Energies
·
2023
·Vol. 16
·期 13
·5112
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IF 3.2
Jinlin Liu,Yu Wang,Zilong Zhong,Zhou Zhou,Dongliang Chen,Weijie Wang,Shuaixing Mai
Air-conditioning systems account for 40–60% of the energy consumption of buildings, and most of this figure corresponds to the cooling and dehumidification process of air-conditioning units. Compared with traditional compressed air-conditioning systems, solid adsorption dehumidification systems possess good potential to improve indoor air quality and reduce buildings’ energy consumption. However, there are still some problems that prevent the use of solid adsorption dehumidification systems, such as their complexity and high regeneration temperatures. The key to solving the above problem is the discovery of more suitable adsorbents. In this paper, poly N-isopropylacrylamide/polypyrrole (PNIPAm/PPy) hydrogel was selected as the research object, and the performance of the dehumidification material and its potential for application in solid dehumidification systems were studied. It was found that the pore structure of PNIPAm/PPy was relatively complex and that there were abundant pores with uneven pore sizes. The minimum pore size was about 4 μm, while the maximum pore size was about 25 μm, and the pore sizes were mostly distributed between 8 and 20 μm. Abundant and dense pores ensure good hygroscopic and water-releasing properties of the resulting hydrogel. The PPy inside the hydrogel acts as both a hygroscopic and photothermal agent. In an environment with a relative humidity of 90%, 60%, and 50%, the hygroscopic efficiency of PNIPAm/PPy reached 80% in about 75, 100, and 120 min, and the corresponding unit equilibrium hygroscopic capacity values were 3.85 g/g, 3.72 g/g, and 3.71 g/g, respectively. In the initial stage, the moisture absorption increased with the increase in time; then, the increase in moisture absorption decreased. When the temperature was below 40 °C, the hygroscopic performance of PNIPAm/PPy was almost temperature-independent. The PNIPAm/PPy with different thicknesses showed similar moisture absorption efficiency. The lowest desorption temperature of PNIPAm/PPy was 40 °C, which indicates that low-grade energy can be used for material desorption. And the higher the temperature, the faster the desorption rate of PNIPAm/PPy and the higher the desorption amount. It can be seen that the PNIPAm/PPy hydrogel presents good desorption performance and can be used repeatedly.Keywords:heat and mass transfer in porous media;dehumidification material;hydrogel;solid dehumidification system;hygroscopic efficiency;desorption performance
研究领域:
材料科学
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环境工程
·
热能工程
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
·
IF 19
Zhihui Chen,Xinge Yang,Qingyang Shao,Ruzhu Wang
Humidity control is crucial for applications such as green building design and equipment preservation. However, traditional dehumidification methods often suffer from limitations such as high energy consumption, poor scalability, or inefficient moisture transfer. Herein, inspired by the hierarchical porous microstructure in trees, a biomimetic sorbent monolith with vertically aligned channels and robust structure is fabricated through direct-ink-writing 3D printing technology for sorption-based dehumidification. Owing to abundant pore structure ranging from millimeter to micrometer scales, the monolith exhibits fast water uptake and facile regeneration. This study investigates its potential to achieve rapid dehumidification under a wide relative humidity (RH) range of 60–90%. One piece of monolith reduces the RH of a space 6750 times its own volume from 90% to below 60% in 25 min and maintains it with ultra-low energy consumption. Besides, the monolith fabricated by 3D printing is easy to be scaled up with low costs meeting the demands of large-scale production and practical deployment. It is expected that the monolith may fulfill diverse humidity needs while broadening the applications of 3D printing technology.
