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Comparative study on the properties of wood vinegar prepared from the pretreated Chinese fir: Effect of hydrothermal parameters and hydrogen peroxide

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JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS 2022年 167卷

作者： Xu, Jiaqing Zhang, Shouyu Zhou, Yi Liu, Simeng Lang, Sen Yang, Jifan Wu, Yuxin Univ Shanghai Sci & Technol Sch Energy & Power Engn Shanghai 200093 Peoples R China Shanghai Key Lab Multiphase Flow & Heat Transfer P Shanghai 200093 Peoples R China Tsinghua Univ Dept Thermal Engn Beijing 100084 Peoples R China Univ Shanghai Sci & Technol Sch Energy & Power Engn Dept Thermal Engn Shanghai 200093 Peoples R China

Hydrothermal (HT) pretreatment and hydrothermal oxidative (HO) pretreatment are efficient in upgrading the quality of wood vinegar (WV), while little research pays attention to the systemic comparison between the effects of HT and HO pretreatment on the resulted WV. Therefore, in the present study, the response surface method is adopted first to analyze the effect of HT temperature, solid-to-liquid ratio (S/L), and retention time on the physicochemical properties of WV prepared from Chinese fir (CF). Then, the main compositions (hemicellulose, cellulose, and lignin) of the pretreated CF are quantitatively measured, and the comparative study between the effects of HT pretreatment and HO pretreatment on the yield, density, and compositions of the resulted WV is carried out based on CF composition. The results show that HT temperature is the main parameter that affects the physicochemical properties of the resulted WV. With the increase of HT temperature, the cellulose content of CF samples increases first at 180-230 degrees C and then decreases at 260-280 degrees C, the hemicellulose content decreases, and the lignin enriches. The cellulose enrichment gives rise to the increasing WV yield at 180-200 degrees C and the increasing WV density at 180-230 degrees C. While the dramatic cellulose decomposition at 230-280 degrees C results in the decreasing WV yield at 230-280 degrees C and the decreasing WV density at 260-280 degrees C. The cellulose is the main component that contributes to the yield and density of WV. Moreover, due to the cellulose enrichment, the contents of the organic compounds, especially the phenols, ketones, and aldehydes, increase dramatically at 180-230 degrees C, contributing to the lower pH value of the resulted WV. However, HO pretreatment aggravates the decomposition of CF components. During HO pretreatment, the decreases in the hemicellulose content and cellulose content are advanced to 160-200 degrees C and 180-230 degrees C respectively, and

关键词： Chinese fir Hydrothermal pretreatment Hydrothermal oxidative pretreatment Pyrolysis Wood vinegar Chemical composition

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Physics-Based Probabilistic Assessment of Creep-Fatigue Failure for Pressurized Components by Extended Direct Steady Cycle Analysis-Driven Neural Network

SSRN

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SSRN 2022年

作者： Wang, Xiaoxiao Ma, Zhiyuan Yang, Jie Chen, Haofeng Xuan, Fuzhen Department of Mechanical & Aerospace Engineering University of Strathclyde James Weir Building 75 Montrose Street GlasgowG1 1XJ United Kingdom Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering School of Energy and Power Engineering University of Shanghai for Science and Technology Shanghai200093 China School of Mechanical and Power Engineering East China University of Science and Technology Shanghai200237 China

To achieve a high-reliability design with a feasible balance between accuracy and efficiency, the physics-based probabilistic assessment for creep-fatigue failure is proposed under the probabilistic Linear Matching Method (pLMM) framework. At the physical level, the structural failure mechanism is reflected in the prepared training database, which is generated by the direct method, extended Direct Steady Cycle Analysis (eDSCA) procedures. And to efficiently express the relationship between design parameters and structural responses implicitly, the extended DSCA-driven neural network (EDDNN) is built with the superior fitting quality of damage and lifetime. With the benchmarks of pressurized structures provided, the applicability of the proposed probabilistic analysis approach in solving practical problems is demonstrated, where the reliability-based evaluation diagram is established according to different requirements. Furthermore, a novel data classification scheme is proposed to deal with the randomness in creep damage-dominated probabilistic assessment. © 2022, The Authors. All rights reserved.

