At present,China's chemical industry is facing big challenges of resources and environment,while green chemical technologies could provide ways to promote the sustainable development of China's chemical industry. This article proposed that the degree of green chemical technologies can be measured by atomic economy,energy consumption and low carbon of full life cycle. Then,it summarizes three basic ways to realize green chemistry,including low carbonization,clean processes and energy conservation. Moreover,this article reviews the development and application of green chemical technologies in China,involving in the chemical transformation of renewable biomass resources,green chemical process,high efficient reactor or separation equipment,green solvents,homogeneous catalysis used at low reaction temperature,green hydrogen production and utilization of carbon dioxide,etc. Finally,outlook is given,and it is suggested that the green carbon science concept should always be committed,and special attentions could be paid on direct conversion technologies,energy management in the input and intermediate process,and output CO₂ intensive transformation,etc.

Ionic liquids are described as “green solvents” since there is a large degree of cation/anion combinations which make them with the possibility of tuning their properties,as well as their very low volatility. Ionic liquids have been widely used in catalysis,separation and electrochemistry. Thereinto,ionic liquids have been regarded as an efficient extractant for extraction organic compounds. In this work,the ionic liquids used in the separate of hydrocarbon compounds,organic acids,alcohols,phenols and nature compounds by extraction were summarized and reviewed. The mechanism of the ionic liquids extraction process and the effect of extraction conditions were discussed in detail. It was concluded that the strong hydrogen bond,π-π,van der Waals and electrostatic interactions between ionic liquids and solute molecule make ionic liquids be potential solvents to replace some conventional organic solvents for the extractive separation of organic compounds. Meanwhile,the high viscosity and high costs as well as the recovery of the ionic liquids after extraction process could limit the industrial utilization of ionic liquids,and thus it is still an urgent task.

Distillation is the most widely used key separation technology in chemical engineering,which has been extensively used in separation process in industry,such as petroleum,chemical engineering,fertilizer,pharmaceutical,environment protection,etc. Distillation possesses extensive application and technical mature,but also faces some disadvantages as huge capital investment and high energy consumption. Thus,it is of significant social-economic meanings to research and develop new as well as high-efficient mass transfer unit and develop new energy-saving distillation technique. The research progress of distillation process is summarized in this article,including types of distillation column,hydraulic performance,mass transfer performance,scale-up,energy saving,process intensification,etc. For hydraulic performance of tray column,the gas-liquid flow situation,pressure drop,weeping and entrainment are introduced. For hydraulic performance of packing column,pressure drop,flooding and holdup are studied. But the current study is still relying on empirical correlation and lack of the rigorous theoretical model. As for the study of gas-liquid mass transfer,the mass-transfer theory is mainly reviewed,but the scientific and accurate model has not been put forward. The study of scale-up includes tray,gas-liquid distributor and support device. The process energy-saving and intensification technology is reviewed,including process- coupling,process energy-saving,recovery of low grade waste heat,special distillation. Finally,the prospects of mass-transfer,process intensification and development direction of process integration are proposed.

Near infrared spectroscopy (NIR) is currently the most widely used Process Analytical Technology (PAT) in the pharmaceutical industrial. It's application in the quality control of Chinese herbal medicines has also attracted much attention in recent years. Chinese herbal medicines are often very complex in composition,and the production processes are distinctive from that for pharmaceutical chemicals. As a result,the use of NIR in the Chinese herbal medicine domain faces major challenges,in particular in chemometric model development. This paper provides a review of chemometric methods for NIR model development with the focus on NIR application in on-line quality control in the production of Chinese herbal medicines. The topics include calibration data collection,pre-processing,selection of data for model development and validation,and wave number selection,as well as model building and performance assessment. It is emphasized that construction of models with good performance should be an iterative process integrating spectral pre-processing (e.g. smoothing,derivative method,standardized algorithm,data enhancement algorithm,and principal component analysis),wave number selection (e.g. genetic algorithm,random frog) and linear and nonlinear model construction algorithms (e.g. partial least squares,neural networks and support vector machines). A future platform is envisaged as one that shares data and integrates sophisticated algorithms in the background and presents users with friendly,easy to use,intelligent and semi-automated interfaces. Review and discussions has been made based on practical case studies.

