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1.
《分离科学与技术》2012,47(8):1262-1272
Carbon dioxide and nitrogen dioxide were simultaneously absorbed into aqueous 2-amino-2-methyl-1-propanol (AMP) in a stirred semi-batch tank with a planar gas-liquid interface within a range of 0–4.0 kmol/m3 of AMP, 0.03–0.3 atm of CO2, 0.005–0.2 atm of NO2, and 298–318 K. Absorption data of each gas in the CO2-AMP and NO2-AMP systems were obtained to verify their reaction regimes, based on film theory, respectively, which were then used to analyze the simultaneous absorption mechanisms of CO2 and NO2 in the CO2-NO2-AMP systems. The measured absorption rates of CO2 and NO2 were compared to those formulated by an approximate solution of the mass balances with simultaneous reactions. 相似文献
2.
《分离科学与技术》2012,47(16):3888-3910
Abstract Carbon dioxide and sulfur dioxide were simultaneously absorbed into aqueous 1,8-diamino-p-menthane (DAM) in a stirred semi-batch tank with a planar gas-liquid interface within a range of 0–2.0 kmol/m3 of DAM, 0.01–0.12 mole fraction of CO2, 0.001–0.012 mole fraction of SO2, and 298-318 K. Absorption data of each gas in the CO2-DAM and SO2-DAM systems are obtained to verify their reaction regimes, based on film theory, respectively, which are used to analyze the simultaneous absorption mechanisms of CO2 and SO2 in the CO2-SO2- DAM systems. In the simultaneous absorption rate of CO2 and SO2 into DAM solution, the absorption of CO2 belongs to the second-order reaction of finite rate and the absorption of SO2 belongs to the instantaneous reaction regime. 相似文献
3.
This work presents an experimental and theoretical investigation of CO2 absorption into aqueous blends of 2-amino-2-methyl-1-propanol (AMP) and diethanolamine (DEA). The CO2 absorption into the amine blends is described by a combined mass transfer-reaction kinetics-equilibrium model, developed according to Higbie's penetration theory. The model predictions have been found to be in good agreement with the experimental rates of absorption of CO2 into (AMP+DEA+H2O). The good agreement between the model predicted rates and enhancement factors and the experimental results indicate that the combined mass transfer-reaction kinetics-equilibrium model with the appropriate use of model parameters can effectively represent CO2 mass transfer for the aqueous amine blends AMP/DEA. 相似文献
4.
《分离科学与技术》2012,47(4):497-507
Carbon dioxide was absorbed into aqueous solution of potassium threonate (PT) at different concentrations of PT and CO2, and temperatures in the range of 0.1–1.0 kmol/m3, 10.1–101.3 kPa, and 293-313 K, respectively, using a stirred semi-batch vessel with a planar gas-liquid interface. Both the reaction order and rate constant were determined from gas absorption rates under the fast pseudo-first-reaction regime. The reaction was found to be first order with respect to both CO2 and PT, and its activation energy has been found to be 40.6 kJ/mol. From a comparison of the reaction kinetics by the overall reaction scheme with those by the elementary reaction scheme based on the zwitterions mechanism, the overall reaction between CO2 and PT has been found to be equivalent to the formation of zwitterions. 相似文献
5.
The simultaneous absorption of hydrogen sulfide and carbon dioxide into di-isopropanolamine (DIPA) solution was investigated in a 183 cm long, 2.72 cm OD wetted-wall column at atmospheric pressure. The influence of liquid flow rate, gas flow rate, temperature and liquid concentration on the absorption rate, overall gas-phase mass transfer coefficient and selectivity factor were studied at a constant gas feed ratio. The results show that the absorption rate of CO2 increases rapidly with increasing liquid flow rate (the Reynolds number of the turbulent liquid film ranges from 2600 to 4350) but increases moderately with increasing gas flow rate (G = 18-91 L/min), indicating that it is liquid-phase mass transfer controlled. In contrast, the absorption rate of H2S increases very slowly with increasing liquid flow rate but increases rapidly with increasing gas flow rate, indicating that it is gas-phase mass transfer controlled. The absorption rate of CO2 also increases with increasing temperature (26-80°C) but H2S absorption rate decreases with increasing temperature. When the concentration of DIPA solution increases from 0.2 to 2.6 mol/L, the absorption rate of both CO2 and H2S increases but with a larger rate of increase for CO2 For selective H2S removal, it is preferable to operate at low liquid and high gas flow rates, low temperatures and low DIPA concentrations. 相似文献
6.
