From b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b Mon Sep 17 00:00:00 2001 From: priyanka Date: Wed, 24 Jun 2015 15:03:17 +0530 Subject: initial commit / add all books --- 905/CH6/EX6.1/6_1.sce | 83 ++++++++++++++++++++++++++++++ 905/CH6/EX6.10/6_10.sce | 97 +++++++++++++++++++++++++++++++++++ 905/CH6/EX6.11/6_11.sce | 42 +++++++++++++++ 905/CH6/EX6.12/6_12.sce | 71 +++++++++++++++++++++++++ 905/CH6/EX6.13/6_13.sce | 65 +++++++++++++++++++++++ 905/CH6/EX6.14/6_14.sce | 65 +++++++++++++++++++++++ 905/CH6/EX6.2/6_2.sce | 53 +++++++++++++++++++ 905/CH6/EX6.3/6_3.sce | 44 ++++++++++++++++ 905/CH6/EX6.4/6_4.sce | 134 ++++++++++++++++++++++++++++++++++++++++++++++++ 905/CH6/EX6.7/6_7.sce | 69 +++++++++++++++++++++++++ 10 files changed, 723 insertions(+) create mode 100755 905/CH6/EX6.1/6_1.sce create mode 100755 905/CH6/EX6.10/6_10.sce create mode 100755 905/CH6/EX6.11/6_11.sce create mode 100755 905/CH6/EX6.12/6_12.sce create mode 100755 905/CH6/EX6.13/6_13.sce create mode 100755 905/CH6/EX6.14/6_14.sce create mode 100755 905/CH6/EX6.2/6_2.sce create mode 100755 905/CH6/EX6.3/6_3.sce create mode 100755 905/CH6/EX6.4/6_4.sce create mode 100755 905/CH6/EX6.7/6_7.sce (limited to '905/CH6') diff --git a/905/CH6/EX6.1/6_1.sce b/905/CH6/EX6.1/6_1.sce new file mode 100755 index 000000000..8d33946a8 --- /dev/null +++ b/905/CH6/EX6.1/6_1.sce @@ -0,0 +1,83 @@ +clear; +clc; + +// Illustration 6.1 +// Page: 324 + +printf('Illustration 6.1 - Page: 324\n\n'); + +// solution +//*****Data*****// +// n-heptane - a n-octane - b +T1 = 303; // [K] +P = 1; // [bar] +D = 0.6; +W = 0.4; +zf = 0.5; + +// Parameters for componenr 'A' +Tc_a = 540.3; // [K] +Pc_a = 27.4; // [bar] +A_a = -7.675; +B_a = 1.371; +C_a =-3.536; +D_a = -3.202; + +// Parameters for component 'B' +Tc_b = 568.8; // [K] +Pc_b = 24.9; // [bar] +A_b = -7.912; +B_b = 1.380; +C_b = -3.804; +D_b = -4.501; + +// Using equation 6.5 +// x_a = 1-(T/Tc_a); +// P_a = Pc_a*exp((A_a*x_a+B_a*x_a^1.5+C_a*x_a^3+D_a*x_a^6)/(1-x_a)); // [bar] + +// x_b = 1-(T/Tc_b); +// P_b = Pc_b*exp((A_b*x_b+B_b*x_b^1.5+C_b*x_b^3+D_b*x_b^6)/(1-x_b)); // [bar] + +// m_a = P_a/P; +// m_b = P_b/P; + +// Solution of simultaneous equation +function[f]=F(e) + f(1) = e(2) - (e(3)*Pc_a*exp(((A_a*(1-(e(1)/Tc_a))+B_a*(1-(e(1)/Tc_a))^1.5+C_a*(1-(e(1)/Tc_a))^3+D_a*(1-(e(1)/Tc_a))^6))/(1-(1-(e(1)/Tc_a)))))/P; + f(2) = 1-e(2) - ((1-e(3))*Pc_b*exp((A_b*(1-(e(1)/Tc_b))+B_b*(1-(e(1)/Tc_b))^1.5+C_b*(1-(e(1)/Tc_b))^3+D_b*(1-(e(1)/Tc_b))^6)/(1-(1-(e(1)/Tc_b)))))/P; + f(3) = (-W/D) - ((e(2)-zf)/(e(3)-zf)); + funcprot(0); +endfunction + +// Initial guess +e = [400 0.6 0.4]; +y = fsolve(e,F); +T = y(1); // [K] +Yd = y(2); +Xw = y(3); + +printf("The composition of the vapor and liquid and the temperature in the separator if it behaves as an ideal stage are %f, %f and %f K respectively\n\n",Yd,Xw,T); + +// For the capculation of the amount of heat to be added per mole of feed +T0 = 298; // [K] +lambdaA = 36.5; // [Latent heats of vaporization at To = 298 K ,kJ/mole] +lambdaB = 41.4; // [Latent