Urbanism greatly enhanced the material aspects of living and the cultural aspects of city life accompanied with,however,the fire disasters in the ancient time of our human being. Entering the industrial civilization with the invention of steam engine and electrical power supply,the industrial systems became large and complex,in which a failure of a local component might cause a global damage and shutdown of the whole production process. The energy crisis in the last century called forth larger plant capacity and higher operation parameters in order to increase the energy and process efficiency,which led to the industrial accidents highly interruptive,greater risky and of significant social influence. Safety is thus a fundamental need of our human being to have an ease and poetic life. In retrospect,the paper reviews the evolution of safety technology during the history of human civilization. The concept of Safety 4.0 as an indispensable mate of Industry 4.0 is proposed,which aims the life cycle safety,including the safety (health) monitoring,smart network control and intelligent safety assessment. Some excellent industrial cases and research progresses are examined and discussed. Recommendations are made on the priority areas in science and technology for implementing Safety 4.0.

Recently,the big data technology has been applied in many field widely,such as finance,trade and medical healthy. But the applications in process industries are only in the beginning stages. In this paper,the characteristics,analyzing methods and applications of the data in process industries are introduced. The data obtained by the process industry have the characteristics of high dimension,strong nonlinearity,uneven sample distribution and low signal-to-noise ratio except from the characteristics of volume,variety,velocity and variability. The big data technology has emerged and developed to be available in analyzing data from the process industries. The analyzing methods based on the industrial data include dimension reduction analysis,cluster and classification analysis,correlation analysis and prediction analysis according to their functions. In this paper,the applications of the big data technology in process industries are summarized from three aspects including process optimization,process monitoring and fault diagnosis and prediction of product properties and yield. It is found that the big data will play a more important role if the production data in the process industries can be combined with the market data of raw material and product.

In turbulent flow drag reduction applications,surfactant additive is more applicable than polymer for the flow with high shear or in the closed circulation system due to its reversible mechanical degradation advantage. However,there is not enough understanding of the complicated rheology and drag-reduction mechanism of surfactant solution,limiting its practical application in the drag reduction field. This review introduces the research progress of surfactant drag reduction conducted by the authors in recent years on microstructure,complicated rheology characteristics,turbulent structure,as well as their relations with drag reduction and heat transfer,and analyzes the combined drag reduction effect of surfactant additives in the flow and microgroove fabricated on the wall. The stretch devices can significantly improve the heat transfer performance of surfactant drag-reducing flow with a lower pressure loss penalty. To the shortages of present surfactant drag reduction research,several suggestions are given for the future study. The first is to develop environmentally friendly and effective surfactant,the second is optimal design and layout of heat transfer enhancement device for drag-reducing flow,the third is the study on synergetic effect of drag reduction by combing surfactant drag reduction and other drag-reducing ways,and the final one is practical industrial application research on the scale-up,anticorrosion and persistence effect of surfactant drag reduction.

This paper tends to give an overview on the principle,the state-of-the-art development of research and applications of chemical conversion processes at ultra-high temperature in the thermal plasma reactors. As an extreme means for process intensification,thermal plasma can provide ultra-high temperature reaction conditions,adjustable oxidative,reductive or inert gas atmosphere,which allows it as a feasible technique to implement clean and highly efficient conversion of low-quality feedstock and hard-to-treat intermediates and wastes. Thermal plasma technique is therefore one of the frontier areas of modern reaction engineering. Meanwhile,the thermal plasma reactions are strongly coupling with the extreme mass/heat transfer processes,which lead to a more complex reaction conditions. Therefore,it is essential to combine the unique characteristics and conversion principles properly to enable a clean,flexible and profitable process. This paper reviews typical thermal plasma processes,involving plasma pyrolysis to produce acetylene,solid waste treatment and nanomaterials synthesis. The potential perspectives of such unique techniques in the applications for the fields of energy,chemicals,environment and materials are discussed.

