This review aims to introduce the droplet-based microfluidics which has been growing rapidly in recent years. Some of the basic droplet operations are summarized focusing on fluid flow pattern, mass transfer and reaction both inside droplets and at interface of droplets. Some of typical examples of existing as well as potential applications of droplet-based microreactors in various fields are also discussed. The developed technologies and techniques provide means to precisely control droplet volumes and accurately manipulate behavior of individual droplet(e.g., generation of droplets, coalescence and fission, mixing and reactions inside the droplets). As a result, each individual droplet acts as a small batch reactor under confined conditions. Accordingly, these small flowing batch reactors together form a new type of novel continuous-flow reactors. Besides the usual advantages brought by microfluidics, e.g., intensified mass and heat transfer and easy scale-up, droplet-based microfluidics have unique features, such as ability to avoid cross contamination, rapid mixing of fluids inside the droplets, independent control of each droplet and high throughput. These features allow them to be widely used in many fields, such as preparation of functional materials, chemical synthesis, biochemical engineering, and so on.

Fluid catalytic cracking(FCC) is an important process in converting heavy oil into light distillates. The modelling of FCC riser reactors is essential in the development of novel FCC processes and new equipment, as well as the steady operation and optimization of FCC units. This paper reviewed the coupled flow-reaction models for FCC risers between flow models and reaction models. The evolvements of the coupled flow-reaction models were also reviewed. The applications of the coupled CFD flow-reaction models were presented and the decoupling methods in solving the coupled models were addressed. Meanwhile, the disadvantages of the coupled CFD flow-reaction models were analyzed and the requirement of online sampling technologies for industrial FCC riser reactors was pointed out. Finally, the studies on the coupled flow-reaction models were summarized. This review would provide reference for investigations in novel modeling approaches for FCC riser reactors and for validations of the coupled models.

The monomolecular mechanism, bimolecular mechanism, pseudounimolecular mechanism and cyclo-transition state mechanism for olefin isomerization over the zeolite catalysts were reviewed. The monomolecular mechanism and bimolecular mechanism have been accepted by more researchers. Olefins were considered to be isomerized mainly through monomolecular mechanism and by-products are generated through bimolecular mechanism. Light olefin aromatization is a conjunct polymerization process over zeolite catalysts. The advances of olefin aromatization over metal modified zeolite catalysts were also discussed. The introduction of metal led to a new reaction path, raising the conversion of olefins and the selectivity of aromatics in light olefin aromatization.

Methods of quantum mechanics and their research applications on the mechanism of benzene alkylation with short-chain olefins in recent years were reviewed. Software based on quantum mechanics and their applications were also introduced. The controversial concerted and stepwise mechanism on the alkylation between benzene and short-chain olefins was elaborated by different model sizes and variable computational methods. The future of computational method for research on the mechanism of benzene alkylation with short-chain was also discussed. The hybrid QM/MM (quantum mechanics/molecular mechanics) approach that combines the strengths of the QM (accuracy) and MM (speed) approaches will be a more effective way to study chemical reaction mechanism.

With the numerical simulation and the experiment methods, the safety valve overpressure relief process and the gas dynamic problem are studied. The relief valve interior steady flow field of moving parts was analyzed by using the domain decomposition and paths analysis methods, the dynamic force balance, the distribution of velocity and the stress characteristics of the paths in the interior and external flow field were studied as well. The results showed that according to the balance of vertical(Y) direction force, experimental lift data came from total pressure, of which the static force was the main part. The dynamic force was important to the recoil force. The clearance force was balanced. The dynamic force mainly came from the high speed gas in the sealing surface and the disc holder ruffled. The static force was the main part of the valve core lift. The research on balance of horizontal(X) direction force showed that valve core was dynamically balanced, but unbalanced horizontal vibration force may exist in the disc holder, leading to a partial load during the open and return process. This partial load may lead to displacement deviation, flutter, chatter and damage the sealing surface, whether combining the valve core and the disc holder into one element or not. By using the experimental setup and the new sensor, the valve core pressure, lift, lifting height and the data of disc holder in monitoring points were successfully obtained, and the recoil force was calculated. The results showed that the 3D simulation was consistent with the sensor testing data.

The simplex method was used to optimize the operation strategy of the combined cooling heating and power (CCHP) system under typical loads of winter and summer days when the system was used in office buildings, the optimization goals were smallest primary energy consumption, lowest running costs and lowest carbon dioxide emissions. The CCHP system was compared with the traditional system. For different optimization goals, a different operation strategy was adopted. In winter, when smallest primary energy consumption was taken as optimization goal, in more time the system ran with the mode of heating deciding power. When lowest running costs or lowest carbon dioxide emissions was taken as optimization goal, all day the system ran with the mode of power deciding heating. When the minimum of the three indicators combined was taken as optimization goal, in more time the system ran with the mode of heating deciding power. In summer, when smallest primary energy consumption was taken as optimization goal, the traditional system was better than the CCHP system. When lowest running costs or lowest carbon dioxide emission was taken as optimization goal, all day the system ran with the mode of power deciding cooling. When the minimum of the three indicators combined was taken as optimization goal, in more time the system ran with the mode of cooling deciding power.

