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1.
The solubility of hydrogen sulfide and carbon dioxide in an aqueous solution containing 35 wt% methyldiethanolamine (MDEA) (3.04 kmol/m3, 4.52 mol/kg) has been measured at 40° and 100°C at partial pressures of the acid gas up to 530 kPa. Some data for hydrogen sulfide in a 50 wt% solution of MDEA (4.38 kmol/m3, 8.39 mol/kg) were also obtained. Also, densities of CO2-aqueous MDEA solutions were measured at 40°C. 相似文献
2.
Mixed solvents are a combination of chemical and physical solvents and have some advantages over traditional treating solvents for the removal of acid gases from gas streams. The solubility of H2S and CO2in a mixed solvent consisting of AMP (2-amino-2-methyl-l-propanol), sulfolane, and water has been measured at 40 and 100°C at partial pressures of the acid gas to 6000 kPa. The solubility in the mixed solvent was compared with the solubility in an aqueous solution of equivalent amine concentration. At solution loadings less than 1 mol acid gas/mol amine, the solubility of the acid gas is lower in the mixed solvent than in the corresponding amine solvent. At higher loadings, the trend is reversed and the solubility is greater in the mixed solvent. The results are rationalized in terms of the effect of the physical solvent component on the chemical reaction and physical vapor-liquid equilibria. The solubility model of Deshmukh and Mather was used to correlate the data. 相似文献
3.
Byung Don Lee Dong Min Kim Jungho Cho Sang Wook Park 《Korean Journal of Chemical Engineering》2009,26(3):818-823
A comparative study has been performed to compare the 30 wt% of 2-amino-2-methyl-1-propanol (AMP) aqueous solution and 30
wt% of methyldiethanol amine (MDEA) aqueous solution to capture carbon dioxide contained in the flue gas stream. The equilibrium
constants for each electrolyte reactions have been used to estimate the carbon dioxide absorption process. Henry’s constants
for each binary pairs between solute gases and solvent have been used to estimate solubility of the gas components. 相似文献
4.
Mixed solvents are a combination of chemical and physical solvents and are used for the removal of acid gases from gas streams. The solubility of CO2 in a mixed nonaqueous solution of methyldiethanolamine (MDEA) (50 wt.%) and triethylene glycol monomethj'l ether (TEGMME) (50 wt.%) has been measured at 40°C. The data are compared with solubility data of CO2 in pure TEGMME. The solubility of CO2 has been measured at 40°C and 100°C in an aqueous mixed solvent consisting of MDEA (40 wt.%) and TEGMME (40 wt. %) and water (20 wt.%) at partial pressures of CO2 up to 12 MPa. The solubility results were compared with the solubility in the nonaqueous mixed solvent and previously reported data of aqueous MDEA. The solubility model of Deshmukh and Mather was used to correlate the data. 相似文献
5.
The solubility of mixtures of hydrogen sulfide and carbon dioxide in a 50 mass per cent aqueous solution of methyldiethanolamine (MDEA) solution has been measured at 40°, 70° and 100°C. Partial pressures of the acid gases ranged from 0.08 to 10 450 kPa. 相似文献
6.
Lienda Handojo Yudiyanto Michael Dannish Prihartoni Ratna Frida Susanti Yestria Yaswari Anggit Raksajati 《分离科学与技术》2018,53(14):2259-2266
Aqueous amino solvents, such as monoethanolamine (ETA/MEA), methyl diethanolamine (MDEA) or amine blends, are the most widely used solvents in commercial CO2 or acid gas separation applications. These commercial solvents have various disadvantages, such as the possibilities of the solvent to be degraded. This research examines the impact of non-oxidative thermal degradations on the performance of the CO2 absorption and the degradation mechanism of amine solvents. The impact of degradation was conducted by measuring the CO2 solubility of solvent that had been heated to 120°C for 2 h. Although the performance of CO2 absorption was not significantly reduced, the degradation of amines was found. Supported by Fourier Transform Infrared (FTIR) and Gas Chromatography/Mass Spectrometer result, the suspected products of non-oxidative thermal degradation of MDEA were MEA and acetone. 相似文献
7.
8.
Mixed solvents are a combination of chemical and physical solvents and have some advantages over traditional treating solvents for the removal of acid gases from gas streams. The solubility of H2S and CO2in a mixed solvent consisting of AMP (2-amino-2-methyl-l-propanol), sulfolane, and water has been measured at 40 and 100°C at partial pressures of the acid gas to 6000 kPa. The solubility in the mixed solvent was compared with the solubility in an aqueous solution of equivalent amine concentration. At solution loadings less than 1 mol acid gas/mol amine, the solubility of the acid gas is lower in the mixed solvent than in the corresponding amine solvent. At higher loadings, the trend is reversed and the solubility is greater in the mixed solvent. The results are rationalized in terms of the effect of the physical solvent component on the chemical reaction and physical vapor-liquid equilibria. The solubility model of Deshmukh and Mather was used to correlate the data. 相似文献
9.
