ENERGY
·
2020
·
IF 6.082
Xiaoya Zang,Xuebing Zhou,Lihua Wan,Jing Wang,Deqing Liang
Cyclopentane (CP) is an alkane that combines with water to form hydrates. Here, we investigate the hydrate thermal dynamics and formation kinetics of a synthesized ternary gas mixture of CH 4 /CO 2 /N 2 with CP additives. The results indicated that CP shifts the phase equilibrium conditions of ternary gas mixture hydrates to higher temperature and lower pressure. Under a constant pressure, the largest temperature offset can be approximately 20 K. Meanwhile, the ternary gas mixture of CH 4 /CO 2 /N 2 formed structure II hydrates with added CP. The kinetics study indicated that the hydrate reaction started immediately when accompanied by stirring. The consumption of CO 2 gas was greater than that of CH 4 and N 2 . The ratio of the volume of CP to the volume of water had a considerable influence on the effective reaction time, CH 4 recovery factor (R CH4 ), and CO 2 split ratio (S CO2 ) under all experimental conditions. R CH4 and S CO2 were higher when the CP-to-water volume ratio was 0.308. The largest values of R CH4 and S CO2 were 3.098 and 0.908, respectively, when the CP-to-water volume ratio was 0.308 at 7.0 MPa and 280.1 K. These results favor the use of CP as an additive to separate CO 2 and purify CH 4 in gas mixtures.
研究领域:
化学工程
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
Energies
·
2023
·Vol. 16
·期 12
·4681
·
IF 3.2
Xianbing Hu,Lingjie Sun,Chengyang Yuan,Man Li,Hongsheng Dong,Lunxiang Zhang,Lei Yang,Jiafei Zhao,Yongchen Song
The separation of azeotropic mixtures has conventionally been one of the most challenging tasks in industrial processes due to the fact that components in the mixture will undergo gas–liquid phase transition at the same time. We proposed a method for separating azeotropes using hydrate formation as a solid–liquid phase transition. The feasibility of hydrate-based separation is determined by analyzing the crystal structure and chemical bonds of hydrate. Taking the azeotrope cyclopentane and neohexane in petroleum as an example, cyclopentane (95%) was purified to 98.56% yield using the proposed hydrate-based cyclopentane purification technology. However, this is difficult to achieve using conventional distillation methods. The proposed method is simple in operation and yields a good separation effect. This study provides a new method for separating cyclopentane and neohexane.Keywords:azeotrope;cyclopentane;neohexane;hydrate;phase transition
研究领域:
化学工程
·
石油化工
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2021
·
IF 5.909
Yamei Yang,Rui Du,Changrui Shi,Jiafei Zhao,Yongchen Song,Lunxiang Zhang,Zheng Ling
With the rapid development of agriculture, controlling phosphorus emissions is a pressing challenge for preventing water eutrophication . A graphite-promoted cyclopentane (CP) hydrate-based desalination was proposed to remove K 3 PO 4 from effluents. It was found via the in situ optical microscopy that the reaction temperature and the concentration of feeding K 3 PO 4 solution significantly affect the morphologies and amount of the as-produced CP hydrate crystals. The lower reaction temperature produces more crystals with irregular shapes, while fewer crystals formed in K 3 PO 4 solution with higher concentration. The reaction temperature, time and feeding concentration-dependent desalination and salt enrichment performances were studied. It was found that desalination efficiency linearly increases with the elevated reaction temperature ranging from − 2 °C to 3 °C; however, water recovery declines with temperature. The temperature-dependent water recovery is due to the strong driving force for hydrate formation at low temperatures. The time-dependent water recovery shows a three-stage feature, including exponential growth, linear increase, and stable stages, owing to the interaction between the driving force of supercooling and the increasing K 3 PO 4 concentration during the reaction processes. The desalination efficiency shows an inverted volcanic shape with the increased concentration of feeding K 3 PO 4 solution. The pre-melting effect plays a critical role in improving desalination efficiency at high K 3 PO 4 concentrations. A maximum desalination efficiency of 85.0% was reached for treating an artificial solution with salinity as high as 42452 mg/L. Both desalted water and concentrated phosphorus-containing solution can be recovered by this method, which is attractive for producing freshwater with potential for recovery of resources.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
DESALINATION
·
2017
·
IF 5.527
Yi-Ning Lv,Shan-Shan Wang,Chang-Yu Sun,Jing Gong,Guang-Jin Chen
To make application of hydrate based desalination technology practical, the kinetic behaviors and separation capability were examined for cyclopentane hydrates formed from brine in cyclopentane dispersion systems at 274.1 K/277.1 K with initial salinity of 3 to 5 wt% for water fractions from 20.0 to 90.0 vol% and rpms from 300 to 500. The excess cyclopentane addition into brine and cyclopentane dispersion significantly increased the yield of dissociated water when the removal efficiency stayed around 80%. This implies enhanced kinetics and controlled encapsulation of residual brine into the hydrate phase for brine in cyclopentane dispersion systems. More hydrates formed under lower temperature or initial salinity. Higher rpm could further promote hydrate formation but would adversely affect the removal efficiency. Desalination efficiency was enhanced with washing during vacuum filtration and effects of ratio of washing water/dissociated water on the removal efficiency were considerable. An inverse correlation exists between the removal efficiency and the yield of dissociated water under the same conditions. Lower temperature (274.1 K) and 60% water cut should be optimal for higher yield of dissociated water from brine in cyclopentane dispersion. The ratio of washing water/dissociated water and rpm conditions should be adjusted depending on the situation.