Experiment and calculation of solubility are the foundation of research on solid-liquid equilibrium(SLE) thermodynamics, and provide the important parameters for optimization of industrial crystallization processes. In this study, the research object was 4-acetamidobenzoic acid. Under normal atmospheric pressure, the solubilities of 4-acetamidobenzoic acid in methanol+ethanol mixed solvents (ethanol mass fraction of 0, 20%, 40%, 60%, 80%, 100%, respectively) were measured with a dynamic method at temperatures ranging from 277.95K to 323.35K, and subsequently the thermodynamic phenomena of the dissolution process were analyzed. The experimental data were correlated with the modified Apelblat equation and Jouyban Acree model. The solubilities of calculated values were in good agreement with the experimental results. The average relative deviations of the modified Apelblat equation and Jouyban Acree model were 0.702%, 1.105%, respectively. The thermodynamic parameters of dissolution of 4-acetamidobenzoic acid were calculated, and the result showed that dissolution entropy and dissolution enthalpy were greater than zero. The dissolution process was endothermic, enthalpy change was the main contributor to dissolution process.

According to Fischer-Tropsch synthesis(F-T) reaction kinetics of Fe-based catalysts, a two-dimension model has been developed with COMSOL-Multiphysics by coupling flow, mass transfer, chemical reactions and heat transfer fields. The characteristics of Fischer-Tropsch synthesis in micro-channel has been studied with this model. Detailed research has been taken on the effect of the thickness of catalytic layers and cooling velocity to F-T reactions, heat and mass transfer performance. The numerical results show that, along the axial direction, temperature increased slowly and then declined quickly. By increasing the thickness of catalytic layers, the temperature peak moved away from outlet, CO conversion was improved, methane selectivity increased while C₅₊ selectivity decreased slightly. It's possible to have better temperature control, improve C₅₊ selectivity, and significantly reduce the selectivity of CH₄ by increasing cooling velocity. Under the set researching conditions (the cross-sectional dimension of the micro-channel is 0.6×0.6mm² with a length of 200mm), the preferred catalyst thickness is 0.10mm, also, with the enhancement of the cooling capacity on cooling side, the preferred thickness increases.

The influence of internals on 78.5L airlift loop reactor was studied and optimal values were obtained for theoretical guidance of industrial equipment. Fluent software was used to establish a mathematical model to compare with experiment result. The influence of height ratio between gas liquid separation zone and external tube, length ratio between diversion tube and external tube, and diameter ratio between diversion tube and external tube on flow behavior of airlift loop reactor was investigated. The error between simulation and experiment results was small, and the mathematical model could be used to predict flow behavior of airlift loop reactor. Circulation resistance became larger when length ratio between gas liquid separation zone and external tube was too large. Reactor flow achieved the best performance when the ratio was 0.34-0.36. Increasing length ratio between diversion tube and external tube could increase gas holdup and liquid circulation rate, but an overly large ratio would cause bubbles coalescence, which would affect flow performance. Reactor flow achieved the best performance when the ratio was 0.60-0.62. Increasing diameter ratio between diversion tube and external tube could improve flow. Loop resistance was larger when ring gap area was too small and reactor flow achieved the best performance when diameter ratio was 0.73-0.77.

Based on CFD method, the wall attrition of hydrocyclones for the separation of dispersed phase particles was simulated using the Reynolds stress model and discrete phase model in Fluent software. Results showed that the main attrition on the hydrocyclone wall was local attrition. In the annular region of the entrance, the main attrition was shock attrition. In the region of the cylinder and cone, the main attrition was grinding attrition. The most worn part was near the underflow port. The most worn part of the annular space of the entrance ranged from 100°to 110°in circumferential direction. The distribution of the attrition on the surface of the cylinder body wall was a downward spiral banding. The attrition was more serious on the cone wall to the end of the cone. And the peak attrition appeared at the underflow port. In the solid-liquid hydrocyclone, the attrition on the wall was more serious where the particle concentration was higher. The attrition rate increased with increasing feed velocity. The results can provide certain guidance to the design and application of hydrocyclone separator.

Using the existing facilities of a circulating fluidized bed(CFB) utility boiler, a cold CFB test rig with a riser of 60m in height and 400mm in internal diameter was built in this research. The study focused on the impacts of the fluidizing velocity and material density on the axial and radial voidage distributions of bed materials inside the riser. The results showed that the voidage distribution was closely correlated with fluidizing velocity and material density. For a given initial height of bed materials, when the bed materials of lower dense phase was not empty, voidage in the lower dense phase zone increased with the increase in fluidizing velocity and voidage in the upper dilute phase zone decreased. Furthermore, the radial gradient of voidage in the upper dilute phase zone also increased. Under a certain fluidizing velocities, more materials with lower densities were brought into the upper dilute phase zone, resulting in increasing radial gradient of voidage in the upper dilute phase zone.

