<\/p>\n\n\n\n
Part \u2013 1 demonstrated applications of the models developed based on the experimental Vapor- Liquid Equilibrium (VLE) and Vapor-Liquid-Liquid Equilibrium (VLLE) data data measurements presented in RR-242 [3]. The models can be used for estimation of solubilities of selected hydrocarbons in pure water, unloaded amine solution, loaded amine solution with CO2<\/sub>\u00a0and\/or H2<\/sub>S.<\/a><\/p>\n\n\n\n Figure 1- Process flow diagram of MDEA acid gas recovery unit [3]<\/p>\n\n\n\n <\/p>\n\n\n\n This tip will focus on the following design variables:<\/a><\/p>\n\n\n\n <\/p>\n\n\n\n <\/p>\n\n\n\n Solubility of Selected Hydrocarbons in Pure Water:<\/strong><\/p>\n\n\n\n Solubility of selected hydrocarbons in pure water can be estimated using Equation 1 [4] or Figure 2.<\/p>\n\n\n\n Where T is the temperature in K and the correlation parameters, E, F and Tmin<\/sub>, are shown in Table 1.<\/p>\n\n\n\n Table 1- Equation 1 parameters, E, F and Tmin<\/sub> [3].<\/p>\n\n\n\n Figure 2 was generated using Equation 1 and its parameters in Table 1. The solubility of these selected hydrocarbons in pure water will be used to estimate their solubilities in amine solution in the proceeding sections.<\/p>\n\n\n\n Figure 2. Solubility of selected hydrocarbons in pure water [4].<\/p>\n\n\n\n <\/p>\n\n\n\n <\/p>\n\n\n\n Estimation\u00a0of solubility of hydrocarbons in amine solution by the GPA Midstream RR-242 Model [4]<\/strong><\/p>\n\n\n\n Equation 2 with its corresponding parameters will be used to estimate the solubility of selected hydrocarbons in unloaded and loaded amine solutions.<\/p>\n\n\n\n Where:<\/p>\n\n\n\n For simplicity and easiness of reading the figures, using the model (Equation 2) similar charts like Figures 3 and 4 or Table 2 were generated in Part \u2013 1 [1].<\/p>\n\n\n\n Figure 3 – Relative solubility of benzene (Fig 3), toluene (Fig 4), and Ethylbenzene (Fig 5) in loaded 50 wt % (13.1 mol-%) MDEA-Water [1]<\/em><\/strong><\/p>\n\n\n\n <\/p>\n\n\n\n Convert 50 wt% MDEA to mole % MDEA<\/strong><\/a><\/p>\n\n\n\n Basis 100 kg of MDEA solution<\/strong><\/p>\n\n\n\n Mass of MDEA = 50 kg MW of MDEA = 119.17 kg\/kmol<\/strong><\/p>\n\n\n\n Mass of water = 50 kg MW of water = 18 kg\/kmol<\/strong><\/p>\n\n\n\n Figure 4 – Solubility of benzene, toluene, and ethyl benzene in unloaded 50 wt % MDEA solution [1]<\/p>\n\n\n\n <\/p>\n\n\n\n Table 2 \u2013 Solubility (x0) of benzene, toluene, and ethylbenzene in unloaded 50 wt % MDEA solution [1]<\/p>\n\n\n\n <\/p>\n\n\n\n <\/p>\n\n\n\n Example 1\u2013 Single Component Hydrocarbon\u00a0<\/strong><\/p>\n\n\n\n This example and its solution on solubility of a single-component benzene in loaded 13.1 mol% (50 wt%) MDEA in water solution were presented in part 1 and shown in Appendix A of this tip.