Accurate measurement of gas-solids reaction characteristics,calculation of reaction kinetics and analysis of reaction mechanism are important to studies and developments of process engineering technologies in areas of energy,chemical engineering,and metallurgy. Analyzing various existing gas-solids reaction analysis approaches and instruments,we propose the use of micro fluidized bed (MFB) to realize isothermal differential reaction under conditions with rapid heating and low diffusion limitation. After systematic studies on hydrodynamics of micro fluidized bed,we have developed a micro fluidized bed reaction analyzer (MFBRA) and further verified its applications for many typical gas solids reactions,including pyrolysis,combustion,gasification,reduction,catalysis,and absorption. These applications well demonstrated MFBRA for its inherent advantages of intensified heat and mass transfer,minimized diffusion limitation and online real-time isothermal differential reaction. It particularly is applicable to analysis of rapid complex reactions and enables several extended functions for gas-solids reaction analysis like using steam atmosphere,on-line particle sampling and decoupling of reactions in series. MFBRA provides actually an effective TGA-complementary approach and instrument for gas-solids reaction analysis.

This paper discusses the lattice Boltzmann model at representative elementary volume (REV) scale for porous media. According to different treatments of porous media,the lattice Boltzmann model at REV-scale for porous media can be classified into two categories,the partially bouncing-back model and the resistance model. The advantages and disadvantages of various models are analyzed. The Generalized lattice Boltzmann equation (GLBE model) in the resistance model is most widely used. Firstly,the force item of the GLBM model is based on the method proposed by Guo et al,which can be accurately recovered to the macroscopic equation without discretization error. Secondly,the equilibrium distribution function and the force items involve porosity,which reflects the characteristics of porous media. This review introduces the application of the lattice Boltzmann model at REV-scale in porous media with flow,heat transfer,mass transfer,chemical reaction and phase transition. We should take the pore scale factors into consideration when studying momentum transport,heat transport,mass transport and reaction engineering in porous media at REV-scale. The anisotropic nature of process parameters should be considered at the larger engineering scale. It gives some predictions and perspectives of applications for the lattice Boltzmann model at REV-scale.

With the advantages of high energy density,safe and reliable aqueous electrolyte and low cost,zinc-air batteries show important potential as well as challenge for electrical energy conversion and storage. These batteries used in pure electric vehicles,mobile tools and electricity storage for new energy power generations,have promising market and applications. However,some issues related to electrode structure and electrocatalyst in cathode and zinc dendrite growth in anode restrict its further development and application. This paper analyzes the critical scientific issues in zinc air batteries,especially for the electrocatalyst of air electrode,electrode configuration,dendritic growth in zinc negative electrode,discusses the battery performance in details,and points out the main barriers in developing advanced battery technology. In summary the development of novel electrocatalyst,air electrode,manufacturing technology for long-term cycle life and low cost zinc air batteries are urgent problems to be settled at present.

School of Chemical Engineering and Technology,Xi'an Jiaotong University,Xi'an 710049,Shaanxi,China)Abstract:Thermochemical energy storage is the key technique to guarantee long term and steady supply of solar energy due to its advantages of high energy density,low heat loss as well as transportability over long distance. In this work,the development of CO₂ reforming of methane that has been applied in the solar thermochemical energy storage system was summarized. Particular emphasis was put on the studies of methane reforming catalyst,methane reforming reactor,and thermal analysis of thermochemical energy storage system. New high-efficiency catalysts and reforming reactors were the main interests of the current researches. Radiation heat loss,non-uniform temperature distribution,time-varying radiation heat flux,as well as the mismatching between energy and chemical reaction restricted the improvement of thermochemical energy storage efficiency. In order to further improve the performance of thermochemical energy storage system and establish its optimization design theory,some key questions were proposed to be answered,including the relationship between the catalytic performance and properties/structure parameters of the catalyst,the interaction mechanism of thermal radiation absorption,heat/mass transfer and thermochemical reaction characteristics of the chemical reactor,as well as the time-varying dynamic features and matching relationship with radiation heat flux of the thermochemical system.