关键词： Failure (mechanical)

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Process design and energy analysis on synthesis of liquid fuels in an integrated CCUS system

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APPLIED ENERGY 2023年 351卷

作者： Luo, Ning Dou, Binlin Zhang, Hua Yang, Tiebing Wu, Kai Wu, Chunfei Chen, Haisheng Xu, Yujie Li, Wei Univ Shanghai Sci & Technol Sch Energy & Power Engn Shanghai Key Lab Multiphase Flow & Heat Transfer P Shanghai 200093 Peoples R China Queens Univ Belfast Sch Chem & Chem Engn Belfast BT7 1NN North Ireland Chinese Acad Sci Inst Engn Thermophys Beijing 100190 Peoples R China Zhejiang Univ Dept Energy Engn Hangzhou 310027 Peoples R China

Under the high attention of the international community to CO2 emissions, the capture utilization and storage (CCUS) and the CO2 hydrogenation fuel production have become two popular directions, especially for the combination of the two processes. In this paper, the production of liquid fuels via the methanol synthesis pathway in an integrated CCUS system based on Aspen Plus models was studied. The NH3-CO2-H2O absorption was used to capture CO2 and hydrogen was provided by water electrolysis using renewable energy sources. A two-stage reactor with a recirculating stream was specified for the process of CO2 hydrogenation to synthesize methanol, and the liquid fuel dimethyl ether (DME) was reproduced by dehydrating methanol (power-to-Liquid). The amount of absorbent used for the carbon capture process was determined and the yield differences due to the number of cycles in the intermediate methanol synthesis reaction were analyzed. It is possible to convert 4.15 t of CO2 per tonne of DME produced at the mass material balance of the process. The optimization of the heat exchange network and the energy requirements for the total process were evaluated. It is calculated that the energy involved in producing 1 ton of DME in the process model is 176 GJ. The analysis of the overall process and the evaluation of models could provide options for the possibility of CCUS engineering application.

关键词： Carbon capture utilization and storage (CCUS) CO2 hydrogenation Synthetic fuels power-to-liquid Energy requirement

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The evolution of catalytically active calcium catalyst during steam gasification of lignite char

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CARBON 2021年 172卷 162-173页

作者： Zhang, Jie Tang, Jia Liu, Lijuan Wang, Jie Univ Shanghai Sci & Technol Sch Energy & Power Engn Shanghai 200093 Peoples R China Shanghai Key Lab Multiphase Flow & Heat Transfer Shanghai 200093 Peoples R China Ningde Amperex Technol Ltd 1 Xingang Rd Ningde 35200 Fujian Peoples R China Zhengzhou Univ Sch Phys & Microelect 100 Sci Ave Zhengzhou 450001 Henan Peoples R China East China Univ Sci & Technol Dept Chem Engn Energy 130 Meilong Rd Shanghai 200237 Peoples R China

Coal or coal char/pyrocarbon gasification is a viable way to produce cheaper hydrogen. The gasification of three different lignites and their pretreated samples showed that either the intrinsic calcium in lignite or the extrinsic calcium added by ion exchange had high catalytic activity. It was proven that most of the calcium in the lignite was organically associated, which was mainly bound to carboxyl groups and highly dispersed at an atomic level. Furthermore, Yuxi lignite was demineralized to investigate the catalytic characteristics of calcium and potassium catalysts on steam gasification. The changes of gasification rate, gas compositions and oxygen chemisorption capacity with carbon conversion hinted that the catalytic mechanism of calcium was different from that of potassium. X-ray absorption near edge structure (XANES) analysis revealed that carboxyl-bound calcium was the active form of the catalyst, and the deactivation of the calcium catalyst in the gasification process was due to the transformation of carboxylbound calcium to other chemical forms. The organically bound calcium also led to the porous char structures at the early gasification stage, which improved the catalytic activity. (C) 2020 Elsevier Ltd. All rights reserved.

