------------- ----------------------84.3.2 优化设计程序框图-------------------------------------------- -----------------------84.3.2.1 函数调用关系--------------------------------------------------------------------95 优化设计计算5.1 数据预处理---------------------------------------------------------------------------------105.1.1 进塔物料的计算----------------------------------------------------------------------105.1.2 塔顶蒸气温度的计算----------------------------------------------------------------105.1.3 等板高度的计算----------------------------------------------------------------------10Ⅰ5.1.4 产品汽化潜热的计算----------------------------------------------------------------115.1.5 最小回流比的确定-------------------------------------------------------------------115.1.6 填料单价的计算----------------------------------------------------------------------115.2. 塔径的计算---------------------------------------------------------------------------------13 5.3 填料层高度的计算-------------------------------------------------------------------------13 5.4 精馏塔塔体年投资折旧费及维修费用的计算-----------------------------------------13 5.5 冷凝器年运转费用的计算----------------------------------------------------------------145.5.1 冷凝器冷却水最佳出口温度的确定----------------------------------------------145.5.2 冷却水用量及冷凝器传热面积的计算-------------------------------------------145.5.3 精馏塔塔体年投资折旧费及维修费用的计算----------------------------------15 5.6 再沸器年运转费用的计算----------------------------------------------------------------15 5.7 填料年折旧费用的计算-------------------------------------------------------------------15 5.8 汽液负荷-------------------------------------------------------------------------------------155.8.1 气相负荷-------------------------------------------------------------------------------155.8.2 液相负荷-------------------------------------------------------------------------------155.9 年总费用与回流比的关系--------------------------------------------------------------156 填料塔水力学性能校核6.1 泛点率校核--------------------------------------------------------------------------------- 17 6.2 径比校核-------------------------------------------------------------------------------------17 6.3 喷淋密度校核-------------------------------------------------------------------------------176.4 填料塔压降----------------------------------------------------------------------------------177 附属设备的设计与选型7.1 塔顶冷凝器--------------------------------------------------------------------------------- 187.1.1 冷凝器传热量-------------------------------------------------------------------------187.1.2 冷凝器传热推动力-------------------------------------------------------------------187.1.3 初估冷凝器传热面积----------------------------------------------------------------197.1.4 冷凝器传热系数的校核-------------------------------------------------------------197.1.5 冷凝器传热面积的校核-------------------------------------------------------------227.1.6 冷凝器壳程、管程流动阻力-------------------------------------------------------22 7.2 接管选型------------------------------------------------------------------------------------ 247.2.1 进料口接管的选型-------------------------------------------------------------------247.2.2 冷却水接管的选型-------------------------------------------------------------------257.2.3 塔顶蒸气接管选型------------------------------------------------------------------ 25Ⅱ7.2.4 塔顶产品接管选型-------------------------------------------------------------------257.2.5 塔底产品接管选型-------------------------------------------------------------------267.2.6 塔顶产品回流接管选型-------------------------------------------------------------267.2.7 塔底加热蒸气接管选型------------------------------------------------------------- 26 7.3 冷却水输送泵7.3.1 塔高的计算---------------------------------------------------------------------------277.3.2 冷却水输送泵选型------------------------------------------------------------------27 7.4 