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Effects of Hydrothermal and Hydrothermal Oxidation Pretreatments on Physicochemical Properties of High Value-Added Biochar Fuel Pellets and Activated Carbon Materials

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SSRN 2023年

作者： Lang, Sen Zhang, Shouyu Yang, Jifan Zhou, Yi Liu, Simeng Xu, Zihang Han, Xiuyuan Huang, Jiantian School of Energy and Power Engineering University of Shanghai for Science and Technology Shanghai200093 China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering Shanghai200093 China Huazhan Aerospace Electric Appliance Co. LTD Aerospace Science and Industry Corporation Suzhou215129 China

In this paper, cotton stalk (CS) and Chinese fir sawdust (FS) were treated for hydrothermal pretreatment with or without H2O2, and then respectively pyrolyzed and activated to prepare biochar pellets and activated carbon materials. The results show that compared with hydrothermal pretreatment (HT), hydrothermal oxidation (HTO) pretreatment has stronger degradation ability of hemicellulose and cellulose. With the increase of pretreatment temperature, some decomposed substances repolymerize to form lignin-like substances. In the 160-260oC temperature range, the physical properties of biochar pellets prepared under HT 230oC and HTO 200oC are the best, and crystalline cellulose plays a key role in it. The calorific value and energy density of the biochar pellets obtained after pretreatment were consistent with the variation trend of their physical properties. The combustion characteristics of treated CS/FS biochar pellets gradually decreased with the increase of temperature. Compared with CS, FS biochar have better energy density and physical properties due to high cellulose content. The CS-HTO200-A has the highest specific surface area and pore volume, which is 118.1% and 111.7% higher than that of raw materials, and mainly consists of micropores. Cellulose is beneficial to increase the specific surface area of activated carbon, while lignin has the opposite effect. © 2023, The Authors. All rights reserved.

关键词： Physicochemical properties

Experimental and Kinetic Modeling Study on the Oxidation and Laminar Combustion Characteristics of Natural Gas

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SSRN 2023年

作者： Chen, Xiaoxiao Zeng, Wen Zheng, Weilin Hu, Erjiang Ma, Hongyu Liaoning Key Lab of Advanced Test Technology for Aerospace Propulsion System Shenyang Aerospace University Liaoning Shenyang110136 China State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Shanxi Xi'An710049 China AECC Shenyang Engine Research Institute Shenyang110015 China

The oxidation process in the flow tube reactor at the conditions of P=0.1 MPa, T=500-1850 K, f=0.5, 1.0, 3.5, and the laminar combustion process in the constant volume combustion bomb at the conditions of P=0.1, 0.2, 0.3 MPa, T=300, 350, 400 K, f= 0.7-1.4, the O2 contents of 15%, 18% and 21%, the CO2 and H2O contents of 0%, 10%, and 20% of natural gas (0.9 methane/0.07 ethane/0.03 propane, mole fraction) were experimental tested. In the oxidation process of natural gas, with the equivalence ratio increasing, the starting and ending temperatures for oxidation reaction of natural gas are increased, the reaction temperatures corresponding to CO generation and consumption are higher, and the amount of NO production is decreased. In the the laminar combustion process of natural gas, at the conditions of higher pressure, equivalence ratio, CO2 and H2O contents, the flame front is not smooth as a large number of cracks and cell structures appear, and the flame is unstable. Moreover, with the initial temperature and oxygen content increasing or the initial pressure, CO2 and H2O contents decreasing, the laminar flame speed is increased. Furthermore, combined the path sensitivity analysis, rate of production analysis, reaction path analysis and the decoupling method, a reduced reaction mechanism (including 40 species and 189 reactions) of natural gas was developed. Through comparing with the calculated results by the Aramco 2.0 mechanism and the corresponding test data, the reduced reaction mechanism can well predict the oxidation, ignition delay and laminar combustion characteristics of natural gas under various conditions. © 2023, The Authors. All rights reserved.

