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Table of Content
28 August 2022, Volume 48 Issue 8
    Pomelo biochar as an electron acceptor to modify graphitic carbon nitride for boosting visible-light-driven photocatalytic degradation of tetracycline
    Feng Guo, Chunli Shi, Wei Sun, Yanan Liu, Xue Lin, Weilong Shi
    2022, 48(8):  1-11.  doi:10.1016/j.cjche.2021.06.027
    Abstract ( 14 )   PDF (9531KB) ( 1 )  
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    In this study, biochar (BC) derived from pomelo was prepared via a high-temperature calcination method to modify the graphitic carbon nitride (g-C3N4) to synthesize the BC/g-C3N4 composite for the degradation of the tetracycline (TC) antibiotic under visible light irradiation. The experimental results exhibit that the optimal feeding weight ratio of biochar/urea is 0.03:1 in BC/g-C3N4 composite could show the best photocatalytic activity with the degradation rate of tetracycline is 83% in 100?min irradiation. The improvement of photocatalytic activity is mainly attributed to the following two points: (i) the strong bonding with π-π stacking between BC and g-C3N4 make the photogenerated electrons of light-excited g-C3N4 transfer to BC, quickly and improve the separation efficiency of carriers; (ii) the introduction of BC reduces the distance for photogenerated electrons to migrate to the surface and increases the specific surface area for providing more active sites. This study provides a sustainable, economical and promising method for the synthesis of photocatalytic materials their application to wastewater treatment.
    Tuning alginate-bentonite microcapsule size and structure for the regulated release of P. putida Rs-198
    Jiawei Dong, Yanhui He, Junfen Zhang, Zhansheng Wu
    2022, 48(8):  12-20.  doi:10.1016/j.cjche.2021.03.056
    Abstract ( 8 )   PDF (6695KB) ( 0 )  
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    In this study, different sizes of microcapsules with alginate and bentonite as natural macromolecular materials were prepared to investigate the release property of Pseudomonas putida Rs-198. The characteristics of three microcapsules were evaluated by SEM, FTIR, TG-DSC, XRD and wall thickness. The sizes of three microcapsules (MA, MB, and MC) were 1270.50, 831.79 and 42.52?μm, respectively. First, the encapsulation efficiency of three MA, MB, and MC microcapsules were 82.20%, 90.41%, and 85.84%, respectively. Second, the contact angles of MA and MB samples were similar, while smaller microcapsules MC have higher contact angle (85.05°), indicating poor hydrophilia and decreasing the swelling degrees. Third, the release cumulant of Rs-198 and macromolecule BSA linear stage was fitted to self-established mathematic model. Results show that the microcapsule size had a considerably positive effect on release detail. The large microcapsule possessed strong leak-tightness for Rs-198 as a slow-release microbial agent. Furthermore, the porosity of microcapsules determined their swelling and release and may affect bacterial growth and survival. In conclusion, the Rs-198 microcapsule with different sizes will be pertinently selected based on the characteristics of agricultural production requirements.
    Molecular reconstruction of vacuum gas oils using a general molecule library through entropy maximization
    Na Wang, Chong Peng, Zhenmin Cheng, Zhiming Zhou
    2022, 48(8):  21-29.  doi:10.1016/j.cjche.2021.06.007
    Abstract ( 6 )   PDF (2993KB) ( 0 )  
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    Vacuum gas oil (VGO) is the most important feedstock for hydrocracking processes in refineries, but its molecular composition cannot be fully acquired by current analysis techniques owing to its complexity. In order to build an accurate and reliable molecular-level kinetic model for reactor design and process optimization, the molecular composition of VGO has to be reconstructed based on limited measurements. In this study, a modified stochastic reconstruction-entropy maximization (SR-REM) algorithm was applied to reconstruct VGOs, with generation of a general molecule library once and for all via the SR method at the first step and adjustment of the molecular abundance of various VGOs via the REM method at the second step. The universality of the molecule library and the effectiveness of the modified SR-REM method were validated by fifteen VGOs (three from the literature) from different geographic regions of the world and with different properties. The simulated properties (density, elemental composition, paraffin-naphthene-aromatics distribution, boiling point distribution, detailed composition of naphthenes and aromatics in terms of ring number as well as composition of S-heterocycles) are in good agreement with the measured counterparts, showing average absolute relative errors of below 10% for each property.