<\/p>\n\n\n\n Multicomponent Hydrocarbons Phase: <\/strong>GPA RR 242 [4] has presented the solubility measurements using a hydrocarbon phase consisting of equimolar amounts of Benzene, Toluene and Ethylbenzene. The acid gas used was CO2. The results are presented in Table 5. To evaluate the accuracy of Eq 2 GPA RR-242 Model [4], <\/strong>we estimated the solubility of Benzene, Toluene and Ethylbenzene into loaded MDEA (50 wt %) aqueous solution for the conditions listed in Table 5 – GPA RR 242. In addition, a step – by – step hand calculations are shown in Example 2, the yellow highlighted values are the corresponding measured values reported in the highlighted row of Table 5.<\/strong><\/p>\n\n\n\n Table 5 – Solubility of Benzene, Toluene and Ethylbenzene into loaded MDEA (50 mass-%) aqueous solution Sapphire Apparatus. Hydrocarbon phase consists of x<\/em><\/strong>1<\/em><\/strong>=0.3329, x<\/em><\/strong>2<\/em><\/strong>=0.3335, x<\/em><\/strong>3<\/em><\/strong>=0.3336 <\/em><\/strong>[Table 5-GPA RR 242]<\/em><\/strong><\/p>\n\n\n\n a is loading mol acid gas\/mol amine, T is temperature, P is Pressure, \ud835\udc65\u0305 \u2013 average mole fraction, n – number of analyzed samples, \u03c3 – standard deviation<\/p>\n\n\n\n <\/p>\n\n\n\n <\/p>\n\n\n\n Example 2 \u2013 Multicomponent Hydrocarbons Phase<\/strong><\/p>\n\n\n\n Determine the solubility of benzene, toluene, and ethylbenzene in loaded 13.1 mol% (50 wt%) MDEA in water solution in terms of scf of gas\/gal of solvent (std m3<\/sup> of gas\/m3<\/sup> of solvent) at 60 \u00b0C (140 \u00b0F), 333 K (600 \u00b0R).<\/p>\n\n\n\n The hydrocarbon phase consists of xB = 0.3329, xT = 0.3335, xEB = 0.3336. Rich amine solution acid gas loading, = 0.41 mol acid gases\/ mole MDEA, MDEA MW =119.17<\/p>\n\n\n\n 50 wt % MDEA solution density =1017.3 kg\/m3<\/sup> (8.49 lbm\/gal)<\/p>\n\n\n\n <\/p>\n\n\n\n <\/p>\n\n\n\n Solution<\/strong><\/p>\n\n\n\n From Fig 3 presented in Part 1 (July 2022 TOTM), for = 0.41 mol acid gases\/ mole MDEA,<\/p>\n\n\n\n relative solubility solubilities are, (x\/x0<\/sub>)B<\/sub> = 0.52 (x\/x0<\/sub>)T<\/sub> = 0.46 (x\/x0<\/sub>)EB<\/sub> = 0.36<\/p>\n\n\n\n From Table 2 or Fig 4 presented in Part 1, for T =60 \u00b0C (140 \u00b0F),<\/p>\n\n\n\n the solubilities in unloaded MDEA are, (x0<\/sub>)B<\/sub> = 0.00464 (x0<\/sub>)T<\/sub> = 0.00216 (x0<\/sub>)EB<\/sub> = 0.00084<\/p>\n\n\n\n Specified compositions (mole fractions) of hydrocarbon phase are, xB = 0.3329, xT = 0.3335, xEB = 0.3336<\/p>\n\n\n\n Figure 3 – Relative solubility of benzene (Fig 3), toluene (Fig 4), and Ethylbenzene (Fig 5) in loaded 50 wt % (13.1 mol-%) MDEA-Water<\/em><\/strong><\/p>\n\n\n\n <\/p>\n\n\n\n Table 2- Solubility of benzene, toluene, and ethyl benzene in unloaded 50 wt % MDEA solution<\/p>\n\n\n\n <\/p>\n\n\n\n <\/p>\n\n\n\n Solution \u2013 SI<\/strong><\/a><\/p>\n\n\n\n Benzene:<\/strong> (x\/x0<\/sub>)B<\/sub> = 0.52 (x0<\/sub>)B<\/sub> = 0.00464 <\/p>\n\n\n\n For xB = 1, x= x0<\/sub>(x\/x0<\/sub>) = (0.00464) (0.52) = 0.00242 kmol Ben\/kmol Sol<\/p>\n\n\n\n For xB = 0.3329, x= x0<\/sub>(x\/x0<\/sub>) (xB) = (0.00464) (0.52) (0.3329) = 0.0008 (vs. 0.00093) kmol Ben\/kmol Sol<\/p>\n\n\n\n The yellow highlighted values are the