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
Membranes
·
2022
·Vol. 12
·期 1
·65
·
IF 4.562
Jun Pan,Kun Chen,Zhaoliang Cui,Omar Bamaga,Mohammed Albeirutty,Abdulmohsen Omar Alsaiari,Francesca Macedonio,Enrico Drioli
Due to the good hydrophobicity and chemical resistance of poly(ethylene trifluoroethylene) (ECTFE), it has been an attractive potential material for microfiltration, membrane distillation and more. However, few porous hydrophobic ECTFE membranes were prepared by thermally induced phase separation (TIPS) for membrane condenser applications. In this work, the diluent, di-n-octyl phthalate (DnOP), was selected to prepare the dope solutions. The calculated Hassen solubility parameter indicated that ECTFE has good compatibility with DnOP. The corresponding thermodynamic phase diagram was established, and it has been mutually verified with the bi-continuous structure observed in the SEM images. At 30 wt% ECTFE, the surface contact angle and liquid entry pressure reach their maximum values of 139.5° and 0.71 MPa, respectively. In addition, some other basic membrane properties, such as pore size, porosity, and mechanical properties, were determined. Finally, the prepared ECTFE membranes were tested using a homemade membrane condenser setup. When the polymer content is 30 wt%, the corresponding results are better; the water recovery and condensed water yield is 17.6% and 1.86 kg m−2h−1, respectively.Keywords:membrane condenser;hydrophobic membrane;ECTFE membrane;thermally induced phase separation
研究领域:
化学工程
·
材料科学
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膜技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Polymers
·
2023
·Vol. 15
·期 18
·3678
·
IF 5
Yimo Liu,Zhongbao Liu,Zepeng Wang,Weiming Sun
The water sorption and desorption properties of solid adsorbent materials are crucial in rotary dehumidification systems. Metal organic frameworks (MOFs) and hydrogels are mostly at the laboratory stage due to factors like the synthesis process and yield. In this study, we utilized an eco-friendly and large-scale synthesis method to prepare polyacrylamide (PAM) hydrogels (yielding approximately 500 mL from a single polymerization). Subsequently, PAM was then coated onto glass fiber paper (GFP), which serves as a commonly employed substrate in desiccant wheels. By incorporating the hygroscopic salt LiCl and optimizing the content of each component, the water sorption performance of the composite was notably improved. The water sorption and desorption performances, as well as cycling stability, were evaluated and compared with composites containing aluminum fumarate, LiCl, and GFP (AlFum-LiCl&GFP). The results revealed that PAM-LiCl&GFP outperformed AlFum-LiCl&GFP in terms of sorption capacity throughout various relative humidity (RH) levels. It achieved a water uptake of 1.06 g·g−1at 25 °C and 30% RH, corresponding to a water sorption rate coefficient K of 15.32 × 10−4s−1. Furthermore, the lower desorption temperature (60 °C) resulting in a desorption ratio of 82.6%, along with the excellent cycling stability and effective performance as a desiccant wheel module, provide evidence for the potential application of PAM-LiCl&GFP in desiccant wheels.
研究领域:
材料科学
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环境工程
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化学工程
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能源效率
✓ 已验证
产品关联
DOI
PubMed
高影响因子
STAR Protocols
·
2023
·
IF 0
Zhipeng Luo,Jiayun Wang,Yu Pan,Peng Gao,Hua Zhang,Ruzhu Wang
Summary Desiccant-coated heat exchangers provide a practical solution for the efficient removal of moisture from the air. Here, we present a protocol to synthesize an ultra-hygroscopic polymer to develop a LiCl loaded in curdlan hydrogel (LiCl@Cur)-coated heat exchanger for deep dehumidification. We describe steps for preparing the curdlan gel solution, hydrogel, LiCl solution, and LiCl@Cur. We then detail procedures for preparing curdlan-coated and LiCl@Cur-coated heat exchangers. The coated heat exchanger described in this protocol has a maximum dehumidification capacity of 12 g/kg. For complete details on the use and execution of this protocol, please refer to Pan et al. (2023). 1
研究领域:
材料科学
·
环境工程
✓ 已验证
DOI
PubMed
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2023
·
IF 8.2
Xinhong Han,Yiwen Xue,Rui Lou,Shaoqiu Ding,Shurong Wang
Sorption dehumidification, as an energy-saving and eco-friendly approach, has been emerging in application for air dehumidification. Here, a prospective method is proposed to prepare biomass-based hygroscopic aerogels that are easily applicable, sustainable, high-efficient, and recyclable. The chitosan-based aerogel with a porous and hydrophilic network acts as the carrier and water reservoir for the uniformly distributed lithium chloride hygroscopic salt, and provides the hygroscopic salt with more liberal water channels to facilitate moisture capture and transfer. As a consequence, the prepared chitosan/polyvinyl alcohol@lithium chloride (chitosan/PVA@LiCl) hygroscopic aerogel exhibits an excellent moisture absorption capacity of up to 2.77 g g −1 at a relative humidity of 90 %. Meanwhile, as the chitosan/PVA@LiCl aerogel is set in a closed space about 2200 times larger than its own volume, the relative humidity can be reduced from 90 % to 32 % within 2 h, and further lower to 25 % after 4 h. Furthermore, combined with multi-walled carbon nanotubes, the photothermal hygroscopic aerogel is obtained that can rapidly desorb water under sunlight, thus to realize energy-free cycle. Overall, the renewable biomass-based aerogel materials with the advantages of simple preparation and excellent hygroscopic performance provides a new path for the development of sorption dehumidification technology.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Qianling Ma,Xu Zheng
Adsorption technologies for adsorption-based dehumidification and water harvesting from the atmosphere have great potential for energy-saving and environmental protection. The key to successful utilization of these technologies is desired properties of adsorbents. However, most existing adsorbents fail to have the characteristic of both high adsorption capacity and good desorption ability under low regeneration temperature such as at 40 °C. In this work, we grafted a thermo-responsive polymer (Poly(N-isopropylacrylamide) PNIPAM) to silica gel and impregnated with lithium chloride to prepare a composite adsorbent. The adsorption capacity of this composite can reach 1.70 g g −1 at 20 °C&70%RH, and 56% of adsorbed moisture can be released within 60 min at 40 °C&10%RH. This method offers a promising route to develop high-performance thermo-responsive composite adsorbents for desiccant coated heat exchanger (DCHE)-based dehumidification and adsorption-based atmospheric water harvesting (ABAWH).
