MDEA与哌嗪、二乙醇胺混合溶液吸收二氧化碳速率研究

Absorption rate of CO2 into aqueous solution of N-methyldiethanolamine (MDEA) blended with diethanolamine (DEA) and piperazine (PZ) was studied and a kinetic model was established. It is shown that homogeneous activation mechanism could explain this absorption process. The absorption rate coefficients of carbon dioxide into MDEA aqueous solution blended with DEA, PZ or DEA PZ were compared with each other. The results demonstrated that the different activation effect of DEA, PZ and DEA PZ on the carbon dioxide absorption comes from the difference in CO2 combination rate, transport of PZ and DEA to MDEA and the regeneration rate of PZ and DEA.     

填料塔中混合胺吸收二氧化碳的研究

在填料塔中考察了常压下混合胺吸收剂[20%乙醇胺(MEA)+2% N-甲基二乙醇胺(MDEA),20%羟乙基乙二胺(AEE)+2% MDEA]对CO_2的吸收与解吸效果.同时测得了AEE+MDEA混合胺体系吸收剂脱除空气中体积分数约10%的CO_2的体积总传质系数K_Ga_v的近似值,并考察了进口气体中CO_2摩尔流量、气体流量、液体流量等因素对K_Ga_v的影响.实验结果表明,AEE+MDEA吸收效果明显好于MEA+MDEA,并且二者解吸效果相同;K_Ga_v随CO_2摩尔流量、气体流量、液体流量增大而增大.     

DETA-MDEA复合溶液吸收与解吸CO2实验研究

以烯胺吸收剂DETA(二乙烯三胺)为主吸收剂与辅助吸收剂MDEA(N-甲基二乙醇胺)按摩尔配比20:1～20:6进行复配,通过一次循环吸收、解吸实验,对比其在313 K温度下的吸收量、吸收速率以及393 K温度下的再生速率、再生量以及它们的降解率。以筛选出较好的20:4DETA+MDEA烯胺复配药剂为基础,进行6次循环吸收-解吸实验,考察循环吸收、解吸性能与胺降解率;以智能高压反应釜分别考察了20:4DETA+MDEA降解性能,对CO_2负载、温度、铁离子的降解性能的影响进行了探讨。     

填料塔中AEE与MEA混胺对低浓度CO2的吸收

在常压下考察了体积分数20%乙醇胺（MEA）+2% N-甲基二乙醇胺（MDEA）与20%羟乙基乙二胺（AEE）+ 2% N-甲基二乙醇胺（MDEA）有机胺水溶液对CO2的吸收及解吸效果。考察了静态吸收和中试动态吸收实验。实验结果表明：在吸收温度及解吸温度相同的条件下,20%羟乙基乙二胺（AEE）+2% N-甲基二乙醇胺（MDEA）吸收剂对CO2的吸收及解吸效果要好于20%乙醇胺（MEA）+2% N-甲基二乙醇胺（MDEA）,而且不易降解。达到同样的解吸效果,20%羟乙基乙二胺（AEE）+2% N-甲基二乙醇胺（MDEA）吸收剂的能耗要低10%左右,具有较好的工业应用前景。     

MDEA醇胺法脱硫在焦化中的应用

N-甲基二乙醇胺(MDEA)因其对H2S和CO2混合气体具有很好的选择性脱硫性在炼厂气脱硫中广泛应用,但在焦炉煤气净化中应用还相对较少,本文主要对MDEA醇胺脱硫在焦炉煤气净化中应用所产生的问题进行了分析研究,并提出了相应的解决办法。     

活化甲基二乙醇胺溶液吸收CO2的动力学

采用圆盘塔在常压、温度３０～７０℃、ＭＤＥＡ（甲基二乙醇胺）浓度１．７５～４．２１ｋｍｏｌ／ｍ３、哌嗪浓度０．０４１～０．２１ｋｍｏｌ／ｍ３条件下，研究了活化ＭＤＥＡ吸收ＣＯ２的动力学。动力学数据证实了ＣＯ２与哌嗪之间进行着拟一级均匀［４］活化反应机理，其吸收速率可由并行拟一级快速可逆反应吸收来表示：　式中：ｋｐ＝２．９８×１０（１１）ｅｘｐ（－６４２４／Ｔ），表观活化能为５３．４１ｋＪ／ｍｏｌ。     

醇胺吸收和解吸CO2的研究

本文利用常压搅拌吸收和解吸装置在一定条件下对乙醇胺（ＭＥＡ）、二乙醇胺（ＤＥＡ）、甲基二乙醇胺（ＭＤＥＡ）及乙－氨基－２甲基－１－丙醇（ＡＭＰ）吸收和解吸ＣＯ２的速率进行了比较和研究。     

功能化离子液体-MDEA复配体系吸收CO2

采用一步法合成了两种功能化离子液体四乙铵-丙氨酸盐([N2222][Ala])和四乙铵-丝氨酸盐([N2222][Ser]),利用IR和1H NMR对其结构进行了表征,并测定了其玻璃转化温度和分解温度;同时,在40℃下分别将[N2222][Ala]和[N2222][Ser]与MDEA进行复配,考察复配后的体系对CO2吸收性能;实验结果表明,[N2222][Ala]和[N2222][Ser]的加入对MDEA吸收CO2均有不同程度的增强作用,当加入质量分数为10%时,体系对CO2吸收量分别增加了8.63%和5.40%。此外,研究了20～60℃温度范围内复配体系的密度、黏度等,并比较了吸收前后黏度的变化。     