A novel thermoelectric cooling device with a liquid cooling system was developed and assembled for sub-ambient temperature cooling of chips in over-clocking or super calculating testing system was set up and experiments were conducted to investigate the refrigeration performances of device in various application conditions. Results showed that the maximum heat dissipating capacity was 7W/cm² when case temperature was the same as ambient temperature, operating voltage of TEC was 48V and the cooling air flowrate was 3-5m/s. TEC was conducive to heat dissipation especially in high ambient temperature (35℃). The case temperature of the heat source was reduced by 5.4℃ at the input heat flux of 23.78W/cm², operating voltage of TEC 16-48V, and cooling air flowrate of 5m/s. In addition, the liquid cooling system was beneficial to coefficient of performance(COP) of TEC. The maximum COP and heat flux were 3.5 and 15W/cm² respectively at the case temperature was 10℃ higher than ambient temperature, operating voltage of TEC 4-48V and the cooling air flowrate of 3-5m/s.

Fine particles are dangerous to environment and mankind, and could not be removed by common dust separator. The rotating packed bed combines various dust removal mechanisms, and has high collection efficiency and low power consumption. A pilot-scale system was set up by using fly ash with average particle size of 2.25μm as fine particles and cross-flow rotating packed bed as wet scrubber in this paper. A method of measuring particle size distribution of dust and calculating the classification efficiency using Mastersizer was proposed. The system was investigated at different rotating speeds, liquid-gas ratios, and gas flowrates. Classification efficiency increased with increasing rotating speed and liquid-gas ratio, and removal efficiency could be up to 96%. These data provided strong support to industrialization of high gravity wet cleaning. Results of fitted regression of classification efficiency showed that correlation coefficient R was 0.9808. Classification efficiency of cross-flow rotating packed bed was higher than common wet dust collector and impact of particle size was less. Cross-flow rotating packed bed can be used to remove fine particles in gas and has broad application prospect.

The rich reserves of oil shale in China have the potential to relieve the shortage of oil supply. However, there is few systematic quantitative analysis on energy utilization and economic performance of oil shale retorting process. This paper takes two representative oil shale retorting processes as case study, Fushun retort and gas full circulation retort. Based on process modeling and simulation, this paper analyzes materials flow and exergy flow of the two processes to find the causes of mass and exergy losses. Economic performance indicators of these two processes are analyzed. The exergy loss of the Fushun retorting process was 19.5% higher than that of the gas full circulation retorting process;while the total capital investment of gas full circulation retorting process was 1.69 billion, 0.5 billion higher than that of the Fushun retorting process. However, the gas full circulation retorting process can produce 5.4t/h more shale oil and 84.8MW electricity, which makes the return on investment 10% higher than that of the Fushun retorting process.

The release of gaseous products in oil shale pyrolysis by microwave heating was investigated in a microwave heating test device. The effects on release of gaseous products in oil shale pyrolysis by microwave heating with different microwave powers from 30 percent to 80 percent of 1600W, heating temperature from 773K to 1173K, different pyrolysis temperature stages and different catalysts were studied. Microwave heating enhanced the release of H₂, CO and C₂H₄. The release amount of hydrocarbons had a maximum at 50 percent microwave power of 1600W. A large amount of pyrolysis gas released at low temperature from 423K to 623K came from release of adsorbed gas and breakage of unstable branches and groupes. With increasing temperature, more gas was released from dehydrogenation, aromatization, condensation and free radical reaction of organic matter. Catalysts promoted gas release. However, different catalysts had different effects on pyrolysis gas composition. adsorption of molecular sieve (5A and 13X) promoted secondary decomposition and polymerization of organic matter. Clay catalysts (bentonite and activated clay) enhanced catalytic hydrogenation of organic matter under proton acid, sped up breakage of organic chains and improved groups stability.Metal catalysts (MoS₂, FeS and Ni₂O₃) firstly increased heating rate and enhanced pyrolysis, secondly, promoted generation and transfer of hydrogen free radicals.

Shengli brown coal was gasified by using a laboratory entrained flow reactor at 900℃ under the atmospheres of H₂O, O₂ and their mixture, and pore structure features were investigated. The shapes of adsorption isothermal curves obtained from the chars under various atmospheres were Type II and the shapes of the adsorption loop curves were Type H3. There was a relatively continuous and integral pore system of chars with similar pore structures. Pore diameter distribution was influenced by reaction atmosphere. The quantity of macropores of char was less under all three atmospheres;the order of mesoporesfrom more to less was H₂O > O₂> H₂O+1%O₂, and the order of micropores was the reverse. The specific surface area of char presented the trend of increasing at first, then maintaining steady with the increase of H₂O. The specific surface area of char during gasification under H₂O+1%O₂ mixture atmosphere increased by more than 30 times. It increased linearly with the increase of O₂ at low concentration of oxygen. The relational expression for conversion versus ratio of micropore volume and total pore volume, and conversion versus specific surface area was X=0.196(V_m/V)+45.651, X=0.037S+48.066.