    High-loading Pt-alloy catalysts for boosted oxygen reduction reaction performance
    Wei Hong, Xinran Shen, Jian Wang, Xin Feng, Wenjing Zhang, Jing Li, Zidong Wei
    2022, 48(8):  30-35.  doi:10.1016/j.cjche.2021.10.017
    Abstract ( 3 )   PDF (5338KB) ( 1 )  
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    To improve performance of membrane electrode assembly (MEA) at large current density region, efficient mass transfer at the cathode is desired, for which a feasible strategy is to lower catalyst layer thickness by constructing high loading Pt-alloy catalysts on carbon. But the high loading may induce unwanted particle aggregation. In this work, H-PtNi/C with 33% (mass) Pt loading on carbon and monodisperse distribution of 3.55?nm PtNi nanoparticles, was prepared by a bimodal-pore route. In electrocatalytic oxygen reduction reaction (ORR), H-PtNi/C displays an activity inferior to the low Pt loading catalyst L-PtNi/C (13.3% (mass)) in the half-cell. While in H2-O2 MEA, H-PtNi/C delivers the peak power density of 1.51?W·cm?2 and the mass transfer limiting current density of 4.4?A·cm?2, being 21% and 16% higher than those of L-PtNi/C (1.25?W·cm?2, 3.8?A·cm?2) respectively, which can be ascribed to enhanced mass transfer brought by the thinner catalyst layer in the former. In addition, the same method can be used to prepare PtFe alloy catalyst with a high-Pt loading of 36% (mass). This work may lead to a range of catalyst materials for the large current density applications, such as fuel cell vehicles.
    Location and size regulation of manganese oxides within mesoporous silica for enhanced antibiotic degradation
    Min Lu, Mengxuan Liu, Chunli Xu, Yu Yin, Lei Shi, Hong Wu, Aihua Yuan, Xiao-Ming Ren, Shaobin Wang, Hongqi Sun
    2022, 48(8):  36-43.  doi:10.1016/j.cjche.2021.08.009
    Abstract ( 2 )   PDF (7007KB) ( 0 )  
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    Refractory antibiotics in domestic wastewater are hard to be completely eliminated by conventional methods, and then lead to severe environmental contamination and adverse effects on public health. In present work, advanced oxidation processes (AOPs) are adopted to remove the antibiotic of sulfachloropyridazine (SCP). Nanosized Mn2O3 was fabricated on the SBA-15 material to catalytically activate potassium peroxydisulfate (PDS) to generate reactive oxygen radicals of ?OH and SO4- for SCP degradation. The effects of location and size of Mn2O3 were explored through choosing either the as-made or template-free SBA-15 as the precursor of substrate. Great influences from the site and size of Mn2O3 on the oxidation activity were discovered. It was found that Mn2O3 with a large size at the exterior of SBA-15 (Mn-tfSBA) was slightly easier to degrade SCP at a low manganese loading of 1.0–2.0?mmol?g?1; however, complete SCP removal could only be achieved on the catalyst of Mn2O3 with a refined size at the interior of SBA-15 (Mn-asSBA). Moreover, the SO4- species were revealed to be the decisive radicals in the SCP degradation processes. Exploring the as-made mesoporous silica as a support provides a new idea for the further development of environmentally friendly catalysts.
    Cross-metathesis of biomass to olefins: Molecular catalysis bridging the gap between fossil and bio-energy
    Wenjuan Yan, Zhenchao You, Kexin Meng, Feng Du, Shuxia Zhang, Xin Jin
    2022, 48(8):  44-60.  doi:10.1016/j.cjche.2021.10.008
    Abstract ( 3 )   PDF (11382KB) ( 0 )  
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    Terminal olefins are important building blocks for the industry of biofuels, oligomers, and lubricants production. The industrial processes for production of olefins involving oligomerizationofethylene or cracking of petrochemical waxes have several flaws including low yield and high cost in product separation. Cross-metathesis of bio-derived unsaturated fatty esters and olefins with ethylene (ethenolysis), allows the conversion of sustainable waste biomass to various renewable olefins with much safer, less toxic, sustainable, and zero-CO2 emission processes. To our best knowledge, however, a comprehensive summary of key advances in this field (since 2017) is yet to be available, particularly on molecular features of homogeneous and heterogeneous catalysts. This paper presents a critical review on molecular structures of metal complex and oxide catalysts for ethenolysis of olefins and oleochemicals. The influence of cationic centers, coordination conditions, nature of ligands, operating conditions on catalyst performances will be systematically discussed along with relevant reaction mechanism. The key challenges for rational design of coordinated cationic hybrids have been summarized, which will provide insights to technological advancement of large-scale production of oleochemical-derived olefins.
    Liquid-phase epoxidation of propylene with molecular oxygen by chloride manganese meso-tetraphenylporphyrins
    Xian-Tai Zhou, Ling-Ling Wang, Yang Li, Hong-Bing Ji
    2022, 48(8):  61-65.  doi:10.1016/j.cjche.2021.08.006
    Abstract ( 1 )   PDF (1455KB) ( 0 )  
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    Propylene molecule owns two active sites, the direct epoxidation of propylene by dioxygen is still a challenge due to the limitation of selectivity. In this work, the direct liquid-phase propylene aerobic epoxidation protocol by chloride manganese meso-tetraphenylporphyrin (MnTPPCl) was developed. The conversion of propylene was 12.7%, and the selectivity towards PO (propylene oxide) reached up to 80.5%. The formation of PO was attributed to the mechanism via high-valent Mn species, which was confirmed by means of in situ UV–vis spectrum.