heats of vaporization at To = 298 K ,kJ/mole] +CpA = 0.187; // [kJ/mole.K] +CpB = 0.247; // [kJ/mole.K] +CLA1 = 0.218; // [ 298-303 K, kJ/mole.K] +CLB1 = 0.253; // [ 298-303 K, kJ/mole.K] +CLA2 = 0.241; // [ 298-386 K, kJ/mole.K] +CLB2 = 0.268; // [ 298-386 K, kJ/mole.K] +// Bubble point calculated when 'D' approaches 0 and Dew point calculated when 'D' approaches 1 +Tbp = 382.2 // [Bubble point of the mixture, K] +Tdp = 387.9 // [Dew point of mixture, K] + +HF = (T1-T0)*(Xw*CLA1+CLB1*(1-Xw)); // [kJ/mole] +HW = (Tbp-T0)*(Xw*CLA2+CLB2*(1-Xw)); // [kJ/mole] +HG = (Tdp-T0)*(Yd*CpA+(1-Yd)*CpB) + Yd*lambdaA +(1-Yd)*lambdaB; // [kJ/mole] + +f =1 // [feed] +// Using equation 6.4 +deff('[y] = f14(Q)','y = W/D + (HG-(HF+Q/f))/(HW -(HF+Q/f))'); +Q = fsolve(40,f14); +printf("The amount of heat to be added per mole of feed is %f kJ/mole\n\n",Q); \ No newline at end of file diff --git a/905/CH6/EX6.10/6_10.sce b/905/CH6/EX6.10/6_10.sce new file mode 100755 index 000000000..39503f7cf --- /dev/null +++ b/905/CH6/EX6.10/6_10.sce @@ -0,0 +1,97 @@ +clear; +clc; + +// Illustration 6.10 +// Page: 371 + +printf('Illustration 6.10 - Page: 371\n\n'); + +// solution +//*****Data*****// +// A-toluene B-1,2,3-trimethyl benzene C-benzene +// Solution of above three are ideal +// Feed +za = 0.40; +zb = 0.30; +zc = 0.30; +// Bottom +FRAd = 0.95; // [recovery of toluene in distillate] +FRBw = 0.95; // [recovery of 1,2,3-trimethyl benzene in the bottom] +P = 1; // [atm] + +// First estimate of distillate composition +xc = 40/70; +xa = 30/70; +xb = 0; +// The bubble point temperature for this solution is +Tb = 390; // [K] +// The corresponding parameters for benzene, toluene and 1,2,3-trimethyl benzene +// For toluene +Tc_a = 568.8; // [K] +Pc_a = 24.9; // [bar] +A_a = -7.912; +B_a = 1.380; +C_a =-3.804; +D_a = -4.501; +// For 1,2,3-trimethyl benzene +Tc_b = 664.5; // [K] +Pc_b = 34.5; // [bar] +A_b = -8.442; +B_b = 2.922; +C_b =-5.667; +D_b = -2.281; +// For benzene +Tc_c = 540.3; // [K] +Pc_c = 27.4; // [bar] +A_c = -7.675; +B_c = 1.371; +C_c =-3.536; +D_c = -3.202; + + +// At the estimated reboiler temperature of 449.3 K +Tr = 449.3; // [K] +// P = [Toluene;1,2,3-trimethyl benzene;Benzene] +P1 = zeros(3,6); +// P = [Tc Pc A B C D] +P1 = [568.8 24.9 -7.912 1.380 -3.804 -4.501;664.5 34.5 -8.442 2.922 -5.667 2.281;540.3 27.4 -7.675 1.371 -3.536 -3.202;]; + +for i=1:3 + P1(i) = P1(i,2)*exp((P1(i,3)*(1-Tr/P1(i,1))+P1(i,4)*(1-Tr/P1(i,1))^1.5+P1(i,5)*(1-Tr/P1(i,1))^3+P1(i,6)*(1-Tr/P1(i,1))^6)/(1-(1-Tr/P1(i,1)))); +end +PA1 = P1(1); // [bar] +PB1 = P1(2); // [bar] +PC1 = P1(3); // [bar] +alphaAB1 = PA1/PB1; +alphaCB1 = PC1/PB1; + +// At the estimated distillate temperature of 390 K +Td = 390; // [K] +// P = [Toluene;1,2,3-trimethyl benzene;Benzene] +P2 = zeros(3,6); +// P = [Tc Pc A B C D] +P2 = [568.8 24.9 -7.912 1.380 -3.804 -4.501;664.5 34.5 -8.442 2.922 -5.667 2.281;540.3 27.4 -7.675 1.371 -3.536 -3.202;]; + +for i=1:3 + P2(i) = P2(i,2)*exp((P2(i,3)*(1-Td/P2(i,1))+P2(i,4)*(1-Td/P2(i,1))^1.5+P2(i,5)*(1-Td/P2(i,1))^3+P2(i,6)*(1-Td/P2(i,1))^6)/(1-(1-Td/P2(i,1)))); +end + +PA2 = P2(1); // [bar] +PB2 = P2(2); // [bar] +PC2 = P2(3); // [bar] +alphaAB2 = PA2/PB2; +alphaCB2 = PC2/PB2; + +// The geometric-average relative volatilities are +alphaAB_avg = sqrt(alphaAB1*alphaAB2); +alphaCB_avg = sqrt(alphaCB1*alphaCB2); + +// From equation 6.66 +Nmin = log(FRAd*FRBw/((1-FRAd)*(1-FRBw)))/log(alphaAB_avg); + +// From equation 6.67 +FRCd = alphaCB_avg^Nmin/((FRBw/(1-FRBw))+alphaCB_avg^Nmin); // [fractional recovery of benzene in the distillate] + +printf("The number of equilibrium stages required at total reflux is %f.\n",Nmin); +printf("The recovery fraction of benzene in the distillate is %f.\n\n",FRCd); +printf('Thus, the assumption that virtually all of the LNK will be recovered in the distillate is justified.'); \ No newline at end of file diff --git a/905/CH6/EX6.11/6_11.sce b/905/CH6/EX6.11/6_11.sce new file mode 100755 index 000000000..f045cde12 --- /dev/null +++ b/905/CH6/EX6.11/6_11.sce @@ -0,0 +1,42 @@ +clear; +clc; + +// Illustration 6.11 +// Page: 376 + +printf('Illustration 6.11 - Page: 376\n\n'); + +// solution +//*****Data*****// +// 1-toluene 2-1,2,3--trimethylbenzene 3-benzene +// Basis: 100 kmol/h of feed +F = 100; // [kmole/h] +// Since feed is saturated, therefore +q = 0; +// From example 6.10 +x1d = 0.3; +x2d = 0.3; +x3d = 0.4; +a12 = 3.91; +a32 = 7.77; +a22 = 1; +// Equ 6.78 gives +deff('[y] = f14(Q)','y = 1- a12*x1d/(a12-Q)-a22*x2d/(a22-Q)-a32*x3d/(a32-Q)'); +Q = fsolve(2,f14); + +// From the problem statement +// d1 = D*x1d d2 = D*x2d +d1 = F*x1d*0.95; // [kmol/h] +d2 = F*x2d*0.05; // [kmol/h] +d3 = F*x3d*0.997; // [kmol/h] + +// Summing the three distillate, d1,d2 and d3 +D = d1+d2+d3; // [kmole/h] + +Vmin = a12*d1/(a12-Q)+a22*d2/(a22-Q)+a32*d3/(a32-Q); + +// From the mass balance +Lmin = Vmin-D; // [kmol/h] +// Minimum reflux ratio +Rmin = Lmin/D; +printf("The minimum reflux ratio is %f\n\n",Rmin); \ No newline at end of file diff --git a/905/CH6/EX6.12/6_12.sce b/905/CH6/EX6.12/6_12.sce new file mode 100755 index 000000000..48339d962 --- /dev/null +++ b/905/CH6/EX6.12/6_12.sce @@ -0,0 +1,71 @@ +clear; +clc; + +// Illustration 6.12 +// Page: 377 +printf('Illustration 6.12 - Page: 377\n\n'); + +// solution +//*****Data*****// +// Componenets A-propane B-pentane C-methane D-ethane E-butane F-hexane +// x-mole fraction a-relative volatility +xA = 0.25; aA = 4.08; +xB = 0.11; aB = 1.00; +xC = 0.26; aC = 39.47; +xD = 0.09; aD = 10.00; +xE = 0.17; aE = 2.11; +xF = 0.12; aF = 0.50; +// Since propane and pentane are light and heavy key respectively +// Methane and ethane are LNK, hexane is a HNK, while butane is a “sandwich component,” meaning that it has a volatility intermediate between the keys. + +FRlkd = 0.98; +FRhkd = 0.01; +// For methane +D_CR = (aC-1)/(aA-1)*FRlkd + (aA-aC)/(aA-1)*FRhkd; +// For ethane +D_DR = (aD-1)/(aA-1)*FRlkd + (aA-aD)/(aA-1)*FRhkd; +// For butane +D_ER = (aE-1)/(aA-1)*FRlkd + (aA-aE)/(aA-1)*FRhkd; +// For hexane +D_FR = (aF-1)/(aA-1)*FRlkd + (aA-aF)/(aA-1)*FRhkd; +// Since the