三乙醇胺与烯胺混合胺液脱碳性能及配比优选实验研究

胺法脱碳以其脱除效果好、能耗低等优点在天然气预处理中得到广泛应用。目前国内外普遍采用以甲基二乙醇胺为主体的复配胺液为吸收剂,为适应寻找经济、高效的新型吸收剂的需求,本文选取同为叔胺的三乙醇胺(TEA)为主体进行实验研究,在TEA反应机理的研究基础上,添加二乙烯三胺/三乙烯四胺(DETA/TETA)进行混合胺液的吸收解吸性能分析,对比优选出综合表现较好的混合胺液,考察其不同配比下吸收、解吸及贴近实际生产的循环利用效果,完成配比优选研究。结果表明:添加烯胺后,可大大提高吸收性能,但会降低解吸效果;TEA+DETA吸收和解吸性能优于TEA+TETA;TEA+DETA的优选配比为2.0/1.0和2.4/0.6;经循环实验验证,2mol/L TEA+1mol/L DETA综合效果最佳。     

TEA混合胺液脱碳性能实验研究

针对吸收法捕集二氧化碳开发新型高效吸收剂对于提高吸收性能意义重大。目前国内外普遍采用以一乙醇胺(MEA)、二乙醇胺(DEA)和甲基二乙醇胺(MDEA)为主体的复配胺液为吸收剂,但对以三乙醇胺(TEA)为主体的混合胺研究较少。TEA的吸收容量大,解吸效果好,经济性优良,其不足在于吸收速率较低。为此,本文在TEA反应机理的研究基础上,保持总胺浓度3 mol×L~(-1)不变,分别添加乙醇胺(MEA)、哌嗪(PZ)、羟基乙基哌嗪(AEP)、羟乙基乙二胺(AEEA)进行混合胺液的吸收解吸性能分析,对比优选出综合表现较好的混合胺液,并进一步考察其不同配比下吸收、解吸效果,完成配比优选研究。结果表明:开发的混合胺相对于纯TEA溶液,吸收性能均显著提高;相对于纯TEA溶液,只有添加了AEP的混合胺液解吸效果有所提高,其余几种均有所下降;TEA+AEP吸收和解吸性能均显著优于其余几种混合液;经实验验证,TEA+AEP的优选配比为1.5 mol×L~(-1):1.5 mol×L~(-1),综合效果最佳。     

天然气半贫液脱碳工艺三元胺液配方优选

为实现天然气脱碳工厂降本增效目标，基于某工厂PZ活化MDEA半贫液工艺，在现有设备能力下进一步提升胺液性能，进行三元复配胺液配方筛选以替代原有吸收剂。本文针对单一胺液的贫液、半贫液及富液分别进行实验，确定合适的主体胺液及添加剂，将胺液进行三元复配后通过实验探究三元复配胺液的吸收及再生性能，旨在寻找吸收容量大、吸收速率快、解吸率高、循环溶解度高、再生能耗低综合性能优的胺液配方。通过研究发现，单一胺液中AMP、DETA及PZ吸收性能较优，TEA再生能耗最低，解吸率最高；对于三元复配胺液而言，当MDEA/DEEA为主体胺液时，两种胺液配方贫液状态下的吸收速率和吸收负荷均较高，MDEA/TEA双主体胺液的最终解吸率高于MDEA/DEEA双主体胺液，TEA的加入显著提高了胺液的解吸率；筛选得到的三元高效胺液配方18%MDEA+18%TEA+4%PZ的半贫液循环溶解度高于原PZ活化MDEA配方，再生能耗较低，可代替PZ活化MDEA胺液应用于天然气半贫液脱碳工艺。     

MDEA活化胺液在天然气预处理工艺中的吸收性能

目前天然气预处理工业中存在各种不同类型的胺液活化剂,不同的胺液活化剂具有各自的优缺点,其中,最常用的是甲基二乙醇胺(MDEA)的活化胺液。本文通过实验研究了以MDEA为主吸收剂,添加5种不同种类胺液活化剂(MEA、DEA、TEA、DETA、TETA)的吸收性能,包括吸收速率、吸收负荷等,并对实验结果进行了对比分析。实验结果表明:在本文实验条件下,MDEA与伯胺、仲胺的混合胺液吸收负荷较高,综合脱碳效果较好;MDEA与烯胺的混合胺液可以显著提高反应速率,但会受到胺液中CO2负荷的影响;TEA吸收速率最慢,不适合做MDEA的活化剂。本文研究内容为混合胺液工业应用提供了技术指导。     

