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Integrated adsorption and absorption process for post-combustion CO

Gongkui Xiao, Penny Xiao, Andrew Hoadley, Paul Webley

《化学科学与工程前沿（英文）》 2021年第15卷第3期页码 483-492 doi: 10.1007/s11705-020-1964-3

摘要： This study explored the feasibility of integrating an adsorption and solvent scrubbing process for post-combustion CO capture from a coal-fired power plant. This integrated process has two stages: the first is a vacuum swing adsorption (VSA) process using activated carbon as the adsorbent, and the second stage is a solvent scrubber/stripper system using monoethanolamine (30 wt-%) as the solvent. The results showed that the adsorption process could enrich CO in the flue gas from 12 to 50 mol-% with a CO recovery of >90%, and the concentrated CO stream fed to the solvent scrubber had a significantly lower volumetric flowrate. The increased CO concentration and reduced feed flow to the absorption section resulted in significant reduction in the diameter of the solvent absorber, bringing the size of the absorber from uneconomically large to readily achievable domain. In addition, the VSA process could also remove most of the oxygen initially existed in the feed gas, alleviating the downstream corrosion and degradation problems in the absorption section. The findings in this work will reduce the technical risks associated with the state-of-the art solvent absorption technology for CO capture and thus accelerate the deployment of such technologies to reduce carbon emissions.

关键词： vacuum swing adsorption monoethanolamine post-combustion CO₂ capture integrated process

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Pressure swing adsorption/membrane hybrid processes for hydrogen purification with a high recovery

Baojun Li,Gaohong He,Xiaobin Jiang,Yan Dai,Xuehua Ruan

《化学科学与工程前沿（英文）》 2016年第10卷第2期页码 255-264 doi: 10.1007/s11705-016-1567-1

摘要： Hydrogen was recovered and purified from coal gasification-produced syngas using two kinds of hybrid processes: a pressure swing adsorption (PSA)-membrane system (a PSA unit followed by a membrane separation unit) and a membrane-PSA system (a membrane separation unit followed by a PSA unit). The PSA operational parameters were adjusted to control the product purity and the membrane operational parameters were adjusted to control the hydrogen recovery so that both a pure hydrogen product (>99.9%) and a high recovery (>90%) were obtained simultaneously. The hybrid hydrogen purification processes were simulated using HYSYS and the processes were evaluated in terms of hydrogen product purity and hydrogen recovery. For comparison, a PSA process and a membrane separation process were also used individually for hydrogen purification. Neither process alone produced high purity hydrogen with a high recovery. The PSA-membrane hybrid process produced hydrogen that was 99.98% pure with a recovery of 91.71%, whereas the membrane-PSA hybrid process produced hydrogen that was 99.99% pure with a recovery of 91.71%. The PSA-membrane hybrid process achieved higher total H recoveries than the membrane-PSA hybrid process under the same H recovery of membrane separation unit. Meanwhile, the membrane-PSA hybrid process achieved a higher total H recovery (97.06%) than PSA-membrane hybrid process (94.35%) at the same H concentration of PSA feed gas (62.57%).

关键词： hydrogen purification PSA membrane separation hybrid process

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Molecular size characterization of heavy oil fractions in vacuum and solution by molecular dynamic simulation

Wenpo REN, Honggang CHEN, Chaohe YANG, Honghong SHAN,

《化学科学与工程前沿（英文）》 2010年第4卷第3期页码 250-256 doi: 10.1007/s11705-009-0281-7

摘要： Two kinds of heavy oils were fractionated into eight fractions by Liquid-Solid Adsorption Chromatography, respectively, and samples were collected to measure properties. According to the elemental analysis, molecular weight and H-NMR data, average molecular structures of polycyclic aromatic and heavy resin were constructed with improved Brown-Ladner (B-L) method and several corrections. And then, the most stable conformations of polycyclic aromatic and heavy resin in vacuum and toluene solution were obtained by molecular dynamic simulation, and the molecular size was gotten via the radius of gyration analysis. The results showed that the radius of gyration of polycyclic aromatic and heavy resin was 0.55–0.70 nm in vacuum and 0.60–0.90 nm in toluene solution. With molecular weight increasing, the molecular size in vacuum and toluene solution also increased. Due to the swelling behavior of solvent, the alkyl side chains of heavy oil molecule in solution were more stretched. Thus, the molecular size in toluene solution was larger than that in vacuum.