feed is 66% vaporized +q = 1-0.66; + +// Now equation 6.82 is solved for two values of Q +deff('[y] = f14(Q1)','y = 0.66 - aA*xA/(aA-Q1)-aB*xB/(aB-Q1)-aC*xC/(aC-Q1)-aD*xD/(aD-Q1)-aE*xE/(aE-Q1)-aF*xF/(aF-Q1)'); +Q1 = fsolve(1.2,f14); + +deff('[y] = f15(Q2)','y = 0.66 - aA*xA/(aA-Q2)-aB*xB/(aB-Q2)-aC*xC/(aC-Q2)-aD*xD/(aD-Q2)-aE*xE/(aE-Q2)-aF*xF/(aF-Q2)'); +Q2 = fsolve(2.5,f15); + +// Basis: 100 mole of feed +F = 100; // [mole] +// Let d1 = Dxad, d2 = Dxbd, d3 = Dxcd, and so on +d1 = F*xA*FRlkd; // [moles of propane] +d2 = F*xB*FRhkd; // [moles of pentane] +d3 = F*xC; // [moles of methane] +d4 = F*xD; // [moles of ethane] +d6 = F*xF*0; // [moles of hexane] +// And d5 is unknown +// Applying equation 6,78 for each value of Q + +// Solution of simultaneous equation +function[f]=H(e) + f(1) = e(1) - aA*d1/(aA-Q1)-aB*d2/(aB-Q1)-aC*d3/(aC-Q1)-aD*d4/(aD-Q1)-aE*e(2)/(aE-Q1)-aF*d6/(aF-Q1); + f(2) = e(1) - aA*d1/(aA-Q2)-aB*d2/(aB-Q2)-aC*d3/(aC-Q2)-aD*d4/(aD-Q2)-aE*e(2)/(aE-Q2)-aF*d6/(aF-Q2); + funcprot(0); +endfunction + +// Initial guess +e = [90 5]; +y = fsolve(e,H); +Vmin = y(1); // [mole] +d5 = y(2); // [d5 = Dxed, mole] + +// From equ 6.84 +D = d1+d2+d3+d4+d5+d6; // [mole] +// From mass balance +Lmin = Vmin-D; // [mole] +// For minimum reflux ratio +Rmin = Lmin/D; +printf("The minimum reflux ratio is %f\n\n",Rmin); \ No newline at end of file diff --git a/905/CH6/EX6.13/6_13.sce b/905/CH6/EX6.13/6_13.sce new file mode 100755 index 000000000..5e05bd264 --- /dev/null +++ b/905/CH6/EX6.13/6_13.sce @@ -0,0 +1,65 @@ +clear; +clc; + +// Illustration 6.13 +// Page: 380 +printf('Illustration 6.13 - Page: 380\n\n'); + +// solution +//*****Data*****// +// A-benzene B-toluene C-1,2,3-trimethylbenzene +// From example 6.10 +Nmin = 4.32; // [stages] +// From example 6.11 +Rmin = 0.717; // [minimum reflux ratio] +// For R = 1 +R = 1; +X = (R-Rmin)/(R+1); +// From equ 6.88 +Y = 1-exp((1+54.4*X)/(11+117.2*X)*(X-1)/sqrt(X)); +// Fro equ 6.86 +N = (Y+Nmin)/(1-Y); +// From example 6.10 99.7% of the LNK (benzene) is recovered in the distillate// , 95% of the light key is in the distillate, and 95% of the heavy key is in// the bottoms + +// For a basis of 100 mol of feed, the material balances for three components // are +// For distillate +nAd = 39.88; // [LNK, moles of benzene] +nBd = 28.5; // [LK, moles of toluene] +nCd = 1.50; // [HK, moles of 1,2,3-trimethylbenzene] +nTd = nAd+nBd+nCd; // [total number of moles] +xAd = nAd/nTd; +xBd = nBd/(nTd); +xCd = nCd/(nTd); + +// For bottoms +nAb = 0.12; +nBb = 1.50; +nCb = 28.50; +nTb = nAb+nBb+nCb; +xAb = nAb/nTb; +xBb = nBb/nTb; +xCb = nCb/nTb; + +D = nTd; +W = nTb; +// From problem statement +Zlk = 0.3; +Zhk = Zlk; +// Substituting in equation 6.89 +// T = Nr/Ns +T = (Zhk/Zlk*W/D*(xBb/xCd)^2)^0.206; + +// Solution of simultaneous equation +function[f]=H(e) + f(1) = e(1)-e(2)*T; + f(2) = e(1)+e(2)-N; + funcprot(0); +endfunction + +// Initial guess +e = [5 4]; +y = fsolve(e,H); +Nr = y(1); // [number of stages in rectifying section] +Ns = y(2); // [number of stages in stripping