Among numerous techniques existing for reducing CO2 emissions, CO2 capture by absorption in aqueous alkanolamine solutions was specifically studied in this work. For the choice of the adequate amine solution, two major criteria must be taken into account: absorption performances (higher with primary and secondary amines) and energy costs for solvent regeneration (more interesting with tertiary and sterically hindered amines). The different types of amines can also be mixed in order to combine the specific advantages of each type of amines, an activation phenomenon being observed. Aqueous solutions of (piperazinyl‐1)‐2‐ethylamine (PZEA, a polyamine known as absorption activator) and 1‐amino‐2‐propanol (AMP, a sterically hindered amine), pure or mixed with other amines, are experimentally compared with respect to CO2 removal performances by means of absorption test runs achieved in a special gas‐liquid contactor at 25 °C. The positive impact of addition of PZEA to monoethanolamine (MEA), N‐methyldiethanolamine (MDEA), and AMP solutions was clearly highlighted. The absorption performances have also been satisfactorily simulated with coherent physicochemical data. 相似文献
10.
The solubility of H2S, CO2 and their mixtures in a 3.43 molar solution of 2-amino-2-methyl-1-propanol (AMP) has been determined at 50°C at partial pressures between 4 and 5650 kPa. A mathematical model has been used to correlate the data for the individual gases in the solvent. The parameters obtained have been used to predict the partial pressures in the four-component system. In general the predicted values are in good agreement with the experimental data. 相似文献
11.
Absorption rates for CO2 into aqueous solutions of TEA, MDEA and blends of MEA with MDEA and TEA were measured in a stirred cell by a method similar to that used by Laddha and Danckwerts (1981). Second order rate constants for CO2-TEA and CO2-MDEA were obtained from the single amine data for temperatures in the range of 25-60°C. A modified pseudo first order model based on the film theory is used to predict the rate of absorption of CO2 into mixed amine solutions. This model accounts for the variation of amine concentration in the film and assumes a shuttle mechanism for rate enhancement. Bulk liquid concentrations of the various species present are obtained from a simplified thermodynamic model. The model predicts absorption rates that are in agreement with experimental measurements. 相似文献
12.
Measurements of kinetics rates of CO2 in aqueous solutions of methyldiethanolamine (MDEA), piperazine (PZ), and mixtures of (MDEA + PZ), (PZ + sulfolane) and (MDEA + sulfolane) were carried out using the stopped flow technique, and reported in terms of pseudo-first-order rate constants (k0). When possible, the second-order reaction rate constants (k2) were regressed from the data. Experiments were performed over new concentration ranges of (10–60), (200–800), (200–800, 10–40), (10–40, 10–200), and (200–800, 10–200) mol/m3 for the above-mentioned five systems, respectively, and at temperatures varying from (298.15–313.15 K). When sulfolane was added to the amine solution, pseudo-first-order rate constants in the mixed solvents were higher than in aqueous MDEA and PZ solutions at all temperatures. The kinetic rates were highest at 298.15 K and decreased at higher temperatures for aqueous (MDEA + sulfolane) solutions but increased with temperature for aqueous (PZ + sulfolane) systems. Reaction orders for both PZ and MDEA were practically one at all sulfolane concentrations and temperatures. The base catalysis mechanism was used to regress very well data for aqueous MDEA and (MDEA + sulfolane + water) and the termolecular mechanism was used for (PZ + sulfolane + water) system. Both the zwitterion and termolecular models were able to fit the experimental data for the aqueous PZ system well. Finally, the termolecular and a hybrid model based on the combination of the Zwitterion and base catalysis mechanisms were able to successfully correlate the experimental data for the mixed aqueous (MDEA + PZ) systems. 相似文献
13.
