APPLIED ENERGY
·
2019
·
IF 8.426
Zain Ali Saleh Bairq,Hongxia Gao,Yufei Huang,Haiyan Zhang,Zhiwu Liang
A significant impediment to the widespread adoption of amine-based post-combustion technique for CO 2 capture from flue gas is the huge energy demand for amine solvent regeneration. In this study, five novel bifunctional heterogeneous catalysts e.g., SO 4 2− /ZrO 2 /SiO 2 with different molar ratios of zirconia and SO 4 2− /ZrO 2 as a parent catalyst were synthesized and applied to evaluate their effectiveness in enhancing the CO 2 desorption and solvent regeneration of 5M monoethanolamine solution with CO 2 loading of 0.5 ± 0.01 mol CO 2 /mol monoethanolamine at 97 °C. The catalysts were characterized by Fourier transform-infrared spectrometry, pyridine-infrared spectroscopy, X-ray diffraction, N 2 -adsorption-desorption, and ammonia-temperature programmed desorption. The results demonstrated that these catalysts can significantly reduce the heat duty for CO 2 desorption by 36.48% compared to without catalyst and enhance desorption rate by 35.1%. The results also showed that SO 4 2− /ZrO 2 /SiO 2 15% presented the highest efficiency compared to the other SO 4 2− /ZrO 2 /SiO 2 ratios and the super solid acid catalyst SO 4 2− /ZrO 2 . Additionally, to investigate if the catalysts induce any unfavorable effects on the amine, the absorption of CO 2 by regenerated amine solvent was studied. Finally, a reaction mechanism for the amine solvent regeneration with the synthesized catalyst e.g., SO 4 2− /ZrO 2 /SiO 2 was suggested.
研究领域:
化学工程
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环境科学
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DOI
高影响因子
APPLIED ENERGY
·
2017
·
IF 7.182
Xiaowen Zhang,Xin Zhang,Helei Liu,Wensheng Li,Min Xiao,Hongxia Gao,Zhiwu Liang
In this work, the regeneration of rich CO 2 -loaded monoethanolamine (MEA) solvent with two catalysts (e.g. SAPO-34 and SO 4 2− /TiO 2 ) was investigated in order to reduce the energy requirement for solvent regeneration. The regeneration behavior with and without catalyst of a 5M MEA solution with an initial CO 2 loading of 0.5 mol CO 2 /mol amine at 96 °C was studied to compare their CO 2 desorption rate and heat duties. The results show that the two solid acid catalysts can reduce the heat duty for solvent regeneration and increase the CO 2 desorption rate in comparison with blank test. The mechanism of CO 2 desorption with catalyst in 5M MEA was proposed based on the result of catalyst characterization (e.g. N 2 absorption/desorption experiment, Py-IR, NH 3 -TPD, FT-IR and XRD) to better understand the desorption process. The results indicate that SAPO-34 with the higher joint value of Brϕnsted/Lewis acid sites ratio (B/L) and mesopore surface area (MSA) shows the faster CO 2 desorption rate and lower heat duty than SO 4 2− /TiO 2 . Based on the experimental results, the addition of solid acid catalysts into amine solution could be considered as one of choices to reduce the heat duty for CO 2 desorption from CO 2 -loaded amine solvent.
研究领域:
化学工程
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环境科学
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催化
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2021
·
IF 13.273
Yinqiao Zhang,Juhong Zhan,Bin Wang,Jun Huang,Shubo Deng,Gang Yu,Sridhar Komarneni,Yujue Wang
This research evaluated integrating ultraviolet (UV) irradiation with electrochemical chlorine (Cl 2 ) and/or hydrogen peroxide (H 2 O 2 ) production for micropollutant abatement in water treatment. Combining UV with anodic Cl 2 production (E-UV/Cl 2 ) effectively abated gemfibrozil and naproxen, but ineffectively abated ibuprofen due to its low reactivity with chlorine radicals (e.g., ClO• and Cl 2 - •). In comparison, combining UV with cathodic H 2 O 2 production (E-UV/H 2 O 2 ) more effectively abated ibuprofen, but less efficiently abated gemfibrozil and naproxen due to the significant scavenging of •OH by the water matrix. Moreover, simultaneously producing Cl 2 and H 2 O 2 during UV irradiation (E-UV/Cl 2 /H 2 O 2 ) in an undivided reactor did not further enhance micropollutant abatement compared to the E-UV/H 2 O 2 process because of the mutual consumption of anodically generated Cl 2 and cathodic generated H 2 O 2 . In contrast, by separating the anodic and cathodic compartments with an anion exchange membrane and operating the E-UV/Cl 2 /H 2 O 2 process in an anode-to-cathode configuration, all test micropollutants could be adequately abated through the sequential oxidation with the selective chlorine radicals and non-selective •OH in the anodic and cathodic compartments. In general, the concentrations of micropollutants could be abated by 84–100% with a short hydraulic residence time (HRT) of 9.4 min and feasible energy demand (E EO ≤ 3.15 kWh/m 3 -log) in the selected groundwater and secondary wastewater during the E-UV/Cl 2 /H 2 O 2 process in the divided reactor. The results indicate that different synergistic effects can be obtained for micropollutant abatement by combining UV and electrochemical processes in varying configurations, and the divided E-UV/Cl 2 /H 2 O 2 process is a more robust and energy-efficient method for micropollutant abatement during decentralized water treatment.