研究领域:
材料科学
·
环境工程
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Yanshu Luo,Bingqiong Tan,Xianghui Liang,Shuangfeng Wang,Xuenong Gao,Zhengguo Zhang,Yutang Fang
MIL-100(Fe) has been proven to have good hydrothermal stability and high vapor uptake and is considered as a promising dehumidification material. However, reduction of the production cost and assembly of the adsorbent and glass fiber paper substrate into the MIL-100(Fe) monolith are challenging. This work presented a dry gel conversion strategy for the rapid synthesis of the MIL-100(Fe) monolith at low temperatures. The porosity and crystalline phase of the products obtained under different crystallization temperatures and times were carefully studied. XRD and SEM characterization indicated that the MIL-100(Fe) crystal could be conveniently synthesized on the substrate at a low temperature of 50–70 °C and in a short time of 2–6 h. The spherical particles assembled from crystals dispersed evenly and tightly on the glass fiber paper. The synthesized MIL-100(Fe) monolith had a thickness of about 270 μm and a MIL-100(Fe) loading of 77.7%. Dynamic and static water vapor adsorption tests revealed that the monolithic adsorbent obtained at 50 °C for 6 h had the largest vapor saturation adsorption capacity (0.581 g/g) and the fastest adsorption rate. Moreover, the monolith owned a low regeneration temperature (below 80 °C) and a satisfactory cycle stability. Convenient equipment, mild synthetic conditions, low renewable energy consumption, and good performance will promote its application in the rotary dehumidification system.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2022
·
IF 16.744
Lurong Ge,Yaohui Feng,Yanjun Dai,Ruzhu Wang,Tianshu Ge
Composite sorbents with hygroscopic salts (like LiCl and CaCl 2 ) impregnated porous matrixes obtained special attention in the past years, especially for solid desiccant dehumidification. However, the drawback of strong corrosivity limited their practical implementation. Alternatively, ionic liquid (1-ethyl-3-methylimidazole acetate) with less corrosivity is confined into ordered mesoporous MCM-41 to fabricate composite sorbent in this study, overcoming the poor mass transfer or limited adsorption capacity of single sorbent. Comprehensive characterizations including SEM, TEM, XRD, FTIR and N 2 adsorption prove that the ionic liquid is encapsulated in ordered channels of MCM-41. Sorption isotherms and kinetics indicate that the composite sorbent has superior water sorption performance (0.5 g/g at 20 °C/70 % RH), fast sorption rate under wide humidity range and potential of low temperature-driven regeneration. Moreover, the leakage test and corrosion experiment reveal that the composite sorbent has long-term stability and is corrosion-free to metal components. Further, the dehumidification performance using desiccant coated heat exchanger with reported composite sorbent is evaluated, showing 5 times higher dehumidification capacity than that of MCM-41 and 2 times higher than traditional silica gel (typical ARI summer, 35 °C, 40 % RH). This study identifies a feasible way of using ionic liquids to develop energy-efficient, safety-ensured and low-cost composite sorbents for water sorption-related applications.