B.P. Mandal 《Chemical engineering science》2005,60(22):6438-6451
This work presents an experimental and theoretical investigation of the simultaneous absorption of CO2 and H2S into aqueous blends of 2-amino-2-methyl-1-propanol (AMP) and diethanolamine (DEA). The effect of contact time, temperature and amine concentration on the rate of absorption and the selectivity were studied by absorption experiments in a wetted wall column at atmospheric pressure and constant feed gas ratio. The diffusion-reaction processes for CO2 and H2S mass transfer in blended amines are modeled according to Higbie's penetration theory with the assumption that all reactions are reversible. The blended amine solvent (AMP+DEA+H2O) has been found to be an efficient mixed solvent for simultaneous absorption of CO2 and H2S. By varying the relative amounts of AMP and DEA the blended amine solvent can be used as an H2S-selective solvent or an efficient solvent for total removal of CO2 and H2S from the gas streams. Predicted results, based on the kinetics-equilibrium-mass transfer coupled model developed in this work, are found to be in good agreement with the experimental results of rates of absorption of CO2 and H2S into (AMP+DEA+H2O) of this work. 相似文献
7.
《分离科学与技术》2012,47(16):3261-3275
Abstract Carbon dioxide was absorbed into aqueous polyethylene oxide (PEO) solution containing monoethanolamine (MEA) in a flat‐stirred vessel to investigate the effect of non‐Newtonian rheological behavior of PEO on the rate of chemical absorption of CO2, where the reaction between CO2 and MEA was assumed to be a first‐order reaction with respect to the molar concentration of CO2 and MEA, respectively. The liquid‐side mass transfer coefficient (kL), which was obtained from the dimensionless empirical equation containing the properties of viscoelasticity of the non‐Newtonian liquid, was used to estimate the enhancement factor due to chemical reaction. PEO with elastic property of non‐Newtonian liquid made the rate of chemical absorption of CO2 accelerate compared with Newtonian liquid based on the same viscosity of the solution. 相似文献
8.
《分离科学与技术》2012,47(14):3265-3278
Abstract The chemical absorption rate (RA) of CO2 was measured into the aqueous nanometer sized colloidal silica solution of 0–31 wt% and diethanoleamine of 0–2 kmol/m3 in the flat‐stirred vessel with the impeller size of 0.034 m and its agitation speed of 50 rev/min at 25°C and 0.101 MPa, and compared with the values estimated from the model based on the film theory accompanied by chemical reaction. The value of the volumetric liquid‐side mass transfer coefficient (kLa) of CO2, which was used to estimate the value of RA, was obtained by the empirical correlation formula presenting the relationship between kLa and the rheological behavior of the aqueous colloidal silica solution. The value of RA in the aqueous colloidal silica solution was decreased by the reduction of kLa due to the elasticity of the solution. 相似文献
9.
《分离科学与技术》2012,47(11-12):3003-3019
Abstract Carbon dioxide was absorbed into aqueous solution of sodium glycinate (SG) at different SG concentrations, CO2 partial pressures, and temperatures in the range of 0.5–3.0 kmol/m3, 25–101.3 kPa, and 298–318 K, respectively, using a stirred semi-batch vessel with a planar gas-liquid interface. Both the reaction order and rate constant are determined from gas absorption rates under the fast reaction regime. The reaction was found to be first order with respect to both CO2 and SG. The activation energy for the CO2-SG reaction has been found to be 59.8 kJ/mol. The second-order reaction rate constants were used to obtain the theoretical values of absorption rate based on the film theory. 相似文献
10.