With the development of electric furnace steelmaking, the demand for the raw material, direct reduced iron is growing. The study of direct reduction characteristics and mechanism becomes more urgent. Past researches have mainly concentrated in process conditions, energy conservation and emissions reduction, but comparison of reaction speed control models is relatively few. In this paper, the effect of reduction temperature on carbon-containing pellets was investigated under nitrogen atmosphere from 950℃ to 1100℃. X-ray diffraction was used to identify the changes of iron phase. The reaction kinetics parameters were estimated based on thermogravimetric experiments and different speed control model equations. The estimated results were compared with the experimental results. Temperature played a vital role in the reduction process. Reduction of Fe₃O₄ to form FeO began below 950℃, and reduction of FeO to form Fe mainly began at 1000℃. Reduction rate increased rapidly between 950℃ and 1100℃. Through the comparison of different speed control models, it was concluded that the reduction process was controlled by three-dimensional gas diffusion.

The existence forms of sodium in high sodium content coals from Zhundong area in Xinjiang Uygur Autonomous Region, China, were determined with the three-step-extraction method. The contents of sodium in Wucaiwan coal ash prepared at different temperatures and the treated coals ash prepared at 815℃ were measured. Release and transformation of sodium in coal were investigated during combustion process. The traditional determination method was compared with the analysis method by microwave digestion and inductively coupled plasma atomic emission spectrometry. Most of sodium in Wucaiwan coal existed mainly in the form of water-soluble sodium. During the combustion process, release of sodium from coal samples, especially water soluble sodium and ammonium-acetate soluble sodium, mainly took place ahead of 815℃. There was transformation among different forms of sodium during the combustion process. The main transformations were water soluble sodium to insoluble sodium and insoluble sodium to organic sodium. The analysis method by microwave digestion and inductively coupled plasma atomic emission spectrometry for measuring sodium in coal was more accurate.

Ash fusion characteristics are very important to co-gasification of biomass and coal. To study the effects of biomass on ash fusion temperatures(AFTs) of lignite, the mixtures of peanut shells, corn straw and pine wood chips with Husheng lignite at different mass ratios were investigated. The trend of AFTs change of mixtures was examined on an intelligent ash fusion analyzer. X-ray fluorescence spectrometer (XRF) and X-ray diffract-meter (XRD) were used to analyze the reason causing AFTs change. Three kinds of biomass all could make the AFTs of Husheng lignite decrease to some extent, which was related to ash content and ash composition of the mixtures. A non-linear relationship was shown between the mixing proportion and AFTs of mixtures. The formation of mullite in mixed ashes (peanut shell or corn straw with Husheng lignite) resulted in fluctuation of the trend of AFTs change. For the mixed sample of pine wood chips and Husheng lignite, the decrease of kyanite with a high melting point (MP), the increase of anorthite with a low MP, and the generation of low MP leucite and augite led to the decrease of AFTs.

Catalytic gasification of coal has been widely investigated. As a catalyst for coal gasification, calcium has been concerned by many researchers. In this paper, the types of calcium that can play catalyst role in coal gasification are summarized. The mechanism and influencing factors of calcium catalytic coal gasification are discussed. It is pointed out that calcium can accelerate the coal gasification rate more effectively because of the synergistic effect when it is selected to catalyze coal gasification together with other materials. Meanwhile, the research on calcium catalytic coal gasification in the near future is prospected. It is suggested that the mechanism of calcium catalytic coal gasification should be further discussed. It is necessary to develop the catalytic coal gasification technology using limestone or slaked lime mixed with other materials, such as black-liquor.

The study on catalyst activity in Nd-catalized isoprene rubber(NdIR) is of practical value and theoretical significance. In this paper, both experimental and theoretical researches on the activity of catalyst in NdIR are reviewed since it was born 50 years ago. It is indicated that the effective percentage of neodymium is only 10% or so, although the activity has been increased by at least two orders of magnitude through experimental researches, i.e. there is a theoretical room at least 9 times for activity improvement. In recent years, the experimental research progress is slow. On the other hand, recent theoretical researches on catalyst activity based on quantum chemical calculation indicate that quantum chemistry theory and methods, such as DFT, relativistic effect, effective core potential (ECP), etc. have improved the acuracy and efficiency for quantum chemical caculation of lanthanide compounds, which facilitates the research on catalyst activity of NdIR. The future research progress will be achieved in combining experimental and theoretical research to build a qantitative structure-activity relationship(QSAR) for developing more active catalysts.