Polyvinylidene fluoride (PVDF) microporous flat membranes were cast with different kinds of PVDFs and four mixed solvents [trimethyl phosphate (TMP)–N,N‐dimethylacetamide (DMAc), triethyl phosphate (TEP)–DMAc, tricresyl phosphate (TCP)–DMAc, and tri‐n‐butyl phosphate (TBP)–DMAc]. The effects of different commercial PVDFs (Solef® 1015, FR 904, Kynar 761, Kynar 741, Kynar 2801) on membrane morphologies and membrane performances of PVDF/TEP–DMAc/PEG200 system were investigated. The membrane morphologies were examined by scanning electron microscopy (SEM). The membrane performances in terms of pure water flux, rejection, porosity, and mean pore radius were measured. The membrane had the high flux of 143.0 ± 0.9 L m?2 h?1 when the content of TMP in the TMP–DMAc mixed solvent reached 60 wt %, which was 2.89 times that of the membrane cast with DMAc as single solvent and was 3.36 times that of the membrane cast with TMP as single solvent. Using mixed solvent with different solvent solubility parameters, different morphologies of PVDF microporous membranes were obtained. TMP–DMAc mixed solvent and TEP–DMAc mixed solvent indicated the stronger solvent power to PVDF due to the lower solubility parameter difference of 1.45 MPa1/2 and the prepared membranes showed the faster precipitation rate and the higher flux. The less macrovoids of the membrane prepared with TEP (60 wt %)–DMAc (40 wt %) as mixed solvent contributed to the higher elongation ratio of 96.61% ± 0.41%. Therefore, using TEP(60 wt %)–DMAc (40 wt %) as mixed solvent, the casting solution had the better solvent power to PVDF, and the membrane possessed the excellent mechanical property. The microporous membranes prepared from casting solutions with different commercial PVDFs exhibited similar morphology, but the water flux increased with the increment of polymer solution viscosity. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 相似文献
14.
The modified Clegg‐Pitzer equation is used to correlate and predict the vapor‐liquid equilibrium of the CO2‐MDEA‐H2O system. Simulated annealing (SA), a computational stochastic technique for finding near global minimum solutions to optimization problems, has been used for parameter estimation in the model to predict VLE of CO2 in aqueous MDEA solution. The solubility of CO2 in aqueous solutions of 23.8 wt % and 30.0 wt % of N‐methyldiethanolamine (MDEA) has been measured over the temperature range of 303‐323 K and CO2 partial pressure range of 1 to 100 kPa. The model predicted equilibria have been found to be in good agreement with the experimental results of VLE measurement of this work as well as those in the open literature. In this work, the SA technique has been used as an alternative to the traditional Levenberg‐Marquardt (LM) technique, to predict the VLE data accurately. 相似文献
15.
《分离科学与技术》2012,47(5):1091-1110
Abstract High pressure liquid extraction (HPE) and subcritical fluid (CO2+ethanol) extraction (SCE) were used for the extraction of total phenolic compounds (TPC) from sour cherry pomace. Antiradical efficiency (AE) of the extracts was also determined. Ethanol was the solvent for HPE and co‐solvent for SCE. Combinations of pressure (50, 125, 200 MPa), temperature (20, 40, 60°C), solid/solvent ratio (0.05, 0.15, 0.25 g/ml) and extraction time (10, 25, 40 min) were variables for HPE according to the Box‐Behnken experimental design. The variables used for SCE were pressure (20, 40, 60 MPa), temperature (40, 50, 60°C), ethanol concentration (14, 17, 20 wt%) and extraction time (10, 25, 40 min). For HPE, TPC, and AE at the optimum conditions (176–193 MPa, 60°C, 0.06–0.07 g solid/ml solvent, 25 min) were found as 3.80 mg gae/g sample and 22 mg DPPH?/g sample, respectively. TPC and AE at the optimum conditions (54.8–59 MPa, 50.6–54.4°C, 20 wt% ethanol, 40 min) for SCE were determined as 0.60 mg gae/g sample and 2.30 mg DPPH?/g sample for sour cherry pomace, respectively. 相似文献
16.
Denis Andzheevich Sapegin Galina Nikolaevna Gubanova Elena Nikolaevna Popova Svetlana Viktorovna Kononova 《应用聚合物科学杂志》2021,138(10):49982
A series of novel asymmetric membranes from polymer composites of poly(amide-imide) with various content of sulfonated polyimide (1–6 wt%) was obtained through the nonsolvent-induced phase separation process. Selective transport properties of the obtained materials were investigated in terms of pervaporation separation of methanol/methyl-tert-butyl ether mixtures at different temperatures. The introduction of the sulfonated polyimide to the poly(amide-imide) matrix leads to a significant increase in membrane flux and an overall decrease in the process selectivity. Composite membranes having 1 wt% sulfonated polyimide in the matrix showed increased values of membrane flux (0.960 kg m−2 h−1 in comparison with 0.682 kg m−2 h−1 for unmodified membranes at 40°C, 10 wt% methanol), while having similar selectivity values (79.2 wt% methanol in permeate in comparison with 82 wt% for unmodified membranes at 40°C, 10 wt% methanol). Modified membrane showed the highest separation factor of 147 while separating methanol from its 3 wt% mixture with methyl-tert butyl ether at 52°C with the overall flux of 1.01 kg m−2 h−1. A semiempirical mathematical model was developed and applied to test the efficiency of obtained membranes in the hybrid process of methanol/methyl-tert-butyl ether mixtures separation. 相似文献
17.