关键词： Lignite char Catalytic gasification Calcium catalyst Potassium catalyst Catalytic mechanism

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Catalytic Gasification of Large Particle Size Biomass with Loaded Aaems Under Oxygen-Steam Atmosphere

SSRN

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SSRN 2023年

作者： Ren, Jiyun Yang, Kaixuan Li, Yuhang Bai, Yang Jiang, Jiahao Huang, Xiaole Deng, Lei Che, Defu State Key Laboratory of Multiphase Flow in Power Engineering School of Energy and Power Engineering Xi’an Jiaotong University Xi’an710049 China Shanghai Power Equipment Research Institute Co. Ltd. Shanghai200240 China Xi’an Thermal Power Research Institue Co. Ltd. Xi’an710032 China

To evaluate the effect of alkali and alkaline earth metals species (AAEMs) on the catalytic gasification of large particle size biomass, a vertical fixed-bed reactor is conducted for candlenut wood gasification under the oxygen-stream atmosphere. The gasification chars derived from gasification are characterized by SEM, X-ray CT, BET, and FTIR. Tar and syngas are analyzed via GC-MS and GC respectively. Advanced X-ray CT technology provides beneficial visualization to assist in the interpretation of the catalytic gasification of large particle size biomass loaded with AAEMs. The results indicate a progressive augmentation of AAEMs content along the radial direction and end surface for all loaded samples and gasification chars, which could also be visualized from the 3D reconstruction of X-ray CT. Many large pores (40-60 μm) aligned along the grain direction collapse after gasified and generate numerous micropores in gasification chars. 10-20 μm pores are more prominent in chars loaded with KCl and CaCl2. The char loaded with CaCl2 has more well-developed pores, a larger specific surface area, and -OH compounds, aldehydes, ketones and carboxylic acids. The addition of AAEMs facilitates the high generation of M1 compounds (contains 1 benzene ring) in the tar and suppresses the enhancement of other compounds, M4 compounds, and long-chain alkanes. H2 and CO concentrations augments and declines by loading AAEMs. The highest H2 concentration of 62.1% is detected by the addition of CaCl2. When loaded with KCl, the syngas calorific value reduces by 1.37%, while loaded with NaCl, CaCl2, and MgCl2 show an augmentation of 11.48%, 10.56%, and 2.55%, respectively. A decrement of CnHx concentration in syngas derived from samples loaded with KCl and MgCl2 and an increment one loaded with NaCl and CaCl2 are acquired. © 2023, The Authors. All rights reserved.

关键词： Oxygen

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Numerical study on the flow characteristic of shell-side film flow of floating LNG spiral wound heat exchanger

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INTERNATIONAL JOURNAL OF heat AND MASS transfer 2022年 187卷 122198-122198页

作者： Ren, Yan Cai, Wei-hua Jiang, Yi-qiang Wu, Wei-dong Yang, Qi-guo Chen, Jie Univ Shanghai Sci & Technol Sch Energy & Power Engn Shanghai Peoples R China Shanghai Key Lab Multiphase Flow & Heat Transfer Shanghai Peoples R China Northeast Elect Power Univ Sch Energy & Power Engn Jilin Jilin Peoples R China Harbin Inst Technol Dept Bldg Thermal Energy Engn Harbin Peoples R China CNOOC Gas & Power Grp Beijing Peoples R China

A mathematic-physical model was established to investigate the shell-side flow characteristic of film flow in spiral wound heat exchanger (SWHE), which was used for floating liquefied natural gas (FLNG). The numerical study was carried out based on CLSVOF model and dynamic contact angle model, and the numerical accuracy was validated by experimental data. According to the results under static conditions, the shell-side frictional pressure drop gradient increased with decreasing pressure and increasing mass flux and heat flux. Sloshing motion could significantly shorten the process of film flow in the heat exchanger, promote the early occurrence of flow pattern transition and lead to the remarkable change in frictional loss. Therefore, the effects of sloshing parameters and working parameters on shell-side frictional pressure drop gradient were investigated, where sloshing amplitude, sloshing period, pressure and mass flux respectively were 5 similar to 15 degrees , 5 similar to 15 s , 0.2 similar to 0.6 MPa and 60 similar to 100 kg / (m(2)center dot s) . As a result, in order to maintain the stable operation of FLNG SWHE, the heat exchanger should be placed near the gravity center of FLNG, and the shell-side pressure and mass flux should be respectively increased to 0.6 MPa and 80 kg / (m(2)center dot s) , as far as possible. These results will provide some instructions in the design and operation for FLNG SWHE. (c) 2022 Elsevier Ltd. All rights reserved.