The current main technology progress of natural gas to ethylene were introduced,including natural gas to ethylene through methanol,Fischer-Tropsch synthesis route,and oxidative coupling of methane. Technical and economic evaluation of these processes were performed,and the conclusions are:the large-scale application of natural gas to ethylene technology mainly depends on the natural gas supply and it's price. Under the conditions of sufficient gas supply and reasonable price,the technology of natural gas to ethylene through methanol will get a rapid development,while the applications of Fischer-Tropsch synthesis and oxidative coupling of methane technology at present has not yet been mature and it is necessary to continue to intensify their research and development for the realization of their industrial application.

Oil consumption is a key factor of China's energy security. The analysis of future development tendency of China's oil consumption is conducive to planning oil production,oil import and refining structure adjustment,and is of great significance to ensure the national economy run normally. In this paper,the oil consumption structure over past 15 years was analyzed. With the “peak oil” theory,a prediction model for oil consumption at low,baseline and high scenarios was established by factor analysis method and Logistic model,which utilized historical data and the influence factors (such as economic development level and industry development status,etc) of oil consumption. Check and error analysis of this prediction model indicated that it had high accuracy. Considering the energy efficiency and alternative fuels,we predicted and analyzed the future development tendency of China's oil consumption. The predicted results showed that there would be a lasting growth in China's oil consumption for the next 10—20 years,and the peak value will come around 2038,of about 660—780 million tons. China should prepare for refining capacity planning and reasonable structure layout in advance.

Six major factors in the development process of industrial oil refining catalysts were introduced in this paper,and their influence on the catalyst performance were discussed as well as the regulations of the physicochemical properties of catalysts by means of various techniques,including using inorganic additives modification,organic additives modification,ultrasonic auxiliary means etc. to improve the acid properties,specific surface,pore structure,and bulk density etc. The interaction of the support and metal,the dispersion and curing degree of active metal,MoS₂ (WS₂) in length and number of layers of lamellae could be adjusted through these techniques,which realized the control of the morphology of catalytic activity center. Through the selection of raw materials and the optimization of the production progress,we could reduce the catalyst cost. The activity and stability of catalyst system could also be improved by rationally designing the catalyst form. The application of some technical and regulation means in the progress of industrial oil refining catalysts was introduced,then the course of improving the commercial catalyst activity was given,and some new ideas to improve the performance of catalysts was pointed out. Finally,some new materials and methods that used in oil refinery were also mentioned.

C4 alkanes of n-butane and isobutane are mainly from refineries and petrochemical plants. At Present,most C4 alkanes are used as fuel or in other low value consumptions,which could not realize the high value of their utilizations. With the development of the fine chemical industry and the improvement of resource utilization rate,the comprehensive utilization of C4 alkanes has attracted more and more attentions. The technical progress in the preparation of organic chemicals from the catalytic oxidation of C4 alkanes is reviewed,including the oxidation of n-butane to maleic anhydride and acetic acid,the oxidation of isobutane to methacrylic acid and tert-butyl hydroperoxide. The features of catalytic oxidation of C4 alkanes were summarized. The biomimetic catalytic oxidation technology is considered to play key role in the catalytic oxidation of C4 alkanes under mild conditions.

In this paper, the research progress of the fixed bed catalyst and fluidized bed catalyst and their advantages and disadvantages are introduced. The influences of the factors during Ni-based catalyst and Pd-based catalyst preparation process on their catalytic performance are introduced. Researches on the catalysts with high catalytic activity and selectivity for the hydrogenation reaction are reviewed. The characteristics and research progress of hydrogenation reactors are also introduced and compared. Based on the detailed comparisons between the fluidized bed and fixed bed, it is concluded that the production with fluidized bed has many advantages of relative lower cost, less anthraquinone degradation, high catalyst utilization rate and high hydrogenation efficiency. From an application perspective, the differences between fluidized bed and fixed bed are introduced. The paper finally points out that the production with fluidized bed has become the developing tendency of the anthraquinone route and will replace the process with fixed bed. The practical research difficulties, developing trend and some suggestions for the development of the anthraquinone route are presented.