    Enhancing laccase stability and activity for dyes decolorization using ZIF-8@MWCNT nanocomposite
    Pascal Habimana, Yanjun Jiang, Jing Gao, Jean Bernard Ndayambaje, Osama M. Darwesh, Jean Pierre Mwizerwa, Xiaobing Zheng, Li Ma
    2022, 48(8):  66-75.  doi:10.1016/j.cjche.2021.05.044
    Abstract ( 2 )   PDF (4503KB) ( 0 )  
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    The continuous use of chemical dyes in various industries, and their discharge into industrial effluents, results in severe problems to human life and water pollution. Laccases have the ability to decolorize dyes and toxic chemicals in industrial effluents as green biocatalysts. Their possible industrial applications have been limited by poor reusability, low stability, and loss of free laccase action. In this research, laccase was immobilized on zeolitic imidazolate framework coated multi-walled carbon nanotubes (Laccase@ZIF-8@MWCNTs) via metal affinity adsorption to develop an easy separable and stable enzyme. The optimum reaction conditions for immobilized laccase are at a pH of 3.0 and a temperature of 60?℃. The immobilized laccase was enhanced in storage and thermal stability. The results indicated that Laccase@ZIF-8@MWCNTs still maintained 68% of its original activity after 10 times of repeated use. Most importantly, the biocatalytic system was applied for decolorization of different dyes (20?mg·L?1) without a mediator, and up to 97.4% for Eriochrome black T and 95.6% Acid red 88 was achieved in 25 min. Biocatalysts with these properties may be used in a variety of environmental and industrial applications.
    Low-temperature dry reforming of methane tuned by chemical speciations of active sites on the SiO2 and γ-Al2O3 supported Ni and Ni-Ce catalysts
    Yimin Zhang, Ruiming Zeng, Yun Zu, Linhua Zhu, Yi Mei, Yongming Luo, Dedong He
    2022, 48(8):  76-90.  doi:10.1016/j.cjche.2021.08.027
    Abstract ( 1 )   PDF (18714KB) ( 0 )  
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    The cognition of active sites in the Ni-based catalysts plays a vital role and remains a huge challenge in improving catalytic performance of low temperature CO2 dry reforming of methane (LTDRM). In this work, typical catalysts of SiO2 and γ-Al2O3 supported Ni and Ni-Ce were designed and prepared. Importantly, the difference in the chemical speciations of active sites on the Ni-based catalysts is revealed by advanced characterizations and further estimates respective catalytic performance for LTDRM. Results show that larger[Nin0] particles mixed with [Ni-O-Sin]) species on the Ni/SiO2(R) make CH4 excessive decomposition, leading to poor activity and stability. Once the Ce species is doped, however, superior activity (59.0% CH4 and 59.8% CO2 conversions), stability and high H2/CO ratio (0.96) at 600?℃ can be achieved on the Ni-Ce/SiO2(R), in comparison with other catalysts and even reported studies. The improved performance can be ascribed to the formation of integral ([Nin0]-[CeIII-□-CeIII]) species on the Ni-Ce/SiO2(R) catalyst, containing highly dispersed [Nin0] particles and rich oxygen vacancies, which can synergistically establish a new stable balance between gasification of carbon species and CO2 dissociation. With respect to Ni-Ce/γ-Al2O3(R), the Ni and Ce precursors are easily captured by extra-framework Aln-OH groups and further form stable isolated ([Nin0]-[Ni-O-Aln]) and [CeIII-O-Aln] species. In such a case, both of them preferentially accelerate CO2 adsorption and dissociation, causing more carbon deposition due to the disproportionation of superfluous CO product. This deep distinguishment of chemical speciations of active sites can guide us to further develop new efficient Ni-based catalysts for LTDRM in the future.