研究领域:
化学工程
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2025
·
IF 2.1
Wenyu Li,Kexin Ren,Hongyu He,Zhao Lei,Yuhang Chen,Maogang He,Ying Zhang
Cyclopentane is an excellent working fluid in high-temperature organic Rankine cycle (ORC) systems. Currently, experimental measurements of the speed of sound in cyclopentane at temperatures above 353 K are not available in the literature. In this study, the speed of sound in cyclopentane is measured by the Rayleigh–Brillouin scattering method. Using the existing experimental equipment, the data are measured along six isobaric lines from 2.0 to 10.0 MPa at a temperature range of 349.40 to 525.97 K. The expanded relative uncertainty of the speed of sound measured in this experiment can be estimated to be 0.86% with the confidence level of 0.95 (coverage factor k = 2). The average absolute relative deviation (AARD) between our experimental data and calculated values with the equation of state (EOS) proposed as mentioned in this paper in the liquid-phase region is 0.99%, which confirms the effectiveness of the experimental results and the accuracy of the EOS. Furthermore, the data on the speed of sound from experimental results and the literature for cyclopentane are also fitted into a correlation formula related to the temperature and pressure, facilitating engineering applications.
研究领域:
热力学
·
工程热物理
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2025
·
IF 7.5
Yang Liu,Peilong Li,Yan Zhang,Xiaofang Lv,Yisong Yu,Qianli Ma,Chuanshuo Wang,Xiaoyan Li,Shidong Zhou,Bingcai Sun
Addressing the blockage issues arising from hydrate formation and aggregation in complex multiphase systems has long been a significant focus in the field of flow assurance for oil and gas pipelines. There is an urgent need to develop and identify cost-effective, efficient, and environmentally friendly hydrate anti-agglomerants. A micro-mechanical force device and a rheometer were employed to investigate the anti-agglomeration effects of Span80 and amide-based surfactants (DPLA and DPCA) in gas–water and oil–water systems. The results indicated that in the gas–water system, compared to the surfactant-free system, the addition of varying concentrations of surfactants lead to a reduction in cohesive force of hydrate particles by 70.39 % to 84.10 % (1 wt% Span 80). The amide-based surfactant, DPLA, reaches a maximum reduction of 82.38 % (from 21.51 ± 0.78 mN/m to 3.79 ± 0.29 mN/m) with a concentration of 0.5 wt%. The cohesive force between hydrate particles and wall droplets was reduced by 40.35 % to 54.59 %, with the maximum reduction of 54.59 % (from 484.28 ± 26.28 mN/m to 219.88 ± 21.36 mN/m at 0.3 wt% DPCA). Compared to Span80, amide-based surfactants demonstrated similarly excellent performance in reducing cohesive forces. Considering the significant changes in the surface morphology of hydrate particles upon the addition of surfactants, this study also revealed a strong positive correlation between both liquid bridge width and circularity with cohesive force (r 1 = 0.8233, r 2 = 0.6066), while surface roughness exhibited a weak negative correlation (r 3 = − 0.3821). In the oil–water system, although the critical time for hydrate formation in DPLA or DPCA-containing emulsions was markedly shortened compared to the base emulsion, both peak viscosity and steady viscosity of hydrate slurries were significantly reduced at medium to high concentrations of DPLA or DPCA. The maximum reductions in steady viscosity and peak viscosity for the DPLA-containing system were 93.94 % (0.6 wt%) and 78.59 % (0.4 wt%), respectively, while for the DPCA system, they were 89.55 % (0.8 wt%) and 55.95 % (0.8 wt%). Although DPCA and DPLA promoted hydrate formation, they still demonstrated excellent anti-agglomeration efficacy and potential for synergistic effects. The anti-agglomeration capability of DPCA was slightly weaker than that of DPLA, with both exhibiting comparable effects at medium to high concentrations.