关键词： Sensitivity analysis

Surface display of CadR protein on Rhodopseudomonas palustris CGA009 for enhanced heavy metal bioremediation

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Journal of Hazardous Materials 2025年 494卷 138592页

作者： Wang, Minmin Gao, Zixuan Jiang, Qiushi Mu, Xuefang Jiang, Youmin Li, Yanjing Zhang, Sihu Cao, Wen Guo, Liejin State Key Laboratory of Multiphase Flow in Power Engineering Xi'an Jiaotong University Xianning West Road Xi'an710049 China

Heavy metal pollution poses significant ecological and public health risks, and surface display engineering shows promise for bioremediation in this area. Although anoxygenic photosynthetic purple nonsulfur bacteria (PNSB) have been effectively applied to degrade pollutants due to their metabolic versatility, the use of surface display technology in PNSB remains very limited. In this study, we constructed a surface display system using Rhodopseudomonas palustris CGA009 as the host. The metal-binding protein CadR was fused with outer membrane protein A (OmpA) and expressed in CGA009. SDS-PAGE and immunofluorescence analysis identified the successful expression of the fusion protein on the cell surface. In addition, we used flow cytometry to explore the enhancement effects of linker peptides and different promoters on surface display efficiency under different light intensities. The surface display system enhanced the heavy metal resistance of the host bacteria, and the maximum removal rate of Cd2 + reached 95.6 %. By means of Langmuir isotherm analysis, the maximum biosorption capacity of the system for Cd2+ is 101.11 mg/g. The system demonstrates feasibility for application in complex real-world environmental samples. The presence of various metal ions does not interfere with the system's specific adsorption of Cd²⁺. It can stably maintain an adsorption efficiency of over 80 % under conditions of pH 6–8, temperatures of 20–35°C, and light intensity of 1000–6000 lux. Additionally, the system achieves a removal efficiency of 94.3 % in Cd wastewater. In summary, this study provides a reference for the development of photosynthetic bacterial surface display systems and provides an advanced bioremediation strategy for heavy metal contaminated wastewater. © 2025 Elsevier B.V.

关键词： Bioremediation

Enhanced Clathrate Hydrate Phase Change with Open-Cell Copper Foam for Efficient Methane Storage

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SSRN 2022年

作者： Yang, Liang Li, Chunxiao Pei, Junhua Wang, Xin Liu, Ni Xie, Yingming Cui, Guomin Liu, Daoping School of Energy and Power Engineering University of Shanghai for Science and Technology Shanghai200093 China Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering University of Shanghai for Science and Technology Shanghai200093 China

Rapid phase change of hydrate with high gas storage capacity is very important for the application of natural gas hydrates technology. Three pieces of open-cell copper foam (CF) with different pore densities (or pores per inch, PPI) herein were immersed in sodium dodecyl sulfate (SDS) solution for enhancing methane storage in solid hydrate. The promotion effects of CF on the methane hydrate formation in the metal-embedded systems were investigated via an unstirred tank reactor. The results demonstrated that the surface of CF skeleton is covered with abundant micro holes and micro grooves, which can provide many metal nuclei for gas–water crystallization. The nest-like metal skeleton acts as crisscross "highway" for the crystallization heat transfer. Methane hydrate was quickly formed in the SDS/CF systems, but CF with the pore densities of 5 and 30 PPI was not favorable for conversion of more water to hydrate. Compared with these two composite systems, the SDS solution with the 15 PPI CF were able to store more methane at a faster formation rate. A theoretical model based highly porous two-phase systems was used to predict the effective thermal conductivity (ETC) of the metal foam filled with hydrate. It was found that the ETC of the hydrate/CF composite was significantly enhanced by employing CF matrix, and the low pore density CF had a more positive impact on improving the ETC of the composite. Further comparative experiments conducted at various pressures indicated that the solutions with 15 PPI CF exhibited higher methane storage capacities and larger hydration rates than the simple SDS solution, especially at the low pressure. © 2022, The Authors. All rights reserved.

关键词： Methane

Energy and exergy analyses of a novel recirculated regenerative rotary desiccant wheelassisted dehumidification system 33

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Energy and exergy analyses of a novel recirculated regenerat...