填料支承结构-------------------------------------------------------------------------------28 7.5 液体分布装置-------------------------------------------------------------------------------287.7 液体收集再分布装置----------------------------------------------------------------------298 设计结果汇总------------------------------------------------------------------------------------299 设计心得------------------------------------------------------------------------------------------31 参考文献---------------------------------------------------------------------------------------------- 31 附录一甲醇和水部分物性参数-----------------------------------------------------------------32 附录二甲醇—水汽液平衡数据（摩尔组成）-------------------------------------------------33 附录三优化设计程序源代码--------------------------------------------------------------------34化工原理课程设计学生姓名：黄圣楠学号：081000115专业班级：10级生工（1）班____指导教师：张星___2013年1月24日。
甲缩醛_甲醇_甲醛_水四元系的汽液平衡研究
收稿日期:1998-04-03*国家85攻关项目/万吨级聚甲醛工艺过程的开发研究0子课题,江西省自然科学基金项目1第20卷第4期1998年12月 南昌大学学报(工科版)Journal of Nanchang U niv ersity(Engineering &T echno logy)Vol.20No.4Dec.1998甲缩醛-甲醇-甲醛-水四元系的汽液平衡研究*邱祖民(南昌大学化学工程系,南昌330029)倪柳芳 张迎军(上饶地区技术监督局,上饶334000) (南昌市民政建筑工程公司,南昌330008)章标明 朱露(江西抚州造纸厂,临川344000) (南昌市工业合作联社,南昌330008)摘要 用新型泵式沸点仪测定了常压下甲缩醛-甲醇-甲醛-水四元系在不同液相组成时的沸点,采用/甲醛虚拟饱和蒸汽压0的处理方法,用Wilson 方程对所测数据进行了关联,建立了该系统汽液平衡的热力学模型,并推算了平衡的汽相组成1关键词 沸点仪,汽液平衡,甲缩醛,甲醇,甲醛,甲醛虚拟饱和蒸汽压中图法分类号 O 642142甲缩醛-甲醇-甲醛-水四元系的汽液平衡数据为甲缩醛氧化制甲醛生产工艺所需,该系统汽液平衡数据,此前尚未见过报导1本文针对甲醛与活性溶剂水及甲醇具有强烈的缔合反应且甲缩醛易挥发的特点,采用新型泵式沸点仪112测其沸点,用/甲醛虚拟饱和蒸汽压0的处理方法12~32,不考虑甲醛与活性溶剂的化学反应平衡,仅用传统的活度系数模型,对所测数据进行关联,由文献142可知,以Wilson 方程为佳,从而建立该四元系的汽液平衡热力学模型1所用测试装置新型泵式沸点仪与以往沸点仪的显著差异在于溶液循环机理不同,由原来的过热汽体夹带液体循环,改为泵使液体循环,从而达到液体循环量大,汽相冷凝量小,能适用于具有缔合反应及汽相易凝固等复杂系统的汽液平衡数据测定,使测定精度大幅度提高1本文所测四元系中,甲醛与水及甲醇具有强烈的缔合反应,关联该类物系相当困难11991年,Brandani 152同时考虑汽液两相中的物理作用力及化学作用力,虽较好地关联了含甲醛多元系的汽液平衡,但模型复杂,计算工作量大,还要作许多假设才能求解1而甲醛虚拟饱和汽压法用甲醛与水二元系实验数据,在表观组成上进行计算,得出甲醛在活性溶液中的虚拟饱和蒸汽压,进而用于多元系推算,结果表明,与实验值相近,与用Brandani 模型的计算精度相当11 实验部分111 试剂甲缩醛由华东理工大学、浙江大学联合反应所制备,用金属钠将所含的微量水反应掉,再经精馏提纯;甲醇为上海试剂厂生产的分析纯试剂,经精馏提纯;甲醛水溶液为上海溶剂厂生产的新鲜液,经精馏提纯,并保温存放1水为离子交换水经二次蒸馏提纯1112 实验装置采用自行设计的泵式沸点仪,在拟静态下操作1压力控制采用二级自动控制系统(压力波动小于29141995Pa)1113 实验数据附表为011013M Pa 下测得的甲缩醛-甲醇-甲醛-水四元系液相组成与沸点的数据,推算的泡点温度及汽相组成也列于附表1附表 011013M Pa 下甲缩醛-甲醇-甲醛-水四元系汽液平衡数据t b cal /e t b exp /e X 水甲醇甲缩醛甲醛Y 水甲醇甲缩醛甲醛41.9341.920.01740.00730.97260.00270.02690.00860.96450.000141.7841.830.03320.01230.95280.00170.03940.01280.94770.000043.1743.210.07270.16360.72020.04350.03270.10270.86410.000545.6745.540.23180.18830.45890.12100.05790.08220.85860.001251.4051.890.38530.20580.17770.23120.08300.08940.82430.003457.0157.120.48970.20030.09340.21660.11820.11780.75870.005376.0476.550.73730.20740.01110.04420.33260.41250.24920.005765.3466.450.64340.18990.04240.12340.19490.19750.60090.006899.1998.980.99640.00300.00010.00050.96830.02220.00880.000858.0359.130.58840.17750.07340.16070.14000.12660.72840.005066.7567.210.67430.20110.03640.08820.21140.24110.54210.005376.0176.230.74670.19560.01160.04610.33510.39120.26760.006282.7083.280.78310.15230.00510.05950.44080.38190.16310.014262.0562.110.93260.00020.03170.03550.20800.00030.78820.003491.1290.880.97740.01420.00310.00530.70890.07700.20940.004642.5642.560.00250.06580.90330.02840.00280.06590.93080.000542.4142.630.00230.12730.84390.02650.00180.11000.88780.000342.4242.760.00220.16470.80770.02540.00150.13180.86650.000342.4842.890.00210.20290.77080.02420.00120.15140.84710.000256.3356.630.25930.52920.11740.09410.07200.36510.56160.001356.9857.410.28070.50430.11130.10370.07850.35270.56720.001557.4258.360.30020.48170.10570.11240.08470.34150.57200.001858.5158.910.33730.43840.09520.12910.09700.31950.58110.002558.8859.490.34880.42510.09190.13420.10100.31280.58360.002742.8843.500.08210.18660.70900.02230.03400.11820.84760.000243.3244.060.18