Please wait a minute...
Table of Content
05 January 2018, Volume 69 Issue 1
    Preliminary study on controlling nanoconfined fluid behavior and modelling molecular thermodynamics: progress in development of high-specific surface area TiO2
    LU Xiaohua, JIANG Guancong, ZHU Yudan, FENG Xin, LÜ Linghong
    2018, 69(1):  1-8.  doi:10.11949/j.issn.0438-1157.20171495
    Abstract ( 442 )   PDF (2713KB) ( 994 )  
    References | Related Articles | Metrics

    Due to prominent influence of interfacial properties and complicated coupling effect of diffusion and reaction mechanisms, molecular behaviors of nanoconfined fluid at interface are difficult to control which becomes a bottleneck of new technology development (e.g. membrane process, heterogeneous catalysis) in modern chemical industry. Confinement behavior of fluid molecules at interface was studied on chemically stable high-specific surface area titanium oxide on the basis of recent research progress of this group. The effects of diffusion and reaction mechanisms on interfacial fluid behaviors were assessed separately and controlling mechanism was explored. Further, preliminary study on proposed molecular thermodynamic model was performed by atomic force microscopy, which was able to correlate interfacial friction and molecular interaction, and to provide molecular parameters for the thermodynamic model.

    Dancing droplet: interface phenomena and process regulation
    MA Xuehu, LAN Zhong, WANG Kai, CHEN Yansong, CHENG Yaqi, DU Bingang, YE Xuan
    2018, 69(1):  9-43.  doi:10.11949/j.issn.0438-1157.20171230
    Abstract ( 922 )   PDF (4259KB) ( 1040 )  
    References | Related Articles | Metrics

    The droplets with different dynamics exist in a variety of industry, including phase change heat transfer, micro-scale chemical engineering, spray cooling, pesticide spraying and microfluidic chip. Interface phenomena has been proved a very important factor for droplet dynamics, which is one of the arc in the field of droplet manipulation. In the past decades, researchers have carried out a series of scientific researches on multiscale wetting, interfacial effect-driven droplet dynamic behaviors, and achieved distinctive and innovative results. In this review, the theoretical basis of multi-scale wetting is presented firstly. Secondly, liquid-solid interfacial interactions in the process of the droplet nucleation, the wetting of liquid on nano and micro structures, droplet jumping, droplet multi-directional migration, and impact of droplet are discussed in detail. Meanwhile, the typical applications of droplet dynamics manipulation such as phase change heat transfer, inkjet printing, pesticide spraying, and microfluidic chip are introduced. Finally, the perspectives of the future development of droplet manipulation are proposed for further intensification and control of related industrial processes.

    Overview of microinterface intensification in multiphase reaction systems
    ZHANG Zhibing, TIAN Hongzhou, ZHANG Feng, ZHOU Zheng
    2018, 69(1):  44-49.  doi:10.11949/j.issn.0438-1157.20171400
    Abstract ( 748 )   PDF (836KB) ( 1153 )  
    References | Related Articles | Metrics

    Gas-liquid systems with low reaction rates such as hydrogenation and oxidation are widely present in modern industrial processes. These reactions are generally controlled by mass transfer. Therefore, mass transfer intensification in multiphase reaction systems has been one research hotspot in chemical engineering. Except studies on reactors intensified by external field or micro-channel (micro-fluidics), most studies were focused on traditional reactors with interface scale of millimeter to centimeter by means of stirring and mixing, bubble size distribution, flow pattern, and structure-effect relationship. It has rarely been studied how to build a microinterface system and to evaluate its effects in reactors with a diameter of several meters. In this paper, the microinterface reaction intensification in heterogeneous systems was discussed. The micro-interface definition, microinterface reaction intensification, structure-effect regulation, structure and formation principle of microinterface reactors, techniques of microparticle measurement and interface characterization were briefly described. The challenges and problems in microinterface reaction intensification was also presented for discussion.

    Membrane separation based on mechanism of confined mass transfer
    JIN Wanqin, XU Nanping
    2018, 69(1):  50-56.  doi:10.11949/j.issn.0438-1157.20171124
    Abstract ( 705 )   PDF (3056KB) ( 1316 )  
    References | Related Articles | Metrics

    In this article, the research background and current status of membrane separation based on confined mass transfer are stated. The key scientific problems of this field and the corresponding research ideas for the problems are analyzed in detail. The current research progresses of membranes based on confined mass transfer in China are summarized. The possible directions of future study are proposed.

    Cryogen transient flashing spray cooling: state of art
    CHEN Bin, ZHOU Zhifu, XIN Hui
    2018, 69(1):  57-68.  doi:10.11949/j.issn.0438-1157.20171012
    Abstract ( 531 )   PDF (1286KB) ( 630 )  
    References | Related Articles | Metrics

    With the rapid development of laser dermatology, the epidermis cooling technology becomes more and more important, and it is of great potential for commercial application. Cryogen spray cooling (CSC) with several tens of milliseconds has been successfully applied in laser treatment of vascular diseases, which can protect epidermis from the thermal injuries due to the absorption of melanin and hence increase the incident laser energy, leading to the improvement in therapeutic outcomes. CSC involves flashing atomization and boiling heat transfer on cooling surface. The majority of previous studies were conducted experimentally. The research progresses of the mechanism of flashing atomization, spray characteristics, heat transfer dynamics and the enhancement were summarized for the past 20 years. The typical research methods and results were compared and analyzed, and the different factors to influence the heat transfer dynamics of CSC were investigated. New spray techniques, such as using lower point cryogens and hypobaric pressure method, are effective to enhance cooling capacity. Finally, the remaining difficulties in this field were clarified and the potentials of the ongoing research were pointed out.

    Review and prospect of CO2 electro-reduction in ionic liquids
    FENG Jianpeng, ZHANG Xiangping, SHANG Dawei, GAO Hongshuai
    2018, 69(1):  69-75.  doi:10.11949/j.issn.0438-1157.20170992
    Abstract ( 478 )   PDF (552KB) ( 773 )  
    References | Related Articles | Metrics

    The increasing emission of carbon dioxide (CO2) caused by unrestrained consumption of fossil fuel in recent hundred years has created globally ecological, environmental, and social problems. On the other hand, CO2 is also a cheap, abundant and renewable C1-feedstock, which can be converted into alcohols, ethers, acids and other chemicals. Compared to many other CO2 recycle techniques, electrochemical reduction of CO2 is more attractive for its clean and controllable process to produce chemicals under mild conditions. This review summarized recent research progresses in electrochemical reduction of CO2 in ionic liquid (ILs) electrolytes. First, major reactions and mechanism of CO2 electro-reaction in ILs were introduced. Then, scientific challenges of ILs on efficient CO2 activation and conversion were discussed. Finally, the application of new functional ILs should be taken as future research focus in CO2 electrochemical reduction.

    Research progress of chemical process stability analysis
    JIANG Hao, CHEN Bingzhen
    2018, 69(1):  76-87.  doi:10.11949/j.issn.0438-1157.20170883
    Abstract ( 621 )   PDF (846KB) ( 798 )  
    References | Related Articles | Metrics

    Chemical processes may experience a large number of disturbances. Stability is a key of chemical process operability, related to product quality and process safety directly. It is a criterion to determine whether a process can return to its original operating point when disturbance disappears. The research on stability can help to understand and adjust the nonlinear behaviors in chemical processes, such as multiple steady state and oscillation. Therefore, with the consideration of stability analysis, the chemical processes can be operated smoothly and safely under disturbance for a long time. This review concludes the progress in stability analysis from four aspects:multiple steady state and stability analysis, optimization with guaranteed stability, dynamic behavior adjustment of chemical processes, and stability analysis under uncertainty.

