INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2018
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IF 3.141
Wenhua Xu,Yuanhai Su,Yang Song,Minjing Shang,Li Zha,Qinghua Lu
Cyclobutanetetracarboxylic dianhydride (CBDA) was prepared by photodimerization of maleic anhydride in capillary microreactors within Taylor flow under UV irradiation. Both inert gas and ultrasound were introduced into this photochemical process to avoid the potential channel clogging resulting from the CBDA deposition. Higher input power of the Hg lamp, lower reactant concentration, longer residence time, and smaller inner diameter of the capillary were found to result in higher CBDA yield. The yield of CBDA could reach as high as 66.3% at an actual residence time of 30 min in the capillary microreactor with 0.5 mm inner diameter. According to the analysis of energy conversion, only low effective photoelectric transformation efficiencies could be achieved in this photochemical process. However, the photonic efficiency for this photodimerization carried out in capillary photomicroreactors was much higher compared to batch photoreactors and was comparable with that for other photochemical transformations using similar photomicroreactors and light sources.
研究领域:
化学工程
·
光化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2020
·
IF 10.652
Qiang Zhang,Zhengya Dong,Shuainan Zhao,Zhikai Liu,Guangwen Chen
Ultrasound effect on the hydrodynamics and mass transfer behavior of gas–liquid Taylor flow is studied in ultrasonic microreactors with different frequencies (20, 28, 40 kHz) and channel dimensions (0.5 × 0.5, 1.0 × 1.0, 1.5 × 1.5, 2.0 × 2.0 mm 2 ). Upon ultrasound irradiation, intense bubble oscillation is excited on the slug bubble, accompanied by cavitation microstreaming vortices around it. The amplitude of bubble oscillation decreases with the decrease of channel dimension as a result of the confinement effect. Channel dimension of 1.0 × 1.0 mm 2 is considered as the critical dimension above which the confinement effect would be eliminated. More intensive bubble oscillation and cavitation microstreaming are observed at lower ultrasound frequency, where more significant mass transfer enhancement is also observed. At frequency of 20 kHz, the overall volumetric mass transfer coefficient is improved by 22 times at the power density of 0.14 W/mL. Adding surfactant (SDS) in the liquid increases the amplitude of bubble oscillation due to the decrease of interfacial tension. Such an increase in the oscillation amplitude enlarges the specific surface area, leading to an increase in the overall volumetric mass transfer coefficient with the increase of surfactant concentration. The detailed effect that how gas–liquid mass transfer would be enhanced by ultrasound is quantified by a mass transfer model, which could predict both the liquid side mass transfer coefficient and the specific surface area satisfactorily.
研究领域:
化学工程
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超声技术
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传质动力学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING RESEARCH & DESIGN
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2023
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IF 3.9
Zihao Qiao,Zezhi Chen,Huijuan Gong,Yu Wang,Huiqiang Yu,Lu Chen
This study proposes a novel millimeter-scale channel absorber for the first time, which involves carbon dioxide (CO 2 ) absorption in the channel to achieve efficient CO 2 absorption while avoiding clogging. CO 2 absorption experiments were conducted on such a channel absorber with an inner diameter of 2.3 mm to study its CO 2 mass transfer and absorption characteristics. Al 2 O 3 particles were introduced as solid impurities to evaluate its anti-clogging performance. The experimental results showed that a stable Taylor flow could be formed in the channel in appropriate gas and liquid flowrate ranges. The liquid-side volume mass transfer coefficient ( K L a ) reached 0.34 s −1 using a 6% DEA solution as the absorbent, which was approximately one order of magnitude higher than that of the conventional packed towers. When Al 2 O 3 to a maximum extent of 2 wt% was added into the absorbents, no clogging was observed, and the values of K L a even increased. Due to the excellent CO 2 absorption mass transfer and anti-clogging performance, millimeter channel absorbers have promising industrial applications for CO 2 absorption. Therefore, means and application scenario for applying millimeter-scale channel absorber in the industrial CO 2 absorption have been proposed.