480.16580.62980.01960.05450.09330.85200.000243.5944.380.26930.14860.56550.01660.06380.07970.85630.000243.8244.490.34700.13280.50430.01590.06940.06970.86070.000243.9644.610.40700.12060.45800.01440.07270.06340.86370.000244.8745.720.36350.21460.40900.01290.06770.11050.82160.000145.5646.720.39870.19570.36240.04320.07160.09550.83250.000445.9047.170.41460.18710.34130.05700.07330.08930.83680.000646.3947.590.43640.17540.31240.07580.07580.08150.84190.000847.0847.780.46440.16040.27520.10000.07920.07240.84730.001287.2986.180.66770.04860.00620.27750.48400.08820.33770.0901#18#南昌大学学报(工科版)1998年续附表t b cal /e t b exp /e X 水甲醇甲缩醛甲醛Y 水甲醇甲缩醛甲醛56.4755.270.62830.04570.06490.26110.12910.02350.83970.007775.3374.820.41340.40040.01430.17190.22120.55400.21040.014375.4378.450.83700.05670.01580.09050.34360.10890.53060.016959.9059.450.72250.14230.05710.07810.16320.13630.69740.003154.8354.820.69970.13770.08700.07560.12830.10430.76550.001957.5857.970.63380.21890.07880.06850.13740.18100.67980.001862.8063.960.49560.24590.06030.19820.15180.19580.64490.007558.8158.820.48480.23940.08320.19260.12660.16030.70780.005254.9555.380.46700.23070.11680.18550.10560.12990.76090.003642.1041.950.01310.00100.98040.00550.02280.00120.97580.000142.3242.370.05480.00400.91840.02280.05050.00340.94560.000542.3442.700.05220.05140.87470.02170.03960.04230.91780.000443.1243.370.11580.05110.78500.04810.05600.03200.91130.000743.2843.780.10330.15350.70030.04290.04160.09190.86610.000543.2242.400.00440.04310.90210.05040.00520.04150.95230.001042.9542.480.00410.10460.84420.04710.00340.08810.90770.000742.8842.670.00400.14320.80760.04520.00280.11210.88450.000644.2444.550.13210.12510.65280.09000.04890.06490.88510.001144.9545.580.20410.11500.56560.11530.05950.05180.88740.001445.0245.990.33500.09600.47270.09630.07110.04150.88630.001245.2145.390.58080.06060.29790.06070.08180.02930.88800.000889.8290.480.96690.00430.00430.02450.66880.02040.29150.019489.6289.410.98350.00180.00450.01020.67440.00930.30770.008682.4083.140.96260.00430.00870.02440.50090.01600.47150.011781.8883.330.93050.03750.00840.02360.47750.12680.38660.009071.2069.810.92040.03710.01920.02330.30660.08520.60420.004072.8972.540.89960.03810.01760.04470.32380.08330.58460.008353.0250.660.85020.03600.07160.04220.13020.03320.83510.001453.5450.580.84410.03640.06920.05030.13270.03310.83240.001855.0554.680.81850.06560.06710.04880.14000.06150.79670.001756.0755.690.80870.06450.06260.06420.14550.05950.79250.002457.4156.370.79680.06320.05710.08290.15330.05770.78550.003558.6656.540.78630.06200.05240.09930.16090.05650.77800.004559.4657.110.78030.06130.04960.10880.16610.05610.77260.005266.0465.000.62970.24250.04000.08780.19710.27520.52320.004566.7965.650.59470.28450.03780.08300.19630.32920.47050.004167.3366.700.56090.32530.03560.07820.19310.38120.42200.003767.5767.210.54010.35030.03430.07530.19010.41230.39410.003567.8067.730.51380.38220.03260.07140.18530.45160.36000.003167.9468.200.48950.41110.03110.06830.18000.48590.33120.002964.6865.220.04620.92570.00890.01920.01870.93080.05020.000365.3166.360.09960.87390.00840.01810.04040.90830.05090.000366.9268.230.14470.80890.00770.03870.06130.88550.05230.000968.6469.220.17740.76180.00720.05360.07780.86740.05340.001464.9966.440.17380.74650.02720.05250.06820.75430.17640.001163.4965.860.17180.73790.03840.05190.06380.70280.23250.000956.8657.250.16890.67510.10490.05110.04980.49300.45670.0006#19#第4期邱祖民等:甲缩醛-甲醇-甲醛-水四元系的汽液平衡研究d t =0.71,d t(max )=3.02,d t 为绝对平均温度偏差,d t(max)为最大偏差12 热力学模型由于是在虚拟组分上进行计算,可不必考虑其溶剂中的真实组分,也不必考虑甲醛的溶剂化反应1选用截至两项的维里方程计算汽相的逸度系数,用既简单又适用于甲醛多元系142的Wilson 方程计算液相的活度系数,用式p s c F =p c F ex p(4.5+4.5/T r -11.91/T 2r )122作为甲醛的虚拟饱和蒸汽压,并将此作为甲醛的标准态,其余组分按其饱和液体的逸度选取标准态1相平衡方程为p s i U s i X i exp 1V L mi (p -p s