    Research progress in synthesis of (-)-Ambrox
    YANG Shaoxiang, TIAN Hongyu, LIU Yongguo, DING Rui, SUN Baoguo
    2018, 69(1):  88-101.  doi:10.11949/j.issn.0438-1157.20171017
    Abstract ( 893 )   PDF (1523KB) ( 892 )  
    References | Related Articles | Metrics

    (-)-Ambrox has been recognized as the prototype of all ambergris odorants and used as a valuable ingredient in various flavor and fragrance formulations, because of its unique scent and scent fixative function. In current commercial synthesis processes of (-)-Ambrox, major starting raw materials include sclareol, β-dihydroionone and homofarnesol. All these chemical routes have many problems in terms of green chemistry. This review summarized recent progress in Ambrox synthesis and especially expounded progress with sclareol. Among them, one-pot synthesis using sclareol and hydrogen peroxide in the presence of polyoxometalates catalyst has advantages of easy operation and low pollution, which is a potential green synthetic technique.

    Sonochemical microreactor-synergistic intensification of ultrasound and microreactor
    DONG Zhengya, CHEN Guangwen, ZHAO Shuainan, YUAN Quan
    2018, 69(1):  102-115.  doi:10.11949/j.issn.0438-1157.20171366
    Abstract ( 595 )   PDF (19624KB) ( 342 )  
    References | Related Articles | Metrics

    Both microreactor and sonochemistry technologies are important means to enhance chemical process, regardless of advantages and disadvantages in each technique. The concept of “sonochemical microreactor” is elucidated, which synergistic intensification can be achieved by integration of microreactor with sonochemistry technology. Ultrasound is used to intensify fluid mixing, enhance multi-phase mass transfer, prevent and dredge clogging in microchannel. In the meantime, microreactor is used to effectively control sound and bubble fields, and resolve scaling-up challenges of acoustic cavitation process. Further, acoustic cavitation behavior, regulation law of sound and bubble fields in sonochemical microreactor, and intensification mechanism of multi-phase mixing and mass transfer are presented indetail. Finally, future development direction in this area is envisioned. Further study on the spatiotemporal phenomena at ultrasonic cavitation interface is the fundamental for realization and optimization of ultrasonic intensification.

    Thermodynamics and topology in methanol conversion process over zeolites
    CAI Dali, ZHANG Chenxi, HOU Yilin, CHEN Zhaohui, WANG Yao, CUI Yu, WEI Fei
    2018, 69(1):  116-127.  doi:10.11949/j.issn.0438-1157.20171231
    Abstract ( 425 )   PDF (7004KB) ( 331 )  
    References | Related Articles | Metrics

    Novel modern coal chemical technology is not only a new sparkling spot in development of fundamental organic chemical industry in China, but also another revolution in chemical industry worldwide. Coal manufacturing processes for chemical products include gasification, water gas shift, methanol synthesis, and methanol conversion to hydrocarbon, which methanol conversion over zeolites plays a key role. Related researches on methanol conversion were reviewed in both thermodynamics and topological model. The thermodynamic equilibrium model for conversion of multimethylbenzene to olefins and thermodynamics mechanism of olefin formation were studied from thermodynamic mechanism and product distributions of hydrocarbons and olefins synthesized from methanol conversion over ZSM-5 catalyst. The zeolite topological structure model was based on discrete Ising model. Phase-transition phenomenon in SAPO-34 deactivation and non-uniform distribution of coke was explained from similarity between zeolite channel blockage and “liberty” in the game of Go. Guided by these models, work on designing hierarchical structures of zeolites were illustrated, which greatly enhanced selectivity and lifetime of catalysts. These concepts show their importance for accurately understanding mechanisms of methanol reaction on zeolites and zeolite deactivation, product distribution and enhancement of catalyst selectivity.

    Progress in inorganic nanomedicine carriers for tumor diagnosis and treatments
    KANG Yao, WANG Suzhen, FAN Jiangli, PENG Xiaojun
    2018, 69(1):  128-140.  doi:10.11949/j.issn.0438-1157.20171179
    Abstract ( 777 )   PDF (46139KB) ( 948 )  
    References | Related Articles | Metrics

    Nanomedicine, as an integrated platform, has the potential to accurately monitor tumor for early diagnosis and dramatically improve the targeted, long-lasting and combinational therapy. Compared with traditional therapeutics, nanomedicine would effectively improve the drug accumulationand controlled release in the tumor sites to improve the therapeutic effect. Recently, all kinds of nanomedicines are designed and synthesized for tumor diagnosis and treatment based on inorganic nanocarriers, such as quantum dots, gold nanoparticles, silicon nanoparticles and so on. They might be adjusted and promoted their properties by core-shell structure, surface modification and other strategies. In this review, the inorganic nanometer materials as nano drug carriers applied in tumor diagnosis and treatment were summarized; nano drug design strategies and mechanisms of tumor diagnosis and treatment were introduced in detail, and the future of inorganic nano drugs in tumor diagnosis and treatment of clinical application was prospected.

    Research and development on technique of lithium recovery from salt lake brine
    LIU Dongfan, SUN Shuying, YU Jianguo
    2018, 69(1):  141-155.  doi:10.11949/j.issn.0438-1157.20171164
    Abstract ( 971 )   PDF (768KB) ( 1255 )  
    References | Related Articles | Metrics

    In recent years, as the development of nuclear power, the aerospace and the electric car industry, the global lithium demand increases every year. The lithium resources from brine account for about 65% of global lithium resources and 58% of global lithium products are obtained from brine. Hence, more and more researchers focus on the materials, technique and devices of lithium recovery from brine for more than a decade. The key technique of lithium recovery from brine, including precipitation, membrane, extraction and adsorption, is analyzed according to the characteristic of lithium resources around the world, particularly in China. Besides, the feasibility and future research interests of each technique are reviewed.

    Molecular simulation on interfacial behaviors of protein at chromatographic surfa
    ZHANG Lin, SUN Yan
    2018, 69(1):  156-165.  doi:10.11949/j.issn.0438-1157.20171214
    Abstract ( 326 )   PDF (1983KB) ( 316 )  
    References | Related Articles | Metrics

    Protein behavior at chromatographic surface is a fundamental significance for the improvement on the adsorption capacity, the recovery yield of native protein, and the mass transfer in protein chromatography. Molecular simulation, a research tool with unique advantages in the examination of microscopic process, has been widely used to explore the molecular insights into adsorption phenomena at chromatographic surface. This article focuses on an overview of the molecular simulation studies on protein behavior at chromatographic interface, including protein orientation, conformational transitions, and protein transport. First of all, the simulation results about protein orientation at chromatographic surface are summarized, with emphasis on the dominant factors controlling this process. The possible improvement on adsorption capacity by the regulation of protein orientation is discussed. Then, simulation studies on the protein conformational transition at chromatographic surface are summarized, especially on the protein unfolding process. The possible enhancement on recovery yield of native protein by manipulating protein structure is discussed. Finally, the simulations about protein transport within adsorbents are presented, and accomplished with the discussion on the challenge to examine the mass transfer in chromatography using molecular simulations. Based on the successful applications reviewed herein, the application of molecular simulation to explore the microscopic process related to adsorption capacity, native yield and mass transfer at chromatographic surface is concluded. This would be helpful for the rational design of chromatographic surface and thus the development of high-performance protein chromatography.