Due to the special ion transfer characteristic in ion exchange membranes (IEMs),the processes based on them such as electrodialysis and diffusion dialysis can achieve the separation and classification of the ions,which are found more and more important applications in the clean production,energy-saving and emission reducing,etc. This paper reviews the frontier progress in the preparation,application of IEMs and the corresponding modules. Additionally,the problems to be solved and the future development are also directed. For the membrane preparation,the novel IEMs structures such as the three phase structure derived from two phase structure,the porous structure derived from dense structure and the electro-nanofiltration are developed herein. The obtained membranes exhibit both high flux and high selectivity,diversifying membrane functions. For the applications of IEMs,the integration of electrodialysis and diffusion dialysis is reported,resulting in better separation effect and lower cost. In the meantime,the membrane module is optimized and a novel spiral wound membrane module is developed,which has overcome the drawbacks of traditional plate counterpart. It is worth mentioning that the application fields of IEMs are also expanded from primary water treatment to the separation and purification of complex waste solutions. The progress proposed in this manuscript will guide for the development of IEMs and will undoubtedly speed up their industrialization.

Ceramic nanofiltration (NF) membranes have been widely studied and utilized in many different fields,including food,pharmaceutical and water purification due to their high resistance to harsh environments. Therefore,much research has been focused on the development of ceramic NF membranes. This work reviewed and analyzed in detail the progress of preparation of ceramic NF membranes such as sol-gel,chemical vapor deposition (CVD),atomic layer deposition (ALD) and surface grafting method. The sol-gel process was considered as a preferred technique for the production of ceramic NF membranes owing to its characteristics of easy operation and non-toxicity. CVD and ALD methods could control pore-size reduction employing several reaction chemistries such as TiO₂,Al₂O₃,SiO₂ and others. The surface grafting technique was a key point for surface modification of ceramic membranes. When the grafting molecule size had a magnitude equal to the pore size of the membranes,the surface grafting process would inevitably affect the membrane pore size. The application of ceramic NF membranes was also briefly introduced,indicating that ceramic NF membranes were the technology of choice in treatment of liquid phase under harsh conditions. In the future,the relationship between microstructure of ceramic NF membranes and separation performance as well as separation mechanism of ceramic NF membranes in the solvent will attract more attentions.

Flexible metal-organic frameworks(MOFs)have both highly ordered coordination network and cooperative structural transformability. Their strutures can respond to temperature,pressure,guest adsorption/desorption,and other external stimuli. In recent years,flexible MOFs has showed great potential in gas adsorption,gas separation and sensing. However,most reports on flexible MOFs are limited to the mechanism study on structural transformation,while their applications on chemical industry has been insufficiently investigated. In this review,emphasis is given on the recent progress in the gas adsorption and separation on flexible MOFs. And the relationships between adsorption/separation properties and framework features are detailed analyzed. In addition to the experimental aspect,theoretical investigations of adsorption equilibrium and diffusion dynamics via molecular simulations are also briefly reviewed. Therefore,more efforts should be made to design and synthesis new flexible MOFs with highly adsorption selectivity and diffusion properties for green and efficient gas separation process.

Coal tar pitch is abundant as a byproduct of coke production in iron-steel industry in China. However,the traditional methods cannot efficiently convert coal tar pitch into value-added products and how to make effective use of coal tar pitch remains a big challenge. This review has summarized several techniques for further processing of coal tar pitch,with a focus on the synthesis and applications of high performance functional materials including mesophase pitch, porous carbons,carbon fibers,two dimensional nano-sized carbon materials and carbon based composites. This review highlights that the strong π-π interactions between highly condensed polycyclic aromatic molecules in coal tar pitch is the bottle-neck that hinders the efficient conversion of coal tar pitch into functional carbon materials with tuned structure and properties. The molecular structure and properties of coal tar pitch can be improved through catalytic condensation,oxidization or co-pyrolysis. With coal tar pitch as precursor,methods including templating, physical/chemical activation, surface induction and catalytic graphitization have been developed for the controlled synthesis of high performance carbon materials. Novel methods that can tune the molecular structure of coal tar pitch are highly demanded to improve the performance of coal tar pitch based carbon materials and related researches should be intensified.