《分离科学与技术》2012,47(8):1661-1677
Abstract On the basis of experimental data for carbon dioxide absorption into aqueous nanometer sized colloidal silica solution as a non‐Newtonian fluid, a dimensionless correlation for volumetric liquid‐side mass transfer coefficient (kLa) of CO2 in the flat‐stirred vessel was proposed. In addition to ordinary liquid properties and operating parameters such as impeller size and speed in the vessel, Deborah number, which is defined as the product of the characteristic material times of the liquid and agitation speed in the flat‐stirred vessel and represents the viscoelastic behavior of non‐Newtonian fluid, was used to present unified expressions for kLa in Newtonian as well as non‐Newtonian liquid. The values of kLa in the aqueous colloidal silica solution were reduced due to elasticity of the solution. 相似文献
11.
醇胺法吸收二氧化碳在填料塔中的应用 总被引:2,自引:0,他引:2
采用工业流程中的填料吸收塔和解吸塔,研究了乙醇胺(MEA)、哌嗪(PZ)、二乙烯三胺(DETA)、三乙烯四胺(TETA)与N-甲基二乙醇胺(MDEA)的混合溶液作为吸收剂对模拟合成气中CO2的吸收性能. 结果表明,胺活化性能依次为TETA>DETA>PZ>MEA;含TETA的吸收液可将尾气中CO2的浓度降至0.05%(mol),CO2脱除率达98.62%;增加活化剂浓度和降低气体流量有利于提高CO2脱除率;吸收-解吸循环条件下吸收速率是随吸收时间和活化剂浓度变化的指数递减函数. 相似文献
12.
Sheng-Chih Ho Ji-Miao Chen Meng-Hui Li 《Journal of the Chinese Institute of Chemical Engineers》2007,38(3-4):349-354
Heat capacities of aqueous solutions of sulfolane with 2-amino-2-methyl-1-propanol (AMP) were measured over the temperature range from 303.15 to 353.15 K with a differential scanning calorimeter. Twelve solutions of sulfolane + AMP + water that cover the mole fractions of water from 0.6 to 0.8 were studied. The liquid heat capacities of sulfolane alone and of binary mixtures such as sulfolane + water and sulfolane + AMP were also studied. The heat capacities of sulfolane and sulfolane + water were found to be in good agreement with those values reported in the literature. A Redlich-Kister type equation was applied to represent the composition dependence of the heat capacities of binary and ternary systems. For 132 data points of sulfolane + AMP + water, the fitted results of heat capacity calculations (overall average absolute percentage deviation (AAD%)) were 0.3 and 7.7% for the molar heat capacity and the excess molar heat capacity, respectively. The heat capacities of aqueous mixtures of sulfolane with AMP presented in this study can be used to estimate the head load of absorbents in acid gas capture process when using sulfolane + AMP + water as the absorbent. 相似文献
13.
《分离科学与技术》2012,47(16):3537-3554
Abstract Carbon dioxide was absorbed into the aqueous xanthan gum (XG) solution in the range of 0–0.151 wt% containing monoethanolamine (MEA) of 0–2 kmol/m3 in a flat‐stirred vessel with the impeller of 0.05 m and agitation speed of 50 rpm at 25°C and 0.101 MPa to measure the absorption rate of CO2. The volumetric liquid‐side mass transfer coefficient (kLaL) of CO2 decreased with increasing XG concentration, and was correlated with the empirical formula having the rheological behavior of XG solution. The chemical absorption rate of CO2 was estimated by the film theory using the values of kLaL and physicochemical properties of CO2 and MEA. The aqueous XG solutions made the rate of absorption of CO2 accelerated compared with the Newtonian liquid based on the same viscosity of the solution. 相似文献
14.
