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The molar heat capacities of 38 pure solvents used for CO2 capture studies are reported in the temperature range of 303.15–393.15 K and atmospheric pressure. Existing structural similarities between these compounds were explored using a group additivity analysis (GAA) and molecular connectivity principles in terms of the reported heat capacity data. Group additivity yields the estimates of CH3, CH2, CH, C, ?CH, NH2, NH, N, ?N–, OH, O and ?O group contributions to the molar heat capacities at each investigated temperature. Molecular connectivity approach provides a single equation that models the molar heat capacities of amines over the investigated temperature range. Absolute average deviations for the GAA were found to be <2.5%, and <3% for the molecular connectivity analysis. The developed equations were tested by predicting the molar heat capacities of solvents newly proposed for CO2 capture. Les capacités calorifiques molaires de trente huit (38) solvants purs utilisés pour les études de capture du CO2 sont rapportées dans la gamme de température de (303.15 à 393.15) K et à pression atmosphérique. Les similitudes structurelles existantes entre ces composés ont été explorées à l'aide d'une analyse additivité de groupe et les principes de connectivité moléculaire en termes de capacité thermique. L'analyse fournit les estimations de la contribution des groups CH3, CH2, CH, C, ?CH, NH2, NH, N, ?N–OH, O et S = aux capacités calorifiques molaires à chaque température étudiée. L'approche de connectivité moléculaire fournit une seule équation qui modélise les capacités calorifiques molaires des amines dans l'intervalle de température étudié. Les écarts absolus moyens pour l'analyse additivité des groupes ont été de moins de 2.5%, et de moins de 3% pour l'analyse de la connectivité moléculaire. Les équations développées ont été testées en prédisant les capacités calorifiques molaires des solvants nouvellement proposés pour la capture du CO2. © 2011 Canadian Society for Chemical Engineering 相似文献
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R. Ramazani S. Mazinani A. Hafizi A. Jahanmiri B. Van der Bruggen S. Darvishmanesh 《分离科学与技术》2016,51(2):327-338
The influence of addition of 2-(1-piperazinyl)-ethylamine (as a promoter) on the solubility and absorption rate of carbon dioxide (CO2) in aqueous potassium carbonate solution (as a main solvent) was investigated experimentally, using a vapor liquid equilibrium (VLE) equipment in temperatures from 303.15 to 323.15 K and CO2 initial partial pressures between 25 and 75 kPa. The experimental data showed that the addition of 2-(1-piperazinyl)-ethylamine to potassium carbonate solution results in a significant enhancement in the solubility and absorption rate of CO2. The response surface methodology was applied to explore the relationship between independent parameters on the CO2 loading capacity of blended solution. 相似文献
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化学溶剂吸收法是最有应用潜力的燃烧后二氧化碳脱除技术之一,较高的溶剂再生能耗阻碍了其进一步的工业应用。液-液相变溶剂由于具有降低吸收再生能耗的潜力,成为新型吸收剂的研究热点。综述了液-液相变溶剂的研究现状,从溶剂组成及其相变机理角度出发,将液-液相变溶剂分为热致相变溶剂、有机胺-低吸收速率胺溶剂、化学-物理溶剂、有机胺-离子液体溶剂四类吸收剂,分别介绍各类溶剂的研究进展,重点阐述其吸收性能及相变机理,并分析比较了各溶剂的优缺点。分析表明液-液相变溶剂节能潜力较大,今后的研究工作应侧重于相变溶剂的设计原则及分层机理的深入探讨。 相似文献
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Hai Yu 《中国化学工程学报》2018,26(11):2255-2265
Aqueous ammonia (NH3) is a promising alternative solvent for the capture of industrial CO2 emissions, given its high chemical stability and CO2 removal capacity, and low material costs and regeneration energy. NH3 also has potential for capturing multiple flue gas components, including NOx, SOx and CO2, and producing value-added chemicals. However, its high volatility and low reactivity towards CO2 limit its economic viability. Considerable efforts have been made to advance aqueous NH3-based post-combustion capture technologies in the last few years: in particular, General Electric's chilled NH3 process, CSIRO's mild-temperature aqueous NH3 process and SRI International's mixed-salts (NH3 and potassium carbonate) technology. Here, we review these research activities and other developments in the field, and outline future research needed to further improve aqueous NH3-based CO2 capture technologies. 相似文献