section] +disp(Ns,Nr); +printf('Rounding the estimated equilibrium stage requirement leads to 1 stage as a partial reboiler, 4 stages below the feed, and 5 stages above the feed.'); diff --git a/905/CH6/EX6.14/6_14.sce b/905/CH6/EX6.14/6_14.sce new file mode 100755 index 000000000..3b8d49507 --- /dev/null +++ b/905/CH6/EX6.14/6_14.sce @@ -0,0 +1,65 @@ +clear; +clc; + +// Illustration 6.14 +// Page: 387 +printf('Illustration 6.14 - Page: 387\n\n'); + +// solution +//*****Data*****// +// a-acetone b-methanol c-water +yna = 0.2971; yn1a = 0.17; ynIa = 0.3521; mnIa = 2.759; xna = 0.1459; +ynb = 0.4631; yn1b = 0.429; ynIb = 0.4677; mnIb = 1.225; xnb = 0.3865; +ync = 0.2398; yn1c = 0.4010; ynIc = 0.1802; mnIc = 0.3673; xnc = 0.4676; + +Fabv = 4.927; // [mol/square m.s] +Facv = 6.066; // [mol/square m.s] +Fbcv = 7.048; // [mol/square m.s] +aI = 50; // [square m] +Vn1 = 188; // [mol/s] +Vn = 194.8; // [mol/s] +//*****// +printf('Illustration 6.14(a) - Page: 387\n\n'); +// Solution(a) + +ya = (yna+ynIa)/2; +yb = (ynb+ynIb)/2; +yc = (ync+ynIc)/2; + +Rav = ya/Facv+yb/Fabv+yc/Facv; +Rbv = yb/Fbcv+ya/Fabv+yc/Fbcv; + +Rabv = -ya*(1/Fabv-1/Facv); +Rbav = -yb*(1/Fabv-1/Fbcv); +// Thus in matrix form +Rv = [Rav Rabv;Rbav Rbv]; +kv = inv(Rv); // [inverse of Rv] +// From equ 6.99 +b = [yna-ynIa;ynb-ynIb]; +J = kv*b; + +// From equ 6.98 +Jc = -sum(J); // [mol/square m.s] + +printf("The molar diffusional rates of acetone, methanol and water are %f mol/square m.s, %f mol/square m.s and %f mol/square m.s respectively.\n\n",J(1,1),J(2,1),Jc); + +printf('Illustration 6.14(b) - Page: 388\n\n'); +// Solution(b) +Ntv = Vn1-Vn; // [mol/s] + +// From equation 6.94 +Nta = aI*J(1,1)+ya*Ntv; +Ntb = aI*J(2,1)+yb*Ntv; +Ntc = aI*Jc+yc*Ntv; +printf("The mass transfer rates of acetone, methanol and water are %f mol/s ,%f mol/s and %f mol/s respectively.\n\n",Nta,Ntb,Ntc); + +printf('Illustration 6.14(c) - Page: 389\n\n'); +// Solution(c) + +// Approximate values of Murphree vapor tray efficiency are obtained from // equation 6.105 + +EMG_a = (yna-yn1a)/(mnIa*xna-yn1a); +EMG_b = (ynb-yn1b)/(mnIb*xnb-yn1b); +EMG_c = (ync-yn1c)/(mnIc*xnc-yn1c); + +printf("The Murphree vapor tray efficiencies for acetone, methanol and water are %f, %f and %f respectively.\n\n",EMG_a,EMG_b,EMG_c); \ No newline at end of file diff --git a/905/CH6/EX6.2/6_2.sce b/905/CH6/EX6.2/6_2.sce new file mode 100755 index 000000000..9b730e030 --- /dev/null +++ b/905/CH6/EX6.2/6_2.sce @@ -0,0 +1,53 @@ +clear; +clc; + +// Illustration 6.2 +// Page: 326 + +printf('Illustration 6.2 - Page: 326\n\n'); + +// solution +//*****Data*****// +// a-benzene b-toluene c-orthoxylene +T = 373; // [K] +P = 101.3; // [kPa] +Pa = 182.7; // [kPa] +Pb = 73.3; // [kPa] +Pc= 26.7; // [kPa] +Zfa = 0.5; +Zfb = 0.25; +Zfc = 0.25; +//*****// +// Therefore +ma = Pa/P; +mb = Pb/P; +mc = Pc/P; +// Let Feed is 1 kmole +// Therefore D+W = 1 + +// Solution of simultaneous equation +function[f]=F(e) + f(1) = e(1)+e(2)-1; + f(2) = e(2)/e(1) + (e(3)-Zfa)/(e(4)-Zfa); + f(3) = e(3)-ma*e(4); + f(4) = e(5)-mb*e(6); + f(5) = 