33rd International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems, ECOS 2020

作者： Han, Xiaoqu Wu, Wenxiang Chong, Daotong Su, Minqi Zhang, Dan Yan, Junjie State Key Laboratory of Multiphase Flow in Power Engineering Xi'An Jiaotong University Xi'an China MOE Key Laboratory of Thermal Fluid Science and Engineering Xi'An Jiaotong University Xi'an China

The indoor air humidity and temperature in the marine cabins could be as high as 80% and 40 °C - 50 °C, respectively, which may cause security risks to crews and devices. The incorporation of solid desiccant wheel for improved dehumidification and air quality control would contribute to energy saving in air conditioning system through waste heat recovery for regeneration. In the present work, a novel recirculated regenerative rotary desiccant wheel-assisted dehumidification system was proposed. The energy and exergy performances of the system under variable working conditions were quantitatively studied based on experimental tests. The dehumidification effectiveness, dehumidification performance coefficient (DCOP), sensible energy ratio and coefficient of performance (COP) were introduced as key energetic indicators. The effects of air bypass ratio (50% - 85%), process air temperature (28 °C - 40 °C), relative humidity of process air (60%RH - 80%RH) and regeneration air temperature (130 °C - 150 °C) on the system performances were obtained. It was found the COP of the system ranged between 0.4 and 1.8, while the exergy efficiency was only 4% - 11%. An optimal bypass ratio existed which was determined 55%-60%. Overall, the energy saving and exergy consumption characteristics of the proposed system at various working conditions were explored to prompt its practical application. © ECOS *** right reserved.

关键词： Waste heat

An Experimental Study on the Hypergolic Process Enhanced by Pre-Ignition Heat Release: [Amim][Dca]/Furfuryl Alcohol Blends Reacting with White Fuming Nitric Acid

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SSRN 2022年

作者： Wu, Yingtao Wang, Zhi Fei, Lihan Guo, Yang Liu, Yang Tang, Chenglong Huang, Zuohua State Key Laboratory of Multiphase Flow in Power Engineering Xi’an Jiaotong University Xi’an710049 China Research Center of Energetic Material Genome Science Institute of Chemical Materials China Academy of Engineering Physics Mianyang China

The hypergolic ignition behaviors of [AMIM][DCA] (1-allyl-3-methylimidazolium dicyanamide)/furfuryl alcohol (FA) blends reacting with white fuming nitric acid (WFNA) are investigated using drop test approach. Morphology results from two high speed cameras and temperature profiles from an infrared camera are combined in analyzing the hypergolic process. A typical hypergolic process observed in this work involves a mixing dominant stage, a stage with moderate temperature rising and vapor/secondary droplets emerging, and a stage with violent temperature rising accompanied by flame occurrence. Two kinds of delay times are used to characterize the hypergolic process which are found to be nonmonotonic with the variations of FA fractions. FA, though not hypergolic with WFNA, exhibits extensive pre-ignition heat release due to its physical and chemical properties, which enhances the hypergolic process of [AMIM][DCA]/FA blends with WFNA. © 2022, The Authors. All rights reserved.

关键词： Ionic liquids

Waterside Corrosion of M5 Alloy in Simulated Primary Coolant and Supercritical Water: Influences of Aqueous Environments

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SSRN 2022年

作者： Jiang, Guanyu Liu, Lu Xu, Donghai Li, Yanhui Kuang, Wenjun Wang, Mingjun Key Laboratory of Thermo-Fluid Science & Engineering Ministry of Education School of Energy and Power Engineering Xi’an Jiaotong University Shaanxi Province Xi’an710049 China State Key Laboratory for Mechanical Behavior of Materials Xi'an Jiaotong University Xi'An710049 China State Key Laboratory of Multiphase Flow in Power Engineering Department of Nuclear Science and Technology Xi'an Jiaotong University Xi'An China

M5 alloy is highly potential to serve as cladding materials in nuclear reactors. In this work, corrosion characteristics of M5 alloy in lithiated/borated water and pure supercritical water were investigated, and influences of aqueous environments on the corrosion process were clarified. Oxide films formed on the alloy mainly consisted of m-ZrO2. In the coolant environment, Li+ and OH- shared a synergistic effect on the occurrence and acceleration of waterside corrosion. Boric acid can react with OH- to induce B-(OH) formation and participate in the generation of zirconium borate to alleviate the accelerated corrosion effect by LiOH. In supercritical water, M5 alloy showed weight loss due to localized oxide exfoliation, and dissolved oxygen resulted in serious pitting of the oxide film. The microcrack density and porosity were significantly larger than those in the coolant environment, and long transverse cracks parallel to the O/M interface existed. Oxide deposition in two environments was both observed, and the phenomenon was discussed. © 2022, The Authors. All rights reserved.