i )/R /T 2C i =p Y i U Cip s c F U s F X F exp 1V L mF (p -p s cF )/R /T 2C F =p Y F U CF甲缩醛-甲醇-甲醛-水四元系中所含二元系的Wilson 模型参数如下:系统水-甲醇122甲缩醛-水142水-甲醛122甲醇-甲缩醛142甲醇-甲醛142甲醛-甲缩醛132参数225.3444.1629.12271.70.5875.0-65.9903.8-3450.230507153 结果及讨论推算的泡点温度及汽相组成列于附表,可见推算的泡点温度平均绝对偏差为0171e ,最大绝对偏差为3102e 1针对这样复杂的系统,用新型泵式沸点仪测定,极大地减轻了实验工作量1此外,用甲醛虚拟饱和蒸汽压及Wilson 方程的计算方法处理甲醛系统,能方便地建立含甲醛多活性组分系统汽液平衡的热力学模型,此模型除具有简便易算、很适合于工程计算的特点外,还具有预测功能,仅用二元系的模型参数推算四元系的汽液平衡数据,能取得这样的精度还是满意的1若为了提高精度,也可将三元系及四元系的数据并入,回归出最佳模型参数1符号说明p )压力;R )气体常数;T ,t )温度;V )体积;X )表观液相组成;Y )表观汽相组成;C )活度系数;U )汽相逸度系数;U C)汽相分逸度系数上角标:c )临界态;L )液相;s )饱和态;c )虚拟态下角标:b )泡点;F )甲醛;i )组分;m )摩尔量;r )对比参考文献112 邱祖民,骆赞椿,胡英1泵式沸点仪1高校化学工程学报,1997,11(1):74122 邱祖民,骆赞椿,胡英1含甲醛多元系汽液平衡的模型化1高校化学工程学报,1996,10(3):225132 邱祖民1含甲醛多元系统的汽液相平衡研究:1学位论文21上海:华东理工大学,1993142 邱祖民,骆赞椿,胡英1甲醇-水、甲缩醛-甲醇和甲缩醛-水系统的汽液平衡1高校化学工程学报,1994,8(2):106~118152 Brandani S,Brandini V ,Di G iacomo G.Fluid P hase Equilibria,1991,63:27(下转第34页)参考文献112Eric T all,A ctiv e X开发人员指南1北京:机械工业出版社,1997122周长发1多媒体计算机技术开发与应用1北京:电子工业出版社,1995132王健1网络互联与系统集成1北京:电子工业出版社,1996Research of Web.s Strange Place Design and ManufactureDai Jianmin(N anchang Science and T echnology I nf or mation Center,N anchang330003)Xie Q iangM echanical and Electr ionic Engineering College,N anj ingiUniver sity of A er onautics and A s tr onautics,N anj ing210016ABSTRAC T The article has expounded in detail the strange place design and manufacture system.s research and development with multimedia technology and w eb browser.KEY WORDS multimedia,web,strange place desig n and manufacture(上接第20页)Study on Vapor Liquid Equilibria of theMethylal-Methanol-Formaldehyde-Water SystemQiu Zumin(Chemical Engineering Dep ar tment,N anchang University,N anchang330029)N i Liufang(Shangr ao S up er visor y Of f ice of T echnicality,Shangr ao334000)Zhang Y ingjun(N anchang Civil A dministr ation A r chitectur al Engineer ing Comp any,N anchang330008)Zhang Biaoming(Jiangx i Fuz hou M ake Pa p er Plant,L inchuan344000)Zhu Lu(N anchang I ndustry I ntegr ated Comp lex,N anchang330008)ABSTRAC T The boiling points of the methylal-methanol-formaldehyde-water system w ere determined at the atmospheric pressure w ith a new motive cottrell pump-ebulliometer. T hese data had been treated w ith formaldehybe hy pothetical saturation-vapor pressure (FHSVP)and the Wilson equation,setting up the thermodynamic model of this system on the v apor equilibria(VLE).The equilibrium composition of the vapor phase had been calculated.。
5.3 汽液平衡的计算
(i = 1,2,L, N )
• 常减压条件下的汽液平衡是一类最常见的汽液平衡，通 常将汽相作为理想气体，液相作为非理想溶液处理，上 式简化为 Py i = Pi s xi γ i (i = 1,2, L , N ) • 只涉及一个活度系数模型和蒸汽压方程，而不再需要状 态方程 ，在常、减压汽液平衡计算中广泛使用 。
ˆ v = Py fi i
Ki = yi
和
ˆ l = f x = Ps x fi i i i i
Pi s
由式（5-1）得到汽液平衡常数
xi
=
P
查附录A-2的Antoine方程常数，并由Antoine方程计算出 各组分在373.15K时的饱和蒸汽压分别是
s P1
= 0.18005 ,
s P2
= 0.07气相分压
P − P2s x1 = s H 1, 2 − P2 H 1, 2 y1 = x1 P p1 = H 1, 2 x1 s p 2 = P2 (1 − x1 )
• 对于Henry常数很大的情况，以上结果再简化成
P − P2s P2s x1 = , y1 = 1 − , p1 = P − P2s H 1, 2 P
汽液平衡的准则和计算方法
●混合物汽液平衡准则（基于偏摩尔自由焓或化学位）
ˆ ˆ f i v = f i l (i = 1,2,L, N )
以组分逸度系数来表示
ˆiv yi = pϕil xi ˆ pϕ
(i = 1 , 2K N )
◆状态方程法(EOS—Equation of State）
基于一个状态方程模型和混合法则来描述汽液 平衡的方法，EOS法要求状态方程能同时适用 于汽、液两相。
分离工程--02 汽液相平衡-1
p
a Vm2
Vm
b
RT
式中：a , b 范德华常数
范德华方程
若用
Vm
V n
代入以上方程，可得：
p
n2a V2
V
nb
nRT
当 p 0 , Vm , 范德华方程 理想气体状态方程
从现代理论看来，范德华对于内压力与 b 的导出都
不尽完善，精确测定表明，a 、b 不但与气体性质有关，
2.2.1 逸度系数(或逸度)与P-V-T的基本关系
利用均匀体系的基本热力学关系式可以导出逸度(或 逸度系数)与以P、T为独立变量的热力学关系式：
RT ln
fiv yi P
RT lniV
p
0 [Vi
RT p
]dp
（2-17）
RT ln
fiv yi P
RT lniV
p [( V ni
8a 27Rb
,
pc
a 27b2
由于Vm,c不容易测准,所以一般以Tc、pc 求算 a 、b
a 27R2Tc2 64 pc
, b RTc 8 pc
范德华方程特点： 1.方程虽然准确度不高，很少用于实际
Ki
yi xi
fiL0 iL fiV0 iV
pisi0L pi0V
f (T , p)
（2-13）
上式说明，理想系的平衡常数也只与T,P有关.