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
CHEMICAL ENGINEERING JOURNAL
·
2023
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IF 15.1
Hongye Li,Xunli Zhang,Qingqiang Wang,Nan Jin,Haisheng Wei,Yuchao Zhao
There are still technical challenges associated with surface fouling and clogging in microchannels when conducting multiphase catalytic reactions involving solid particles. In this study, a Pickering emulsion was employed to enhance the oxidation of benzyl alcohol (BNOH) catalyzed by Pd/SiO 2 nanoparticles under Taylor flow in a microchannel reactor. The reaction characteristics of benzyl alcohol/water Pickering emulsion in a microchannel reactor were studied experimentally. The characteristic results showed that the O/W Picking emulsion system was superior to the W/O Picking emulsion system for the catalytic oxidation reaction. The influences of a wide range of operational variables were characterized on the conversion of reactants and the selectivity of the desired product. The optimized reaction conditions included: reaction temperature 403 K, CB 5 wt%, O 2 /BNOH (mol/mol) 0.76 and tube length 8 m. Under the optimal operating conditions, the conversion of BNOH and the selectivity of benzaldehyde were found to be 86.53% and 99.79%, respectively. In addition, the interfacial transport-reaction mechanism in Pickering emulsions under Taylor flow in microchannels was proposed from the perspective of multiphase mass transfer. This development provided significant insights and guiding for effectively performing multiphase catalytic reactions involving solid catalyst particles in microchannel reactors.
研究领域:
化学工程
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2024
·Vol. 15
·期 1
·1-10
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IF 14.7
Li Chunsong,Zhang Haochen,Liu Wenxuan,Sheng Lin,Cheng Mu-Jeng,Xu Bingjun,Luo Guangsheng,Lu Qi
The oxidative dehydrogenation of propane, primarily sourced from shale gas, holds promise in meeting the surging global demand for propylene. However, this process necessitates high operating temperatures, which amplifies safety concerns in its application due to the use of mixed propane and oxygen. Moreover, these elevated temperatures may heighten the risk of overoxidation, leading to carbon dioxide formation. Here we introduce a microchannel reaction system designed for the oxidative dehydrogenation of propane within an aqueous environment, enabling highly selective and active propylene production at room temperature and ambient pressure with mitigated safety risks. A propylene selectivity of over 92% and production rate of 19.57 mmol m Cu −2 h −1 are simultaneously achieved. This exceptional performance stems from the in situ creation of a highly active, oxygen-containing Cu catalytic surface for propane activation, and the enhanced propane transfer via an enlarged gas-liquid interfacial area and a reduced diffusion path by establishing a gas-liquid Taylor flow using a custom-made T-junction microdevice. This microchannel reaction system offers an appealing approach to accelerate gas-liquid-solid reactions limited by the solubility of gaseous reactant.
研究领域:
化学工程
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催化
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微反应器技术
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气液固反应
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产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2017
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IF 2.895
Rong Chen,Hao Feng,Xun Zhu,Qiang Liao,Dingding Ye,Jian Liu,Ming Liu,Gang Chen,Kun Wang
Visualization study on the interaction of the Taylor flow behavior and the catalytic activity in a gas-liquid-solid microreactor for nitrobenzene hydrogenation was performed under the long-term operation. The results showed that the gas slug length was first declined rapidly due to hydrogen consumption and then almost unchanged along the flow direction. After operating with a few hours, the variation of the gas slug length became obscure at the upstream due to the nanocatalyst deactivation but obvious at the downstream. Finally, the gas slug length was nearly unchanged. Corresponding to the long-term operation, the nitrobenzene conversion was first kept stable and then gradually declined, which well responded to the flow behaviors. Besides, effects of the inlet nitrobenzene concentration and flow rates on the flow behaviors were also explored. This work reveals the inherent interaction between the Taylor flow behavior and catalytic reaction under the long-term operation.
研究领域:
化学工程
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催化
·
微流控
✓ 已验证
产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2023
·
IF 4.2
Zhenbin Xu,Tingting Wang,Jianmeng Wu,Lulu Wang,Xiangping Zhang,Haifeng Dong,Changyu Sun
In this paper, the two-phase flow and mass transfer process of CO2 and [C2OHmim][Lys]/MDEA mixed aqueous solution in a T-shaped microchannel were investigated systematically. By using a high-speed camera connected to a computer, the two-phase flow patterns were recorded online, including the Taylor flow and a small amount of Taylor-bubbly flow. And the effects of ionic liquid concentration and two-phase flow ratio (QG/QL) on bubble length, specific surface area, gas holdup, and mass transfer coefficient were studied experimentally. The results indicate that the blended solution of [C2OHmim][Lys]/MDEA could significantly enhance two-phase mass transfer compared to single N-methyldiethanolamine aqueous solution. The reaction mechanism between CO2 and ionic liquid/amine mixed aqueous solution was also analyzed. On the basis of experimental data, some new correlations for predicting the bubble initial length and the volumetric mass transfer coefficient were proposed, which matched well with the experimental data. This work is helpful to provide new ideas for the design of CO2 absorbents and further improve the data of gas–liquid mass transfer in microchannels.
研究领域:
化学工程
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环境科学
·
微流控
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）