Stimuli-responsive smart hydrogels with three-dimensional networks composed of cross-linked hydrophilic polymer chains can dramatically change their volume or other properties in response to various external stimuli,which are similar to bio-tissues. Due to such stimuli responsiveness,they show remarkable potential for numerous applications,such as artificial cartilages,artificial muscles and tissue engineering scaffolds,for which high mechanical properties are highly desired. Improving the mechanical properties of the stimuli-responsive smart hydrogels is one of the critical issues for their developments and applications. This review briefly introduces the design,fabrication and mechanism of stimuli-responsive smart hydrogels with high mechanical properties. Four types of smart hydrogels of ultra-low crosslinking hydrogels,nanocomposite hydrogels,topological hydrogels,and double network hydrogels,are introduced. Finally,the perspectives and challenges of stimuli-responsive smart hydrogels with high mechanical properties are discussed. The future work should focus on the trade-off effect of the stimuli-responsiveness and the mechanical properties of stimuli-responsive smart hydrogels,as well as their variations on environmental stimuli.

With the advantages of proper phase change temperature,high latent heat,cheap raw materials and high thermal conductivity (compared with organic phase change materials),the inorganic hydrated salts are considered as ideal heat storage materials in the field of middle and low temperature heat utilization. However,the hydrated salts have also defects of supercooling,phase separation and leakage,which have significantly limited their applications. The traditional researches on hydrated salts focused on the choice of nucleating agents and thickening agents. Recently,some researchers on the composite or encapsulation of inorganic hydrous salt showed up,greatly promoting the work of improving the performance of hydrated salts. In this paper,the solutions for supercooling and phase separation and the researches on phase change composites of several common inorganic hydrated salts are summarized. Compared with single phase change materials,the phase change composites have many superior properties. Preparing inorganic hydrated salts phase change composites with porous materials package and micro encapsulation technology may become the research hotspots for solving the problem of inorganic hydrated salts leakage in the future.

With the development and application of chemistry,chemical engineering arises at the historic moment. Similarly,with the development of biology and engineering requirement,synthetic biology,known as“the third revolutions of biology”,was born. Synthetic biology is the engineering of biology. From the point of view of engineering,it designs and creates parts,devices or modules,and employs them to modify and optimization of existing natural biological system,but how to engineer complex life system is the key scientific problem which synthetic biology researchers have long been exploring. In this paper,the main four characteristics of engineering biology are systematically illustrated:①modularization and standardization;②orthogonality;③robustness;④compatibility,as well as the corresponding research progress. Finally,from the point of view of“Design-Build -Test”cycle,proposals for how to further engineer biology in the future are addressed.

Improving the yield and production efficiency of bio-based products is the goal of bio-manufacturing and bio-industry. Because of the advantages of fast growth,simple nutritional requirement and convenient gene manipulation,microorganisms are often used as chassis of bio-based products. Thus,the growth regulation and control of microbial cells are particularly important in the process of bio-manufacturing,as the microbial cell growth will directly or indirectly affect the synthesis efficiency of bio-based products. The growth of microorganisms can be affected not only by external conditions such as temperature,dissolved oxygen and pH,but also by their own cell growth mechanism. The cell growth mechanism can be referred to cell division regulation,essential genes expression regulation and programmed cell death. This paper reviewed the molecular regulation of microbial cell growth and division through molecular biology,synthetic biology and systematic biology methods to improve the biological reaction rate and the yield of target products,which provides new insights for the development of efficient bio-manufacturing process in chemical engineering,food industry,bio-pharmaceuticals,environmental protection and other fields.

CO₂,as a vital metabolic product and reaction substrate in living organisms,can make gas exchange with external environment,which is crucial to ensure the normal physiological activities of living organisms. The transfer of CO₂ in organisms,especially in cells,is of great significance for controlling the emission of CO₂,constructing efficient carbon cycle and exploring the carbon capture technology. This review presents a brief overview of the research progress on CO₂ transport mechanisms in organisms,including the detailed analysis of different models about the CO₂ transmembrane transport mechanisms,and in particular the facilitated transport of CO₂ by aquaporin protein,with the conclusion that the aquaporin-mediated CO₂ permeation plays an important role in membrane with a low intrinsic CO₂ permeability. Recent researches also show that the water channels and central pore along the fourfold axis of the tetramer of aquaporin are supposed to function in the CO₂ transmembrane transport. Moreover,the existence of carbonic anhydrase and HCO₃^–-Cl^– transporter can accelerate intracellular acidification process,thus increase the CO₂ transmembranetransport rate. This review could offer theoretical reference for developing new biomimetic membrane materials and carbon capture technology.