关键词： dynamic simulation molecular dynamic behavior molecule Adsorption Chromatography

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Structural optimal design of a swing vane compressor

Junjie MA,Xiang CHEN,Zongchang QU

《能源前沿（英文）》 2019年第13卷第4期页码 764-769 doi: 10.1007/s11708-016-0449-z

摘要： In this paper, a novel swing vane rotary compressor (SVC) was introduced, which had significant advantages—simple mechanism, reduced frictional loss, reliable operation, and a comparatively higher compression ratio. Based on the swing vane compressor geometry model, thermodynamic model and kinetic model, the mathematical model of optimum design was established, and further theoretical and experimental studies were conducted. The length of the cylinder, radius of the rotor and cylinder were defined as design variables and the reciprocal of EER as objective function. The complex optimization method was adopted to study the structure of the swing vane compressor. The theoretical model could provide an effective method for predicting compressor performance, which would also contribute to structural optimization of the SVC. The study shows that the friction loss of the compressor are greatly reduced by optimized design in a given initial value, and the EER increased by 8.55%.

关键词： swing vane compressor simulation optimization design

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Bioenergy recovery from landfill gas: A case study in China

Wei WANG, Yuxiang LUO, Zhou DENG

《环境科学与工程前沿（英文）》 2009年第3卷第1期页码 20-31 doi: 10.1007/s11783-009-0012-9

摘要： Landfill gas (LFG) utilization which means a synergy between environmental protection and bioenergy recovery was investigated in this study. Pressure swing adsorption technology was used in LFG purification, and laboratory experiment, pilot-scale test, and on-site demonstration were carried out in Shenzhen, China. In the laboratory experiment, A-type carbon molecular sieve was selected as the adsorbent by comparison of several other adsorbents. The optimal adsorption pressure and adsorption time were 0.25 MPa and 2 min, respectively, under which the product generation rate was 4.5 m /h and the methane concentration was above 90%. The process and optimization of the pilot-scale test were also reported in the paper. The product gas was of high quality compared with the National Standard of Compressed Natural Gas as Vehicle Fuel (GB18047-2000), when the air concentration in feed gas was under 10.96%. The demonstration project was composed of a collection system, production system, and utilization system. The drive performance, environmental protection performance, and economic feasibility of the product gas – as alternative fuel in passenger car, truck, and bulldozer – were tested, showing the feasibility technology for LFG utilization.

关键词： landfill gas (LFG) compressed purified landfill gas (CPLG) pressure swing adsorption (PSA) alternative vehicle fuel demonstration project

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Lateral displacement of soft ground under vacuum pressure and surcharge load

Chin-Yee ONG, Jin-Chun CHAI

《结构与土木工程前沿（英文）》 2011年第5卷第2期页码 239-248 doi: 10.1007/s11709-011-0110-1

摘要： Surcharge load (e.g. embankment fill) will induce settlement and outward lateral displacement, while vacuum pressure will induce settlement and inward lateral displacement of a ground. Ideally, combination of surcharge load and vacuum pressure can reduce or minimize the lateral displacement. Laboratory large scale model (length: 1.50 m, width: ~0.62 m, height: 0.85 m) tests and finite element analyses (FEA) were conducted to investigate the main influencing factors on lateral displacement of a soft clayey ground under the combination of vacuum pressure and surcharge load. For the conditions investigated, the results indicate that the outward lateral displacement increases with the increase of the ratio of surcharge load to vacuum pressure ( ) and the loading rate of the surcharge load ( ). Also, it is shown that for a given and condition, lateral displacement reduces with the increase of the initial undrained shear strength ( ) of the ground. To predict the lateral displacement of a ground under the combination of surcharge load and vacuum pressure, the loading conditions in terms of and , and value of the ground have to be considered.

关键词： vacuum consolidation lateral displacement PVD finite element analysis surcharge load

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Numerical study of conduction and radiation heat losses from vacuum annulus in parabolic trough receivers

Dongqiang LEI, Yucong REN, Zhifeng WANG

《能源前沿（英文）》 2022年第16卷第6期页码 1048-1059 doi: 10.1007/s11708-020-0670-7

摘要： Parabolic trough receiver is a key component to convert solar energy into thermal energy in the parabolic trough solar system. The heat loss of the receiver has an important influence on the thermal efficiency and the operating cost of the power station. In this paper, conduction and radiation heat losses are analyzed respectively to identify the heat loss mechanism of the receiver. A 2-D heat transfer model is established by using the direct simulation Monte Carlo method for rarefied gas flow and heat transfer within the annulus of the receiver to predict the conduction heat loss caused by residual gases. The numerical results conform to the experimental results, and show the temperature of the glass envelope and heat loss for various conditions in detail. The effects of annulus pressure, gas species, temperature of heat transfer fluid, and annulus size on the conduction and radiation heat losses are systematically analyzed. Besides, the main factors that cause heat loss are analyzed, providing a theoretical basis for guiding the improvement of receiver, as well as the operation and maintenance strategy to reduce heat loss.