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
JOURNAL OF MEMBRANE SCIENCE
·
2024
·
IF 8.4
Zhiguang Zhang,Xiaolong Ren,Guolong Huo,Xiaowei Zhou,Hao Chen,Hongjun Zhang,Shuanyan Kang,Xiuling Chen,Nanwen Li
6FDA-based polyimide air-dehumidification membrane has been considered as one of the most advanced technologies for the energy-saving heating, ventilation, and air-conditioning systems due to their excellent solubility and processing. Nevertheless, there are few reports about the effect of free volume and hydrophilic groups on dehumidification performance. Herein, we propose to tune the free volume and hydrophilicity of 6FDA-based polyimides by tuning the hydrophilicity/hydrophobicity of diamines and/or introducing of hydrophilic carboxylic acid groups, and thus to develop a system that would support high H 2 O/N 2 separation performance for dehumidification and retain excellent mechanical properties. It is found that 6FDA/mPDA membrane shows much higher H 2 O/N 2 separation performance (i.e., H 2 O permeability 12480 Barrer and H 2 O/N 2 separation factor of 13867) than that of the 6FDA/TFDB and 6FDA/DAM membranes even though its lower FFV. It is suggested that the FFV had a negligible effect on the H 2 O/N 2 separation performance. Although the introduction of highly hydrophilic –COOH groups could significantly increase the H 2 O/N 2 separation performance of hydrophobic 6FDA/TFMB and 6FDA/DAM membranes, the performance is still lower than that of 6FDA/mPDA membrane with similar hydrophilicity. In addition, we found that more –COOH groups to polymers can lead to the possible formation of hydrophilic/hydrophobic separation in membrane which will result in the rapid water vapor condensation and thus unstable air-dehumidification. Thus, the excessive hydrophilicity of 6FDA/mPDA-DABA showed a decreased H 2 O/N 2 separation performance compared with 6FDA/mPDA membrane. These results indicated that the excellent H 2 O/N 2 separation performance mainly depends on reasonable hydrophilicity of polyimide membrane without excessive hydrophilic groups and high FFV.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Bioresources and Bioprocessing
·
2022
·Vol. 9
·期 1
·1-17
·
IF 4.983
Fan Jie,Yu Qiongfen,Li Ming,Chen Jie,Wang Yunfeng,Zhang Ying,Li Guoliang,Ma Xun,Zhong Hao,Yu Yamei
Lignin is a renewable bioresource that can be used for a variety of value-added applications. However, the effective separation of lignin from lignocellulosic biomass remains an ongoing challenge. In this study, lignin was extracted from waste palm fiber and successfully converted into a dehumidifying material. The following four process parameters of lignin extraction from palm fiber were optimized systematically and comprehensively using the response surface methodology: reaction time, extraction temperature, ethanol concentration and solid/liquid ratio. The results revealed that under the optimum processing conditions (111 min of extraction at 174 °C using 73% ethanol at 1/16 g/mL solid/liquid ratio), the extraction yield of lignin was 56.2%. The recovery of ethanol solvent was as high as 91.8%. Further, the lignin could be directly used without purification to produce lignin-based activated carbon fibers (LACFs) with specific surface area and total pore volume of 1375 m2/g and 0.881 cm3/g, respectively. Compared with the commercial pitch-based activated carbon fiber, the LACF has a higher specific area and superior pore structure parameters. This work provides a feasible route for extracting lignin from natural palm fiber and demonstrates its use in the preparation of activated carbon fiber with a remarkable performance as a solid dehumidification agent.
研究领域:
生物质能
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Yingtian Xu,Junwei Xie,Runfeng Lin,Yuqi Zhu,Jiayi Wu,Rujing Hou,Runping Niu,Yichang Pan
Membrane separation is a promising technology relative to the mature distillation technique due to its high energy efficiency. Incorporating nanoparticle to polymer matrix to fabricate mixed-matrix membranes (MMMs) is one of effective ways to overcome the typical trade-off relationship between gas permeability and selectivity. Although silica based MMMs were studied for natural gas dehydration and desalination , it is rarely been investigated for air dehumidification . Herein, membrane material with high water vapor affinity of Pebax 1074 was applied as polymer matrix and silica was incorporated as filler to fabricate MMMs. The embedded silica filler can simultaneously enhance water vapor permeability (13–33% up) and H 2 O/N 2 selectivity (40–60% up) at an optimal loading of 1 wt%. The relatively hydrophobic form improved water vapor permeability due to the pronounced enlarged d-spacing and the resultantly enhanced diffusivity coefficient . The more hydrophilic filler enhanced more H 2 O/N 2 selectivity than that of the counterpart because of the largely improved water vapor solubility coefficient. The concomitant improvement of both water vapor permeability and its selectivity makes it stand out from the various previously reported membranes, demonstrating its potential for scale-up application.
研究领域:
材料科学
·
环境工程
✓ 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）