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胆碱类低共融溶剂是一种新型的离子液体。它不仅具有传统离子液体的优点,还具有价格低廉、低毒、生物可降解等优势。对胆碱类低共融溶剂在CO2捕集与分离中所涉及的物理性质,如气体的溶解度、CO2的吸收-解吸、密度、稳定性、黏度和表面张力等进行考察,并分析了胆碱类低共融溶剂的结构对各物性的影响。通过与传统离子液体的对比,胆碱类低共融溶剂在CO2捕集与分离中的应用具有一定的优势,如CO2溶解度高,黏度低。然而,胆碱类低共融溶剂在气体的选择性分离、表面张力等的研究还不足,且热稳定性方面还存在瓶颈,因此,其在CO2捕集和分离中的应用还有待进一步探讨。 相似文献
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基于e-NRTL模型,利用Aspen Plus软件建立了氨水吸收CO2的吸收热预测模型,验证了NH3-CO2-H2O体系的汽液平衡、液相组成形态并与前人的实验数据做了对比,进而结合负载CO2的氨水溶液中各离子及分子的变化特征,对CO2吸收过程的反应热随着CO2负载量的变化规律进行了预测并与已发表的数据进行了比较。结果表明,该吸收热模型能够准确地实现氨水吸收CO2过程中汽液平衡、液相反应以及吸收热的计算。氨水吸收CO2的反应热主要受H2O的电离、NH3的电离、NH2COO-的生成与水解、CO2的溶解等反应过程的影响,H2O的电离过程受NH3的电离过程的抑制,对于总吸收热的贡献最大, NH2COO-的反应则随着CO2负载量的增加先放热再吸热。随着温度的升高,总吸收热有所降低,当温度为80℃时,在较低的CO2负载区间[0.2~0.5 mol CO2·(mol NH3)-1],总吸收热约为70.5 kJ·(mol CO2)-1。 相似文献
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Munendra Pal Singh Ahmed Mongy Alatyar Abdallah Sofiane Berrouk Muhammad Saeed 《加拿大化工杂志》2023,101(11):6170-6202
Over the last decades, renewable and clean energy sources are being rigorously adopted along with carbon capture technologies to tackle the increasing carbon dioxide (CO2) concentration level in the environment. CO2 capture is a quintessential option for tackling global warming issues. In this context, the present paper has reviewed the process intensification equipment called a rotating packed bed (RPB), which is highly industry applicable due to high gravity (HiGee) force. This facilitates strong mass transfer characteristics, a compact design, and low energy consumption. In this review, the current research scenario of RPBs using numerical, computational fluid dynamics (CFD), and mathematical modelling, along with different machine learning approaches in the CO2 capture process, has been reviewed. The different geometry designs, hydrodynamic characteristics, performance parameters, research methods, and their effects on CO2 removal efficiency have been discussed. Furthermore, the latest experimental studies are also summarized, especially in the absorption and adsorption domain. Finally, recommendations have been given to support the RPBs in different industrial and commercial applications of CO2 removal. 相似文献
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《Carbon》2014
CO2 capture by solid sorbents is a physisorption process in which the gas molecules are adsorbed in a different porosity range, depending on the temperature and pressure of the capture conditions. Accordingly, CO2 capture capacities can be enhanced if the sorbent has a proper porosity development and a suitable pore size distribution. Thus, the main objective of this work is to maximize the CO2 capture capacity at ambient temperature, elucidating which is the most suitable porosity that the adsorbent has to have as a function of the emission source conditions. In order to do so, different activated carbons have been selected and their CO2 capture capacities have been measured. The obtained results show that for low CO2 pressures (e.g., conditions similar to post-combustion processes) the sorbent should have the maximum possible volume of micropores smaller than 0.7 nm. However, the sorbent requires the maximum possible total micropore volume when the capture is performed at high pressures (e.g., conditions similar to oxy-combustion or pre-combustion processes). Finally, this study also analyzes the important influence that the sorbent density has on the CO2 capture capacity, since the adsorbent will be confined in a bed with a restricted volume. 相似文献
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Jianghua Ling Penny Xiao Augustine Ntiamoah Dong Xu Paul Webley Yuchun Zhai 《中国化学工程学报》2016,24(4):460-467