    Influence of CO2 inleakage on the slight-alkalization of generator internal cooling water
    Tianping Wang, Xuxiang Jia, Yu Wang, Chunsong Ye
    2022, 48(8):  91-97.  doi:10.1016/j.cjche.2021.09.005
    Abstract ( 2 )   PDF (3201KB) ( 0 )  
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    The slight-alkalization of generator internal cooling water (GICW) is widely used to inhibit the corrosion of hollow copper conductor and thereby ensure the safe operation of the generator. CO2 inleakage is increasingly identified as a potential security risk for GICW system. In this paper, the influence of CO2 inleakage on the slight-alkalization of GICW was theoretically discussed. Based on the equilibriums of the CO2-NaOH-H2O system, CO2 inleakage saturation was derived to quantify the amount of the dissolved CO2 in GICW. This parameter can be directly calculated with the measured conductivity and the [Na+] of GICW. The influence of CO2 inleakage on the slight-alkalization conditioning of GICW and the measurement of its water quality parameters were then analyzed. The more severe the inleakage, the narrower the water quality operation ranges of GICW, resulting in the more difficult the slight-alkalization conditioning of GICW. The temperature calibrations of the conductivity and the pH value of GICW show non-linear correlations with the amount of CO2 inleakage and the NaOH dosage. This study provides insights into the influence of CO2 inleakage on the slight-alkalization of GICW, which can serve as the theoretical basis for the actual slight-alkalization when CO2 inleakage occurs.
    Investigation of the redox performance of pyrite cinder calcined at different temperature in chemical looping combustion
    Zhong Ma, Guofu Liu, Hui Zhang, Yonggang Lu
    2022, 48(8):  98-105.  doi:10.1016/j.cjche.2021.11.015
    Abstract ( 2 )   PDF (6284KB) ( 0 )  
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    As an industrial solid waste, pyrite cinder exhibited excellent reactivity and cycle stability in chemical looping combustion. Prior to the experiment, oxygen carriers often experienced a high temperature calcination process to stabilize the physico-chemical properties, which presented significant influence on the redox performance of oxygen carriers. However, the effect of calcination temperature on the cyclic reaction performance of pyrite cinder has not been studied in detail. In this work, the effect of calcination temperature on the redox activity and attrition characteristic of pyrite cinder were studied in a fluidized-bed reactor using CH4 as fuel. A series of pyrite cinder samples were prepared by controlling the calcination temperature. The redox activity and attrition rate of the obtained pyrite cinder samples were investigated deeply. The results showed that calcination temperature displayed significant impact on the redox performance of pyrite cinder. Considering CH4 conversion (80%–85%) and attrition resistance, the pyrite cinder calcined at 1050?℃ presented excellent redox properties. In the whole experiment process, the CO2 selectivity of the pyrite cinder samples were not affected by the calcination temperature and were still close to 100%. The results can provide reference for optimizing the calcination temperature of pyrite cinder during chemical looping process.
    In situ investigation of lysozyme adsorption into polyelectrolyte brushes by quartz crystal microbalance with dissipation
    Fenfen You, Qing-Hong Shi
    2022, 48(8):  106-115.  doi:10.1016/j.cjche.2021.04.016
    Abstract ( 1 )   PDF (8793KB) ( 0 )  
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    A well understanding about protein adsorption into charged polymer brushes is of importance in the elucidation of mechanism and important phenomena (such as “chain delivery” effect) in protein adsorption on polymer-grafted ion exchange adsorbents. In this work, quartz crystal microbalance with dissipation (QCM-D) was introduced to in situ investigate lysozyme adsorption on QCM sensors grafted with poly(3-sulfopropyl methacrylate) (pSPM) via atom transfer radical polymerization. It was achieved by analyzing frequency (f) and energy dissipation (D) shift simultaneously on pSPM-grafted sensors. The result showed that an initial decrease in ΔD was typical of lysozyme adsorption on pSPM-grafted sensor and more significant with an increase of chain length and grafting density. It was attributed to significant water release in the hydration layer of protein and polymer chains in lysozyme adsorption into pSPM brushes. On pSPM-grafted sensors with long and dense chains, furthermore, lysozyme transitioned from monolayer to multilayer adsorption and the maximum adsorbed amount was obtained to be 374.0?ng·cm?2 among all pSPM-grafted sensors in this work. The results in D-f plot further revealed that lysozyme adsorption into pSPM brushes increased the rigidity of adsorbed layer and little structure adjustment of adsorbed lysozyme. It was unfavorable for “chain delivery” effect for facilitated transport of adsorbed protein. This work provided valuable insight into protein adsorption in pSPM brushes and outlined a feasible approach to increasing mass transport in polymer-grafted ion exchange adsorbents.