研究领域:
石油工程
·
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2023
·
IF 7.4
Hao-Yang Li,Xiao-Sen Li,Yi-Song Yu,Zhao-Yang Chen
The morphologies of methane (CH 4 ) hydrate formation in the system containing different mole ratios of tetrahydrofuran (THF) and cyclopentane (CP) at two different temperatures are systematically studied in this work. The results showed that for all cases conducted at 274.2 K, a hydrate film quickly covers the entire interface between the oil (CP) and the THF solution phase after gas loading, and then a hydrate layer forms, thereby significantly decreasing the following gas-liquids mass transfer efficiency. Raman spectrum shows this hydrate layer is caused mainly by pure THF hydrate. Interestingly, as the temperature increase to 278.2 K, the hydrate layer breaks. This is because, after hydrate layer formation, hydrate still grows at the contact interface of the metal, gas, and liquid phase, and then moves upward. In this process, liquids are gradually transported to the reaction front to form hydrate by capillary force and the hydrate layer’s downward curvature gradually increases as the consumption of liquid until rupture. Besides, typical reaction kinetics shows that there are three stages of hydrate formation in the THF + CP + CH 4 system at 278.2 K. (1) hydrate layer formation (pure THF hydrate formation); (2) CP-CH 4 hydrate formation; (3) large amount of THF-CH 4 hydrate formation (after hydrate layer rupture). Further, this work also confirmed that after the hydrate layer rupture, the CH 4 occupancy in 5 12 cages of sII at the same temperature and promoter’s mole fractions is independent of the type of promoters (CP, THF, and CP + THF) used in the system.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS COMMUNICATIONS
·
2017
·
IF 3.33
Xi Zheng,Jiping Ma,Min Wang,Song Shi,Zhiqiang Sun,Jie Xu
Coupling reaction of cyclohexyl hydroperoxide (CHHP) decomposition and cyclohexane oxidation in the process of catalytic decomposition of CHHP was identified via cyclopentane instead of cyclohexane used as solvent. A method was established to evaluate this coupling reaction. Based on this method, it can be accurately distinguished the product of cyclohexanol and cyclohexanone (K/A oil) derived from whether decomposition of CHHP or oxidation of cyclohexane. The established method is of great significance to the further study of the coupling reaction.
研究领域:
化学工程
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Heliyon
·
2024
·
IF 3.4
Quang Nhat Tran,Nhi Ngoc Thi Vo,Thao Thi Pham,Hai Son Truong-Lam
Freshwater scarcity is a critical issue in Vietnam, particularly in the Mekong Delta, a densely populated region with an agriculture-based economy. This scarcity is largely driven by saltwater intrusion during the dry season, severely affecting both agriculture and the local economy. In response, advanced desalination technologies have been proposed. In this study, we investigated the use of cyclopentane (CP), a liquid guest molecule, and 1,1,1,2-tetrafluoroethane (R134a), a gaseous guest molecule, as hydrate formers to desalinate saline water from the Mekong Delta. This study aimed to evaluate and compare the freshwater recovery efficiencies of these hydrate formers and assess the potential of hydrate technology for practical application in the region. We performed thermodynamic and kinetic investigations on sodium chloride solutions (1.0–3.5 wt%), representing the salinity levels of seawater in the Mekong Delta, to establish a laboratory-scale desalination system. The results showed a consistent thermodynamic trend: the higher concentration of samples leads to the longer time of hydrate formation to achieve the conversion of water into hydrates exceeding 60 %. Additionally, the CP and R134a hydrate structures were characterized using Raman spectroscopy, which revealed significant changes in the water peak and C–H band signal during the hydrate formation process. After a single-stage hydrate treatment using CP and R134a, the removal efficiencies for ions and total dissolved solids in saline water samples from the Mekong Delta exceeded 75 % and 70 %, respectively. These findings serve as a reference for developing a larger-scale hydrate-based desalination technology to address the challenges of saltwater intrusion in the Mekong Delta region.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
MOLECULES
·
2023
·Vol. 28
·期 6
·2444
·
IF 4.6
Yan Wang,Peng Dou,Xiaofeng You,Qing Liu,Zhaoyang Fei,Xian Chen,Zhuxiu Zhang,Jihai Tang,Mifen Cui,Xu Qiao