Different VSA(Vacuum Swing Adsorption) cycles and process schemes have been evaluated to find suitable process configurations for effectively separating CO2 from flue gases from different industrial sectors. The cycles were studied using an adsorption simulator developed in our research group, which has been successfully used to predict experimental results over several years. Commercial zeolite APGIII and granular activated carbon were used as the adsorbents. Three-bed VSA cycles with- and without-product purge and 2-stage VSA systems have been investigated. It was found that for a feed gas containing 15% CO2(representing flue gas from power plants), high CO2 purities and recoveries could be obtained using a three-bed zeolite APGIII VSA unit for one stage capture, but with more stringent conditions such as deeper vacuum pressures of 1–3 k Pa. 2-stage VSA process operated in series allowed us to use simple process steps and operate at more realistic vacuum pressures. With a vacuum pressure of 10 k Pa, final CO2 purity of 95.3% with a recovery of 98.2% were obtained at specific power consumption of 0.55 MJ·(kg CO2)-1from feed gas containing15% CO2. These numbers compare very well with those obtained from a single stage process operating at1 k Pa vacuum pressure. The feed CO2 concentration was very influential in determining the desorption pressure necessary to achieve high separation efficiency. For feed gases containing N 30% CO2, a singlestage VSA capture process operating at moderate vacuum pressure and without a product purge, can achieve very high product purities and recoveries. 相似文献
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Supercritical propane (SC-propane) was found to be a promising solvent for grafting (3-aminopropyl)triethoxysilane (APS) onto synthesized SBA-15 for CO2 capture. The influence of operating conditions in SC-propane for CO2 adsorption at different pressures (8.3–13.8 MPa), temperatures (85–120 °C), and periods of time (4–16 h) were evaluated. The CO2 adsorption conditions under different partial pressures, temperatures and moisture were evaluated. The results showed a reduction in pore characteristics and an increased amount of grafted APS with increasing pressure and temperature after grafting. After grafting in SC-propane at 11.0 MPa and various temperatures for 16 h, a 3–20% increase in the amount of grafted APS and a 6–49% increase in the CO2 adsorption capacity over the toluene refluxing was observed. The time required for grafting in SC-propane could be reduced while maintaining higher nitrogen content and CO2 adsorption capacity compared with grafting in toluene refluxing. 相似文献
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In this work, an air-blast atomizing column was used to study the CO2 capture performance with aqueous MEA (mono-ethanol-amine) and NaOH solutions. The effects of gas flow rate, the liquid to gas ratio (L/G), the CO2 concentration on the CO2 removal efficiency (η) and the volumetric overall mass transfer coefficient (KGav) were investigated. The air-blast atomizing column was also compared with the pressure spray tower on the studies of the CO2 capture performance. For the aqueous MEA and NaOH solutions, the experimental results show that the η decreases with increasing gas flow rate and CO2 concentration while it increases with increasing L/G. The effects on KGav are more complicated than those for η. When the CO2 concentration is low (3 vol%), KGav increases with increasing gas flow rate while decreases with increasing L/G. However, when the CO2 concentration is high (9.5 vol%), as the gas flow rate and L/G increases, KGav increases first and then decreases. The aqueous MEA solution achieves higher η and KGav than the aqueous NaOH solution. The air-blast atomizing column shows a good performance on CO2 capture. 相似文献
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大量的化石燃料燃烧导致温室气体排放增加,全球气候变暖。世界各国以全球协约的方式减排CO2,我国也由此提出“碳达峰·碳中和”目标。CO2捕集以及转化制液体燃料和化学品是双碳目标下行之有效的碳减排措施之一,不仅可以实现CO2的资源化利用,同时也缓解了国家能源安全问题。本文以燃煤电厂烟气CO2捕集和CO2合成甲醇为研究对象,分析了基于四种不同CO2捕集技术的CO2耦合绿氢制甲醇工艺。对四种不同CO2捕集技术的CO2制甲醇工艺进行了严格的稳态建模和模拟,分析和比较了不同CO2捕集技术情景下的CO2制甲醇工艺的技术和经济性能。结果表明,MEA、PCS、DMC和GMS情景的单位甲醇能耗分别是7.81、5.48、5.91和4.66 GJ/ t CH3OH,GMS情景的单位能耗最低,其次是PCS情景,但随着更高效相变吸收剂的开发,PCS情景的单位甲醇产品的能耗将降低至2.29~2.58 GJ/t CH3OH。四种情景的总生产成本分别是4314、4204、4279和4367 CNY/ t CH3OH,PCS情景的成本最低,更具有经济优势。综合分析表明PCS情景的性能表现最好,为可用于燃煤电厂最佳的碳捕集技术,为CO2高效合成燃料化学品提供方向,缓解化石燃料短缺和环境污染问题。 相似文献