1-e(3)-e(5) -mc*(1-e(4)-e(6)); + f(6) = e(2)/e(1) + (e(5)-Zfb)/(e(6)-Zfb); + funcprot(0); +endfunction + +// Initial guess +e = [0.326 0.674 0.719 0.408 0.198 0.272]; +y = fsolve(e,F); +D = y(1); +W = y(2); +Yad = y(3); +Xaw = y(4); +Ybd = y(5); +Xbw = y(6); +Ycd = 1-Yad-Ybd; +Xcw = 1-Xaw-Xbw; + +printf("The amounts of liquid and vapor products are %f and %f respectively\n\n",D,W); +printf("The vapor compositions of components A, B and C are %f, %f and %f respectively\n\n",Yad,Ybd,Ycd); +printf("The liquid composition of components A, B and C are %f, %f and %f respectively\n\n",Xaw,Xbw,Xcw); \ No newline at end of file diff --git a/905/CH6/EX6.3/6_3.sce b/905/CH6/EX6.3/6_3.sce new file mode 100755 index 000000000..f0c585fe9 --- /dev/null +++ b/905/CH6/EX6.3/6_3.sce @@ -0,0 +1,44 @@ +clear; +clc; + +// Illustration 6.3 +// Page: 328 + +printf('Illustration 6.3 - Page: 328\n\n'); + +// solution +//*****Data*****// +// n-heptane - a n-octane - b +P = 1; // [bar] + +// Basis: +F = 100; // [mole] +// Therefore +D = 60; // [mole] +W = 40; // [mole] +xf = 0.5; +// Substituting in equation 6.11 yields +// log(F/W) = Integration of dx/(y_star-x) from xw to 0.50 + +// The equilibrium-distribution data for this system can be generated by calculating the liquid composition (x = xw) at the dew point (D = l.O).for different feed // compositions (y_star = z). +y_star = [0.5 0.55 0.60 0.65 0.686 0.70 0.75]; +x = [0.317 0.361 0.409 0.460 0.5 0.516 0.577]; +for i = 1:7 + f(i) = 1/(y_star(i)-x(i)); +end + +area = [0.317 5.464;0.361 5.291;0.409 5.236;0.460 5.263;0.5 5.376;0.516 5.435;0.577 7.78]; +// LHS of equation 6.11 +a = log(F/W); + +scf(4); +plot(area(:,1),area(:,2)); +xgrid(); +legend('area under curve'); +xlabel("x"); +ylabel("1/(y_satr-x)"); + +// When the area becomes equal to 0.916, integration is stopped; this occurs at +xw = 0.33; // [mole fraction of heptane in residue] +yd =( F*xf-W*xw)/D; // [mole fraction of heptane] +printf("The composition of the composited distillate and the residue are %f and %f respectively\n\n",yd,xw); \ No newline at end of file diff --git a/905/CH6/EX6.4/6_4.sce b/905/CH6/EX6.4/6_4.sce new file mode 100755 index 000000000..577962c84 --- /dev/null +++ b/905/CH6/EX6.4/6_4.sce @@ -0,0 +1,134 @@ +clear; +clc; + +// Illustration 6.4 +// Page: 342 + +printf('Illustration 6.4 - Page: 342\n\n'); + +// solution +//*****Data*****// +T = 298; // [K] +Fa = 200; // [feed, kmole/hr] +zf = 0.6; +yd = 0.95; xd = yd; +xw = 0.05; +q = 0.5; // [Lf/F] +//*****// + +printf('Illustration 6.4(a) - Page: 342\n\n'); +// Solution (a) + +// Solution of simultaneous equation +function[f]=F(e) + f(1) = Fa - e(1)-e(2); + f(2) = zf*Fa - yd*e(1) - xw*e(2); + funcprot(0); +endfunction + +// Initial guess +e = [120 70]; +y = fsolve(e,F); +D = y(1); +W = y(2); +printf("Quantity of liquid and vapor products are %f kmole/h and %f kmole/h respectively\n\n",D,W); + + +printf('Illustration 6.4(b) - Page: 342\n\n'); +// Solution(b) +// VLE data is generated in the same manner as generated