CO₂ methanation is one of the effective ways to realize resource recycling on greenhouse gas, CO₂. This article was aimed to review the research progress in catalysts for catalytic CO₂ hydrogenation to produce methane in the past few years. The Ni-based catalysts were widely studied in literature. The effects of Al₂O₃, SiO₂ and La₂O₃ supports and CeO₂, La₂O₃ additives on the performance of Ni-based CO₂ methanation catalysts were mainly introduced, together with the effects of the structures, electronic performances and chemical properties of supports and additives on the performance of the Ni-based methanation catalysts. The Co-based CO₂ methanation catalysts with ordered mesoporous structures also exhibited superior catalytic activities comparing with the studied Ni-based CO₂ methanation catalysts. The results indicated that the novel structure was also a key factor to affect the catalytic performance of catalytic CO₂ methanation. And CO₂ methanation performance at low temperature can be improved by the modulation of catalyst structures and composition, which could lay a foundation for the industrialization of CO₂ methanation process.

Latest researches on SAPO-34 molecular sieves in methanol to olefins reaction are introduced. It is found that the synthesis process of SAPO-34 molecular sieve can affect its crystallite size, acid strength and other physico-chemical properties, eventually its catalytic properties. The synthetic factors of SAPO-34 molecular sieve, such as the ratio of raw materials and their types, template, F-ions, which can affect its physico-chemical properties and catalytic performance in MTO reaction, are discussed in detail. Regarding the new technologies of SAPO-34 synthesis and catalytic performance optimization, the features and effects of metal-modified, ultrasonic or microwave assisted synthesis of SAPO-34 are reviewed. The trend for the development of SAPO-34 is to obtain higher olefin selectivity, longer life and lower cost by the discovery of new template and new technology for the modification or preparation of molecular sieves.

Co-Pd/TiO₂ catalysts are prepared by impregnation and sol-gel methods, separately. The effect of preparation methods on Co-Pd/TiO₂ catalyst performance is investigated for the direct synthesis of C₂ oxygenates from CH₄ and CO₂ by a step-wise reaction technology. The as-prepared catalysts are characterized by XRD, XPS and nitrogen adsorption-desorption. The results show that the surface property and texture of both impregnation catalyst and sol-gel catalyst have obvious changes after reaction. The existence of CoTiO₃ species in all catalyst samples shows that there is a strong interaction between active metal Co and the carrier TiO₂, and that CO²⁺ can substitute Ti⁴⁺ in the titania lattice. CoO and Pd may act as the active center for this reaction. For both fresh and used catalyst samples, surface Co contents of sol-gel catalyst samples are lower than those of impregnation catalyst samples, while surface Pd contents of sol-gel catalyst samples are higher than those of impregnation catalyst samples. For sol-gel catalyst samples, the formation rates of all products are higher than those of impregnation catalyst samples. Consequently, sol-gel catalyst performs a better catalytic activity compared with impregnation catalyst.

The catalyst of solid superacid SO₄^2-/TiO₂ supported on HZSM-5 was prepared by sol-gel process. The trimethylolpropane oleate was synthesized by direct esterification. The catalyst was characterized by IR, XRD, BET, and SEM. The results show that SO₄^2-/TiO₂ with the form of nanoparticles is supported on the surface of HZSM-5, the BET surface area of the catalyst is up to 309.2m²/g, increasing 45.6m²/g compared with HZSM-5, and the catalyst is with better solid acidity. The effects of catalyst preparation conditions on catalytic reactivity were studied. The optimal condition for the preparation of the catalyst was obtained as follows:the pH for deposition is 8, impregnation concentration of H₂SO₄ is 0.5mol/L, impregnation time is 30min, calcination temperature and time are 550℃ and 4h, respectively. Under the optimal condition, solid superacid SO₄^2-/TiO₂-HZSM-5 catalyst has the best the catalytic performance, the esterification rate of trimethylolpropane oleate is as high as 97.6%, the product can exhibit excellent emulsification resistive property, and oil-water separation time is 5min. After solid superacid SO₄^2-/TiO₂-HZSM-5 catalyst is reused 6 times, the esterification rate of trimethylolpropane oleate decreases by 8.8%, i.e. the catalyst shows good reusability.

Polyaniline/polyacrylic(polyacrylate) composites possess excellent performance of processibility, film-forming properties, adhesion, electrical properties and anti-corrosion properties. In this paper, the research on polyaniline/polyacrylic(polyacrylate) blend composites and polyaniline/polyacrylic (polyacrylate) polymerization composites at home and abroad is reviewed. The preparation methods, properties and applications of various kinds of polyaniline/polyacrylic(polyacrylate) composites are presented. The advantages and disadvantages of these preparation methods are further compared. The blending method is simple and easy to control, so it has wide application. The polymerization method could combine polyaniline with polyacrylic(polyacrylate) at molecular level to improve comprehensive properties. The interpenetrating network polymerization method realizes compatibility of two different molecular chains by network interpenetrating. The paper proposes that composite polyaniline and polyacrylic(polyacrylate) at molecular level is the main development direction in the future.