MDEA复配胺液脱除天然气中H2S性能

为了研究以N-甲基二乙醇胺（MDEA）为主体的MDEA+一乙醇胺（MEA）和MDEA+二乙烯三胺（DETA）两种配方混合胺液脱除H₂S性能,给工业中天然气脱硫配方提供参考和基础数据。利用小型反应釜进行吸收实验,使用单一MDEA胺液进行了工艺参数的筛选,同时考察吸收温度、吸收压力、再生温度对胺液脱除H₂S性能影响,得出升高吸收温度、吸收压力均可在一定程度内提升MDEA胺液的H₂S吸收效果,但当吸收温度过高时会降低胺液的H₂S吸收效果,吸收压力过高会造成脱硫成本的增加,筛选出最优吸收温度50℃,吸收压力5MPa,解吸油浴温度125℃。在优选出的实验工艺参数条件下进行不同添加剂对MDEA胺液脱除H₂S性能影响研究,考察不同配比的MDEA+DETA混合胺液和MDEA+MEA混合胺液脱除天然气中H₂S吸收及解吸性能。通过分析不同配比胺液的吸收负荷、吸收速率及解吸率等指标得出,MDEA单一胺液中添加二乙烯三胺（DETA）、一乙醇胺（MEA）胺液均可提升其H₂S吸收性能但并不利于胺液H₂S解吸性能的提升。性能较优配方为2.4mol/L MDEA+0.6mol/L MEA、2.4mol/L MDEA+0.6mol/L DETA混合胺液。     

混合醇胺/MEA法电厂烟气CO_2吸收性能的实验比较

目前对应用于烟气CO2的吸收液以醇胺MEA为主,但其存在吸收量小、再生能耗高、腐蚀性强等缺点,配方型混合胺溶液已经成为重要的研究方向。本文对部分混合醇胺(MEA+DEA、MEA+TEA、MEA+AMP)的吸收速率和吸收总量进行了实验测定,并与MEA做了比较分析。实验结果表明:在本文的实验条件下,混合胺MEA+AMP的吸收效果优于MEA溶液,而混合胺MEA+TEA的吸收效果最差。为混合胺的研究及工业化应用提供理论指导。     

多种有机胺吸收剂循环利用实验研究

在化学吸收法捕集CO_2的工艺中,吸收剂都是循环使用的。过去的吸收剂性能测定实验通常是测定吸收剂单次使用的性能,而对于吸收剂多次循环之后的性能变化很少提及。以单乙醇胺(MEA)、二乙醇胺(DEA)、三乙醇胺(TEA)、羟乙基乙二胺(AEE)溶液为研究对象,对有机胺溶液多次使用后的吸收与解吸性能进行实验分析测定。实验结果表明:随着循环次数的增加,AEE溶液吸收速度下降明显,而MEA、DEA、TEA溶液经过多次循环后的吸收速率与解吸速率变化不大;随着循环次数的增加,各种有机胺吸收剂的解吸能耗变化大小依次为MEADEATEAAEE;AEE溶液在多次循环反应过程中的解吸能耗变化最小。     

酸性组分对N,N′-二（2-羟丙基）哌嗪吸收/解吸SO2性能的影响

通过添加硫酸、盐酸和氢氟酸模拟研究了SO3、HCl和HF三种酸性气体对N,N’-二(2-羟丙基)哌嗪(HPP)吸收解吸SO2性能的影响。研究结果表明,随着吸收液中硫酸、盐酸和氢氟酸的浓度逐渐增大,吸收液的饱和吸收量和脱硫率逐渐降低,解吸率逐渐增大。添加相同浓度H+的硫酸和盐酸对HPP吸收SO2性能的影响效果基本相当,且大于相同浓度H+的氢氟酸。每摩尔吸收液中添加0.5 mol硫酸或1 mol盐酸,吸收液饱和吸收量减少0.47mol mol 1;每摩尔吸收液中添加1 mol氢氟酸,饱和吸收量减少0.44 mol mol 1,饱和吸收量的理论计算值与实验值偏差率小于±1%。     

TEPA-PZ复配溶液吸收二氧化碳实验研究

以烯胺吸收剂TEPA(四亚乙基五胺)为主吸收剂与辅助吸收剂PZ(哌嗪)按物质的量配比20∶1～20∶6进行复配,通过一次循环吸收、解吸实验,对啊比其在313K温度下的吸收量、吸收速率以及393K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∶4TEPA+PZ烯胺复配药剂为基础,进行6次循环吸收-解吸实验,探讨了循环吸收、解吸性能。     

有机胺溶液吸收燃煤烟气中CO_2的实验研究

有机胺法是最有效的燃煤烟气CO_2捕集技术之一,本文对MEA、DETA、PZ、PG这4种有机胺溶液吸收与解吸CO_2的性能进行研究,并以MEA为主体吸收剂,添加PZ、PG及DETA这3种活化剂,分别研究其活化效果。结果表明,各种吸收剂对CO_2的吸收速率随反应时间增加而降低,富液再生率随解吸温度提高而增大;单一吸收剂对CO_2的吸收能力DETAPZMEAPG,解吸能力PGPZMEA(或DETA);为达到吸收与解吸的平衡,需将它们复配使用。以MEA为主体吸收剂,添加PZ活化效果最好,MEA-PZ摩尔比为0.7∶0.3时,能较好地满足生产要求。     