    Carbon-based membranes with confinement effect for mass transport: from carbon nano-tube membranes to graphene membranes
    LIU Zhuang, WANG Wei, JU Xiaojie, XIE Rui, CHU Liangyin
    2018, 69(1):  166-174.  doi:10.11949/j.issn.0438-1157.20171018
    Abstract ( 477 )   PDF (4586KB) ( 596 )  
    References | Related Articles | Metrics

    When fluid molecules transfer in a confined space where the dimensions of channels for mass transfer lower to the free motion distance of molecules, the intermolecular forces between the fluids and channel wall become the most prominent ones in nanoconfined systems and determine the mass transfer efficiency. Because of the frictionless effect of carbon channels smaller than 10 nm, the mass transfer resistance is small. As a result, both the mass transfer flux and selectivity of the carbon-based membranes could be high, which is expected to break the trade-off effect between flux and selectivity. The recent developments of carbon-based membranes with confinement effect for mass transport are reviewed. Two kinds of carbon-based membranes are briefly introduced, which are aligned carbon nano-tube membranes and stacked graphene-based membranes. The mass transfer mechanism in nanoconfined systems, the fabrication approaches of membranes and the potential applications such as water treatment, dehydration, desalination, ion separation and gas separation are summarized. The development of the carbon-based membrane with confinement effect for mass transport is prospected. The problems and solutions in the future are discussed. This paper will provide valuable guidance for design and application of the next generation of separation membranes with both high permeability and high selectivity achieved via confinement effect.

    Investigation on synthesis conditions of LiNi1-x-yCoxMnyO2 cathode material via co-precipitation
    GENG Shujun, HUANG Qingshan, ZHU Quanhong, JIN Yongcheng, YANG Chao
    2018, 69(1):  175-187.  doi:10.11949/j.issn.0438-1157.20171308
    Abstract ( 578 )   PDF (6113KB) ( 723 )  
    References | Related Articles | Metrics

    Layer-structured spherical cathode material, LiNi1-x-yCoxMnyO2, with high purity can be prepared by co-precipitation with high efficiency and low energy consumption. This method has been widely applied in both fundamental research and industrial production, mainly including co-precipitation and high-temperature calcination processes. The mechanisms and influence factors involved in each procedure were elaborated and analyzed. The nucleation process and the complexation and precipitation reactions of Ni, Co and Mn ions were investigated in the key step of co-precipitation for the preparation of precursor. Based on the established equilibrium equations of reactions and thermodynamics, the two-dimensional variations of the three non-precipitated metal concentrations and their mutual ratios for different pH and amounts of NH3 were thoroughly analyzed. Through the analysis results, theoretical optimum conditions for the cathode material with desired metal-ion ratios were thus proposed for the first time. In addition, by means of analyzing the structural characteristics of the precursor and cathode material as well as the electrochemical activity of the final material, the proper operation conditions were qualitatively investigated. Finally, the scientific method for optimizing the process conditions of LiNi1-x-yCoxMnyO2 cathode material was prospected.

    Advances in reverse electrodialysis and its applications on renewable energy & environment protection
    CHEN Xia, JIANG Chenxiao, WANG Yaoming, XU Tongwen
    2018, 69(1):  188-202.  doi:10.11949/j.issn.0438-1157.20171142
    Abstract ( 790 )   PDF (9794KB) ( 809 )  
    References | Related Articles | Metrics

    Reverse electrodialysis (RED) as an emerging technology to transform salinity power, is deserving much attention due to its superior characters, i.e., sustainability, high energy intensity and environment friendly. The new implementations and current progress of RED and its applications on renewable energy & environment protection were summarized from the viewpoint of elementary factors such as configurations, working mechanism and influencing parameters, by considering the key issues (virtual challenges confronting all the country), i.e., energy shortage and environmental pollution. The single RED operation and the integrations with other technologies were summarized and introduced specifically. The context has made a generalization and summarization of the sphygmology of previous published works in order to provide a reference to the works in progress.

    Chelate ionic liquids: synthesis, properties and applications
    YAO Jia, WANG Guanqi, CHEN Hang, LI Haoran
    2018, 69(1):  203-217.  doi:10.11949/j.issn.0438-1157.20171056
    Abstract ( 603 )   PDF (1244KB) ( 744 )  
    References | Related Articles | Metrics

    Coordination-based ionic liquids (IL) have attracted extensive fascination in past few years, for their exceptional physical properties and potential applications in green separation, catalysis and electrolytes. Among them, chelate ILs are advantageous due to their enhanced multiple-site chelating interactions between metals and ligands. Based on positions of metallic components in molecules, chelate ILs can be divided into four classes, i.e., cation, anion, cation-anion and neutral chelate ILs. The synthesis, physical properties and applications of chelate ILs were reviewed from recent publications. Present issues, challenges and future research directions were also discussed.

    Review of basic and application investigation of reactive distillation technology for process intensification
    GAO Xin, ZHAO Yue, LI Hong, LI Xingang
    2018, 69(1):  218-238.  doi:10.11949/j.issn.0438-1157.20171020
    Abstract ( 993 )   PDF (3486KB) ( 1043 )  
    References | Related Articles | Metrics

    Reactive distillation is one of the typical applications of process intensification concept in chemical engineering. Since the coupling of reaction and separation is highly complex and nonlinear, the effect mechanism of reactive and distillation, coupling method and regulation and optimization for the reactive distillation process is a key for the industrial applications. The general situation of RD technology at home and abroad in recent twenty years is reviewed, from fundamental research to industrial application, including the feasibility analysis of RD process and the method of conceptual design, the optimization of steady state simulation process and the design of dynamic simulation control strategy, the development of efficient internal components which have both the reaction catalysis and mass transfer function as well as the industrial application of RD technology in various fields. Possible solutions to these keys which restrict the wide application of RD technology are discussed. The universal development method of RD process and the new process intensification technology based on RD process are summarized, then the trend of RD technology are pointed out.

    Progress of cellulose pyrolysis mechanism: cellulose evolution based on intermediate cellulose
    LENG Erwei, GONG Xun, ZHANG Yang, XU Minghou
    2018, 69(1):  239-248.  doi:10.11949/j.issn.0438-1157.20170991
    Abstract ( 1017 )   PDF (2846KB) ( 1027 )  
    References | Related Articles | Metrics

    Research of cellulose pyrolysis mechanism is crucial for thermal utilization of biomass and provides guidance for industrial application. Based on the famous Broido-Shafizadeh model, the pyrolysis of cellulose is divided into two steps. First, cellulose turns into an active molten state named intermediate cellulose, and then subsequently generates levoglucosan, 5-hydroxymethylfurfural, glycolaldehyde and other valuable chemical feedstock. In the two steps, the collapse of hydrogen bonds network and the generation of intermediate cellulose at low temperature, the depolymerization reaction and ring cleavage are mainly involved. Focusing on these studies, this work reviews the effects of the degree of crystallinity and different crystallization morphology on cellulose pyrolysis, the depolymerization path of cellulose and the cleavage reaction of pyran rings, especially the generation and characterization of intermediate cellulose. It also introduces the effects of secondary reactions during pyrolysis in detail and proposes some solutions. There are still many unknown and debates on cellulose pyrolysis mechanism, and a deeper understanding of it through experiments and simulations is impending.

    Multiphase flow characteristics and structural optimization in feed injection zone of FCC riser
    FAN Yiping, LU Chunxi
    2018, 69(1):  249-258.  doi:10.11949/j.issn.0438-1157.20171016
    Abstract ( 399 )   PDF (1219KB) ( 512 )  
    References | Related Articles | Metrics

    The flow/mixing condition of feed oil and catalysts in the feed injection zone of FCC riser plays a crucial role in the yield of the desired products. The early relative researches were essentially tentative optimization works. In recent years, large cold model experimental research, theoretical analysis and CFD simulation were widely carried out. It was found that the feed jet secondary flow, which is generated by a Kutta-Joukowski transverse force, contributes considerably to the mixing and flow in the traditional feed injection zone. Therefore, effectively controlling and utilizing the secondary flow is the key factor to optimize the traditional feed injection scheme. The proposed improved scheme has been widely used in commercial units. In the past six years, the downward pointed feed injection scheme has been proved to be a more desired structure by the Kutta-Joukowski transverse force analysis, cold model experiment and CFD simulation. It was shown that the mixing of feed oil and catalysts was intensified while the contacting of two-phase presented more uniform. In other words, the downward pointed feed injection scheme exhibited more obvious advantages comparing with the traditional.