研究领域:
环境科学
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水处理工程
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DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
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2019
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IF 7.149
Chenyu Xu,Jiahui Cai,Zhihua Wang,Mingjiang Ni,Kefa Cen,Yanwei Zhang
In this work, to achieve both clean energy production and carbon emission reduction, a united conversion to couple CO2 mineralization with thermochemical hydrogen production is proposed. Natural magnesium silicate minerals are used to fix CO2 in the form of carbonate minerals, whereas H2O is dissociated to produce H2 in the thermochemical cycle. The integration provides a new solution to the challenges of the high energy consumption and poor economic value of conventional CO2 mineralization processes, and the technical feasibility has been proven. Moreover, the energy economy and CO2 conversion capacity were investigated. Hydrolyzation and carbonation experiments were performed in a homemade reactor, and it was found that an optimal MgI2 hydrolyzation rate of 75% could be achieved without alkali consumption. A detailed simulation of the whole system was also developed. The optimal energy conversion efficiency of the cycle reached 47.6%, which is higher than most of the published theoretical energy efficiency values for sulfur–iodine thermochemical cycles. A modified calculation of the net energy requirement for CO2 mineralization was carried out. Finally, a comparison and an evaluation of the energy efficiencies were made based on the calculation. In the optimal case, the modified net energy requirement is 1.4 MJ/kg CO2, which means that this method is competitive compared to those of previous works.
研究领域:
环境科学
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能源工程
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产品关联
DOI
PubMed
高影响因子
AICHE JOURNAL
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2017
·Vol. 63
·期 8
·3395-3403
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IF 2.836
Min Xiao,Ding Cui,Helei Liu,Paitoon Tontiwachwuthikul,Zhiwu Liang
In this work, the equilibrium CO 2 solubility in the aqueous tertiary amine, N-methyl-4-piperidinol (MPDL) was measured over a range of temperatures, CO 2 partial pressures and amine concentrations. The dissociation constant of the MPDL solution was determined as well. A new thermodynamic model was developed to predict the equilibrium CO 2 solubility in the MPDL-H 2 O-CO 2 system. This model, equipped with the correction factor (C f ), can give reasonable prediction with an average absolute deviation of 2.0%, and performs better than other models (i.e., KE model, Li-Shen model, and Hu-Chakma). The second-order reaction rate constant (k 2 ) of MPDL and the heat of CO 2 absorption (–ΔH abs ) into aqueous MPDL solutions were evaluated as well. Based on the comparison with some conventional amines, MPDL revealed a high-equilibrium CO 2 loading, reasonably fast absorption rate when compared with other tertiary amines, and a low energy requirement for regeneration. It may, therefore, be considered to be an alternative solvent for CO 2 capture. © 2017 American Institute of Chemical Engineers AIChE J , 63: 3395–3403, 2017
研究领域:
化学工程
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环境科学
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2023
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IF 8.6
Rui Zhang,Yufan Li,Xinwei He,Yingjie Niu,Chao'en Li,Mohammad Waleed Amer,Francesco Barzagli
Mixing amines with different properties is considered a smart strategy for developing efficient aqueous solutions for reversible CO 2 capture. Specifically, dual-amine blends containing the tertiary amine 2-dimethylamino-2-methyl-1-propanol (2DMA2M1P) have proven to be particularly advantageous due to significantly lower regeneration costs compared to conventional sorbents. With the aim of formulating high-efficiency sorbents, in this work we evaluated the improvement in the CO 2 capture performance of such dual-amine blends by adding a further amine to form trio-amine systems: the use of three amines with different characteristics could further emphasize the advantages obtainable during both absorption and desorption. We formulated three new different aqueous solutions prepared by mixing 2DMA2M1P with the reaction rate promoter ethanolamine (MEA) and the absorption capacity promoter 2-amino-2-methyl-1-propanol (AMP) in different molar ratios. For each blend, the CO 2 solubility at equilibrium, the CO 2 absorption rate from a gaseous mixture, the regeneration rate at T = 373 K and the energy requirement for desorption were determined experimentally. In addition, to better understand the capture mechanism, 13 C NMR spectroscopy was employed to evaluate the speciation of each blend during the CO 2 absorption. Their CO 2 capture performance was compared with that of the benchmark aqueous MEA and two 2DMA2M1P-based dual-amine mixtures, obtained with the same procedure. As a finding, all formulated trio-amine blends have superior CO 2 equilibrium solubility and desorption performance compared with MEA 5 M. Noteworthy, the comparison with similar dual-amine systems highlighted the role of a suitable third amine in order to obtain enhance both absorption and desorption efficiencies. Among the formulated systems, MEA-2DMA2M1P-AMP (1:2:2) is potentially the most suitable to replace MEA in CO 2 capture processes after a careful cost-benefit analysis on larger scale systems.
研究领域:
化学工程
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环境科学
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材料科学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）