PHYSICS OF FLUIDS
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2023
·Vol. 35
·期 3
·
IF 4.6
Rong Feng,He Limin,Lǚ Yuling,Lu Xiaolei
To investigate the force model and motion law of oil droplets in water near the wetted wall, oil droplets with R 1 = 0.29–0.62 mm and oil films with R 2 = 1–6 mm are solved numerically. In addition to buoyancy, flow resistance, and added mass force, the film-induced force triggered by the wetted wall constraint is also introduced into the force model. The drainage process is described using the Stokes–Reynolds equation, and the Young–Laplace equation is used to calculate the pressure within the water film. The results show that the force model can be coupled with the Stokes–Reynolds–Young–Laplace model equation to better describe the drainage dynamics near the wetted wall. The pressure distribution law is closely related to the shape of the water film, especially when the oil–water interface is in the shape of a dimple, which can lead to the formation of negative pressure zones within the water film. The maximum pressure first grows in an exponential, then logarithmic pattern and eventually approaches the equivalent Laplace pressure. Around the critical size, the direction of the film-induced force changes and the form of action switches between driving and drag forces. The film-induced force's dominant effect is strongest when the curvature radius of the oil film is comparable to the droplet size.
研究领域:
流体力学
·
界面化学
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2024
·
IF 5.2
Yitai Wang,Yinge Bai,Fukang Song,Shaojuan Zeng,Lulu Wang,Xiangping Zhang
Ionic liquids (ILs)-based solvent absorption is a promising green and low regenerative energy consumption technology for CO2 capture. Various functionalized ILs with highly efficient performance have been developed in academia, and the research focuses on thermodynamic properties such as CO2 solubility, gas–liquid equilibrium, and reaction heat. Kinetic studies of CO2 in ILs are also important to evaluate their potential for industrial applications, which need to be studied further. In this work, the mass transfer characteristics of three azole-based IL anhydrous solvents were studied in a wetted-wall column (WWC). At 313.15 K, the total mass transfer coefficient (KG) of fresh [HDBU][Im]/EG, [Cho][Im]/EG, and [Cho][Triz]/EG was 5.40, 2.32, and 0.80 mmol/(m2·s·kPa), respectively. The KG of the three solvents increased along with increase in the temperature. Conversely, when the CO2 loading in the solvent increased, KG decreased. At the initial stage of absorption, the mass transfer resistance of [HDBU][Im]/EG was mainly in the gas phase and then gradually changed to liquid phase. However, due to the excessive viscosity of [Cho][Im]/EG and [Cho][Triz]/EG, the mass transfer resistance was mainly concentrated in the liquid phase. The enhancement factor (E) of [HDBU][Im]/EG was higher than 159, indicating that it had good chemical reaction ability, thereby improving the mass transfer ability. The KG of [HDBU][Im]/EG is 92.12, 307.01, and 117.48% higher than MEA/H2O, MDEA/PZ/H2O, and MEA/AEEA/H2O at 313.15 K, respectively. This work showed that [HDBU][Im]/EG had a good mass transfer performance and great potential in future industrial applications. At the same time, the mass transfer law was summarized to provide theoretical support for CO2 capture technology and reactor design.
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
International Journal of Greenhouse Gas Control
·
2017
·
IF 3.741
Lidong Wang,Shanlong An,Songhua Yu,Shihan Zhang,Yifeng Zhang,Meng Li,Qiangwei Li
CO 2 from coal-fired flue gas is one of the main components of greenhouse gases. Using phase change absorbents as a solvent can effectively decrease the consumption of regeneration energy for CO 2 capture process. This study employed a mixed solution of diethylenetriamine (DETA) and diethylaminoethanol (DEEA) as the new phase change absorbent for CO 2 absorption. The impact of the phase change behavior on the mass transfer characteristics of CO 2 absorption was investigated in a wetted-wall column. Effects of the temperatures, CO 2 loadings, and gas flow rate on the mass transfer coefficient were also conducted. The results indicated that temperature and CO 2 loading had relatively remarkable effects on the total mass transfer coefficient; whereas the gas flow rate had a smaller effect. Kinetic analysis revealed that the mass transfer resistance of CO 2 absorption into the DETA/DEEA phase change absorbent mainly concentrated at the liquid film side. The findings provide a theoretical reference for the development of new CO 2 phase change absorption technology .
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
ENERGY & FUELS
·
2016
·
IF 2.835
Shufeng Shen,Ya-nan Yang
The mass transfer and kinetics of CO2 absorption into aqueous potassium argininate (ArgK) solutions were investigated using a wetted-wall column at concentrations ranging from 0.26 to 1.23 M and temperatures from 298 to 333 K. Absorption rates of CO2 were compared by the absorption flux and a fall-in-pressure method among basic amino acid salts (AAS) and two amine standards for capture technology. Results showed that ArgK has comparable kinetics toward CO2 with the standard monoethanolamine (MEA) but lower kinetics than piperazine (PZ). The kinetic results were interpreted using two models based on zwitterion mechanism and termolecular mechanism for the reactive absorption of CO2. It was found that the partial reaction orders vary from 1.25 to 1.60 with respect to ArgK. Under the pseudo-first-order regime, the overall reaction rate constants were obtained and the individual reaction rate constants in these models were derived. The calculated values from two models agree well with the experimental data within 7.5% AAD.