非理想系
气相、液相中有一相为非理想气体(或非理想溶液)， 该体系称为非理想系。
缩甲醛度对汽态_液态水在PVA均质膜中的吸附_溶解行为的影响
文章编号:1007-8924(2001)05-0062-04缩甲醛度对汽态/液态水在PVA 均质膜中的吸附/溶解行为的影响徐春保 韩宾兵3 李继定 陈翠仙 牟学军(清华大学化学工程系,北京 100084)摘 要:研究了水蒸气和水在不同缩甲醛度的PVA 均质膜中的动态吸附(溶解)行为,结果表明对水蒸气/PVA 均质膜体系,随缩醛度增大,水蒸气的扩散速度减小,溶解度也减小,脱附速度变化不明显;而对水/PVA 均质膜体系,缩醛后,水的扩散速度增大,溶解度随温度和缩醛度增大而减小.关键词:PVA 均质膜;缩甲醛度;吸附;脱附中图分类号:TQ02818 文献标识码:A 聚乙烯醇(PVA )是一种优良的亲水性渗透汽化膜材料[1],广泛应用于脱水的渗透汽化膜过程中.在制膜工艺中,对膜的改性处理是一个必不可少的环节.通过化学反应调节PVA 膜的交联程度可以优化膜的选择性和渗透性,控制溶胀程度,防止引起传递能力不稳定的聚合物再结晶等.原GF T 公司的PVA/PAN 复合膜便是利用马来酸进行交联处理,交联后膜的耐水性大幅度提高,膜对水的选择性也有增加,但膜的渗透通量下降.清华大学用甲醛、乙二醛及戊二醛等对PVA/PAN 复合膜进行了改性处理[2],研究了交联对渗透通量和分离因子的影响,其中甲醛处理的膜对多种有机物的脱水分离有良好的效果,已经成功地用于苯及碳六溶剂油的脱水中试(千吨级)试验[3～5].与马来酸处理不同,甲醛处理后膜的渗透通量增加,而分离因子有所下降.本文实验测定了水蒸气和水在不同缩醛度θ的聚乙烯醇膜中的动态吸附(溶解)、脱附行为,研究了缩醛度对水蒸气/水在PVA 膜中溶解度的影响,以为膜性能的进一步改进、膜的制备以及水在PVA 中扩散机理的研究提供基础数据.1 实验部分111 实验材料实验所用的聚乙烯醇均质膜为自制.制备方法如下:将质量分数为7%的聚乙烯醇加入去离子水中,100℃下搅拌1h ,压滤、静置、真空脱泡后在玻璃板上刮一定厚度的膜.膜自然晾干后在100℃下处理1h ,然后用甲醛溶液处理一定的时间,用去离子水洗净、晾干后备用.膜厚度75～80μm.缩醛度的测定用增重法[6],用下式计算:缩醛度θ=8800(缩甲醛后的质量缩甲醛前的质量-1)甲醛的分子量-18(1)112 实验流程和设备11211 水蒸气在膜中的吸附和脱附图1为水蒸气在膜中的动态吸附、脱附实验装置.该装置由蒸汽发生器、缓冲室、吸附室、恒温水系统、真空系统和数据记录系统组成.吸附实验时,将膜置于吸附室的电子天平挂钩上,关闭缓冲室和吸附室间的阀门后抽真空;同时开启恒温水系统、蒸汽发生器和缓冲室,产生一定温度的水蒸气;待膜的质量在1h 内基本不变后,关闭真空泵,开启缓冲室和吸附室间的阀门,开始吸附过程.膜的质量由计算机收稿日期:2000-11-06;修改稿收到日期:2001-01-08基金项目:国家自然科学基金(20076023)和清华大学基础研究基金资助项目作者简介:徐春保(1973～),男,湖南沅江人,硕士研究生. 3通讯联系人.第21卷 第5期膜 科 学 与 技 术Vo1.21 No.52001年10月MEMBRAN E SCIENCE AND TECHNOLO GY Oct.2001图1 水蒸气在膜中的吸附和脱附实验装置G 1蒸汽发生器;C 1缓冲室;Th 1恒温系统;S 1吸附室;PG 1水银压力计;M 1膜;E 1电子天平;VP 1真空泵;T 1温度显示器;PC 1计算机;V 1阀门实时记录,直至膜的质量在1h 内基本不变为止.吸附过程达平衡后,关闭缓冲室和吸附室间的阀门,同时开启真空系统,开始脱附过程,直至膜的质量在1h 内基本不变为止.吸附和脱附实验的温度为35℃.11212 水在膜中的动态溶解实验将真空脱汽(气)后的PVA 膜置于一定温度的去离子水中,一定时间后取出、快速擦干、称量后重新放入水中,直至膜的质量在015～1h 内基本不变为止.为减少实验误差,溶解度取多次测量的平均值.动态溶解实验的温度为35℃.2 实验结果和讨论211 水蒸气在PVA 均质膜中的吸附、脱附图2 水蒸气在不同缩醛度θ的PVA 膜中的动态吸附(T =35℃)缩醛度θ:1.0;2.20112%;3130116%;4138196%;514715%图2为35℃下水蒸气在不同缩醛度θ的PVA 膜中的动态吸附曲线.曲线横坐标为吸附时间的平方根,纵坐标为某一时刻膜吸附的水蒸气量与平衡状态下膜吸附的水蒸气量之比.由图2可见,水蒸气在PVA 膜中的吸附速度较慢,达平衡的时间较长;随缩醛度增大,吸附达到平衡的时间增加,说明水蒸气在膜中的吸附速度随缩醛度增大而减小.未缩甲醛膜在吸附初期的曲线呈明显的线性,说明此时水蒸气分子在膜中的扩散属正常扩散[7];而缩甲醛膜的吸附呈明显的曲线,显示出反常扩散特性.图3为35℃下水蒸气在不同缩醛度的PVA 膜中的动态脱附曲线,真空度为011MPa.由图3可见,真空脱附条件下,水蒸气从膜中的脱附速度与缩醛度并没有明显的联系,几种缩醛度膜中水蒸气的脱附速度基本相当.图3 水蒸气在不同缩醛度θ的PV A 膜中的脱附(T =35℃)缩醛度θ:1120112%;2.30116%;3.38196%;4.0图4是35℃下水蒸气在不同缩醛度θ的PVA膜中的溶解度,溶解度定义为渗透物(水蒸气或水)在膜中的溶解达平衡条件下,每克干膜中溶解的渗透物的量.由图4可见,随缩醛度θ增大,水蒸气在 第5期徐春保等:缩甲醛度对汽态/液态水在PVA 均质膜中的吸附/溶解行为的影响・63 ・ 膜中的溶解度逐渐减小.图4 水蒸气在不同缩醛度θ的PVA膜中的溶解度(T =35℃)212 水在PVA 均质膜中的溶解图5是35℃下水在不同缩醛度的PVA膜中的动态溶解曲线.由图5可见,与水蒸气在PVA 均质膜中的动态吸附相比,水在PVA 膜中的溶解速度较快,几分钟即可达平稳.实验条件下水在几种缩甲醛度的PVA 膜中的溶解速度基本相当,都明显快于未缩甲醛膜的情形.水在未缩甲醛的PVA 均质膜中的扩散显示出典型的反常扩散特性.图5 水在不同缩醛度θ的PVA 膜中的动态溶解曲线(T =35℃)图6是水在不同温度、不同缩醛度θ的PVA 均质膜中的溶解度.