Resins have enormous potential in the removal of naphthenic acids (NAs) from transformer oil due to their rich porosity and high mechanical and diversified functionality, whereas their poor adsorption capacity limits application. In this work, the polystyrene–diethylamine resin (PS−DEA−x) was prepared by grafting diethylamine (DEA) onto chloromethylated polystyrene (PS−Cl) resin to efficiently adsorb cyclopentane carboxylic acid from transformer oil for the first time. The characterization analysis results indicated that amine contents were significantly enhanced with the increase in DEA. Particularly, resin with a molar ratio of 1:5 depending on chloromethyl to DEA (PS−DEA−5) exhibited the highest amine contents and efficient adsorption of cyclopentane carboxylic acid (static adsorption capacity up to 110.0 mg/g), which was about 5 times higher than that of the pristine PS−Cl. The thermodynamic and kinetic studies showed that the adsorption behaviors could be well fitted to the Langmuir isotherm equation and pseudo−second−order rate equation. Moreover, it was found that 1 g of the PS−DEA−5 can decontaminate about 760 mL transformer oil to meet reuse standards by a continuous stream, indicating its potential application in industry.Keywords:resin;diethylamine;chemical modification;cyclopentane carboxylic acid;transformer oil purification
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Huang Liu,Siyuan Zhan,Ruijing Li,Yong Liu,Ping Guo,Zhouhua Wang,Jianfen Du,Yunfan Wen,Panxiang Dai,Haoqi Liao
This study proposes a high-efficiency natural gas hydrate (NGH) storage method involving the formation of NGH in a water/oil emulsion with the addition of suitable thermodynamic additives. First, the CH 4 hydrate formation conditions in a water/diesel emulsion with the addition of hydrate thermodynamic additives, including tetrabutylammonium bromide (TBAB), tetrahydrofuran (THF), and cyclopentane (CP), were measured for the first time. Interestingly, in contrast to the case of the aqueous solution, both the TBAB and THF could not promote the formation of CH 4 hydrate in the water/diesel emulsion, and they exhibited a hydration inhibition effect. The CP substantially reduced the CH 4 hydrate formation pressure in the water/diesel emulsion, and the resulting hydrate/diesel slurry exhibited good fluidity. The CH 4 storage characteristics of the water/diesel-CP emulsion under hydrate formation conditions were systematically studied. At 276.15 K and 6 MPa, for a water/diesel-CP emulsion containing 30 wt% water cut, the CH 4 storage volume ( S ) per unit volume water in the emulsion reached 152.32 m 3 /m 3 , with the hydrartion reaction rate was 2.27 mmol/min, which was significantly higher than that for pure water, a water-CP solution, and a single water/diesel emulsion. S increased to 163.6 when the water cut decreased to 20 wt%; the entire experimental process lasted 90 min. An increase in the temperature from 274.15 to 282.15 K had a limited influence on S , indicating the wide range of application conditions of the water/diesel-CP emulsion for the production of NGH crystals. Furthermore, in situ particle video microscope observations and focused beam reflectance measurements confirmed the good flowability of the formed CH 4 hydrate/diesel slurry. Continuous production of NGHs can theoretically be achieved using the water/diesel-CP emulsion.
研究领域:
化学工程
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2021
·
IF 3.178
Feifan Niu,Yuanmeng Liu,Xiaoning Wang,Xunqiu Wang
Isobaric vapor–liquid equilibrium (VLE) data for the binary system of (methylcyclopentane + methylcyclohexane) and the ternary system of (methylcyclopentane + cyclohexane + methylcyclohexane) were measured at 101.3 kPa with a dynamic recirculating apparatue, and the temperature ranged from 344.79 to 373.85 K, and the thermodynamic consistency of the experimental date was checked by the Herington area method and Van Ness method. The experimental date was correlated with NRTL, Wilson and UNIQUAC activity coefficient models. The binary VLE date predicted by the binary interaction parameters agreed well with the experimental and literature data. Then, Aspen plus V11 software was used to establish batch distillation model simulation calculation. The experimental results show that the products separated by the batch distillation model meet the requirements. Finally, two sets of 1300 kg/hr separation process were designed and the process was optimized. The energy consumption of scheme I was slightly less than scheme II.
研究领域:
化学工程
·
热力学
✓ 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）