复合溶液膜吸收CO2的性能及其对膜孔润湿的影响

利用自行搭建的CO₂膜吸收实验台，采用聚丙烯（PP）膜组件，以质量分数10%的N-甲基二乙醇胺（MDEA）作为主体胺溶液，添加不同配比的哌嗪（PZ）、乙醇胺（MEA）、甘氨酸钾（PG），考察CO₂脱除效率和传质速率的变化，比较不同复配比的复合溶液表面张力以及对PP膜的浸润性，并以10%MDEA+10%PG混合溶液作为吸收液进行长时间实验。结果表明：添加少量的添加剂对MDEA溶液膜吸收CO₂均有显著的促进作用，当配比小于0.2时，促进作用大小为PZ>MEA>PG；当配比大于0.2时，促进作用大小为PZ>PG>MEA；PZ和MEA均随着添加配比的增加，溶液表面张力减小，而PG相反；表面张力小的溶液对膜浸润性较强，容易造成膜润湿；添加剂质量分数均为10%时，对膜溶胀性和疏水性以及膜孔结构影响大小为PZ>MEA>PG；在20天内，PG/MDEA混合溶液作用下的CO₂脱除效率从89.56%下降为83.09%，对PP的疏水性影响较小，膜组件可以稳定运行。吸收液表面张力对膜吸收法脱除CO₂性能的影响显著。所得结果可为膜吸收CO₂吸收剂复配提供依据，并可为揭示膜吸收CO₂过程中膜润湿导致膜失效的机理以及抑制膜润湿提供实验数据。     

Enhancement of kinetic rates of CO2 in aqueous solutions of piperazine and methyldiethanolamine with addition of sulfolane

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.     

Comprehensive evaluation and sensitivity analysis of regeneration energy for acid gas removal plant using single and activated-methyl diethanolamine solvents

The absorption of acid gas using reactive amines is among the most widely used types of capturing technologies. However, the absorption process requires intensive energy expenditure majorly in the solvent regeneration process. This study simultaneously evaluated the regeneration energy of MDEA and PZ/MDEA solvents in terms of heat of absorption, sensible heat, and vaporization heat. Aspen Hysys version 8.8 simulation tool is applied to model the full acid gas removal plant for the chemical absorption process. The new energy balance technique presents around the absorption and desorption columns to bring a new perspective of energy distribution in the capturing of acid gas plants. Sensitivity analysis of regeneration energy and its three contributors is performed at several operation parameters such as absorber and stripper pressures, lean amine circulation rate, solvent concentration, reflux ratio, and CO₂ and H₂S concentrations. The results show that the heat of absorption of PZ/MDEA system is higher than that for MDEA system for the same operating conditions. The sensible heat is the main contributor in the required regeneration energy of MDEA solvent system. The simulation results have been validated against data taken from real plant and literature. The product specifications of our simulation corroborate with real plant data in an excellent approach; additionally, the profile temperature of the absorber and the stripper columns are in good agreement with literature. The overall results highlight the direction of the effects of each parameter on the heat of absorption, sensible heat, and vaporization heat.     

Absorption Rate of CO_2 into MDEA Aqueous Solution Blended with Piperazine and Diethanolanline

Absorption rate of CO2 into aqueous solution of N-methyldiethanolamine (MDEA) blended with di-ethanolamine (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.     

Absorption of co2 into aqueous tertiary amine/mea solutions

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.     

MDEA-PZ复合胺溶液吸收烟气中CO2实验研究

采用搅拌实验装置,研究不同摩尔配比的MDEA-PZ复合胺溶液对烟道气中CO2的吸收和解吸性能,揭示了吸收速率、吸收量与吸收时间、pH值、电位之间的内在联系;对CO2初始逸出温度、试液再生温度、再生率、再生pH值下降率进行了分析。结果表明,MDEA—PZ二元复合体系吸收效果优于单组分MDEA、PZ的吸收效果。MDEA—PZ复合胺溶液摩尔配比为0．5：0．5时,吸收效果最佳,吸收量约为0．8mol·L^-1;CO2初始逸出温度最低,为54℃;再生温度最低,为102℃;再生率最高,为88．61％;再生pH值下降率最低,为11．39％。MDEA-PZ复合体系的两种组分之间存在正交互作用。     

MEA—MDEA复合胺溶液吸收烟气中二氧化碳实验研究

采用搅拌实验装置,对MEA-MDEA不同配比的复合胺溶液吸收和解吸模拟烟道气中二氧化碳特性进行研究,揭示了吸收速率、吸收容量和酸碱度与时间之间的内在联系,并与目前工业应用较广的MEA、DEA溶液进行了对比分析;对CO2初始逸出温度,试液再生温度,试液再生率,再生pH值下降率进行了细致记录分析。实验结果表明,0．5mol／LMEA-0．5mol／LMDEA是MEA—MDEA复合胺体系中最佳配比溶液。