氨基酸离子液体-MDEA混合水溶液的CO2吸收性能

为改善N-甲基二乙醇胺(MDEA)水溶液对CO₂气体的吸收性能,选择了四甲基铵甘氨酸(［N₁₁₁₁］［Gly］)、四乙基铵甘氨酸(［N₂₂₂₂］［Gly］)、四甲基铵赖氨酸(［N₁₁₁₁］［Lys］)、四乙基铵赖氨酸(［N₂₂₂₂］［Lys］)4种功能性离子液体作为活化剂与其复配组成新型CO₂吸收剂。用恒定容积法考察了总质量分数为30%的混合溶液吸收CO₂的性能,分析了离子液体在水溶液中与MDEA通过质子传递相互促进吸收CO₂的机理。实验结果显示离子液体能够显著提高MDEA水溶液吸收CO₂的速率,且吸收速率随着添加量的增加而提高。在本文所用的几种混合吸收剂中,阴离子为赖氨酸的离子液体混合吸收剂具有较高的吸收负荷;而［N₁₁₁₁］［Gly］-MDEA混合溶液对CO₂的初期吸收速率最快,同时［N_1111^］［Gly］-MDEA混合吸收剂的再生效率高于其他离子液体混合吸收剂,达到98%。     

氨基酸离子液体-MDEA混合水溶液的CO_2吸收性能

为改善N-甲基二乙醇胺(MDEA)水溶液对CO2气体的吸收性能,选择了四甲基铵甘氨酸([N1111][Gly])、四乙基铵甘氨酸([N2222][Gly])、四甲基铵赖氨酸([N1111][Lys])、四乙基铵赖氨酸([N2222][Lys])4种功能性离子液体作为活化剂与其复配组成新型CO2吸收剂。用恒定容积法考察了总质量分数为30%的混合溶液吸收CO2的性能,分析了离子液体在水溶液中与MDEA通过质子传递相互促进吸收CO2的机理。实验结果显示离子液体能够显著提高MDEA水溶液吸收CO2的速率,且吸收速率随着添加量的增加而提高。在本文所用的几种混合吸收剂中,阴离子为赖氨酸的离子液体混合吸收剂具有较高的吸收负荷;而[N1111][Gly]-MDEA混合溶液对CO2的初期吸收速率最快,同时[N1111][Gly]-MDEA混合吸收剂的再生效率高于其他离子液体混合吸收剂,达到98%。     

超重力反应器中甘氨酸钠吸收混合气体中CO_2的实验研究

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。     

Chemical Absorption of Carbon Dioxide into Aqueous Solution of Potassium Threonate

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.     

仲胺和叔胺水溶液吸收CO2的动力学

采用湿壁柱装置,以二乙醇胺、三乙醇胺和N,N-二乙基乙醇胺水溶液为吸收剂,测量了不同醇胺浓度和不同温度下醇胺吸收CO2的反应速度,得到3种吸收剂吸收CO2的本征反应速率常数分别为7.71′1015exp(-8755.2/T) m3/(kmol×s), 9.63′1020exp(-13262.4/T) m3/(kmol×s), 1.19′1028exp(-18231.3/T) m3/(kmol×s). 确定仲胺吸收CO2的反应机理为两性离子机理,叔胺吸收CO2的反应机理为改进的碱催化水合机理.     

Simultaneous Absorption of Carbon Dioxide and Sulfur Dioxide into Aqueous 1,8-Diamino-p-menthane

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.     

Chemical Absorption of Carbon Dioxide into Aqueous PEO Solution of Monoethanolamine

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 (k_L), 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.     

Simultaneous Absorption of Carbon Dioxide and Nitrogen Dioxide into Aqueous 2-amino-2-methy-1-propanol

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.     

Simultaneous Absorption of Carbon Dioxide and Sulfur Dioxide into Aqueous 2-Amino-2-Methy-1-Propanol

Abstract

Carbon dioxide and sulfur 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 mole fraction of CO₂, 0.005–2 mole fraction of SO₂, and 298–318 K. Absorption data of each gas in the CO₂-AMP and SO₂-AMP 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-AMP systems. The measured absorption rates of CO₂ and SO₂ are compared to those formulated by an approximate solution of the mass balances with simultaneous reactions.     

Chemical Absorption of Carbon Dioxide into Aqueous Colloidal Silica Solution with Diethanolamine

Abstract

The chemical absorption rate (R_A) 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 (k_La) of CO₂, which was used to estimate the value of R_A, was obtained by the empirical correlation formula presenting the relationship between k_La and the rheological behavior of the aqueous colloidal silica solution. The value of R_A in the aqueous colloidal silica solution was decreased by the reduction of k_La due to the elasticity of the solution.     

Absorption of Carbon Dioxide into Aqueous Solution of Sodium Glycinate

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.