    Controllable and high-throughput preparation of microdroplet using an ultra-high speed rotating packed bed
    Jing Xie, Xiangbi Jia, Dan Wang, Yingjiao Li, Bao-chang Sun, Yong Luo, Guang-wen Chu, Jian-feng Chen
    2022, 48(8):  116-124.  doi:10.1016/j.cjche.2021.04.011
    Abstract ( 2 )   PDF (6226KB) ( 1 )  
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    Microdroplets and their dispersion, with a large specific surface area and a short diffusion distance, have been applied in various unit operations and reaction processes. However, it is still a challenge to control the size and size distribution of microdroplets, especially for high-throughput generation. In this work, a novel ultra-high speed rotating packed bed (UHS-RPB) was invented, in which rotating foam packing with a speed of 4000–12000 r·min?1 provides microfluidic channels to disperse liquid into microdroplets with high throughput. Then generated microdroplets can be directly dispersed into a continuous falling film for obtaining a mixture of microdroplet dispersion. In this UHS-RPB, the effects of rotational speed, liquid initial velocity, liquid viscosity, liquid surface tension and packing pore size on the average size (d32) and size distribution of microdroplets were systematically investigated. Results showed that the UHS-RPB could produce microdroplets with a d32 of 25–63?μm at a liquid flow rate of 1025 L·h?1, and the size distribution of the microdroplets accords well with Rosin–Rammler distribution model. In addition, a correlation was established for the prediction of d32, and the predicted d32 was in good agreement with the experimental data with a deviation within?±?15%. These results demonstrated that UHS-RPB could be a promising candidate for controllable preparation of uniform microdroplets.
    Fuzzy optimization design of multicomponent refinery hydrogen network
    Chun Deng, Xuantong Lu, Qixin Zhang, Jian Liu, Jui-Yuan Lee, Xiao Feng
    2022, 48(8):  125-139.  doi:10.1016/j.cjche.2021.04.014
    Abstract ( 2 )   PDF (8098KB) ( 0 )  
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    Hydrogen and light hydrocarbon components are essential resources of the refinery. The optimization of the refinery hydrogen system and recovery of the light hydrocarbon components contained in the gas streams are key strategies to reduce the operating costs for sustainable development. Many research efforts have been focused on the optimization of single impurity hydrogen network, and the flowrates of the hydrogen sources and sinks are assumed to be constant. However, their flowrates vary along with the quality of crude oil and refinery processing plans. A general superstructure of multicomponent refinery hydrogen network is proposed, which considers four components, namely H2, H2S, CH4 and , as well as the flowrate variations of hydrogen source and hydrogen sink. The mathematical model based on the superstructure is developed with objective functions, including the minimization of total annualized cost and the maximization of overall satisfaction of the hydrogen network. Moreover, the model considers the removal of hydrogen sulfide and the recovery of light hydrocarbon components (i.e.C2+, ) in the optimization. To verify the applicability of the proposed mathematical model, a simplified industrial case study with four scenarios is solved. The optimization results show that the economic benefit can be maximized by considering both the direct reuse of gas streams from high-pressure separator (HP gas stream) and from low-pressure separator (LP gas stream) and the recovery of the light hydrocarbon streams. The fuzzy optimization method can be used to guide the optimal design of the refinery hydrogen system with multi-period variable flowrates.
    Systematic investigation of SO2 adsorption and desorption by porous powdered activated coke: Interaction between adsorption temperature and desorption energy consumption
    Jun Li, Liqiang Zhang, Xiao Zhu, Mengze Zhang, Tai Feng, Xiqiang Zhao, Tao Wang, Zhanlong Song, Chunyuan Ma
    2022, 48(8):  140-148.  doi:10.1016/j.cjche.2021.08.002
    Abstract ( 2 )   PDF (4970KB) ( 1 )  
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    Porous carbon materials have been widely used for the removal of SO2 from flue gas. The main objective of this work is to clarify the effects of adsorption temperature on SO2 adsorption and desorption energy consumption. Coal-based porous powdered activated coke (PPAC) prepared in the drop-tube reactor was used in this study. The N2 adsorption measurements and Fourier transform infrared spectrometer analysis show that PPAC exhibits a developed pore structure and rich functional groups. The experimental results show that with a decrease in adsorption temperature in the range of 50–150?℃, the adsorption capacity of SO2 increases linearly; meanwhile, the adsorption capacity of H2O increases, resulting in the increase in desorption energy consumption per unit mass of adsorbent. The processes of SO2 and H2O desorption were determined by the temperature-programmed desorption test, and the desorption energies for each species were calculated. Considering the energy consumption per unit of desorption and the total amount of adsorbent, the optimal adsorption temperature yielding the minimum total energy consumption of regeneration is calculated. This study systematically demonstrates the effect of adsorption temperature on the adsorption–desorption process, providing a basis for energy saving and emission reduction in desulfurization system design.