in Example 6.1 by applying Raoult's law +// VLE_data = [T,x,y] +VLE_data = [379.4 0.1 0.21;375.5 0.2 0.37;371.7 0.3 0.51;368.4 0.4 0.64;365.1 0.5 0.71;362.6 0.6 0.79;359.8 0.7 0.86;357.7 0.8 0.91;355.3 0.9 0.96]; +// From figure 6.14 +// The minimum number of equilibrium stages is stepped off between the equilibrium curve and the 45 degree Iine, starting from the top, giving +Nmin = 6.7; +printf("The minimum number of theoretical stages is %f\n\n",Nmin); + +printf('Illustration 6.4(c) - Page: 342\n\n'); +// Solution(c) +// Slope of q-line = Lf/F/(1-(Lf/F)) +s = q/(1-q); +// For minimum reflux ratio +// From figure 6.12 y-intercept is +i = 0.457; +// Therefore Rmin is +Rmin = xd/i -1; +printf("The minimum reflux ratio is %f mole reflux/mole distillate\n\n",Rmin); + +printf('Illustration 6.4(d) - Page: 343\n\n'); +// Solution(d) +R = 1.3*Rmin; +// The y-intercept of the rectifying-section operating line is +ia = xd/(R+1); +// The operating line for the stripping section is drawn to pass through the point x = y = xw = 0.05 on the 45" line and the point of intersection of the q-line // and the rectifying-section operating line. +// Therefore from figure 6.15 +Nact = 13; +// But it include boiler +Nact1 = Nact-1; +printf("The number of equilibrium stages for the reflux ratio specified is %f\n",Nact1); +// For the optimal feed-stage location, the transition from one operating line to the other occurs at the first opportunity +// after passing the operating-line intersection +// Therefore from figure 6.15 shows that +printf("The optimal location of the feed stage for the reflux ratio specified is sixth from the top\n\n"); + +printf('Illustration 6.4(e) - Page: 344\n\n'); +// Solution(e) +L = R*D; // [kmole/h] +V = L+D; // [kmole/h] +// From equation 6.27 +Lst = L+q*Fa; // [kmole/h] +// From equation 6.28 +Vst = V+(q-1)*Fa; // [kmole/h] + +// For 50% vaporization of the feed ( zf = 0.60), from calculations similar to those illustrated in Example 6.1, the separator temperature and the equilibrium // compositions are +Tf = 365.5; // [K] +yf = 0.707; +xf = 0.493; + +// Latent heat vaporisation data at temperature T = 298 K +lambdaA = 33.9; // [kJ/mole] +lambdaB = 38; // [kJ/mole] +// Heat capacities of liquids (298-366 K) +Cla = 0.147; // [kJ/mole.K] +Clb = 0.174; // [kJ/mole.K] +// Heat capacities of gases, average in the range 298 to 366 K +Cpa = 0.094; // [kJ/mole.K] +Cpb = 0.118; // [kJ/mole.K] +// Substituting in equation 6.6 gives +Hf = 0; +Hlf = (Tf-T)*(xf*Cla+(1-xf)*Clb); // [kJ/mole of liquid feed] +// From equation 6.7 +Hvf = (Tf-T)*(yf*Cpa+(1-yf)*Cpb) + yf*lambdaA + (1-yf)*lambdaB; // [kJ/mole of vapor feed] + +Lf = Fa*q; // [kmole/h] +Vf = Fa*(1-q); // [kmole/h] +// From equation 6.3 +Qf = (Hvf*Vf +Hlf*Lf-Fa*Hf)*1000/3600; // [kW] + + +Tlo = 354.3; // [Bubble point temperature, K] +T1 = 355.8; // [Dew point temperature, K] +y1 = 0.95; // [composition of saturated vapor at dew point] +x0 = 0.95; // [composition of saturated liquid at bubble point] +Hv1 = (T1-T)*(y1*Cpa+(1-y1)*Cpb) + y1*lambdaA + (1-y1)*lambdaB; // [kJ/mole of vapor feed] +Hlo = (Tlo-T)*(x0*Cla+(1-x0)*Clb); // [kJ/mole of liquid feed] + +// An energy balance around condenser +Qc = V*(Hv1-Hlo)*1000/3600; // [kW] + +// A flash-vaporization calculation is done in which the fraction vaporized is known (53.8/75.4 = 0.714) and the concentration +// of the liquid residue is fixed at xw = 0.05 +// The calculations yield +Tr = 381.6; // [K] +x12 = 0.093; +y13 = 0.111; +T12 = 379.7; // [Bubble point of the liquid entering in the reboiler, K] + +Hl12 = (T12-T)*(x12*Cla+(1-x12)*Clb); // [kJ/mole of liquid feed] +Hv13 = (Tr-T)*(y13*Cpa+(1-y13)*Cpb) + y13*lambdaA + (1-y13)*lambdaB; // [kJ/mole of vapor feed] + +Hlw = (Tr-T)*(xw*Cla+(1-xw)*Clb); // [kJ/mole of liquid feed] + +// An energy balance around the reboiler +Qr = (Vst*Hv13+W*Hlw-Lst*Hl12)*1000/3600; // [kW] +printf("The thermal load of the condenser, reboiler, and feed preheater are %f kW, %f kW and %f kW respectively\n\n",Qc,Qr,Qf); \ No newline at end of file diff --git a/905/CH6/EX6.7/6_7.sce b/905/CH6/EX6.7/6_7.sce new file mode 100755 index 000000000..566c798f5 --- /dev/null +++ b/905/CH6/EX6.7/6_7.sce @@ -0,0 +1,69 @@ +clear; +clc; + +// Illustration 6.7 +// Page: 358 + +printf('Illustration 6.7 - Page: 358\n\n'); + +// solution +//*****Data*****// +// a-benzene b-toluene +xa = 0.46; +xb = 0.54; +Tb = 395; // [bottom temp., K] +Tt = 360; // [top temp., K] +alphab = 2.26; +alphat = 2.52; +D = 1.53; // [diameter of column, m] +f = 0.81; // [flooding] +deltaP = 700; // [average gas-pressure drop, Pa/tray] +//*****// + +Tavg = (Tb+Tt)/2; // [K] +alpha_avg = (alphab+alphat)/2; + +printf('Illustration 6.7(a) - Page: 359\n\n'); +// Solution(a) + +// Constants for components 'a' and 'b' +Aa = 4.612; +Ba = 148.9; +Ca = -0.0254; +Da = 2.222*10^-5; +ua = exp(Aa+Ba/Tavg+Ca*Tavg+Da*Tavg^2); // [cP] + +Ab = -5.878; +Bb = 1287; +Cb = 0.00458; +Db = -0.450*10^-5; + +ub = exp(Ab+Bb/Tavg+Cb*Tavg+Db*Tavg^2); // [cP] + +// At the average column temperature +ul = ua^xa*ub^xb; // [cP] +K = alpha_avg*ul; +// From the O’Connell correlation +Eo = 0.52782-0.27511*log10(K) + 0.044923*(log10(K))^2; +printf("The overall tray efficiency using the O’Connell correlation is %f.\n\n",Eo); + +printf('Illustration 6.7(b) - Page: 359\n'); +// Solution(b) + +Nideal = 20; // [number of ideal stages] +Nreal = Nideal/(Eo); // [nnumber of real stages] +disp(Nreal); +// Since real stages cannot be fractional, therefore +Nreal = 34; +// From Table 4.3 tray spacing +t = 0.6; // [m] +// Adding 1 m over the top tray as an entrainment separator and 3 m beneath // the bottom tray for bottoms surge capacity, the total column height is +Z = 4+Nreal*t; // [m] +printf("The number of real trays and the total tower height are %f and %f m respectively.\n\n",Nreal,Z); + +printf('Illustration 6.7(c) - Page: 359\n\n'); +// Solution(c) + +// Total gas pressure drop +deltaPc = deltaP*Nreal/1000; // [kPa] +printf("The total gas-pressure drop through the column is %f kPa.\n\n",deltaPc); \ No newline at end of file -- cgit