Amphoteric polyacrylamide, a family of polyampholytes, is a new type of functional polymer. This review firstly describes the structure and properties of amphoteric polyacrylamide, including isoelectric point, charge density, molecular chain morphology, turbidity, viscosity and absorption characteristics. It then outlines the synthesis reactions associated with production of amphoteric polyacrylamide, including modification of macromolecules, grafting and copolymerization, copolymerization of anionic/cationic monomers, and copolymerization of acrylamide and betaine monomers. It also summarizes the synthesis methods of amphoteric polyacrylamide, including:aqueous solution polymerization, inverse emulsion polymerization, inverse microemulsion polymerization, suspension polymerization, and radiation polymerization. At last it illustrates applications in various fields, especially in the paper industry to enhance retention, drainage at wet-end, and improve dry-strength of paper sheets.

Plant cellulose is a natural renewable resource, and application of the modified cellulose has been a research focus. The structure and properties of cellulose are described, and cellulose modification methods are reviewed, including physical, chemical and biological methods. The main method is chemical modification, including esterification, sulfonation, etherification, ether esterification, crosslinking and graft copolymerization, which involve the reactions of hydroxyl groups in the cellulose. Hydrophilcity of cellulose could be enhanced by introduction of ionic groups. Compared with non-modified cellulose, crystallinity and degree of polymerization of modified cellulose decrease significantly, whereas accessibility is improved remarkably, with superior physical and chemical properties. Finally, the research achievements of cellulose derivatives in food, paper and construction industries are reviewed. Research progresses in pharmaceuticals, wastewater treatment and other areas are presented. Future applications of cellulose derivatives are prospected.

Core-shell-structure MOFs materials became a hot spot in the field of chemical and materials over the last decade, and MOFs can act as core or shell. This paper mainly reviews the synthesis methods of core-shell-structure material with MOFs as shell according to different nuclear types, such as epitaxial growth method, and post-synthetic modifications;and summarizes the performances which are better than single core or shell, such as separation selectivity, catalysis, magnetic performance, and the development of the core-shell-structure materials with MOFs as shell in gas adsorption, catalysts, magnetic separation, which bring a large potential for MOFs composite industrialization. The cores include metallic and non-metallic element core, oxides core, and MOFs core. And the core-shell-structure composites with MOFs as shell are prospected for the improvement and development of synthesis methods in order to obtain uniform and stable structure and multi-function.

Amphiphilic block copolymer PSt-b-P(St-alt-MA)-b-PAA was synthesized by reversible addition-fragmentation chain transfer (RAFT) polymerization using S, S'-bis(R, R'-dimethyl-α"-acetic acid)-trithiocarbonate as RAFT agent and styrene, maleic anhydride, acrylic acid as monomers. The self-assembled micelles of PSt-b-P(St-alt-MA)-b-PAA were induced by selective solvent dimethylfomamide. The effects of block length, initial concentration and pH on the self-assembled micelles were investigated through ultra-violet and visible spectrophotometer and laser particle size analyzer. The crosslinked micelles fabricated by chemical crosslinking had stable morphology and diameter as characterized with transmission electron microscope. Block length, initial concentration and pH would affect self-assembly behavior of copolymer and morphology of self-assembled micelle. The micelles crosslinked by ethylenediamine with average particle diameter of 145.5nm had stable morphology and size.

PLGA [poly(1actic-co-glycolic acid)] coaxial electrospinning nanofiber is a biodegradable material with good biocompatibility. In addition, its high porosity and high oxygen permeability would also favor PLGA to become a good pharmaceutical carrier. The technological conditions of electrospinning were studied and flurbiprofen axetil (FA)-loaded PLGA nanofibers were prepared by coaxial electrospinning. The structure and morphology of the nanofiber were characterized by infrared spectrometer (IR) and scanning electron microscope (SEM), respectively. The influence of solvent's proportion on nanofibers'drug release properties was investigated. When positive voltage, negative voltage, receive distance, advancing speed of the shell as well as the core is+15.00kV, -2.50kV, 15cm, 0.4mm/min, 0.1mm/min, respectively. The prepared PLGA/PVP FA-loaded electrospun fibers had a good core-shell structure, and carried successfully about 0.5% FA. Besides, when volume ratio of the shell's mixed solvent (DCM and DMF) and the core's mixed solvent (anhydrous ethanol and DMF) changed, fiber diameter would increase with the decrease of DMF.