    Advances in regeneration system of natural nicotinamide cofactor and its artificial analogues
    ZHU Chenjie, FU Jingwen, TAN Zhuotao, YING Hanjie
    2018, 69(1):  259-271.  doi:10.11949/j.issn.0438-1157.20170964
    Abstract ( 615 )   PDF (1040KB) ( 813 )  
    References | Related Articles | Metrics

    Oxidoreductases have drawn considerable attention as mild and efficient catalysts in the fields of organic synthesis and medical sciences due to they can catalyze regio-, chemo-and stereoselective transformations that cannot be easily achieved by chemical catalysts. Cofactors are required in oxidoreductase-catalyzed reactions, commonly in the form of nicotinamide adenine dinucleotide and nicotinamide adenine dinucleotide phosphate, abbreviated as NAD(H) and NADP(H). Given the high cost and physical instability of NAD(H)/NADP(H), the stoichiometric usage is not practical for industrial applications. After decades, four main strategies such as enzymatic, chemical, electrochemical and photochemical method have been used for the cofactor regeneration. Meanwhile, the development of stable, highly active and inexpensive artificial nicotinamide cofactors particularly 1,4-dihydropyridine derivatives has led to a new breakthrough.

    Dynamic regulation elements and their applications in microbial metabolic engineering
    WU Yaokang, LIU Yanfeng, LI Jianghua, DU Guocheng, LIU Long, CHEN Jian
    2018, 69(1):  272-281.  doi:10.11949/j.issn.0438-1157.20170847
    Abstract ( 585 )   PDF (607KB) ( 552 )  
    References | Related Articles | Metrics

    Metabolic engineering is a key technology for the biosynthesis of various bio-based products such as nutraceuticals, pharmaceuticals, biofuels, and chemicals through the design, construction and optimization of metabolic pathways. Traditional methods, including gene knockout, gene knockdown and gene overexpression usually lead to metabolic imbalance. In contrast, using the regulatory elements derived from the microorganisms themselves to carry out dynamic regulation of metabolic pathways can balance the cell growth and product synthesis, achieving unification of high titer, high yield and high productivity. Microorganisms have the ability to alter their metabolic flux in transcription level by sensing the exchange of environment or intracellular metabolite concentration, and can change the metabolic state using some cis-or trans-regulation elements in post-transcription level, besides allosteric regulation and controlled degradation of pathway enzymes are found in protein level. Dynamic regulation elements can be developed basing on these regulatory mechanisms and can be applied into the dynamic regulation of microbial metabolic. We summarize the dynamic regulation elements in transcription, post-transcription and protein levels respectively, and introduce their applications in microbial metabolic engineering.

    Research progress of separator materials for lithium ion batteries
    WANG Zhenhua, PENG Daichong, SUN Kening
    2018, 69(1):  282-294.  doi:10.11949/j.issn.0438-1157.20170985
    Abstract ( 1576 )   PDF (14472KB) ( 2254 )  
    References | Related Articles | Metrics

    In recent years, lithium-ion battery technology has developed rapidly. As one of the core materials in the battery, the separator determines the performance of lithium-ion battery, because its characteristics influence on the influence rate, cycle and safe performance for batteries. Therefore, we need further research in the fields of separator material and preparation technology. At the present, polyolefin separator is still the main production of the commercial lithium-ion battery separator, but the preparation process is transferring from dry process to wet process. In the field of research, different material systems have been developed, such as PET, PVDF, PMIA and so on. Firstly, the production technology of polyolefin separator briefly introduced. Then the results of nonwoven separator material, coating material research, and new separator preparation technology are mainly reviewed. Finally, the outlooks and future directions in this research field are given.

    Progress in research and industrial development of microstructured reactors for intensifying gas-solid catalytic reactions
    CAO Chenxi, ZHANG Nian, CHU Bozhao, CHENG Yi
    2018, 69(1):  295-308.  doi:10.11949/j.issn.0438-1157.20171118
    Abstract ( 617 )   PDF (7425KB) ( 646 )  
    References | Related Articles | Metrics

    Catalytic processing of light hydrocarbons provides fuels and raw chemicals, and is thus of paramount importance for the energy and chemical industry. However, the harsh conditions and significant heat effects cause undesirable inefficiency, high power consumption and carbon emission of conventional reactors. Microstructured catalytic reactors enable excellent heat and mass transfer and potentially lower the pressure drop with a compact design, thus allowing high-throughput light hydrocarbons processing under strict control of temperature and concentration as demanded by distributed production. This paper summarizes the fabrication technology and key R&D activities with regard to microstructured reactors for intensifying gas-solid catalytic reactions. Representative examples of light hydrocarbons processing in microstructured reactors are reviewed including the endothermic steam methane reforming and the exothermic methanation and ethane oxidative dehydrogenation processes. It is believed that innovative and efficient reactor-catalyst integration could boost even wider applications of the emerging reactor technology, which would eventually reshape the energy and chemical industry.

    Progress of model based SOC and SOH estimation methods for lithium-ion battery
    SHEN Jiani, HE Yijun, MA Zifeng
    2018, 69(1):  309-316.  doi:10.11949/j.issn.0438-1157.20171097
    Abstract ( 1073 )   PDF (477KB) ( 1361 )  
    References | Related Articles | Metrics

    Battery management system (BMS) is an important way to ensure the efficient, reliable and safety operation of lithium-ion battery system. Among the BMS functions, estimation of battery states, especially the state of charge (SOC) and state of health (SOH), is critical to the overall performance. They are not only directly related to battery safety operation during the whole life, but also sever as the urgent prerequisite for implementing other facilities. We reviewed the domestic and foreign development of model-based battery state estimation methods, including battery model and estimation methods of SOC and SOH, in the hope of providing some inspirations to the research in this field.

    Multi-scale effect and catalyst design in catalytic combustion of organic waste gas
    RUI Zebao, JI Hongbing
    2018, 69(1):  317-326.  doi:10.11949/j.issn.0438-1157.20171186
    Abstract ( 399 )   PDF (2177KB) ( 626 )  
    References | Related Articles | Metrics

    Catalytic combustion of heavy air polluting organic waste gases over supported noble metal catalysts has been in extensive study and application, due to high removal efficiency and absence of secondary pollution. However, current technology still suffers from various problems such as high energy consumption and cost. There is a strong correlation between combustion efficiency of organic waste gases and dimensional structures of catalysts so that a multi-scale effect exists from microscopic active sites to catalyst and catalyst bed. A comprehensive consideration of function enhancement and design optimization by catalyst functions at each scale level is an effective way to improve removal efficiency of the supported noble metal catalyst. This review summarizes recent domestic and international design strategy and output with consideration of the multi-scale effect in catalytic organic waste gas combustion system, and provides a prospect for future research direction of organic waste gas combustion catalysts.

    Review on processes and technologies for recovery of valuable metals from spent lithium-ion batteries
    HE Lipo, SUN Shuying, YU Jianguo
    2018, 69(1):  327-340.  doi:10.11949/j.issn.0438-1157.20171194
    Abstract ( 551 )   PDF (3179KB) ( 916 )  
    References | Related Articles | Metrics

    Lithium-ion batteries (LIBs) has been extensively used in electronics, electric vehicles (EVs), and energy storage. As the rapid development of EVs, the consumption of LIBs will substantially increase. Accordingly, large numbers of spent LIBs will be generated. Improper disposal of spent LIBs will not only result in long-term environmental impact, but also is a major waste of resources. Therefore, the recovery of these wastes is quite important, especially for achieving the Li resource supply and demand balance. State-of-the-art techniques for the recovery of valuable metals from spent LIBs were reviewed, and the future direction of the recovery technique was also discussed in this study. The research in the future should be focused on the technology and equipment of the safe and efficient dismantling, the integrated recovery technology of valuable elements, the resynthesis process of electrode materials, and the avoidance of secondary pollution.