由图6可见,随缩醛度θ增加,水的溶解度减小;随温度增加,溶解度也减小.图6 水在不同缩醛度θ的PVA 膜中的溶解度213 汽相/液相水在PVA 均质膜中的吸附(溶解)现象的进一步讨论在PVA 大分子上,每一个基本链节都含有一个羟基,经加热处理后,PVA 产生一定的结晶度,部分羟基被纳入晶格,成为束缚的羟基.当用甲醛对PVA 处理时,位于结构比较疏松的非结晶区的部分羟基与甲醛发生如下的(主要)反应:CH 2CH OHCH 2CH OH+HCHOH +CH 2CH OCH 2CH OCH 2+H 2O反应结果是形成了带亚甲基的含氧六元环,减少了自由羟基的比例,从而减小了PVA 的亲水性,缩醛度θ越高,自由羟基的比例越小,PVA 的亲水性越差,水(汽相或液相)在PVA 中的溶解度越小,这和其它作者关于羟基对渗透物在膜中溶解度的影响的研究结论一致[8].图7 均质PVA 膜中吸附的液体水的脱附行为但汽相和液相水在PVA 膜中的动态吸附(溶解)速度与缩醛度的关系相反,可能缘于吸附(溶解)机理的不同.缩醛反应后,分子内部形成六元环,加大了高分子链之间的空间位阻,减小了高分子链的排列有序性;同时自由羟基的减少削弱了高分子链之间的氢键作用,这两方面的作用可能导致高分子链之间的间隙增加,自由体积增大,这可能是水在缩醛膜中吸附速度快的原因.但水蒸气在缩醛PVA 膜中吸附速度变慢可能缘于其它因素的影响.具体机理还需进一步研究.实验室研究表明,缩醛后膜的渗透通量增加[9].渗透通量与渗透物小分子在膜中的溶解度、扩散速度和脱附速度有关.由于缩醛后水/水蒸气在膜中的溶解度减小,水蒸气在膜中的吸附速度也减小,水蒸气从膜中脱附的速度则变化不大,因而渗透 ・64 ・膜 科 学 与 技 术第21卷 通量的增加主要是液体水在膜中扩散速度增加的结果.上述结论可由图7的实验得到进一步的证实.在该实验中,缩醛度不同的两张PVA 膜吸附水达到平衡后,在真空条件下进行脱附,由图7可见,在初始脱附期间,缩醛度越高,脱附速度越快.3 结论研究了水蒸气和水在不同缩醛度的PVA 均质膜中的动态吸附(溶解)行为,结果表明缩醛度对吸附速度和溶解度有明显的影响,随缩醛度增大,水蒸气和水在膜中的溶解度都下降,吸附速度则呈现出不同的变化趋势.温度对水在PVA 膜中的溶解度也有影响,温度增大,平衡溶解度减小.参 考 文 献[1]北京有机化工厂研究所,编译.聚乙烯醇的性质和应用[M ].北京:纺织工业出版社,1979.[2]余立新,陈翠仙,张立平,等.二醛交联的PVA/PAN 复合膜的渗透汽化脱水性能[J ].膜科学与技术,2000,20(2):23～25.[3]彭 勇,陈翠仙,李继定,等.渗透汽化苯脱水的实验室和工业试验研究(Ⅰ)实验室放大试验[J ].膜科学与技术,2000,20(6):1～3.[4]陈翠仙,李继定,韩宾兵,等.渗透汽化苯脱水的实验室和工业试验研究(Ⅱ)工业试验[J ].膜科学与技术,2000,20(6):4～7.[5]韩宾兵,陈翠仙,李继定,等.渗透汽化苯脱水的实验室和工业试验研究(Ⅲ)计算机模拟[J ].膜科学与技术,2000,20(6)8～12.[6]董纪震,吴宏仁,陈雪英,等编.合成纤维生产工艺学[M ].北京:纺织工业出版社,1989.[7]Frisch H L.S orption and transport in glassy polymers -Areview [J ].Polymer Eng Sci ,198020:2～13.[8]Wang B G ,Y amaguchi T ,Nakao S I.E ffect of molecularassociation on solubility ,diffusion ,and permeability in polymeric membranes [J ].J Polymer Sci ,2000,38:171～181.[9]林 焱.用PVA/PAN 复合膜的渗透汽化放大实验研究[学士论文].北京:清华大学化学工程系,1997.E ffect of formaldehyde acetal degree on sorption(solution)behavior of liquid/vapor w ater in PVA homogeneous membranesX U Chunbao ,HA N B i nbi ng ,L I Ji di ng ,CH EN Cui xian ,M O X uej un(Chemical Engineering Department ,Tsinghua University ,Beijing 100084,China )Abstract :The sorption (solution )behavior of liquid/vapor water in PVA homogeneous membranes with different formaldehyde acetal degrees were studied.The experimental results showed that both the sorption rate and the solubility of water vapor in PVA membranes decrease as the formaldehyde acetal degree increases ,but the formaldehyde acetal degree has little effect on the desorption rate.For the water/PVA homogeneous system ,the solubility of water decreases as the temperature and formaldehyde acetal degree increase.The solution rates of water in PVA membranes with formaldehyde acetal were found to be higher than those in PVA membranes without any formaldehyde acetal.K ey w ords :PVA homogeneous membrane ;formaldehyde acetal degree ;sorption ;desorption欢迎订阅《中国设备工程》(月刊)原刊名《中国设备管理》 邮发代号:82-374创刊于1985年的《中国设备管理》杂志由国家发展计划委员会主管,中国设备管理协会主办,国内外公开发行的设备管理、设备维修技术的综合性技术月刊.