    Co-adsorption behaviors of asphaltenes and different flow improvers and their impacts on the interfacial viscoelasticity
    Hao Zhang, Daiwei Liu, Jiangbo Wen, Guangyu Sun, Chuanxian Li, Xinya Chen, Huihui Zhang, Ze Duan
    2022, 48(8):  149-157.  doi:10.1016/j.cjche.2021.08.018
    Abstract ( 1 )   PDF (4398KB) ( 0 )  
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    Commonly used flow improvers in oilfields, such as ethylene–vinyl acetate copolymer (EVA), poly(octadecyl acrylate) (POA), and polymethylsilsesquioxane (PMSQ) are proven to be effective to enhance the flowability of crude oil. However, the addition of these flow improvers may change the stability of the emulsion and make the crude oil treatment process challenging. In this research, the impacts of different flow improvers on the interfacial properties of the emulsions containing asphaltenes are systematically investigated. The co-adsorption behaviors of the flow improvers and asphaltenes are analyzed through dynamic interfacial tension (DIFT). The rheological properties of the interfacial layer after the adsorption are explored via dilational viscoelasticity. Significant difference is observed in the structural properties of the interface adsorbed by different flow improvers, which is attributed to different interactions between the flow improvers and asphaltenes. To investigate these interactions, conductivity, asphaltenes precipitation, dynamic light scattering (DLS), and contact angle experiments are conducted systematically. Results show that EVA and POA can alter the interfacial properties by changing the asphaltene dispersion state. The interaction between EVA and asphaltenes is stronger than that between POA and asphaltenes due to the difference in molecular structures. Unlike EVA and POA, the change of interfacial property with the addition of PMSQ is attributed to the partial adsorption of asphaltenes on PMSQ.
    A route for the study on mass transfer enhancement by adding particles in liquid phase
    Xing Su, Ning Qiao, Bao-Chang Sun
    2022, 48(8):  158-165.  doi:10.1016/j.cjche.2022.05.013
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    This work presents a route for the study on the absorption performance of gas into liquid under the condition of adding particles in a stirred constant temperature reactor. Two evaluated systems, hydrogen–water and hydrogen–methanol, with the addition of activated carbon particles (ACP) were carried out, respectively. The results showed that the addition of ACP into the water can enhance the mass transfer between hydrogen and water, the enhancement factor increases rapidly with the increase of the ACP content, and then tends to be unchanged. However, for the hydrogen–methanol system, ACP has little effect on the mass transfer performance. In addition, a gas–liquid mass transfer model considering the effect of solid particle enhancement was established based on the shuttle effect and two-film model. Results indicated that the predicted value agreed well with the experimental value in both hydrogen–methanol–ACP and hydrogen–water–ACP systems.
    A new method to forecast multi-time scale load of natural gas based on augmentation data-machine learning model
    Denglong Ma, Ruitao Wu, Zekang Li, Kang Cen, Jianmin Gao, Zaoxiao Zhang
    2022, 48(8):  166-175.  doi:10.1016/j.cjche.2021.11.023
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    Gas load forecasting is important for the economic and reliable operation of the city gas transmission and distribution system. In this paper, a nonlinear autoregressive model (NARX) with exogenous inputs, support vector machine (SVM), Gaussian process regression (GPR) and ensemble tree model (ETREE) were used to predict and compare the gas load based on the gas load data in a certain region for past 3?years. The results showed that the prediction errors for most of days were higher than 10%. Further, simulation data were generated by considering the gas load variation trend, which was then combined with historical data to form the augmentation data set to train the model. The test results indicated that the prediction error of daily gas load in one year reduced to below 7% with a machine learning prediction method based on augmentation data. In addition, the model based on augmentation data set still performed better than original data in predicting the monthly gas load in last year as well as daily gas load in last month and week. Therefore, the method based on augmentation data proposed in this paper is a potentially good tool to forecast natural gas load.
    Glycerol steam reforming over hydrothermal synthetic Ni-Ca/attapulgite for green hydrogen generation
    Yishuang Wang, Na Li, Mingqiang Chen, Defang Liang, Chang Li, Quan Liu, Zhonglian Yang, Jun Wang
    2022, 48(8):  176-190.  doi:10.1016/j.cjche.2021.11.004
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    Glycerol steam reforming (GSR) is one of the promising technologies that can realize renewable hydrogen production and efficient utilization of crude glycerol. To illuminate the functions of Ca content (3%, 6%, 9%, and 12%, by mass) and preparation method for Ni/ATP catalyst structure and its catalytic behaviors, the Ni-xCa/ATP (x?=?3%, 6%, 9%, and 12%, by mass) catalysts are prepared by co-impregnation (ci) and hydrothermal synthesis (hs) method and then tested in GSR. Characterization results of XRD, N2 adsorption–desorption, H2-TPR, HRTEM, XPS, and NH3/CO2-TPD demonstrate that the combined effect between appropriate Ca additive (6%, by mass) and hs enhance catalyst reducibility, uniform distribution of Ca additive and nickel species over ATP, and adsorption for CO2. This attributes to hs method protects the ATP framework through suppressing the interaction of Ca with ATP and promotes the formation of Ni-CaO interface sites. Therefore, Ni-6Ca/ATP-hs exhibits the highest conversion (86.77%) of glycerol to gas product and H2 yield (76.17%) and selectivity (58.56%) during GSR. Furthermore, XRD, HRTEM, TG-DTG and Raman analyses confirm that Ni-6Ca/ATP-hs also reveals outstanding anti-sintering and coke resistance. In addition, the structural evolution process of Ni/ATP catalyst with Ca introduction and hs method is presented. Considering the high performance, simple preparation process and low cost, the as-prepared catalyst providing new opportunities for utilization of glycerol derived from biodiesel industry.