    Chromatographic technology in antibody purification and its progress
    LU Huili, LIN Dongqiang, YAO Shanjing
    2018, 69(1):  341-351.  doi:10.11949/j.issn.0438-1157.20171040
    Abstract ( 826 )   PDF (1019KB) ( 1521 )  
    References | Related Articles | Metrics

    Antibody, especially monoclonal antibody has become an important therapeutic drug which has a broad market demand and prospect. Nowadays the bottleneck of antibody production has shifted from antibody expression to downstream processing. The typical antibody purification process starts with protein A affinity chromatographic to capture the antibody and includes two subsequent polishing steps for impurity removal, such as ionic exchange, hydrophobic interaction or hydroxyapatite chromatography. There are some limitations restricting the development in antibody industry. Therefore, the researchers are committed to develop novel purification methods, including mixed-mode chromatography (MMC) and short peptide biomimetic chromatography which remedy the weakness of traditional methods. According to the recent advances in the purification of monoclonal antibody drugs, protein A affinity chromatography and the novel chromatographic methods and their applications in monoclonal antibody purification are reviewed in the present article.

    Oligomeric structure of enzyme and its catalysis stability
    LIU Hu, LI Chun
    2018, 69(1):  352-362.  doi:10.11949/j.issn.0438-1157.20171058
    Abstract ( 710 )   PDF (8570KB) ( 339 )  
    References | Related Articles | Metrics

    The structure and catalytic stability of enzymes are of intriguing interest in biocatalysis and biotransformation. Compared with monomeric enzymes, the subunit self-assembling of oligomeric enzymes brings superior structural and functional properties. However, a series of problems also exist in the course of preparation and application of oligomeric enzymes, such as poor preparation efficiency, lower utilization of catalytic sites and less catalytic stability. Among them, the weak catalytic stability resulting from subunits dissociation severely limits the wider industrial applications of oligomeric enzymes. Currently, medium engineering, multi-subunit immobilization, subunit interface engineering and fusion protein strategy have been used to improve the oligomeric enzyme stability. Besides, the design strategy of transforming oligomeric enzymes into monomers attempts to solve the preparation and application problems fundamentally and has an extensive application prospect. In this paper, the desirable functions generated by oligomeric enzyme evolution were introduced first. Then, the preparation and application problems were summarized. At last, the strategies for improving oligomeric enzyme preparation and stabilization were reviewed.

    Sorption characteristics and thermal storage performance of expanded vermiculite/CaCl2 composite sorbent
    ZHANG Yannan, WANG Ruzhu, LI Tingxian
    2018, 69(1):  363-370.  doi:10.11949/j.issn.0438-1157.20171024
    Abstract ( 549 )   PDF (3128KB) ( 541 )  
    References | Related Articles | Metrics

    To store low-temperature heat below 120℃, novel expanded vermiculite/CaCl2 composite sorbents with four different salt contents were developed by impregnation methods. Morphologies records, sorption kinetics measurements, simultaneous thermal analyses (STA) and theoretical calculations of energy storage density were implemented on EV/CaCl2 sorbents, with EV and CaCl2·H2O as reference. Scanning electron microscope (SEM) imagines indicate that EV has huge pore volume with numerous layers, which contributes to relative high salt content without the worry issue of solution leakage. Simulative sorption experiment was conducted to identify threshold salt content that composite sorbents can hold without solution leakage. The sorption kinetics and equilibrium sorption capacity were obtained utilizing a constant temperature and humidity chamber, and the influence of salt content and relative humidity on sorption performance was analyzed. The quantitative analysis of total water uptake demonstrates that their sorption process consists of three different phases:physical adsorption, chemical adsorption and liquid-gas absorption of CaCl2 solution. Furthermore, water uptake, sorption heat and reaction temperature of each sorption process were obtained by analyzing the STA measurements. In general, EV/CaCl2 composite sorbent with salt content of 47.9% was selected as the optimal sorbent, whose water uptake,mass energy storage density and volumetric energy storage density can reach as high as 1.12 g·g-1, 1.25 kW·h-1·kg-1, 213.56 kW·h·m-3, respectively.

    Simulation on mixing granular materials in screw conveyor
    QI Huabiao, XU Ji, SONG Wenli, GE Wei
    2018, 69(1):  371-380.  doi:10.11949/j.issn.0438-1157.20171196
    Abstract ( 489 )   PDF (12599KB) ( 354 )  
    References | Related Articles | Metrics

    Flowing and mixing granular materials of two different sizes and densities in an industrial-scale screw conveyor was studied by computer simulation using the discrete element method(DEM). Quantitative analysis results by the Lacey mixing index showed that mixing performance of the screw conveyor was dependent strongly on operational conditions and structural dimensions. Both screw rotating speed and material feeding rate had dominant effects on mixing efficiency, followed by granular material sizes and screw pitch in the mixing region. To reduce energy consumption and improve mixing performance in production, reasonable operation parameters of screw conveyors could be selected according to these findings.

    Flow and back-mixing characteristics in three dimensional up-flow reactor
    WANG Weijie, YONG Yumei, YANG Chao, YU Kang
    2018, 69(1):  381-388.  doi:10.11949/j.issn.0438-1157.20171270
    Abstract ( 310 )   PDF (654KB) ( 321 )  
    References | Related Articles | Metrics

    Using an up-flow reactor with inner diameter of 280 mm, the industrial gas phase with air and the residual oil with the mixture of glycerol and water are simulated. The effects of particle size, particle density, liquid viscosity and the ratio of bed height to diameter under different operating conditions on the total bed pressure drop and its fluctuation, and the axial back-mixing were investigated in an up-flow reactor packed by alumina spherical catalyst particles. A correlation of pressure drop is obtained with the relative error below 12% which is suitable for gas-liquid-solid systems simulated industrial operating system and operating conditions in an up-flow reactor. The total pressure drop decreases with the increase of particle size, the ratio of height to diameter, particle density and liquid viscosity. The pressure fluctuation becomes stronger when the superficial gas velocity increases. The axial back-mixing in the reactor packed by smaller size and smaller density particles with the larger ratio of height to diameter is more serious. Both bed pressure drop and axial back-mixing increase with the increasing superficial gas velocity.

    Effects of drag model and turbulence model on simulation of air-lift internal-loop reactor
    ZHANG Jiabao, CUI Lijie, YANG Ning
    2018, 69(1):  389-395.  doi:10.11949/j.issn.0438-1157.20170830
    Abstract ( 517 )   PDF (1058KB) ( 448 )  
    References | Related Articles | Metrics

    The influence of drag models and turbulence models on the hydrodynamic parameters in an air-lift internal-loop reactor is evaluated. Drag models determine the existence of gas in downcomer, and drag models and turbulence models jointly determine the accuracy of the simulation of gas holdup. Using uniform size bubbles, the Schiller-Naumann, Tomiyama, Grace and Ishii-Zuber drag models are only suitable for lower superficial gas velocity, and there is no gas in downcomer. The capability of DBS-Local drag model was confirmed. Compared with the other four drag models, only DBS-Local drag model can predict the existence of gas in downcomer. DBS-Local drag model combining with the standard k-ε mixture turbulence model can well predict gas holdup, and combining with RNG k-ε dispersed turbulence model can better predict liquid velocity.