为了适应我国经济体制和政府机构改革的需要,使刊物成为一本名实相符,更适合读者需要的工程类综合型杂志,经国家科技部和新闻出版署批准,于2001年7月开始更名为《中国设备工程》.主要栏目有管理论坛、设备要素市场、修理与改造、维护与调整、可靠性与故障分析、状态监测与诊断技术、节能与环保、明星风采、国外设备工程、讲座、信息等.本刊为大16开本64页,每册定价7元,2002年全年定价84元.全国各地邮局均可订阅,漏订可随时向本社订阅.地址:北京市西城区月坛南街38号国家计委 邮编:100824单位:《中国设备工程》杂志社 联系人:曹文通 电话:(010)68052048 68054838 传真:68054837 第5期徐春保等:缩甲醛度对汽态/液态水在PVA 均质膜中的吸附/溶解行为的影响・65 ・ 。
物理化学习题解答(四)
物理化学习题解答(四)习题 p266~2701、在298K 时，有0.10kg 质量分数为0.0947的硫酸H 2SO 4水溶液，试分别用(1)质量摩尔浓度m B ；(2)物质的量浓度c B 和(3)摩尔分数x B 来表示硫酸的含量。
已知在该条件下，硫酸溶液的密度为1.0603×103kg .m -3，纯水的密度为997.1kg .m -3。
解:m (B)= w B × = 0.0947×0.10kg =0.00947kg=9.47gn B = m (B)/M B =9.47/98.079=0.09655molm (A)= - m (B)= 0.10×(1-0.0947)=0.09153kg=91.53g n A = m (A)/M A =91.53/18.015=5.080766mol(1) m B =n B /m (A)= 0.09655/0.09153=1.055mol.kg -1(2) V 溶液= /ρ=0.10/(1.0603×103)=0.0943×10-3 m 3=0.0943dm 3 c B =n B /V=0.09655/0.0943=1.024mol.L -1(3) x B = n B / =0.09655/(0.09655+5.08076)=0.018642、在298K 和大气压力下，含甲醇(B)的摩尔分数x B 为0.458的水溶液的密度为0.8946kg .dm -3，甲醇的偏摩尔体积V B =39.80cm 3.mol -1，试求该水溶液中水的偏摩 尔体积V A 。
解:设n B =1.0mol ，则n 总=n B /x B =1/0.458=2.183mol ，n A =1.183 molm (B)=n B M B =1.0×32.042=32.042g ，m (A)= n A M A =1.183×18.015=21.312g V ={m (A)+m (B)}/ρ=(21.312+32.042)/0.8946= 59.64cm 3V =n A V A +n B V B ，V A =(V -n B V B )/n A =(59.64-1.0×39.80)/1.183=16.77 cm 3.mol -13、在298K 和大气压下，某酒窑中存有酒10.0m 3，其中含乙醇的质量分数为0.96，今欲加水调制含乙醇的质量分数为0.56的酒，已知该条件下，纯水的密度为999.1 kg .m -3，水和乙醇的偏摩尔体积为：w (C 2H 5OH) V (H 2O)/10-6m 3.mol -1 V (C 2H 5OH) /10-6m 3.mol -1∑AA m ∑AA m ∑AA m ∑AA n0.96 14.61 58.010.56 17.11 56.58试计算：(1) 应加入水的体积；(2) 加水后，能得到含乙醇的质量分数为0.56的酒的体积。
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第17卷第3期1998年9月
南昌水专学报
Journal of Nanchang College of Water Conservancy and Hydroelectric Pow er
Vol.17No.3
S ep.1998
甲醇)甲缩醛)甲醛)水四元系的汽液平衡*
邱祖民(南昌大学南昌330029)
柳雪芳(上饶地区工业学校上饶334000)
倪柳芳(上饶地区技术监督局上饶334000)
屈芸(南昌大学南昌330029)
摘要检验了文献[1]热力学模型的准确性,并用该模型推算了难于测定的甲醇)甲醛、甲缩醛)甲醛及甲醇)甲缩醛)甲醛的汽液平衡.
关键词汽液平衡;热力学模型;甲醇;甲醛;甲缩醛
中图分类号O642.4
0引言
针对含甲醛多元系汽液平衡数据难于测准,相应的热力学模型难建且求解困难的特点,笔者采用泵式沸点计建立起来的一套测试装置能较准确地用于含甲醛多元系汽液平衡数据的测定[2].采用甲醛虚拟饱和蒸汽压[3]的方法能方便地建立起含甲醛多元系汽液平衡的热力学模型,且该模型易解,适合于工程计算.文献[1]研究了甲醇)甲缩醛)甲醛)水四元系的汽液平衡行为,使用泵式沸点计测试,甲醛虚拟饱和蒸汽压法处理,建立了该四元系的热力学模型,本文旨在进一步验证该模型的准确性,预测一些不易获取的甲醛多元系汽液平衡数据.
1热力学模型[1]
相平衡方程:P S i f S i X i exp[V L mi(P-P S i)/R/T]r i=P Y i f^i
P S F c f S F X F exp[V L mF(P-P S F c)/R/T]r F=P Y F f^F
式中P S F c=P C F exp[4.5+4.5/T r-11.91/T2r][2]
甲醇)甲缩醛)甲醛)水四元系所含二元系的Wilson模型参数如表1所示.