measured values in Table 5<\/p>\n\n\n\n x = (0.0008 kmol Ben\/kmol Sol) (kmol Sol\/0.131kmol MDEA) = 0.00611 kmol Ben\/kmol MDEA<\/p>\n\n\n\n \u00a0\u00a0 = (0.00611 kmol Ben\/kmol MDEA) (23.64 std m3<\/sup>\/kmol Ben) (kmol MDEA\/119.21 kg MDEA) =\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a00.0012 std m3<\/sup>\u00a0Ben\/kg of MDEA<\/p>\n\n\n\n For each kg of MDEA we need 2 kg of sol (1 kg of MDEA + 1 kg of water)<\/p>\n\n\n\n x = (0.0012 std m3<\/sup> Ben\/kg of MDEA) (kg MDEA\/2 kg Sol) (1017.3 kg Sol \/m3<\/sup> Sol)<\/p>\n\n\n\n = 0.62 std m3<\/sup> of Ben per m3<\/sup> of solution<\/p>\n\n\n\n Or X = (770) [ (x0<\/sub>) (x\/x0<\/sub>) (xB)] std m3<\/sup> of Ben per m3<\/sup> of sol<\/strong><\/p>\n\n\n\n X = (770) [0.0008] = 0.62 std m3<\/sup> of Ben per m3<\/sup> of solution<\/strong><\/p>\n\n\n\n CF<\/strong> = (kmol Sol\/0.131kmol MDEA) (23.64 std m3<\/sup> Ben\/kmol Ben) (kmol MDEA\/119.21 kg MDEA)*<\/p>\n\n\n\n (kg MDEA\/2 kg Sol) (1017.3 kg Sol \/m3<\/sup> Sol) = (770 std m3<\/sup> Ben\/m3<\/sup> Sol)(kmol Sol\/kmol Ben)<\/p>\n\n\n\n The same color terms in the numerator and denominator cancel out.<\/p>\n\n\n\n SI CF= <\/strong>(770 std m3<\/sup> Ben\/m3<\/sup> Sol) (kmol Sol\/kmol Ben)<\/strong><\/p>\n\n\n\n Toluene:<\/strong> (x\/x0<\/sub>)T<\/sub> = 0.46 (x0<\/sub>)T<\/sub> = 0.00216 <\/p>\n\n\n\n For xT = 1, x= x0<\/sub>(x\/x0<\/sub>) = (0.00216) (0.46) = 0.00099 kmol Tol\/kmol MDEA Sol<\/p>\n\n\n\n For xT = 0.3335, x= x0<\/sub>(x\/x0<\/sub>) = (0.00099) (0.3335) = 0.00033 vs. 0.00037 kmol Tol\/kmol Sol<\/p>\n\n\n\n X = (770) [0.00033] = 0.26 std m3<\/sup> of Tol per m3<\/sup> of solution<\/strong><\/p>\n\n\n\n Ethylbenzene (EB)<\/strong>: (x\/x0<\/sub>)EB<\/sub> = 0.36 (x0<\/sub>)EB<\/sub> = 0.00084<\/p>\n\n\n\n For xEB = 1, x= x0<\/sub>(x\/x0<\/sub>) = (0.00084) (0.36) = 0.00030 kmol EB\/kmol MDEA Sol<\/p>\n\n\n\n For xEB = 0.3336, x= x0<\/sub>(x\/x0<\/sub>) = (0.00030) (0.3336) = 0.00010 vs. 0.000085 kmol EB\/kmol Sol<\/p>\n\n\n\n <\/strong>X = (770) [0.00010] = 0.08 std m3<\/sup> of EB per m3<\/sup> of solution<\/strong><\/p>\n\n\n\n Solution – FPS<\/strong><\/p>\n\n\n\n Benzene: <\/strong>(x\/x0<\/sub>)B<\/sub> = 0.52 (x0<\/sub>)B<\/sub> = 0.00464 <\/p>\n\n\n\n For xB = 1, x= x0<\/sub>(x\/x0<\/sub>) = (0.00464) (0.52) = 0.00242 lbmol Ben\/lbmol MDEA Sol<\/p>\n\n\n\n For xB = 0.3329, x= x0<\/sub>(x\/x0<\/sub>) = (0.00464) (0.52) (0.3329) = 0.0008 (vs. 0.00093) lbmol Ben\/lbmol Sol<\/p>\n\n\n\n The yellow highlighted values are the measured values in Table 5<\/p>\n\n\n\n x = (0.0008 lbmol Ben\/lbmol Sol) (lbmol Sol\/0.131lbmol MDEA) = 0.00611 lbmol Ben\/lbmol MDEA<\/p>\n\n\n\n x = (0.00611 lbmol Ben\/lbmol MDEA) (379.5 scf\/lbmol Ben) (lbmol MDEA\/119.21 lbm)<\/p>\n\n\n\n = 0.01945 scf Ben\/lbm of MDEA<\/p>\n\n\n\n For each lbm of MDEA we need 2 lbm of sol (1 lbm of MDEA + 1 lbm of water)<\/p>\n\n\n\n x = (0.01945 scf Ben\/lbm of MDEA) (lbm MDEA\/2 lbm Sol) (8.49 lbm\/gallon Sol)<\/p>\n\n\n\n = 0.083 scf of Ben\/gallon solution<\/p>\n\n\n\n