    Sulfidation effect on low temperature sulfur-resistant methanation catalyst
    WANG Weihan, ZHANG Xiaoshan, LI Zhenhua, WANG Baowei, MA Xinbin
    2018, 69(1):  396-404.  doi:10.11949/j.issn.0438-1157.20171143
    Abstract ( 466 )   PDF (3790KB) ( 244 )  
    References | Related Articles | Metrics

    MoO3/ZrO2 catalyst, which prepared by solution combustion method, achieved the highest CO methanation activity due to its high surface area and effective MoO3 dispersion on ZrO2 support. By study of sulfidation process on methanantion activity, it was found that sulfidation pressure, time and H2S concentration had little effect but sulfidation temperature had significant effect. For one-step constant temperature sulfidation process, the optimum sulfidation temperature was 300℃. Catalyst characterization showed that isothermal sulfidation at 300℃ produced catalyst with complete sulfidation and many MoS2 crystalline, which is helpful to improve methanation activity. Isothermal sulfidation below 300℃ yielded catalyst with incomplete sulfidation and fewer amounts of MoS2 crystalline while isothermal sulfidation above 300℃ resulted aggregation of MoS2 crystalline, which will deteriorate MoO3/ZrO2 catalyst. For stepwise sulfidation process, the optimum sulfidation temperature was 400℃, which resulted catalyst with nearly same methanation activity as that of one-step isothermal sulfidation at 300℃. Therefore, the suitable sulfidation condition for MoO3/ZrO2 catalyst is determined as 0.1 MPa, isothermal 300℃, 3% H2S/H2, and time 4 h.

    Mo/Al2O3-MgO catalyst preparation from MgAl-hydrotalcite and their hydrogenation desulfurization performance
    YUE Yuanyuan, ZHENG Xiaogui, KANG Ying, BAI Zhengshuai, YUAN Pei, ZHU Haibo, BAO Xiaojun
    2018, 69(1):  405-413.  doi:10.11949/j.issn.0438-1157.20170727
    Abstract ( 544 )   PDF (1569KB) ( 859 )  
    References | Related Articles | Metrics

    Diesel production with low/no sulfur content is a major trend in world-wide development of clean fuels. Among many alternative technologies, hydrogenation desulfurization (HDS) is most effective to produce clean diesel at industrial scale, which development of highly active catalysts is the key. In this study, a series of Mo/Al2O3-MgO catalysts were prepared by metal oxide composites of MgAl-hydrotalcite and alumina as carriers with incipient-wetness impregnation method. Their catalytic performance was evaluated on dibenzothiophene (DBT) solution in n-heptane as raw material in a fixed-bed reactor. The results showed that Mg/Al molar ratio, calcination temperature, and additive amount all affected acidity, reduction and sulfidation of the catalysts and stacking degree of MoS2 crystallites. When Mg/Al molar ratio was 3, calcination temperature was 800℃, and hydrotalcite was 10% (mass), the obtained catalyst has the highest HDS activity with up to 96.2% desulfurization rate. Appropriate catalyst acidity and suitable interaction between active component and carrier make it easier to sulfide the active component, which is beneficial to improve stacking degree of MoS2 crystallites and enhance catalytic performance.

    Soft-elastic bionic reactor
    LIU Minghui, ZOU Chao, XIAO Jie, CHEN Xiaodong
    2018, 69(1):  414-422.  doi:10.11949/j.issn.0438-1157.20171120
    Abstract ( 520 )   PDF (4824KB) ( 534 )  
    References | Related Articles | Metrics

    Traditional reactors are usually made of rigid materials, which container walls do not actively participate in mixing and reaction with fluid. Inspired by working mechanism of human and animal digestive systems, a new soft-elastic reactor (SER) was developed to promote mixing through wall movement. The SER, made of silicone rubber with good transparency, toughness and elasticity, had periodic wall movement driven by an easy to operate, stable, and highly reproducible crank-rod system. Systematic experimental study on mixing Newtonian fluids under different operational conditions demonstrated that fluid mixing could be realized in SER and mixing performance could be effectively controlled by frequency and degree of wall deformation. Furthermore, a new Reynolds number calculation was proposed to describe SER mixing. Compared to inclined three paddle agitator at same dimension and experimental condition, the soft-elastic reactor had slightly better mixing performance in low Reynolds number region (10-1000).

    Effect of activated carbon pore size distribution on low-mercury catalyst performance for acetylene hydrochlorination
    JIANG Luo, CHEN Biaohua, ZHANG Jirui, FU Jiquan
    2018, 69(1):  423-428.  doi:10.11949/j.issn.0438-1157.20170982
    Abstract ( 375 )   PDF (2640KB) ( 340 )  
    References | Related Articles | Metrics

    Activated carbon carriers with various pore size distributions were prepared by using pulverized coal as carbon source, dibasic sodium phosphate and potassium phosphate monobasic as adjuvant. The activated carbon carrier and catalyst were characterized by nitrogen adsorption and desorption, methylene blue adsorption, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The effect of pore size distribution on catalyst performance was studied in an isothermal fixed-bed reactor, which simulated industry-scale single tubular conversion unit. The results showed that activated carbon of different specific surface area and pore size distribution can be prepared by adjusting amount of dibasic sodium phosphate, potassium phosphate monobasic and steam. Activated carbon with mesoporosity was obtained to 81%. Activated carbon carrier with high mesopores is beneficial to dispersion of active center, and the corresponding catalyst has excellent stabilized activity and long lifetime at high air velocity.

    Preparation and performance of graphene oxide doped reverse osmosis mixed matrix membrane
    CHEN Xianhong, FU Beijia, ZHONG Mingqiang, XU Lixin, ZHOU Yong, GAO Congjie
    2018, 69(1):  429-434.  doi:10.11949/j.issn.0438-1157.20170977
    Abstract ( 442 )   PDF (4340KB) ( 432 )  
    References | Related Articles | Metrics

    The aromatic polyamide reverse osmosis membrane is poor in anti-fouling performance and chlorine resistance, which is limiting its application in some fields. The commercial reverse osmosis membrane was modified by the secondary interface polymerization method of adding graphene oxide (GO) to the oil phase. The separation performance and chlorine resistance of GO-doped reverse osmosis mixed matrix membranes were evaluated. The properties of the membranes were characterized by water contact angle, Zeta potential,scanning electron microscopy (SEM) and atomic force microscopy(AFM). The results show that the addition of GO increases the hydrophilicity, separation performance and chlorine resistance of the membrane. With 30 mg·L-1GO content, the flux and rejection rate of the membrane reach peak values of (77.7±0.9) L·m-2 ·h-1 and 97.6%±0.5%, increasing 38.4% and 4.5% respectively. When the chlorination intensity is less than 4800 mg·L-1·h, the changes of water flux and salt rejection rate of the membrane are not obvious.

    Preparation of thin-film composite nanofiltration membranes with amino-functionalized graphene oxide by interfacial polymerization
    ZHANG Runnan, LI Yafei, SU Yanlei, JIANG Zhongyi
    2018, 69(1):  435-445.  doi:10.11949/j.issn.0438-1157.20171091
    Abstract ( 506 )   PDF (4129KB) ( 581 )  
    References | Related Articles | Metrics

    A series of thin-film composite (TFC) nanofiltration (NF) membranes were prepared by interfacial polymerization, using amino-functionalized graphene oxide (NGO) as the aqueous monomer. Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), transmission electron microscope (TEM), scanning electron microscope (SEM) and atomic force microscopy (AFM) were applied to measure the chemical compositions and morphologies of the prepared NGO and TFC NF membranes. The effect of NGO and trimesoyl chloride (TMC) concentrations on the separation performance of the TFC NF membranes was investigated systematically. The TFC NF membrane exhibited a high flux of 27.8 L·m-2·h-1 under a relatively low operation pressure (0.2 MPa) and an excellent dye/salt separation performance with high rejections for organic dyes (methyl orange of 74.8%, orange G Ⅱ of 96.0%, Congo red of 98.5% and methyl blue of 99%) and low rejections for inorganic salts (Na2SO4 of 21.4%, MgSO4 of 10.7%, NaCl of 5.3% and MgCl2 of 1.5%). In addition, the TFC NF membrane showed good long term operational stability as well as a satisfying antifouling performance against bovine serum albumin (BSA).