关键词： parabolic trough receiver vacuum annulus rarefied gas DSMC (direct simulation Monte Carlo) heat loss

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活塞驱动变压吸附反应器的模型化

胡鸣,周兴贵,顾峥,袁渭康

《中国工程科学》 2001年第3卷第12期页码 52-57

摘要：

建立了活塞驱动的快速变压吸附反应器模型，根据气缸与床层相通时压力、浓度和流率的连续性要求，提出了模型的边界条件。以2A↔B+C为反应体系，其中C为易吸附组分，A、B为不吸附组分，利用动态模拟软件gPROMS模拟考察了反应器长度、周期长度、活塞运动速率、产品收集速率和基础压力对反应性能和分离性能的影响。

关键词：变压吸附反应器变压吸附多功能反应器动态模拟

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interconnected nano-channels into polyvinylidene fluoride membranes for desalination applications by vacuum

《化学科学与工程前沿（英文）》 2023年第17卷第9期页码 1162-1182 doi: 10.1007/s11705-022-2276-6

摘要： In the present research, for the first time, lycopodium as a novel nanofiller was incorporated into a polyvinylidene fluoride matrix to fabricate lycopodium/polyvinylidene fluoride flat-sheet membrane for desalination applications by vacuum membrane distillation process. The prepared lycopodium/polyvinylidene fluoride membranes and lycopodium were characterized by field emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared, energy dispersive X-ray, and mapping analyses. Water contact angle and liquid entry pressure measurements were also performed. Response surface methodology was applied to optimize membrane structure and performance. The optimized lycopodium/polyvinylidene fluoride membrane exhibits superior performance compared to the neat polyvinylidene fluoride membrane in terms of flux, salt rejection, water contact angle, and hydrophobicity. In vacuum membrane distillation experiments, using a 15000 ppm NaCl solution as a feed at 70 °C, the neat polyvinylidene fluoride membrane, optimum membrane, and agglomerated membrane (with high lycopodium loading) demonstrated 3.80, 25.20, and 14.83 LMH flux and 63.30%, 99.99%, 99.96% salt rejection, respectively. This improvement in flux and salt rejection of the optimized membrane was related to the presence of lycopodium with hydrophobic nature and interconnected nano-channels in membrane structure. It was found that lycopodium, as the most hydrophobic material, effectively influences the membrane performance and structure for membrane distillation applications.

关键词： lycopodium hydrophobicity vacuum membrane distillation desalination

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Novel methods by using non-vacuum insulated tubing to extend the lifetime of the tubing

Chenglong ZHOU,Guojin ZHU,Yongxiang XU,Jifei YU,Xiaoliang ZHANG,Hongzhi SHENG

《能源前沿（英文）》 2015年第9卷第2期页码 142-147 doi: 10.1007/s11708-015-0357-7

摘要： The analysis of the failure mechanics, namely hydrogen permeation of vacuum insulated tubing (VIT), indicated that the failure of VIT could be decreased but could not be avoided. To solve this problem, some measures by using non-vacuum materials were proposed and analyzed in this paper. The results show that to fill the tubing with foam-glass beads or high pressure argon may lead to a good performance.

关键词： vacuum insulated tubing cyclic steam stimulation insulation material thermal conductivity foam-glass hydrogen permeation

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Toward better understanding vacuum ultraviolet–iodide induced photolysis via hydrogen peroxide formation

《环境科学与工程前沿（英文）》 2022年第16卷第5期 doi: 10.1007/s11783-021-1489-0

摘要：

• UV/VUV/I^– induces substantial H₂O₂ and IO₃^– formation, but UV/I^– does not.