    Insights into depolymerization pathways and mechanism of alkali lignin over a Ni1.2–ZrO2/WO3/γ-Al2O3 catalyst
    Xinyu Lu, Dandan Wang, Haoquan Guo, Pengcheng Xiu, Jiajia Chen, Yu Qin, Hossain Mahmud Robin, Chaozhong Xu, Xingguang Zhang, Xiaoli Gu
    2022, 48(8):  191-201.  doi:10.1016/j.cjche.2021.07.018
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    This study performed catalytic depolymerization of alkali lignin over Ni-based catalysts. Effects of different promoters (Zr and W), Ni loadings, reaction temperatures, and the addition of formic acid and catalyst on lignin conversion and products distribution were all investigated. The result showed that the highest oil yield (40.1% (mass)) was obtained at 240?℃ over Ni1.2/γ-Al2O3 promoted by Zr and W species. Quantitative analysis indicates that Zr and W species prefer to lignin depolymerization while Ni active phase prefer to hydrodeoxygenation and hydrogenation. The interconversion of products derived from lignin depolymerization was determined by gas chromatography-mass spectrometer, which demonstrated that phenolic compounds were dominant products in all lignin derived bio-oils, wherein the proportion of vanillin was highest (65.7%) at 180?℃, while that of alkyl guaiacols increased with the increase of temperature (from 12.45% at 180?℃ to 66.67% at 240?℃). Residual lignin obtained after lignin depolymerization was also investigated for detecting differences on functional groups, wherein the disappearing peaks at 1511?cm?1 (stretching of aromatic rings), 1267, 1215 and 1035?cm?1 (vibrations of guaiacyl and syringyl units) were detected by Fourier transform infrared spectrometry. Additionally, the higher O/C ratio measured by elemental analysis also confirmed that alkali lignin was depolymerized effectively under mild conditions.
    Research on prediction model of formation temperature of ammonium bisulfate in air preheater of coal-fired power plant
    Kai Zhang, Fangming Xue, Zhiqiang Wang, Xingxing Cheng
    2022, 48(8):  202-210.  doi:10.1016/j.cjche.2021.09.018
    Abstract ( 1 )   PDF (3389KB) ( 0 )  
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    Ammonium bisulfate (ABS) is a viscous compound produced by the escape NH3 in the NO reduction process and SO3 in the flue gas at a certain temperature, which can cause the ash corrosion of the air preheater in coal-fired power plants. Therefore, it is essential to study the formation temperature of ABS to prevent the deposition of ABS in air preheaters. In this paper, the SO3 reaction kinetic model is used to analyze the SO3 generation process from coal combustion to the selective catalytic reduction (SCR) exit stage, and the kinetic model of NO reduction is used to analyze the NH3 escape process. A prediction model for calculating the ABS formation temperature based on the S content in coal and NO reduction parameters of the SCR is proposed, solving the difficulty of measuring SO3 concentration and NH3 concentration in the previous calculation equation of ABS formation temperature. And the reliability of the model is verified by the actual data of the power plant. Then the influence of S content in coal, NH3/ NOx molar ratio, different NOx concentrations at SCR inlet, and NO removal efficiency on the formation temperature of ABS are analyzed.
    An international comprehensive benchmarking analysis of synthetic biology in China from 2015 to 2020
    Meiru Jiang, Cong Chen, Tao Chen, Chao Zhao, Zhiwen Wang
    2022, 48(8):  211-226.  doi:10.1016/j.cjche.2021.05.036
    Abstract ( 1 )   PDF (11624KB) ( 0 )  
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    As a new interdisciplinary field, synthetic biology has led to valuable innovations in the fields of medicine, chemistry, agriculture, energy and environment. In this paper, we systematically review the development status of global synthetic biology in the past six years, and make an in-depth benchmarking analysis of the field in China. With the aid of Scopus and SciVal, we analyze the scholarly output of synthetic biology in the world and individual countries, including publication distribution, popular journals and eminent institutions. Furthermore, the research focus and concepts, citation impact and collaborations are also examined using numerical index methods such as the field-weighted citation impact (FWCI) and relative activity index (RAI), showing the differences between data more intuitively. This study aims to offer a comprehensive understanding of the research status of synthetic biology in China and the world, offering a benchmarked overview of the results as a reference to guide the development of this field in the future.