Food production and its market economy are the most important sector in national economy and security. Here the characteristics are introduced:food engineering is not a simple application of the chemical engineering principles. Food is a unique material consisting of mostly protein,fat and carbohydrate,which are all large polymeric molecules yet possessing characteristics that are more complex than those usually encountered. Most importantly,all food related phenomena are time-dependent,which are influenced significantly by their water contents. Here,the author has through some examples,e.g. food microstructure characteristics,water activity and its importance,separation and purification technologies in food industry,new emerging food processing technologies,food nutrition engineering,and nano technology applied to food industry,described the nature of food engineering as a multidisciplinary subject linked with biological engineering,chemical engineering,mechanical engineering and electrical and electronic engineering. A typical example,spray drying to make milk powder,is given with a futurd prospect suggested. There is no doubt that the current article reflects only a small part of area of food engineering. Nevertheless,it would make a good read for someone who is interested in food processing.

The pollution in leather industry can be reduced or even eliminated at the origin by applying clean technologies of leather manufacture. COD_Cr,ammonia nitrogen and total chromium are regarded as typical contaminants in leather industry. The development of key clean technologies aiming at reducing these pollutants at the origin is most concerned nowadays. This paper reviews the progress and application situations of some clean technologies,such as hair-saving unhairing technology,beamhouse wastewater recycling technology,non-ammonia deliming technology,non-ammonia bating technology,high-exhaustion chrome tanning technology,chrome tanning wastewater recycling technology,inverse chrome tanning technology and chrome-free tanning technology. The application methods and important process control parameters of these technologies are introduced,and efficiencies of these technologies in reducing discharge of typical contaminants are indicated. Meanwhile,the advantages and shortcomings of these technologies are evaluated. In order to improve the effectiveness of these technologies in practical application,it is suggested that the maturity of these technologies should be further enhanced. At the same time,the future work should focus on the integrated application of these unit technologies through fully investigating process balance between unit technologies,as well as the verification of the integrated system of clean technologies.

The basic principles of coal chemical processes were reviewed in this paper including coal carbonization,coal-to-coke,coal-to-gas and coal-to-oil,and the product direction of coal chemical process was analyzed. The reasons of main pollutants produced by coal chemical process were introduced from the coal properties,the process requirements,and the technology features. The source and composition of the “three wastes” were selectively analyzed from the processes of coal-to-coke and coal-to-gas. Among them,the waste gas came from the incompletely carbonized pulverized coal in the chemical conversion process,the precipitated matters including volatile matter,tar fog and fly ash,the leaked raw gas,as well as CO,CO₂ and NO₂ generated by burning coke on contact with air. The wastewater included dedusting wastewater,surplus aqueous ammonia,phenol and cyanogens wastewater,desulfurization liquid and the water sealing gas. The waste residue included dust,coal dust,acid tar,tar slag and sludge. The gas phase pollutants from coal chemical process mainly included oxycarbide,oxysulphide,ammonia gas,volatile phenol,benzene,benzopyrene,CO,CH₄ and small molecule hydrocarbons. The liquid phase pollutants contained not only ammonia,cyanide,sulphide,benzene,phenol and oil,but also a lot of benzopyrene,naphthalene and other PAHs,and heterocyclic aromatic hydrocarbons including pyridine,carbazole,biphenyl,terphenyl,etc. The pollution characteristics showed wide distribution,complex components,high concentration,coexistence of multiphase mediums with high environment risk. The typical characteristics of the coal chemical wastewater were high concentration/salinity,high pollution (multicomponent),toxic and refractory. The clarification of the relationship between the coal chemical process and pollution characteristics needed researchers to deepen the comprehensive understanding for the basic coal properties,the principles of conversion,purification and application. Therefore,the control technology and strategy should be based on the deep understanding for the chain of resource- product-economy-environment-society and the effective integration system,and the strategic design and logic innovation should be enhanced through the scale,product,technology,management,market and talent.