表1二元系的W ilson模型参数表
系统水)))甲醇甲缩醛)))水水)))甲醛甲醇)))甲缩醛甲醇)))甲醛甲醛)))甲缩醛参数225.3144.1629.12271.70.5875-65.9903.8-3450.23050715
*江西省自然科学基金资助项目
收稿日期:1998-04-30
2模型检验
用该四元系模型可推测所含二元系及三元系的汽液平衡行为.推测结果与文献值比较示于表21
表2011013M Pa下含甲醇、甲缩醛、甲醛、水体系的模型推测值与文献[4~7]值的比较体系文献页n d l d ml d Y W dm Y W d Y M dm Y M d Y D d m Y D d Y F d m Y F F-W4290.220.530.00660.01320.00660.0132 F-W49100.781.660.01640.03430.01440.0343 F-W410160.972.010.02100.03670.02100.0367 M-W440160.611.220.03080.07340.03080.0734
M-W447170.320.640.00400.01530.00400.0153
M-W453150.350.730.00780.02020.00780.0202
D-W425212.985.330.02490.06240.02490.0624
M-F-W4474280.621.900.01260.03800.03630.08900.04260.0850 M-F-W4475300.621.790.01290.03050.02050.06230.02530.0673 M-F-W4554280.621.900.01160.03800.03670.08920.04010.0817
M-W5210.110.41
D-W5221.032.01
F-W3250.351.23
M-D5210.160.44
M-D-W6190.411.85
M-F-W7131.051.95
由表2可见除甲缩醛-水体系的沸点模型推测值与文献值差异较大外,其它尚可.
图10.1013M Pa下甲醇)甲醛二元系的VLE图
)计算的X
M )计算的Y
M
3模型预测
由于难制得纯甲醛用于甲醛多元系的汽
液相平衡测定,而上述模型检验说明根据文献
[1]建立起来的甲醇)甲缩醛)甲醛)水四元
系的热力学模型具有较高的准确性,因此可用
该模型预测甲醇)甲醛、甲缩醛)甲醛二元
系、甲醇)甲缩醛)甲醛三元系的汽液平衡行
为.预测结果分别示于图1~图5.
4结论
模型检验说明该四元系模型无论是用于
其所含组分的二元系还是三元系汽液平衡行为描绘,其准确度皆较高.11
第3期邱祖民、柳雪芳、倪柳芳、屈芸:甲醇)甲缩醛)甲醛)水四元系的汽液平衡
图20.1013M Pa下甲缩醛)甲醛二元系的VLE图)计算的X D)计算的Y
D 图30.1013M Pa下甲醇)甲缩醛)甲醛三元系的VL
E 等温图1-44e;2-46e;3-47e;4-50e;
5-55e;6-60
e
图40.1013M Pa下甲醇)甲缩醛)甲醛三元系的
VLE等Y D图1-30%;2-50%;3-60%;
4-70%;5-80%;6-90%;7-95
%
图50.1013M Pa下甲醇)甲缩醛)甲醛三元系的
VLE等Y M图1-5%;2-10%;3-20%;
4-30%;5-40%;6-50%本文推测了甲醇)甲醛、甲缩醛)甲醛、甲醇)甲缩醛)甲醛的汽液平衡,可供工程研究及设计时参考.
符号说明
d)绝对平均偏差上标:
D)甲缩醛C)临界态
d m)最大绝对偏差L)液相
f)汽相逸度系数s)饱和态
f^)汽相分逸度系数s c)虚拟态
F)甲醛下标:
M)甲醇b)泡点
n)实验点数cal)计算值
12南昌水专学报1998年第3期
P )压力,M Pa D )甲缩醛r )活度系数
exp )实验值R )气体常数,J.mol -1.K -1F )甲醛
t,T )温度,e ,K i )除甲醛外的组分V )体积m )摩尔量W )))水
M )甲醇X )液相组成,mol %r )对比Y )汽相组成,mol %
W )水
参考文献
1 邱祖民、骆赞椿、胡英.甲缩醛)甲醇)甲醛)水四元系的汽液平衡.高校化学工程学报,1998,12(1):61
2 邱祖民、骆赞椿、胡英.泵式沸点仪.高校化学工程学报,1997,11(1):74
3 邱祖民、骆赞椿、胡英.含甲醛多元系汽)液平衡的模型化.高校化学工程学报,1996,10(3):61
4 Gmehling J 、Onken U 、Arlt W.V apor -L iquit Equilibrium Data Collection,Vol.1,DECHEM A(1981)
5 邱祖民、骆赞椿、胡英.甲醇)))水、甲缩醛)))甲醇和甲缩醛)))水系统的汽液平衡.高校化学工程学
报.1994,8(2):106
6 邱祖民、骆赞椿、胡英.甲缩醛)))甲醇)))水三元系的汽液平衡.高校化学工程学报,1997,11(2):189
7 邱祖民、骆赞椿、胡英.甲缩醛)))甲醇)))水三元系的汽液平衡.南昌大学学报(工科版),1996,18(4):42
Vapor Liquid Equilibria of the Methylal
Methanol -Formaldehyde-Water System
Qiu Zumin Qu Yun
(Nanchang University Nanchang 330029)
Liu Xuefang
(Shangrao Industry School Shangrao 334000)
Ni Liufang
(Shangrao Supervisory Office of Technicality Shangrao 334000)
Abstract The thermodynamic model accuracy in the literature[1]w as testified in this paper.T he vapor -liquit equilibria (VLE)of the methylal -formaldehyde,the methanol -formaldehyde,and the methylal-methanol-formaldehyde w as predicted w ith the model,w hich is difficult to determine.
Key words VLE;thermodynamic model;methanol;formaldehyde;methylal
13
第3期 邱祖民、柳雪芳、倪柳芳、屈芸:甲醇)甲缩醛)甲醛)水四元系的汽液平衡。