Methyl methacrylate was synthesized from methyl propionate and trioxyane over K/γ-Al₂O₃ catalyst. The effects of reaction temperature, concentration of MP, source of formaldehyde, K loading on catalyst, raw material mole ratio and calcination temperature of catalyst on the reaction were investigated. The optimum conditions for synthesizing methyl methacrylate were reaction temperature 320℃, concentration of MP 20%, trioxyane as the source of formaldehyde, K loading on catalyst 12.5%, mole ratio of MP to HCHO 1:1, calcination temperature of catalyst 1100℃. Under the optimum conditions, yield and selectivity of MMA were 39.2% and 76.1%, respectively. With the rise of calcination temperature, crystal structure of Al₂O₃ changed. Activity of γ-Al₂O₃ was better than that of α-Al₂O₃, and activity of catalyst was enhanced by forming K-O-Al in K₂Al₁₉O₂₉.

Lactide is an intermediate in the synthesis of polylatic acid(PLA), and its chemical and optical purity have a significant effect on the quality of PLA. In this paper, the process of synthesizing lactide by two-step approach was outlined and the influence of temperature, pressure, reaction time, catalyst and its quantity on the yield and purity of lactide was investigated. Through adopting new technology, new type reaction equipment and developing more efficient and homogeneous catalyst, the problem caused by pyrolysis could be resolved. Various methods for purifying lactide, such as solution crystallization, extraction, distillation and melt crystallization methods, were also discussed. Coupling various refining technologies will have a bright prospect, while integrating melt crystallization with other method is one of the most promising and feasible technical route. Finally, developing novel and environmentally friendly purification technology will still be the key to synthesizing lactide.

Acetylated starch with high degree of substitution (DS>2) was widely used in the field of polymeric materials for its hydrophobicity and thermoplasticity. High DS acetylated starch was prepared by the reaction of native rice starch with acetic acid/acetic anhydride in the presence of p-toluenesulfonic acid as catalyst through ultrasound-enhanced processing. The products were characterized by FTIR, XRD and SEM. The effects of ultrasonic time, ultrasonic temperature and ultrasonic power on DS of acetylated starch were studied. The ultrasonic conditions were optimized by response surface as follows:ultrasonic time 15.67min, ultrasonic temperature 31.33℃ and ultrasonic power 85.60W. The optimal DS of 2.77 was obtained. FTIR spectrometry showed new bands at 1750cm^-1, 1433cm^-1, 1375cm^-1 and 1239cm^-1 associated with acetyl group, proving that acetylated starch with high DS was synthesized successfully. The results of XRD and SEM indicated that the structure of starch granule was destroyed by esterification. The results of the research provided basis for industrial production of high DS acetylated starch.

Isolongifolenone was synthesized from isolongifolene, and in order to optimize the catalytic oxidation condition, orthogonal experiment was conducted with oxygen volume fraction, gas flux, reaction time and reaction temperature chosen as factors．The optimal conditions for industrial production were determined by using the Minitab software analysis as follows, oxygen volume fraction 35%, gas flux around 60mL/min, reaction temperature 60℃ and reaction time 8 hours, and the corresponding conversion rate and yield were 61.79% and 55.49% respectively. In addition, presence of water in the reaction system was investigated, and the results showed that water had a great influence on reaction conversion rate and yield of product. The kinetics of the reaction process was studied. The oxidation reaction was first-order kinetic process with activation energy (64.92kJ/mol). The research data would provide the foundation for industrial production of isolongifolenone．

In this study, 2, 2', 2", 4, 4', 4", 6, 6', 6"-nonanitroterphenyl (NONA) was synthesized starting from 2, 4-chloro-1, 3, 5-trinitrobenzene (DCTNB) and 2, 4, 6-trinitrochlorobenzene (PiCl) through the Ullmann reaction with active copper powder as catalyst. The target product and other by-products were separated through column chromatography.The structures of target product and other by-products were characterized by IR, MS and 1HNMR. The target product was NONA, and the main by-products were HNB and DODECA. Thermal decomposition of NONA was measured by DSC. The pyrolysis temperature of NONA was 380℃ and NONA had good heat stability. This technology cost less by selecting DCTNB as raw material instead of DiBrTNB, and reaction conditions were more moderate. It had a good application prospect.

In this paper, research progress in the electrochemical activation of CO₂ for the synthesis of organic carbonate in ionic liquids have been reviewed, with the focus on the synthesis of DMC (dimethyl carbonate) and cyclic carbonate. The technology of direct and indirect activation of CO₂ and the differences of products from different reaction media and electrode materials are briefed. The key technology for the electrocatalytic reduction of CO₂ and the research emphasis in the future is also discussed. Ionic liquids have attracted more and more attentions in the study of CO₂ fixation and organic sources utilization because of their excellent properties, such as low vapor pressure, high ionic conductivity, easy recycling and high solubility of CO₂. Electrochemistry is a novel, environmentally friendly synthesis technology. It has important practical significance to alleviate the increasingly serious greenhouse effect and to motivate the resources utilization of CO₂.