    Selective adsorption of Pb2+ by sea urchin magnetic nano-Fe3O4@TiO2
    WANG Yaoqiang, ZHAO Yilin, LI Linghui, SU Haijia
    2018, 69(1):  446-454.  doi:10.11949/j.issn.0438-1157.20170835
    Abstract ( 399 )   PDF (4140KB) ( 481 )  
    References | Related Articles | Metrics

    The sea urchin magnetic nano-Fe3O4@TiO2 particles (SUMNPs) with core-shell structure were prepared by sol-gel technique combined with hydrothermal method. The morphologies and surface areas of SUMNPs were characterized by methods such as TEM and SEM. It was confirmed that the sea-urchin magnetic nanomaterial exhibit Fe3O4 microsphere as core and TiO2 as shell, the diameter of the particles is about 400 nm, the specific surface area is 236.082 m2·g-1, and the surface pore size is about 6.274 nm. The adsorption on heavy metal ions showed that, based on the Pb2+ ion radius is large and the layers of elections is more, in the mixed system of Pb2+, Cd2+, Cu2+, Zn2+ and Ni2+, SUMNPs could adsorb Pb2+ with high capacity and high selectivity, and almost no adsorption of other four heavy metal ions. The single Pb2+ adsorption could be fast equilibrium in 5 min and the equilibrium adsorption capacity was 283 mg·g-1. The adsorption process is in accordance with the Langmuir isothermal adsorption model, and the saturated adsorption capacity is up to 458.72 mg·g-1. After desorbed and regenerated by EDTA disodium and NaOH, SUMNPs can be reused more than 8 times. In summary, SUMNPs have excellent selectivity for Pb2+, and have good application prospect in the treatment of pollution and restoration of water ecological environment.

    Preparation of porous carbon material from starch and it's performance for separation of CO2/CH4
    CHEN Minling, WANG Xingjie, XIAO Jing, XIA Qibin, LI Zhong
    2018, 69(1):  455-463.  doi:10.11949/j.issn.0438-1157.20171080
    Abstract ( 513 )   PDF (2356KB) ( 1172 )  
    References | Related Articles | Metrics

    In this work, porous carbon materials were prepared by using starch as carbon source. The starch first went through polymerization under hydrothermal condition and followed by a KOH activation. Their structures and adsorption performances for CO2 and CH4 were characterized and tested. The isosteric heat of adsorption and the selectivity toward CO2/CH4 were estimated based on the adsorption isotherms, and the effect of carbon material structure on its adsorption properties was also discussed. The results showed that the specific surface area and pore volume of the prepared materials increased as more KOH was used, and the pore size distribution also became wider. The derived carbon material had a high specific surface area of 2972 m2·g-1, the H2O adsorption isotherms of the materials showed an IV-typed isotherm. It was found that the CO2 adsorption capacity of the materials mainly depended on the cumulative pore volume with pore size less than 0.8 nm. That is, the larger the ultramicro pore volume(Vd < 0.8 nm) of the material, the greater the CO2 adsorption capacity at 298 K and 101325 Pa. The CO2 adsorption amount on the C-KOH-1 was 4.2 mmol·g-1 in our work, and the isosteric heat of CO2 adsorption was higher than that of CH4, the selectivity toward CO2/CH4 is in the range of 3.7-4.26. At the same time, the water adsorption isotherms of the materials were also examined and the results showed that the materials were mainly hydrophobic, which can be a potential adsorbent being used in the reality.

    Select Filter-Wrapper characteristic variables for yield prediction of fluid catalytic cracking unit
    WANG Jie, CAO Daofan, LAN Xingying, GAO Jinsen
    2018, 69(1):  464-471.  doi:10.11949/j.issn.0438-1157.20170841
    Abstract ( 342 )   PDF (486KB) ( 380 )  
    References | Related Articles | Metrics

    Fluid catalytic cracking is an important means to improve quality of heavy oil. Proper mathematical models are required to investigate influence of operating conditions and raw material properties on product distribution. Selection of suitable input variables largely affects model performances. The input variable selection is currently dependent on understanding mechanisms of FCC process. From the viewpoint of data-driven modeling, a method of selecting Filter-Wrapper characteristic subset was proposed by combination of Filter method using classical RReliefF algorithm and Wrapper method using GA-SVR algorithm. With no requirement of prior FCC knowledge, this method chose input variables by spontaneous data-driven selection of characteristic variables. A model with good prediction accuracy and proper number of input variables was established by taking advantage of a FCCU operating data and selecting input variables for prediction model of the unit dry gas and coke yield. Present work can not only provide a method to variable selection in FCCU modeling and process analysis, but also extend to other industrial process analysis.

    Study of collaborative drag-reducing effect of surfactant solution and longitudinal microgroove channel
    WEI Jinjia, HUANG Chonghai, YU Bo
    2018, 69(1):  472-482.  doi:10.11949/j.issn.0438-1157.20171030
    Abstract ( 412 )   PDF (16901KB) ( 409 )  
    References | Related Articles | Metrics

    A systematic study on the turbulent flow of surfactant solutions in different wide-rib rectangular microgroove channels was carried out by direct numerical simulation. The results showed that the drag reduction performance of surfactant solutions could be further enhanced in the grooved channel with a suitable groove size. The optimal size of microgroove for drag reduction could be enlarged in the surfactant solution. The collaborative drag reduction effect of surfactant solution in grooved channel was mainly the competition result of the “restriction effect” and the “tip effect” of the microgroove. There was a higher shear stress near the grooved tips, but the stress was very small within the grooved valley. If the microgroove not only prevents the near-wall vortices from intruding into the grooved valley effectively, but also presents a better restriction effect on the spanwise motions of the near-wall streamwise vortices, the microgroove will show a drag reduction enhancement effect. On the contrary, if the size of microgroove increases too large to prevent the near-wall vortices from intruding into the grooved valley, the shear stress near grooved tip and within grooved valley will increase, and the microgroove will show drag-increasing performance. The fact that a large number of small and weak secondary streamwise vortices induced in the grooved valley is the key factor to increase the restriction effect and thus enhance the drag reduction of surfactant solutions.

    Influence of Cu-BTC metal-organic frameworks on fermentation of Chinese rice
    ZHANG Xiaoshan, CHEN Yifei, JIANG Haoxi, LIU Changjun
    2018, 69(1):  483-489.  doi:10.11949/j.issn.0438-1157.20171247
    Abstract ( 279 )   PDF (2356KB) ( 679 )  
    References | Related Articles | Metrics

    The application of metal-organic frameworks (MOFs) for chemical processing has become a hot topic now. However, few works can be found in the literature with the influence of MOFs on the bioprocesses in the environment. Cu-BTC MOF crystals were prepared and added into the fermentation process as a case study. A 0.5%(mass) rice leaven, which contains Rhizopus, a kind of microorganism used in rice wine production, was added to the rice. The product composition (glucose, ethanol and lactic acid) was analyzed by high performance liquid chromatography (HPLC). With the increasing addition of Cu-BTC, the concentration of glucose, ethanol and lactic acid reduces, in contrast to normal fermentation process in the absence of Cu-BTC. Besides, MOF-5 also has similar effects on the fermentation process. Obviously, Cu-BTC and MOF-5 have a negative effect on the fermentation process.