关键词： Vacuum ultraviolet Hydrogen peroxide Iodate Hydroxyl radical Redox transition

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高频真空木材干燥的模糊神经网络控制方法研究

姜滨,孙丽萍,曹军,周正

《中国工程科学》 2014年第16卷第4期页码 17-20

摘要：

高频真空木材干燥是一种干燥速度快、能源消耗低、环境污染小的新型联合干燥技术。在木材高频真空联合干燥过程的理论分析基础上，针对神经网络方法建立的木材干燥模型，设计了木材干燥模糊控制器和模糊神经网络控制器。对模糊控制和模糊神经网络两种控制方法进行了仿真实验，结果表明模糊神经网络方法控制效果更好，如温度上升快，控制精度高，稳定性好。模糊神经网络控制方法对实现木材干燥过程的全自动控制具有重要研究意义。

关键词：高频真空木材干燥模糊神经网络

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Enhancement of distillate output of double basin solar still with vacuum tubes

Hitesh N PANCHAL, P K SHAH

《能源前沿（英文）》 2014年第8卷第1期页码 101-109 doi: 10.1007/s11708-014-0299-5

摘要： The latent heat of condensation is lost to the atmosphere; hence it is not utilized to increase distillate output of single basin solar stills. This difficulty was overcome by attaching an additional basin to the main basin. The performance of the double basin solar still was also increased by attaching vacuum tubes to the lower basin; hence the lower basin possessed a higher temperature throughout the day. The latent heat of condensation of the bottom basin was also utilized to increase distillate. But the distillate output of the top basin was even lower compared with that of the bottom basin. This paper proposed a novel approach to increase the distillate output of the double basin solar still attached with vacuum tubes by introducing different sensible energy storage materials like pebbles, black granite gravel and calcium stones to increase the basin area. Experiments were conducted in climate conditions of Mehsana (23.6000° N, 72.4000° E) Gujarat from April to September 2013 with a constant water depth of 2 cm in the top basin with and without the use of basin materials. The results showed that the distillate output of basin material with calcium stones is greater (74%) compared with that of black granite gravel and pebbles. The integration of vacuum tubes with solar still greatly increases the distillate output of the solar still by providing hot water at the lower basin.

关键词： double basin solar still calcium stones pebbles granite gravel distillate output

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低真空管道高速磁悬浮系统技术发展研究

冯仲伟,方兴,李红梅,程爱君,潘永杰

《中国工程科学》 2018年第20卷第6期页码 105-111 doi: 10.15302/J-SSCAE-2018.06.017

摘要：

轮轨式是目前轨道交通技术体系的主流，但由于空气阻力、轮轨黏着、运行噪声等问题的限制，在现有的技术水平下，难以经济地实现运营速度大幅度提高。为满足更高经济运行速度的需求，在利用磁悬浮技术减少轮轨摩擦、振动的基础上，构建低真空运行环境以减小空气阻力和噪声是未来更高速度轨道交通技术发展的重要方向。本文阐述了发展低真空管道高速磁悬浮系统的意义，研究了其技术特点、发展现状，分析了低真空管道高速磁悬浮系统的科学问题和关键技术，并提出了在国家层面立项研究、建设试验线和国家级实验室的政策建议。

关键词：轨道交通低真空管道高速磁悬浮系统技术

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Vacuum promotes metabolic shifts and increases biogenic hydrogen production in dark fermentation systems

Haifa RAJHI,Daniel PUYOL,Mirna C. MARTÍNEZ,Emiliano E. DÍAZ,José L. SANZ

《环境科学与工程前沿（英文）》 2016年第10卷第3期页码 513-521 doi: 10.1007/s11783-015-0777-y

摘要： The successful operation of any type of hydrogen-producing bioreactor depends on the performance of the microorganisms present in the system. Both substrate and partial gas pressures are crucial factors affecting dark fermentation metabolic pathways. The main objective of this study was to evaluate the impact of both factors on hydrogen production using anaerobic granular sludge as inoculum and, secondly, to study the metabolic shifts of an anaerobic community subjected to low partial gas pressures. With this goal in mind, seven different wastewater (four synthetic media, two industrial wastewater, and one domestic effluent) and the effect of applying vacuum on the systems were analyzed. The application of vacuum promoted an increase in the diversity of hydrogen-producing bacteria, such as , and promoted the dominance of acetoclastic- over hydrogenotrophic methanogens. The application of different media promoted a wide variety of metabolic pathways. Nevertheless, reduction of the hydrogen partial pressure by application of vacuum lead to further oxidation of reaction intermediates irrespective of the medium used, which resulted in higher hydrogen and methane production, and improved the COD removal. Interestingly, vacuum greatly promoted biogenic hydrogen production from a real wastewater, which opens possibilities for future application of dark fermentation systems to enhance biohydrogen yields.

关键词： dark fermentation biohydrogen wastewaters vacuum