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
ENERGY & FUELS
·
2016
·
IF 2.835
Qiangwei Li,Yi Wang,Shanlong An,Lidong Wang
Using a K2CO3/piperazine (PZ) mixture as a typical phase-change absorbent has promising applicability for carbon dioxide (CO2) capture in coal-fired power plants that would contribute to low energy consumption for solvent regeneration. In this study, the reaction rate of CO2 with a concentrated K2CO3/PZ mixture was measured in a wetted-wall column. At a CO2 loading close to saturation absorption, correlative physical parameters were calculated. The effects of operating conditions, including gas flow rate, slurry flow rate, PZ concentration, CO2 loading, K2CO3 mass fraction, and temperature, on the absorption rate of CO2 were investigated. The results showed that the absorption rate was sensitive to the effects of the gas flow rate and CO2 loading. The PZ concentration and K2CO3 mass fraction also substantially influenced the CO2 absorption rate. However, minor changes in the CO2 absorption rate were observed when the slurry flow rate and temperature were increased. On the basis of a pseudo-first-order model, the absorption rate determined in this study was found to be controlled by mass transfer in both the gas film and the liquid film. The results can serve as a useful reference for designing CO2 removal systems using K2CO3/PZ mixtures.
研究领域:
化学工程
·
环境科学
·
能源技术
·
气体分离
·
工业催化
✓ 已验证
DOI
高影响因子
Journal of Cleaner Production
·
2022
·
IF 11.072
Zhuang Cao,Lixian Zhao,Yabing Sun,Jingwei Feng
The pollution of water by antibiotics and heavy metals has attracted more and more attention of scholars. Enrofloxacin (EFA) is a typical third generation fluoroquinolone antibiotic , which is widely used in human activities. Hexavalent chromium has been a great threat to human health and ecosystem due to its high mobility, toxicity and carcinogenicity . In this study, EFA-Cr(VI) mixed solution was used as a typical antibiotic - heavy metal simulated wastewater. We used a uniaxial wet-wall dielectric barrier discharge plasma reactor to simultaneously transform Cr(VI) and remove EFA for the first time, and its universality in the degradation of heavy metal pollution caused by other antibiotics was explored, providing a new solution for the simultaneous rapid and efficient treatment of antibiotic and heavy metal-contaminated wastewater. Within 18 min, the presence of hexavalent chromium greatly increased the degradation rate of EFA from 65.1% to 94.6%. The removal rate of hexavalent chromium was increased from 63.9% to 98.3% by the presence of EFA. The effects of initial pollutant concentration , input voltage, gas velocity , liquid circulation velocity, pH, organic matter and heavy metal ions were also investigated in this study. Free radical scavenging experiments showed that •O 2 , - •OH and 1 O played an important role in the detoxification of EFA. The Cr(VI) conversion experiments showed that the EFA degradation intermediates, hydrogen peroxide and •H were the main factors of Cr(VI) reduction in the EFA co-degradation system. The degradation pathway was inferred based on the measured EFA intermediates. The developmental toxicity of EFA and its degradation products was quantitatively studied. The results showed that the toxicity of EFA wastewater was reduced after DBD treatment.
研究领域:
环境科学
·
废水处理
·
等离子体技术
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2016
·
IF 5.31
Lidong Wang,Shanlong An,Qiangwei Li,Songhua Yu,Siyu Wu
Coal-fired flue gas is a major source of greenhouse gas CO 2 . Phase-change absorbents can be used to reduce energy consumption associated with regeneration during CO 2 capture. In this study, N,N-dimethylbutylamine (DMBA) and N,N-dimethylbutylamine (DEEA) were mixed to develop phase-change absorbents, and the reaction kinetics of CO 2 absorption in the absorbents were examined. A bubbling device was used to prepare phase-change absorbents with different CO 2 loading levels. The physico-chemical parameters of the absorbents under different conditions were specified, and the changes in the CO 2 loading of the upper and lower layers of the absorption solutions after a liquid–liquid separation were analyzed. A wetted-wall column was subsequently used to investigate the effects of temperature, CO 2 loading, gas flow rate, and DMBA/DEEA composition ratio on CO 2 absorption rate. This study determined that the flow velocity, reaction temperature, and CO 2 loading affected the CO 2 absorption rates to a certain extent. In addition, comparing the reactive properties of the 4M DMBA + 2M DEEA and 2M DMBA + 4M DEEA absorbents under the same experimental conditions revealed that the 4M DMBA + 2M DEEA absorbent exhibited higher absorption rate and reaction stability. A kinetics model also indicated that the CO 2 absorption of the phase-change absorbents used in this study was mainly affected by the liquid film diffusion process. This study contributes theoretically to the development of CO 2 absorption technologies.
研究领域:
化学工程
·
环境科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
ENERGY & FUELS
·
2023
·
IF 5.3
Hong Yao,Houfang Lu,Kejing Wu,Yingming Zhu,Binshen Wang,Yingying Liu,Yijiao Qiu,Bin Liang
Biphasic solvent 3-dimethylaminopropylamine (DMAPA)/poly(ethylene glycol) dimethyl ether (NHD)/H2O solution is a promising absorbent for CO2 capture. The kinetics of CO2 absorption in both DMAPA/NHD/H2O system and DMAPA/H2O systems was investigated and compared in a wetted wall column reactor with different CO2 loadings at different CO2 partial pressures from 30 to 70 °C. The equilibrium CO2 loadings were also determined. Meanwhile, the density and viscosity for both systems were measured. In both systems, the mass transfer flux of CO2 increases linearly with the increase of CO2 partial pressure. The kinetic data were interpreted by the zwitterion mechanism. The overall mass transfer constant was determined according to the absorption rate experiments performed in the pseudo-first-order regime. The overall mass transfer resistances increase with the increase of CO2 loading and decrease with the increase of temperature. The addition of NHD decreases the equilibrium CO2 loadings at the same CO2 partial pressure and temperature. However, it increases the enhancement factor significantly and can promote both the absorption and the desorption process. It provides basic information not only for the further utilization of DMAPA/NHD/H2O solution, which is helpful for the design of absorption reactor, but also for developing new phase-change absorbents for CO2 capture.
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
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