Or<\/strong> X = (103) [(x0<\/sub>) (x\/x0<\/sub>) (xB)] scf of Ben\/gallon of solution<\/strong><\/p>\n\n\n\n X = (103) [0.0008] = 0.082 scf of Ben\/gallon of solution<\/strong><\/p>\n\n\n\n CF<\/strong> = (lbmol Sol\/0.131lbmol MDEA) (379.5 scf Ben\/lbmol Ben) (lbmol MDEA\/119.21 lbm MDEA)*<\/p>\n\n\n\n (lbm MDEA\/2 lbm Sol) (8.49 lbm Sol \/gallon Sol) = (103 scf Ben\/gallon Sol) (lbmol Sol\/lbmol Ben)<\/p>\n\n\n\n The same color terms in the numerator and denominator cancel out.<\/p>\n\n\n\n FPS CF <\/strong>= (103 scf Ben\/gallon Sol) (lbmol Sol\/lbmol Ben)<\/strong><\/p>\n\n\n\n Toluene:<\/strong> (x\/x0<\/sub>)T<\/sub> = 0.46 (x0<\/sub>)T<\/sub> = 0.00216 <\/p>\n\n\n\n For xT = 1, x= x0<\/sub>(x\/x0<\/sub>) = (0.00216) (0.46) = 0.00099 kmol Tol\/kmol Sol<\/p>\n\n\n\n For xT = 0.3335, x= x0<\/sub>(x\/x0<\/sub>) = (0.00099) (0.3335) = 0.00033 vs. 0.00037 kmol Tol\/kmol Sol<\/p>\n\n\n\n Or<\/strong> X = (FPS CF) [(x0<\/sub>) (x\/x0<\/sub>) (xT)] scf of Ben\/gallon of solution<\/strong><\/p>\n\n\n\n X = (103) [0.00033] = 0.034 scf of Ben\/gallon of solution<\/strong><\/p>\n\n\n\n Ethylbenzene (EB):<\/strong> (x\/x0<\/sub>)EB<\/sub> = 0.36 (x0<\/sub>)EB<\/sub> = 0.00084<\/p>\n\n\n\n For xEB = 1, x= x0<\/sub>(x\/x0<\/sub>) = (0.00084) (0.36) = 0.00030 kmol EB\/kmol MDEA Sol<\/p>\n\n\n\n For xEB = 0.3336, x= x0<\/sub>(x\/x0<\/sub>) = (0.00030) (0.3336) = 0.00010 vs. 0.000085 kmol EB\/kmol Sol<\/p>\n\n\n\n Or<\/strong> X = (103) [(x0<\/sub>) (x\/x0<\/sub>) (xEB)] scf of Ben\/gallon of solution<\/strong><\/p>\n\n\n\n X = (103) [0.00010] = 0.010 scf of Ben\/gallon of solution<\/strong><\/p>\n\n\n\n The estimated soluble BTE in the MDEA solution for example 2 and two other cases are compared with the measured values in Table 5R. This table indicates that the APD (absolute percent difference between the measured and estimated values) for eight out of nine estimated solubilities are less than 17.2. Considering very small amount of solubility, the Model estimation values are good facilities calculations and troubleshooting.<\/p>\n\n\n\n Table 5R \u2013 Measured and estimated solubility of Benzene, Toluene and Ethylbenzene into loaded MDEA (50 wt %) aqueous solution. Hydrocarbon phase consists of xB=0.3329, xT=0.3335, xEB=0.3336<\/p>\n\n\n\n APD = Absolute percent deviation =100*ABS (Exp Avg x \u2013 Model x) \/ (Exp Avg x)<\/p>\n\n\n\n <\/p>\n\n\n\n Summary<\/strong><\/p>\n\n\n\n From the RR-242 developed model based on the experimental results; several conclusions can be drawn.<\/p>\n\n\n\n To learn more about similar cases and how to minimize operational problems, we suggest attending our G4 (Gas Conditioning and Processing)<\/a>,<\/strong>G5 (Advanced Applications in Gas Processing)<\/a>, <\/strong>http:\/\/www.jmcampbell.com\/co2-surface-facilities-pf81.php<\/a> and<\/strong>![\"\"\/](\"https:\/\/i0.wp.com\/petroskills.com\/blog\/totm-graphs\/Aug2022\/image-thumb__1663__auto_fccf2acc643a237e6b70c24f34f42d8f\/1.png?ssl=1\")
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