关键词： Spiral wound heat exchanger Film flow flow characteristic Sloshing conditions Dynamic contact angle

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Protocol for three-dimensional shaping strategy via solidifying polygonal nanofluid drops

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STAR PROTOCOLS 2024年第3期5卷 103299页

作者： Cai, Haoting Tong, Wei Wei, Lichuan Jiang, Yupeng Zhao, Yugang Zhang, Hua Yang, Chun Cheng, Ping Univ Shanghai Sci & Technol Sch Energy & Power Engn Shanghai Key Lab Multiphase Flow & Heat Transfer P Shanghai 200093 Peoples R China Shenzhen Envicool Technol Co Ltd Shenzhen 518129 Peoples R China Nanyang Technol Univ Sch Mech & Aerosp Engn Singapore 639798 Singapore Shanghai Jiao Tong Univ Sch Mech Engn MOE Key Lab Power Machinery & Engn Shanghai 200240 Peoples R China

Mesoscale to nanoscale three-dimensional (3D) fabrication mostly requires complicated industry processing techniques. Here, we present a protocol for 3D shaping control by solidifying a water-based TiO2 nanofluid drop on a polygonal wettability-patterned surface. We detail the steps for preparing stable TiO2 nanofluid and wettability-patterned surfaces. We then describe the experimental procedure to obtain various and precise 3D morphologies by adjusting the deposited TiO2 nanofluid drop volume. This protocol provides a promising technique for future 3D manufacturing. For complete details on the use and execution of this protocol, please refer to Jiang et al.(1)

关键词： Energy Chemistry Material sciences Environmental sciences

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The study on structure design of fender of offshore wind turbine based on fractal feature during collision with ship

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OCEAN engineering 2021年 236卷 109100-109100页

作者： Yue, Xinzhi Han, Zhiwei Li, Chun Zhao, Xinlei Univ Shanghai Sci & Technol Sch Energy & Power Engn Shanghai Peoples R China Shanghai Key Lab Multiphase Flow & Heat Transfer Shanghai Peoples R China Shanghai Elect Wind Power Grp Co Ltd Shanghai 200233 Peoples R China

The number of construction offshore wind turbines (OWTs) is gradually increasing with high clean energy demand and low technology costs. During their service life, a large number of ships will inevitably collide with OWTs, which results in collapse load acting on the OWT foundation. This paper proposes a novel fender for the OWT exposed to extreme collision using the fractal structure, as the first step toward protecting the safety of the OWT structure. The proposed the fractal structure is based by the cartesian circle, which defined by tangent circle theorem, applied to ring protection design. The paper investigates the anti-collision performance of fractal structure fender on the simulated response of the tripod OWT installed in the coastal waters by comparing tradition and fractal structure. Furthermore, the difference of external diameter and different orders are discussed under the collision actions, which are implemented in the LS-DYNA. The results show that with the increase of the order of fractal pores, structure of the first-order fractal pores is good for the fender to absorb enough collision energy and the anti-collision performance of fender increases by the greater mass.