    Chiral LVFFARK enantioselectively inhibits amyloid-β protein fibrillogenesis
    Wei Liu, Xueting Sun, Xiaoyan Dong, Yan Sun
    2022, 48(8):  227-235.  doi:10.1016/j.cjche.2021.05.033
    Abstract ( 1 )   PDF (5923KB) ( 0 )  
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    The modulation of protein aggregation is involved not only in biochemical engineering processes, but also in in vivo biological events such as Alzheimer’s disease (AD) that features amyloid-β protein (Aβ) deposits. Inspired by the different pharmacological efficacy of enantiomers, taking heptapeptide LVFFARK (LK7) as an example, herein the chiral influence of peptide inhibitors on Aβ fibrillogenesis and cytotoxicity was investigated by extensive biophysical and biological analyses. It was intriguing to find that although both L-LK7 and D-LK7 could inhibit Aβ aggregation in a concentration-dependent manner, it was the d-enantiomer that exhibited chirality preference and selectivity for modulation of Aβ self-assembly. As compared with L-LK7 at the same conditions, D-LK7 showed significantly enhanced potency on suppressing cross-β sheet formation, fibrillar Aβ aggregates deposition, Aβ conformational transition, and Aβ-triggered neurotoxicity on cultured cells. For instance, L-LK7 and D-LK7 rescued cells by increasing cell viability from 60% to 62% and 84% at 100?μmol·L?1, respectively. The chiral discrimination of L-LK7 and D-LK7 was further validated by the different elimination efficiency on amyloid accumulation in AD model nematodes. It is considered that the higher binding affinity of D-LK7 to Aβ monomers than that of L-LK7 resulted in the stronger inhibition effect. This work provided new insights into understanding chirality in the interaction with Aβ and the consequent inhibitory effect, and would contribute to the design of anti-amyloid agents.
    Crystallization thermodynamics of 2,4(5)-dinitroimidazole in eleven pure solvents
    Pengbao Lian, Lizhen Chen, Daozhen Huang, Jianxin Xu, Zishuai Xu, Cai Cao, Jiaxiang Zhao, Jianlong Wang
    2022, 48(8):  236-243.  doi:10.1016/j.cjche.2021.07.031
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    2,4(5)-Dinitroimidazole (2,4(5)-DNI) is an important energetic material, and it is also an important precursor for the preparation of drugs and energetic materials. In this study, the solubility of 2,4(5)-DNI in eleven pure solvents (chlorobenzene, benzene, 1,2-dichloroethane, toluene, water, isopropyl alcohol, ethyl acetate, acetonitrile, methanol, 1,4-dioxane and acetone) were measured by using a dynamic test method from 278.15?K to 323.15?K under 101.1?kPa. Four solubility models were used to fit the experimental data, which were ideal model, modified Apelblat equation, polynomial empirical equation, and λh equation. Meanwhile, the relative average deviation and root-mean-square deviation between the experimental data and the fitted data were also calculated. Furthermore, the three thermodynamic parameters, i.e., dissolution enthalpy, dissolution entropy and Gibbs energy were obtained based on solubility data. Finally, the crude product of 2,4(5)-DNI was crystallized with acetone as solvent, and the purity of the crystalline product was greater than 99.5%.
    Preparation and functional study of pH-sensitive amorphous calcium phosphate nanocarriers
    Baolong Niu, Min Li, Jianhong Jia, Lixuan Ren, Xin Gang, Bin Nie, Yanying Fan, Xiaojie Lian, Wenfeng Li
    2022, 48(8):  244-252.  doi:10.1016/j.cjche.2021.08.025
    Abstract ( 2 )   PDF (12943KB) ( 1 )  
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    Recently, multifunctional nanoparticles have shown great prospects in cancer treatment, which have the ability to simultaneously deliver the drug, image and target tumor cells. In this paper, we designed a luminescent nanoparticles platform based on hydrothermal hyaluronic acid/amorphous calcium phosphate (HA-FCNs/ACP) with multifunctional properties for drug delivery, bio-imaging, and targeting treatment. HA-FCNs/ACP shows an ability to load curcumin (Cur) with pH-sensitive responsive drug release behavior and excellent biocompatibility. HA-FCNs/ACP dispersed in the cytoplasm through the overexpressed CD44 receptor that is actively targeted into human lung cancer cells (A549 cells). Meanwhile, the viability of A549 cells was significantly inhibited in vitro. The prepared HA-FCNs and HA-FCNs/ACP both exhibit excellent targeted bioimaging performance on cancer cells. Hence, the as-prepared nanoparticles have promising applications in treating tumor disease.