关键词： Coolants

Study on the Catalytic Performance of Nano-Mesoporous Cobalt-Based Catalysts for Glycerol Dry Reforming

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SSRN 2022年

作者： Dou, Binlin Wang, Yadong Zhang, Hua Wu, Kai Ren, Ruijia Chen, Haisheng Xu, Yujie School of Energy and Power Engineering Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering University of Shanghai for Science and Technology Shanghai200093 China Institute of Engineering Thermophysics Chinese Academy of Sciences Beijing100190 China

Dry reforming is an efficient utilization technology that can convert CO 2 into high-value-added syngas. In this work, nano-mesoporous CeO 2 -supported Co-based catalysts were successfully prepared by the colloidal solution combustion method and used in glycerol dry reforming (GDR) experiments. The characterization results show that the prepared catalyst has a uniform mesoporous structure, and the Co-Fe-Ce catalyst has a higher specific surface area and stronger metal-support interaction than the Co-Ce catalyst. Thermodynamic analysis was conducted using a non-stoichiometric method methodology based on Gibbs free energy minimization. Catalytic experiments were carried out at 650°C to 800°C. The results showed that the Co-Fe-Ce catalyst exhibited higher activity and selectivity in the GDR reaction, and the glycerol conversion of 7CoFeCe at 750 °C reached 84.8%. The 10 h stability experiment shows that the Fe promoter has a positive effect on the stability of the catalyst. The TPO results indicate that Fe doping can suppress filamentous carbon formation. © 2022, The Authors. All rights reserved.

关键词： Catalyst activity

Effect of the Density Difference on Fluid Distribution in Layered Rock Samples

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Energy & Fuels 2025年第9期39卷 4412-4420页

作者： Yongfei Yang Tonghui Liu Yingwen Li Weichen Sun Hai Sun Lei Zhang Junjie Zhong Kai Zhang Jun Yao State Key Laboratory of Deep Oil and Gas China University of Petroleum (East China) Qingdao 266580 P. R. China；Research Center of Multiphase Flow in Porous Media School of Petroleum Engineering China University of Petroleum (East China) Qingdao 266580 P. R. China Geosteering & Logging Research Institute Sinopec Matrix Corporation Qingdao 266071 P. R. China Research Center of Multiphase Flow in Porous Media School of Petroleum Engineering China University of Petroleum (East China) Qingdao 266580 P. R. China

During geological CO2storage, gravity segregation due to fluid density differences significantly affects the efficiency and safety of the process. This can result in premature CO2breakthrough, reduced storage efficiency, and increased leakage risks. This study aims to investigate how gas migrates in layered heterogeneous reservoirs over time due to prolonged density differences and to assess the resulting impact on fluid distribution. We use artificially layered heterogeneous sandstone cores for experimentation. After completing gas injection and water flooding experiments, the core was positioned with the low permeability layer (LPL) at the top and the high permeability layer (HPL) at the bottom for an extended period. Because the effects of density differences are not easily discernible during gas–water two-phase flow under typical driving forces, we applied micro-CT imaging technology to visualize and analyze how density differences influence gas flow within the core. The results demonstrate that during the static placement period following displacement, gas clusters exhibit different flow behaviors at the pore throats. Most gas clusters struggle to overcome the Jamin effect and enter into the upper pores; a few large-volume gas clusters, driven by density differences, partially pass through the throats into the upper pores, while the remaining portions are stranded within the throats, leading to a snap-off phenomenon; while some gas clusters successfully overcome the Jamin effect and enter the upper pores in significant numbers. The experimental findings indicate that the LPL effectively hinder the upward migration of the nonwetting phase gases from bottom and fluid density differences significantly influence gas–water distribution changes. This study provides critical insights for optimizing CO2storage and offers a new perspective on fluid behavior in layered heterogeneous reservoirs.

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