    Dual-membrane assisted heterogeneous Fenton for pulp wastewater treatment
    ZHOU Hongjia, LIU Fei, ZHOU Ming, ZHONG Zhaoxiang, XING Weihong
    2018, 69(1):  490-498.  doi:10.11949/j.issn.0438-1157.20171219
    Abstract ( 416 )   PDF (3248KB) ( 276 )  
    References | Related Articles | Metrics

    Heterogeneous Fenton process is mainly used to degrade wastewater COD. Compared to traditional Fenton process, heterogeneous Fenton can avoid the generation of iron sludge, while the utilization rate of H2O2 still need to be improved. In this work, two type of ceramic membranes assisted heterogeneous Fenton process were proposed. One membrane was used as H2O2 distributor, while another was used for separating and recycling the catalyst. Different catalysts and their COD degradation performance were investigated first. The adding dose and rate of H2O2 and permeate flux were optimized subsequently. The stability of the catalytic and the membrane fouling condition were finally evaluated. The results revealed that cubic Cu2O possessed the best COD degradation performance. When the reaction conditions were that Cu2O (1 g·L-1), H2O2 dosage (0.8 ml·L-1), wastewater permeability (137 L·m-2·h-1) and reaction temperature(30℃), the COD degradation amount of RO(Ⅰ)-RO(Ⅳ) were 11, 130, 291 and 417 mg·L-1. The utilization rate of H2O2 for RO(Ⅰ)-RO(Ⅳ) were 9%, 106%, 232% and 334%, the utilization efficiency of H2O2 exceeded 100% means there are chlorine free radicals play a role in COD degradation. The COD degradation amount increased linearly with increasing of Cl-concentration. The COD degradation rate had an increasing tendency with the decreasing of the permeability of separation membrane. In the 360 min reaction process, Cu2O catalyst may form a reversible cake layer on the surface of the membrane distributor. However, this cake layer has scarcely effect on the permeation resistance. The COD degradation were greater than 65% stably. Moreover, with the increase of conductivity in pulp wastewater, catalysts would become instability with more of Cu ion dissolution. In heterogeneous Fenton process, ceramic membrane can enhance the treatment efficiency to pulp waste water, which performed in increasing of the utilization rate of H2O2 and improving the stability in continuous operation process.

    Characteristics of oxidation stabilization process of coal pitch based spheres
    GUO Yuan, SHAO Yingjuan, ZHONG Wenqi, LI Kaixi
    2018, 69(1):  499-506.  doi:10.11949/j.issn.0438-1157.20171042
    Abstract ( 420 )   PDF (2457KB) ( 559 )  
    References | Related Articles | Metrics

    Oxidation stabilization is the core process in the preparation of coal pitch based spherical activated carbon. Consequently the understanding of process characteristics and kinetic mechanism is the key to accomplish oxidation process optimization. The effects of particle size range, heating rate and oxidative temperature on oxidation stabilization process were discussed by experiments which used coal pitch spheres as the raw materials. The kinetic parameters and reaction mechanism function were determined. The results show that oxidation stabilization mainly consists of four stages, light component pyrolysis, preliminary oxidation, oxidative weight increment and constant temperature oxidative weightlessness, respectively. After oxidation stabilization, carbon and hydrogen content of coal pitch spheres reduce, oxygen content increases, and surface is much smoother. Reducing the particle size and selecting the appropriate heating rate(0.25-0.5℃·min-1) and oxidative temperature(275-325℃) are beneficial for oxidation stabilization. The activation energy reaches the minimum values at particle size range of 0.3-0.6 mm, heating rate of 0.5℃·min-1 and oxidative temperature of 300℃, which are 83.34, 293.19, 302.25 and 357.05 kJ·mol-1 in every stage.

    Alkaline sulfite pretreatment of corncob residue and its reaction kinetic model
    LOU Hongming, LIN Meilu, QIU Kexian, CAI Cheng, PANG Yuxia, YANG Dongjie, QIU Xueqing
    2018, 69(1):  507-514.  doi:10.11949/j.issn.0438-1157.20171023
    Abstract ( 539 )   PDF (2116KB) ( 562 )  
    References | Related Articles | Metrics

    Corncob residues (CCR) were obtained from corncobs by using acid hydrolysis for extraction of xylose. Due to the high content of lignin and low content of hemicellulose in corncob residues, the alkaline sulfite pretreatment was used to treat the corncob residue. The effects of pH, liquid/solid ratio, temperature and the dosage of sodium sulfite on the cellulose retained, delignification, substrate enzymatic digestibility (SED) and yield of lignosulfonate in pretreatment spent liquors were investigated. The results showed that with 10%(mass) sodium sulfite (Na2SO3) and 5%(mass) sodium hydroxide (NaOH) on CCR and 1 h pretreatment at 160℃, the alkaline sulfite pretreatment could make 86.1% of lignin removed and 82.4% of cellulose recovered in pretreatment liquid/solid ratio of 6/1. The SED of CCR increased from 46.4% to 85.1% after 72 h hydrolysis[cellulase loading of 5 FPU·(g glucan)-1], and the yield of lignosulfonate in pretreatment spent liquors was 31.5 g·(100 g CCR)-1 under the same pretreatment condition. Lignin factor (LF) was proposed to predict lignin content of pretreated CCR to guide the scale up test and engineering application. The delignification kinetics and prediction equation for SED of CCR were established based on the experimental data. And reasonable predictions of SED were obtained to within approximately 10% of the experimental data.

    Chemical looping combustion performance of CoFeAlO4 oxygen carrier with self-supported function
    PENG Song, ZENG Dewang, CHEN Chao, QIU Yu, XIAO Rui
    2018, 69(1):  515-522.  doi:10.11949/j.issn.0438-1157.20170980
    Abstract ( 365 )   PDF (4077KB) ( 400 )  
    References | Related Articles | Metrics

    The CoFeAlO4 oxygen-containing materials with spinel structure were synthesized by combustion synthesis. The chemical looping combustion reaction and cycling thermal stability of CoFeAlO4 oxygen carriers were investigated and characterized at different temperatures. The changes in the crystal structure and surface morphology of CoFeAlO4 oxygen carriers were analyzed. The results show that the increase of temperature is beneficial to improve the ability of CoFeAlO4 to convert reducible gas CO, resulting in the reduction rate faster, but redox at high temperature will cause CoFeAlO4 oxygen carrier phase separation, it is difficult to maintain a stable self-supported spinel structure. The analysis of the crystal structure of CoFeAlO4 oxygen carrier crystals before and after the reaction shows that the CoFe2O4 and CoAl2O4 detected after the redox cycle at high temperature is the main reason for the sintering of CoFeAlO4 oxygen carrier and the decrease of its cyclic thermal stability.

    Oxy-coal combustion kinetics and formation characteristics of pollutants based on TG-MS analysis
    LIU Qian, ZHONG Wenqi, SU Wei, BEN Haoxi
    2018, 69(1):  523-530.  doi:10.11949/j.issn.0438-1157.20171038
    Abstract ( 482 )   PDF (725KB) ( 685 )  
    References | Related Articles | Metrics

    Oxy-fuel combustion is one of the most promising CO2 capture technologies. The oxygen-enriched combustion of pulverized coal was simulated in a thermogravimetric analyzer coupled with a mass spectrometry (TG-MS) in order to understand the ignition model and the generation characteristics of pollutants during combustion. Bituminous and anthracite standard coals were selected as the samples. The tests were done with oxygen volume fractions of 21%, 30% and 50% with two kinds of atmospheres (O2/Ar and O2/CO2). In the O2/CO2 atmosphere, both of the ignition temperature and burnout temperature were lower, the combustion rate was improved, the combustion time was shortened, and the combustion performance was much better. Based on the TG/DTG curves, the ignition models of pulverized coal were judged. It was showed that the heterogeneous ignition of pulverized coal happened in O2/Ar atmosphere, while the homogeneous ignition occurred in O2/CO2 atmosphere. Also, the activation energy and pre-exponential factor of coal combustion were calculated by Coats-Redfern method. When the oxygen volume fraction was above 30%, the apparent activation energy of the anthracite coal combustion in O2/CO2 atmosphere was significantly lower than that in O2/Ar atmosphere, indicating an obvious improvement in reactivity. In the same reaction conditions, the activation energy of bituminous coal was lower than that of anthracite coal, and the former was more prone to ignition and combustion, showing better combustion performance. In the atmosphere of O2/CO2, the generation of CO and volatile-NO was promoted, and the formation temperature was lower than in O2/Ar atmosphere. Meanwhile, the abundant CO would lead to NO reduction reaction.