Greenhouse Gases-Science and Technology
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2022
·Vol. 12
·期 3
·362-375
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IF 2.518
Jinxiu Li,Yu Li,Chen Li,Rui Tu,Pengfei Xie,Yi He,Yao Shi
While nonaqueous organic-amine absorbents have great potential in reducing energy consumption of CO 2 capture, their absorption/desorption behaviors are still poorly understood when high-concentration polyamines are used. On the other hand, large scale CO 2 capture demands the use of high-concentration polyamines absorbents. Therefore, we investigated the absorption and microwave regeneration behavior of high-concentration triethylenetetramine (TETA) in three typical organic solvents, including polyethylene glycol 200 (PEG200), diethylene glycol (DEG), and ethylene glycol (EG). The results showed that high-concentration TETA nonaqueous absorbents demonstrate advantages in absorption rate and regeneration energy consumption. The average absorption rate of 2.0 and 5.0 mol/L TETA/EG was 2.84 and 4.70 times that of 0.6 mol/L, respectively. The energy consumption of TETA/EG and TETA/DEG decreased by 29.4 and 25.6% as the concentration increased from 0.6 to 5.0 mol/L. In addition, the high-concentration TETA/PEG200 absorbent demonstrated observable tolerance for water vapor, which usually exists in flue gas. Results also showed that microwave regeneration was superior to conventional conduction heating especially when high-concentration TETA/PEG200 absorbent were used. The energy consumption of microwave regeneration of the absorbent with a concentration of 0.6, 2.0, and 5.0 mol/L was reduced by 65.9, 81.2, and 86.0%, respectively when compared with conduction heating. © 2022 Society of Chemical Industry and John Wiley & Sons, Ltd.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Chenyang Li,Haorui Zhang,Kai Shu,Tong Zheng
Microwave (MW) regeneration offers a promising alternative to energy-intensive, long-cycle thermal regeneration technologies due to its rapid molecular-level heating. However, the role of residual moisture in adsorbents is often neglected in MW regeneration efficiency. Since water is a polar dielectric material, it significantly affects the efficiency of adsorbent regeneration. While 2450 MHz MW frequency has been effective at the laboratory scale, the industrially prevalent 915 MHz frequency has received less attention. This study investigates moisture issues on carbon during MW regeneration through a comparative analysis of moisture removal using 2450 MHz, 915 MHz, and conventional heating (CH) methods. By integrating experimental and simulation approaches, the heat and mass transfer processes of gas, liquid, and solid phases under different heating methods were discussed. The impacts of heating methods and process parameters on drying rate were analyzed, using ketoprofen removal efficiency to evaluate the adsorption performance of the dried material. An economic cost analysis was conducted to inform a proposed strategy for moisture removal during MW regeneration. The results indicate that MW heating offers higher energy utilization than CH. Although 2450 MHz MW heating achieves the highest efficiency, it suffers from poor uniformity, leading to localized excessive temperatures and increased carbon loss. In contrast, MW at 915 MHz provides a more uniform temperature distribution and lower energy consumption. Enhancing vacuum degree improves the drying rate. Therefore, employing MW at 915 MHz under low vacuum conditions can reduce water removal costs in the MW regeneration. This study provides a theoretical foundation for the industrial application of MW regeneration.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2012
·
IF 3.07
Peng Liao,Songhu Yuan,Wenjing Xie,Wenbiao Zhang,Man Tong,Kun Wang
The adsorption kinetics and thermodynamics of nitrogen-heterocyclic compounds (NHCs), pyridine, indole and quinoline, in aqueous solutions on bamboo charcoal (BC), as well as the regeneration of spent BC by microwave radiation, are investigated. BC is produced by incomplete combustion of moso bamboo at high temperature and nitrogen atmosphere. Adsorption kinetics is analyzed using pseudo-first-order and pseudo-second-order as well as Weber–Morris model. The results show that NHC adsorption on BC is predominantly regulated by surface diffusion in initial 1 h followed by intraparticle diffusion in later stage. BC exhibits a strong adsorption affinity to NHCs, and the adsorption isotherms are well described by Freundlich model. Thermodynamic analysis indicates that the adsorption is spontaneous and endothermic. Adsorption site energy analysis illustrates a distribution of adsorption energy, which indicates the heterogeneous sites on BC for NHC adsorption. Furthermore, spent BC with NHC adsorption can be effectively regenerated by MW radiation. The adsorption capacity becomes even higher than that of virgin BC after five times of adsorption–regeneration cycles. This study proves BC is a promising adsorbent for NHC removal in wastewater.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ENERGY & FUELS
·
2020
·
IF 3.421
Yu Li,Jinzhe Gao,Jinxiu Li,Younan Li,Matthew T. Bernards,Mengna Tao,Yi He,Yao Shi
While CO2 capture with nonaqueous solutions is a promising approach, regeneration of the solutions often requires high energy consumption. This energy consumption can be potentially reduced by microwave regeneration, the performance of which is strongly affected by the selection of solvent. Therefore, we investigated the characteristics of microwave regeneration for nine triethylenetetramine (TETA) solutions. The results show that the heating rate of a solution in the microwave was primarily affected by its viscosity, dielectric constant, and heat capacity. The desorption energy consumption of CO2-loaded solutions had a strong linear correlation with the dielectric constant of the solvents over a certain solvent viscosity range (1.4–88.8 mPa·s, 20 °C). A comparison of microwave heating and conductive heating shows that the former performs better when considering regeneration temperature, CO2 recovery, and energy requirement. Under the condition of 800 W, the energy consumption using microwave regeneration for 30 wt % TETA/BDO and TETA/PEG200 solutions decreased by 69% and 76%, while CO2 recovery increased by 2.6 and 2.7 times, respectively, compared to a 30 wt % monoethanolamine aqueous solution regenerated by conductive heating. Therefore, TETA with microwave regeneration represents a promising approach for CO2 capture and recovery.
研究领域:
化学工程
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）