关键词： Offshore wind turbine Collision Fractal structure Fender Ship

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Study on thermal storage effectiveness of a novel PCM concrete applied in buildings located at four cities

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RENEWABLE ENERGY 2023年第1期218卷

作者： Liu, Xinghai Yang, Yingying Sheng, Zhonghua Wu, Weidong Wang, Yuan Dumoulin, Jean Univ Shanghai Sci & Technol Sch Energy & Power Engn Shanghai 200093 Peoples R China Shanghai Key Lab Multiphase Flow & Heat Transfer P Shanghai 200093 Peoples R China Tsinghua Univ Sch Architecture Dept Bldg Sci Beijing Key Lab Indoor Air Qual Evaluat & Control Beijing 100084 Peoples R China Univ Gustave Eiffel I4S Team Inria COSYS SII F-44344 Bouguenais France Univ Shanghai Sci & Technol Sch Energy & Power Engn 516 Jun Gong Rd Shanghai 200093 Peoples R China

The implementation of phase change thermal storage technology represents a high-potential strategy for mitigating energy consumption and reducing heating and cooling loads in buildings. However, the practical thermal storage effectiveness is affected significantly by the outdoor thermal conditions specific to each location. This work studied the thermal behaviors of a novel composite concrete containing phase change material (PCM concrete) when inserted into building envelopes. Numerical simulations have been conducted to assess the full -year impact of this PCM concrete on buildings with multi-layer walls, considering four cities with different climates. Results indicate that this novel PCM concrete demonstrates maximum effectiveness in Paris, effectively reducing indoor temperature fluctuations in summer. Conversely, in the other three cities with high solar-air temperatures in summer, the PCM concrete remains melting, reducing its thermal storage effectiveness. Instead, it performs better thermal behaviors during spring and autumn. In summary, the new PCM concrete demonstrates a good capacity to regulate indoor temperature, however, this effectiveness is primarily impacted by the outdoor solar-air temperature. Therefore, to maximize the latent heat storage potential of PCM, it is crucial to select an appropriate PCM with optimal phase change temperature zones, particularly when this technology is implemented in diverse climatic zones.

关键词： Thermal storage Phase change material Concrete Thermal performance Building energy conservation

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Study on the effect of graphene nanosheets refrigerant oil on domestic refrigerator performance

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INTERNATIONAL JOURNAL OF REFRIGERATION 2020年第0期110卷 187-195页

作者： Yang, Shennan Cui, Xiaoyu Zhou, Yu Chen, Chengmeng Univ Shanghai Sci & Technol Sch Energy & Power Engn 516 Jungong Rd Shanghai 200093 Peoples R China Shanghai Key Lab Multiphase Flow & Heat Transfer Shanghai 200093 Peoples R China Chinese Acad Sci Inst Coal Chem CAS Key Lab Carbon Mat Taiyuan 030001 Peoples R China

Graphene nanosheet have an ultra-thin sheet structure that can easily fill the contact friction surfaces and reduce friction losses. Its thermal conductivity reaches 5,300 W/mK. Therefore, a nanofluid prepared by adding graphene nanosheets to base liquid will have lower coefficient of friction and higher thermal conductivity. In this study, 1:1 mass ratio of graphene nanosheets additive to Span85 dispersant was added to SUNISO 3GS refrigerant oil, using ultrasonic oscillation dispersing and chemical methods to prepare 10 mg/L, 20 mg/L and 30 mg/L graphene nanosheets refrigerant oil. The cooling rate, freezing capacity, and energy consumption of the refrigerator using different concentrations of graphene nanosheets refrigeration oil were compared. The performance of the compressor and the refrigerator were analyzed. The results showed that during the stable refrigerator operation, adding graphene nanosheets to lubricants for the refrigerator had lower suction temperature, discharge temperature, condenser temperature, suction pressure and discharge pressure than pure oil. Both the fresh food compartment and freezer's cooling rates were increased. The increase of the concentration leaded to better freezing capacity of the freezer. The 30 mg/L graphene nanosheets refrigerant oil increased the freezing capacity of the refrigeration system by 11.1%. The on-time ratio, operating current of the compressor and energy consumption were also reduced. Compared with pure oil, the energy consumption in 24 h of the domestic refrigerator using 10 mg/L, 20 mg/L and 30 mg/L graphene nanosheets refrigerant oil dropped by 15.4%, 19.2% and 20.3%. (C) 2019 Elsevier Ltd and IIR. All rights reserved.

关键词： Graphene nanosheets Domestic refrigerator Refrigerant oil Coefficient of friction Energy consumption

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