The citrate absorption of SO2 is currently one of the most successful and economic methods to harness sulfur dioxide pollution. In order to theoretically elucidate the mechanism of SO2 absorption by citrate solution and provide theoretical instruction for experiments and industrial process, the theory of multi-buffer solution, combined with computer numerical calculation methods, was applied to study the distribution parameters of the components of the citrate solution in the process of SO2 absorption and the following results were obtained: (1) HCi2- and H2Ci- in the citrate solution played the dominant role in the absorption and desorption processes; (2) Through the calculation for the buffer capacity of citrate solution, it was found that the pH of the absorption and desorption solution should be in the range of 2~8, while at pH=4.5 the buffer capacity reached its maximum. Some valuable parameters were obtained, which are instructive to the ensuing experiments and industrial design. 相似文献
15.
16.
CO2减排已经成为国际关注的热点问题。近年来,化学吸收法以其效率高、适应范围广、技术成熟等优点,逐渐占据主导地位。采用甘氨酸钠溶液为吸收剂,在超重力反应器中进行了CO2吸收实验,考察了转速、吸收液温度、吸收液浓度、气液比等对CO2吸收率的影响。结果表明:CO2的吸收率随着转速的增加而上升,当转速达到1000 r?min?1后,吸收率基本趋于稳定;CO2的吸收率随着吸收液温度的升高而升高,在90℃时可以达到83%以上;在实验范围内,CO2的吸收率随吸收液浓度的增加略有增加,随气液比的增加而逐渐降低并趋于稳定。 相似文献
17.
Absorption of carbon dioxide by the absorbent composed of piperazine and 2-amino-2-methyl-1-propanol in PVDF membrane contactor 总被引:1,自引:0,他引:1
Su-Hsia Lin Pen-Chi Chiang Meng-Hui Li 《Journal of the Chinese Institute of Chemical Engineers》2008,39(1):13-21
This paper tests the performance of microporous polyvinylidinefluoride (PVDF) hollow fiber in a gas absorption membrane process (GAM) using the aqueous solutions of piperazine (PZ) and 2-amino-2-methyl-1-propanol (AMP). Experiments were conducted at various gas flow rates, liquid flow rates and absorbent concentrations. Experimental results showed that wetting ratio was about 0.036% when used with the aqueous alkanolamine solutions, while that was 0.39% with aqueous piperazine solutions. The CO2 absorption rates increased with increasing both liquid and gas flow rates at NRe < 20. The increase of the PZ concentration showed an increase of absorption rate of CO2. The CO2 absorption rate was much enhanced by the addition of PZ promoter. The resistance of membrane was predominated as using a low reactivity absorbent and can be neglected as using absorbent of AMP aqueous solution. The resistance of gas-film diffusion was dominated as using the mixed absorbents of AMP and PZ. An increase of PZ concentration, the resistance of liquid-film diffusion decreased but resistance of gas-film increased. Overall, GAM systems were shown to be an effective technology for absorbing CO2 from simulated flue gas streams, but the viscosity and solvent-membrane relationship were critical factors that can significantly affect system performance. 相似文献
18.
《分离科学与技术》2012,47(7):1574-1589
Abstract Absorption of carbon dioxide into organic solvents such as DMA, NMP, DMSO, and DMF with the 2-hydroxy ethylammonium lactate (HEAL) ionic liquid was investigated using a batch stirred tank with a plane of gas-liquid interface in a range of 0–2.0 kmol/m3 of HEAL and 298–318 K at 101.3 kPa. The absorption of CO2 was analyzed with the film model accompanied by the zwitterion mechanism of CO2 with HEAL. The proposed model fits the experimental data of the enhancement factor due to the ready, chemical absorption of CO2 in different solvents, temperatures, and HEAL concentrations. The reaction rate constant of CO2 with HEAL was correlated linearly with the solubility parameter of the solvent. 相似文献
19.