Lurqi and BGL coal gasification requires for much water to wash crude gas. The water is polluted by phenol,ammonia and sour gas with COD up to 20000—50000 mg/L. Removal of these pollutants to acceptable levels for biological treatment is the bottleneck in the water treatment process. This paper analyzes the different treatment processes in terms of their advantages and disadvantages as well as industrial status. The analysis shows that the process of ammonia and acidic gas stripping followed by phenol solvent extraction is better than others in industrial implementation. The ammonia is removed in the first stripping tower,decreasing pH of the wastewater. Phenol extraction is improved in acidic condition. In addition,MIBK is used as the solvent with higher distribution coefficient. The recovery of phenol increases to 93％. In this paper,this treatment process is described in detail,followed by brief explanation of key parameters,such as operating temperature and pressure,reflux ratio,feed position,liquid-liquid extraction phase equilibrium and number of extraction stage. Illustration case of this treatment process is the phenol water treatment unit in coal gasification process of China Coal Longhua Harbin Coal Chemical Co.,Ltd. It has been in successful operation for 5 years with daily processing capacity of 5000t wastewater. Comparison with the conventional treatment the process indicates the advantages in treatment performance and operating cost. This treatment process was also installed and successfully ran in coal to fertilizer process by China Coal Ordos Energy Chemical Co.,Ltd.

Spent hydroprocessing catalyst,a hazardous waste generated in petroleum refining industry,can be used as raw materials for metal recovery in order to meet the circular economic requirements of reducing,reusing and recycling. In light of that,this paper reviews the metal recovery and reuse of spent hydroprocessing catalyst. The methods are divided into hydrometallurgical route and pyrometallurgical route after pretreatment. The hydrometallurgical route contains direct leaching and roasting with alkali compounds. The roasting of spent catalysts with sodium and/or potassium salts significantly enhances solubility of some metals in water,which makes the subsequent leaching process easier. The downsides of this approach are equipment corrosion and secondary pollution. This paper also introduces some commercial metal recovery routes,including acid leaching,alkali leaching,water leaching with roasting and pyrometallurgy. Furthermore,the future research directions are shortening the route in the hydrometallurgical process and lowering energy consumption in the pyrometallurgical route.

Much widely distributed renewable lignocellulosic waste could be liquefied to synthesize high quality polymers such as adhesive,resins,and etc. The liquefactant could be used as a new kind activated chemical materials to replace,at least partly,the petroleum-based products. In this paper,various biomass conversion technologies and the available utilization pathways are summarized. Several conventional liquefaction technologies at different reaction conditions such as the high temperature and pressure,fast pyrolysis and atmospheric pressure in the presence of catalyst were reviewed,and the atmospheric catalytic liquefaction technology and its efficient utilization were particularly introduced. Properties of high value-added biomass-based resin polymer such as adhesives,polyurethane materials,and etc. which is prepared using different liquefaction solvents and catalysts,are illustrated. Based on years of authors' practical research,some difficulties and the suggestions in the liquefaction process were presented for the future industrialized application with low cost,environmental friendly and high-efficiency.

In recent years,water resource shortage and water pollution have been becoming more and more serious. Due to the large amount of excess sludge production,the application of traditional activated sludge technology was restrictions in wastewater treatment in some extent. Aerobic granular sludge technology with compact structure,good settle ability,high biomass retention,various microbial functions and less residual sludge is a promissing method in wastewater treatment. In present paper,the effect parameters on the rapid cultivation of granular sludge and formation process,such as the superficial gas velocity,dissolved oxygen level,the organic load and metal ions,were discussed. The influence factors of granular formation mechanism,the structural characteristics and the instability effect of aerobic granular sludge were focused on in order to promote the application of aerobic granular sludge technology in the wastewater treatment.