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大量的化石燃料燃烧导致温室气体排放增加,全球气候变暖。世界各国以全球协约的方式减排CO2,我国也由此提出“碳达峰·碳中和”目标。CO2捕集以及转化制液体燃料和化学品是双碳目标下行之有效的碳减排措施之一,不仅可以实现CO2的资源化利用,同时也缓解了国家能源安全问题。本文以燃煤电厂烟气CO2捕集和CO2合成甲醇为研究对象,分析了基于四种不同CO2捕集技术的CO2耦合绿氢制甲醇工艺。对四种不同CO2捕集技术的CO2制甲醇工艺进行了严格的稳态建模和模拟,分析和比较了不同CO2捕集技术情景下的CO2制甲醇工艺的技术和经济性能。结果表明,MEA、PCS、DMC和GMS情景的单位甲醇能耗分别是7.81、5.48、5.91和4.66 GJ/ t CH3OH,GMS情景的单位能耗最低,其次是PCS情景,但随着更高效相变吸收剂的开发,PCS情景的单位甲醇产品的能耗将降低至2.29~2.58 GJ/t CH3OH。四种情景的总生产成本分别是4314、4204、4279和4367 CNY/ t CH3OH,PCS情景的成本最低,更具有经济优势。综合分析表明PCS情景的性能表现最好,为可用于燃煤电厂最佳的碳捕集技术,为CO2高效合成燃料化学品提供方向,缓解化石燃料短缺和环境污染问题。 相似文献
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利用湿壁塔实验台对燃煤烟气中SO2对氨水溶液[1%~7%(质量)]吸收CO2的影响进行了实验研究,具体分析了不同反应温度(20~80℃)和CO2体积分数(5%~20%)条件下,CO2传质通量及传质系数随SO2浓度和SO2负载量的变化规律。结果表明, SO2浓度由0增至11428 mg·m-3,CO2传质通量及传质系数均有一半左右降幅,而SO2负载量[0.1~0.4 mol SO2·(mol NH3)-1]的增加,同样导致CO2传质通量及传质系数明显减小。氨水浓度及反应温度增加可有效提高CO2传质通量和传质系数,相对降低SO2对CO2传质的影响。CO2浓度的增加可明显提高其传质通量,但是CO2的传质系数有所降低。 相似文献
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Vladimir S. Derevschikov Janna V. Veselovskaya Anton S. Shalygin Dmitry A. Yatsenko Andrey Z. Sheshkovas Oleg N. Martyanov 《中国化学工程学报》2022,46(6):11-20
Potassium carbonate-based sorbents are prospective materials for direct air capture (DAC). In the present study, we examined and revealed the influence of the temperature swing adsorption (TSA) cycle conditions on the CO2 sorption properties of a novel aerogel-based K2CO3/ZrO2 sorbent in a DAC process. It was shown that the humidity and temperature drastically affect the sorption dynamic and sorption capacity of the sorbent. When a temperature at the sorption stage was 29 ℃ and a water vapor pressure in the feed air was 5.2 mbar (1 bar = 105 Pa), the composite material demonstrated a stable CO2 sorption capacity of 3.4% (mass). An increase in sorption temperature leads to a continuous decrease in the CO2 absorption capacity reaching a value of 0.7% (mass) at T = 80 ℃. The material showed the retention of a stable CO2 sorption capacity for many cycles at each temperature in the range. Increasing PH2O in the inlet air from 5.2 to 6.8 mbar leads to instability of CO2 sorption capacity which decreases in the course of 3 consecutive TSA cycles from 1.7% to 0.8% (mass) at T = 29 ℃. A further increase in air humidity only facilitates the deterioration of the CO2 sorption capacity of the material. A possible explanation for this phenomenon could be the filling of the porous system of the sorbent with solid reaction products and an aqueous solution of potassium salts, which leads to a significant slowdown in the CO2 diffusion in the composite sorbent grain. To investigate the regeneration step of the TSA cycle in situ, the macro ATR-FTIR (attenuated total reflection Fourier-transform infrared) spectroscopic imaging was applied for the first time. It was shown that the migration of carbonate-containing species over the surface of sorbent occurs during the thermal regeneration stage of the TSA cycle. The movement of the active component in the porous matrix of the sorbent can affect the sorption characteristics of the composite material. The revealed features make it possible to formulate the requirements and limitations that need to be taken into account for the practical implementation of the DAC process using the K2CO3/ZrO2 composite sorbent. 相似文献
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利用热重分析仪、扫描电镜和氮吸附仪对不同粒径的K2CO3颗粒和负载型K2CO3/Al2O3二氧化碳吸收剂的碳酸化特性进行研究。负载后的吸收剂比表面积和孔隙结构得到较大改善,使得碳酸化反应速率和转化率均提高,吸收剂碳酸化特性得到改善。纯K2CO3颗粒吸收剂的反应速率和转化率随着粒径的增加而减小,负载型吸收剂的反应速率和转化率随着粒径的增加略增大。研究了不同粒径和反应时间对K2CO3/Al2O3颗粒微观结构的影响,结果表明K2CO3/Al2O3颗粒具有较稳定的微观结构。采用负载型粒子模型对K2CO3/Al2O3吸收剂吸收CO2碳酸化过程进行研究,所建立的粒子模型计算结果与试验值吻合较好。利用建立的模型对不同CO2浓度下K2CO3/Al2O3吸收剂碳酸化反应特性进行模拟计算,模拟结果具备一定的合理性和准确性,为开展进一步研究提供了基础。 相似文献