Ali Talimian H.F. El-Maghraby Monika Michálková Dušan Galusek 《Journal of the European Ceramic Society》2021,41(11):5634-5643
Lithium hydroxide, LiOH, in the amounts ranging from 0.1 to 1.2 wt% has been used as a sintering aid to improve the densification of MgAl2O4. The addition of 0.3 wt% LiOH promotes densification and limits grain growth. The activation energy of sintering, calculated using master sintering curve approach, decreases from 790 ± 20 kJ.mol?1 to 510 ± 20 kJ.mol?1 with the addition of 0.3 wt% of LiOH. In addition, MgAl2O4 was also mixed with 10 wt% of LiOH to amplify the formation of reaction products. High-temperature XRD results showed that secondary phases (MgO and LiAlO2) are produced above 1040 °C. The secondary phases start to disappear at T > 1200 °C, and MgAl2O4 is produced. While adding small amounts of LiOH, up to ca. 0.3 wt%, is beneficial for densification and suppressing grain growth, there exists a critical concentration of Li+ that is accounted for by the preferential incorporation of lithium ions into MgAl2O4 crystal lattice. 相似文献
18.
Pallavi Suhasinee Behera Sunipa Bhattacharyya 《International Journal of Applied Ceramic Technology》2021,18(1):81-90
Mullite ceramic was prepared using kaolinite and synthesized alumina (combustion route) by solid-state interaction process. The influence of TiO2 and MgO additives in phase formation, microstructural evolution, densification, and mechanical strengthening was evaluated in this work. TiO2 and MgO were used as sintering additives. According to the stoichiometric composition of mullite (3Al2O3·2SiO2), the raw materials, ie kaolinite, synthesized alumina, and different wt% of additives were wet mixed, dried, and uniaxially pressed followed by sintering at different temperature. 1600°C sintered samples from each batch exhibit enhanced properties. The 1 wt% TiO2 addition shows bulk density up to 2.96 g/cm3 with a maximum strength of 156.3 MPa. The addition of MgO up to 1 wt% favored the growth of mullite by obtaining a density and strength matching with the batch containing 1 wt% TiO2. These additives have shown a positive effect on mullite phase formation by reducing the temperature for complete mullitization by 100°C. Both additives promote sintering by liquid phase formation. However, the grain growth, compact microstructure, and larger elongated mullite crystals in MgO containing batch enhance its hardness properties. 相似文献
19.
Seung-Tae Kim Jeong-Won Kang Jong-seop Lee Byoung-Moo Min 《Korean Journal of Chemical Engineering》2011,28(12):2275-2281
The estimation of regeneration heat of absorbent is important because it is a key factor that has an effect on the process
efficiency. In this study, thermal stability and regeneration heat of aqueous amine solutions such as monoethanolamine (MEA),
2-amino-2-methyl-1-propanol (AMP), N-methyldiethanolamine (MDEA), and 1,8-diamino-pmenthane (KIER-C3) were investigated by
using TGA-DSC analysis. The thermal characteristics of the fresh and CO2 rich amine solutions were estimated. The CO2 rich amine solutions were obtained by VLE experiments at T=40 °C. The regeneration heat of aqueous MEA solution was 76.991–66.707
kJ/mol-CO2, which is similar to heat of absorption. The reproducibility of the results was obtained. The regeneration heat of aqueous
KIER-C3 20 wt% solution (1.68 M) was lower than that of aqueous MEA 30 wt% solution (4.91 M). Therefore, the KIER-C3 can be
used as an effective absorbent for acid gas removal. 相似文献
20.
Modified Fischer‐Tropsch (MFT) syntheses were carried out to convert synthesis gas to C4 hydrocarbons over Fe‐Co/ZrO2 (FT) and SO42—/ZrO2 (SZ) catalysts in a dual reactor system, keeping the FT to SZ catalysts ratio at 1:1.5. Five Fe‐Co/ZrO2 catalysts with different Fe and Co loading, and SZ with 15 wt% SO42— were prepared and extensively characterized using various physico‐chemical methods. The FT synthesis process was initially performed using a Fe‐Co/ZrO2 catalyst in a single reactor and the effects of Fe and Co mass ratio, reaction temperature, space velocity on the production of C4 hydrocarbons and C2‐C4 olefins were investigated. Results indicated that a 3.71% Fe—8.76% Co/ZrO2 mixed oxide catalyst alone at 260°C and 5 h—1 gave high selectivities of C2‐C4 olefins (~26.1 wt%) and total C4 hydrocarbon product (~16.2 wt%). The MFT process 150°C gave higher C4 (~31.6 wt%), isobutane (~22.9 wt%) and C2‐C4 (31.1 wt%) selectivities. 相似文献