High-solid anaerobic digestion, characterized by smaller reactor volume, less energy demand, less amount of residue and more convenient follow-up treatment, is an important method to realize the recycling of solid waste. This paper introduced the effects of the factors such as raw material, inoculation, solid content, temperature, carbon and nitrogen ratio and particle size, on high-solid anaerobic digestion process in detail, and pointed out that these factors were all of great significance and impacted the high-solid anaerobic digestion through changing the startup performances, methane production, volatile solids(VS) degradation rate and system stability. It would be a promising method for high-solid anaerobic digestion to dispose the sludge from domestic wastewater treatment plants. In addition, operating parameters and optimization measures in terms of different factors were provided for the application of high-solid anaerobic digestion in order to help furthering the technology.

Traditional diosgenin production process is simple in technique and easy to operate, but it has significant disadvantages, such as low yield, high energy consumption and environmental pollution. This paper summarized latest research progress in cleaner diosgenin production process, and emphasized the improved process of traditional inorganic acid hydrolysis and the process of non-inorganic acid hydrolysis. Techniques of non-inorganic acid hydrolysis were analyzed in more detail, such as ion exchange resin catalysis, ionic liquid catalysis, biotransformation and thermolysis. The advantages and disadvantages of different processes were compared. The improved process of traditional inorganic acid hydrolysis can increase diosgenin yield and reduce environmental pollution by certain amount, but wastewater and waste residue can still be a problem. The process of non-inorganic acid hydrolysis could have zero pollution, but the shortcomings of low yield and high cost could limit its development. This paper also outlined comprehensive utilization of wastewater and waste residue from producing diosgenin by using Dioscorea zingiberensis C. H. Wright, and summarized the problems in cleaner production process and the utilization of waste residue. The priority of future research was proposed to focus on increasing diosgenin yield in the process of non-inorganic acid hydrolysis, exploring and developing resource utilization of waste residue.

A large number of studies have documented that dissolved organic matter (DOM), with its special structural features in the quinone respiration process, can act as redox mediator to catalyze and transform a variety of organic and inorganic compounds, while the influence of the mechanism is not entirely understood. It is significant to conduct more researches to clarify the chemical and biological mechanisms restraining mediation of dissolved organic matter in transformation of organic pollutants. The chemical and biological mechanisms of nitro aromatic compounds degradation and the catalytic effect of transformation process when DOM acts as the redox electron shuttle mediator are summarized. Meanwhile, the effect of various factors for the catalytic conversion of dissolved organic nitroaromatic compoundsis reviewed. Future researches should concentrate on seeking the dissolved organic matter with higher redox efficiency to reduce pollutants, thus improving the practical applications of redox mediators in catalytic degradation of nitro aromatic compounds.

This paper investigated the CO₂ absorption performance from biogas and regeneration characteristics using N-methyldiethanolamine-based(MDEA)blended solvents respectively promoted by monoethanolamine(MEA), MEA-based glycinate(MEAGLY) and MEA-based sarcosinate(MEASAR)in a bubbling CO₂ absorption/regeneration reactor. Results showed that the CO₂ absorption rates of blended solvents increased with the adding amount of promoters, but CO₂ desorption rates decreased. During the period of temperature increase from the absorption range to regeneration range, all the CO₂-rich solvents were regenerated, and the blended solvents performed better than the single solvents in CO₂ regeneration efficiency. In addition, when mass ratio of MDEA to promoter was 3:2 in the blended solvents, the absorption-regeneration performances were optimal. CO₂ removal costs from biogas of different absorbents were also assessed and compared. Compared to the single MEA with 30% mass fraction, the blended solvents, MDEA/MEAGLY and MDEA/MEA in which the total mass fraction was 30% and the ratio of MDEA to MEAGLY or MEA was 3:2 had the lower CO₂ removal costs by about 12% and 30%, respectively. So MDEA/MEAGLY and MDEA/MEA might be the promising alternatives to replace MEA in the future.

Polyurethane is a kind of important synthetic material, one of whose components is toluene diisocyanate(TDI). In the production of TDI using heavy solvent, thousands of tons of tar residue was obtained as by-products. It is necessary to recycle the residue with great economic value and ecological value. Residue composition was analysed with Fourier transform infrared spectrometer (FTIR) and thermogravimetric analyzer (TGA). Experiments were designed according to tar residue composition. By hydrolysis of diethyl isophthalate (DEIP) in the residue, high purity isophthalic acid (IPA) was obtained as product. Multiple factors affectingp the yield of isophthalic acid were investigated, such as reaction temperature, reaction time, sodium hydroxide ratio, raw material particle size, and conditions that prevented the formation of impurity. Hydrolysis reaction kinetic parameters of DEIP in the tar residue were calculated by fitting experimental data:reaction order was 3, activation energy was 69.086kJ/mol. Reaction conditions for industrial production were summarized:tar residue was ground to 150μm, NaOH:residue=0.3:1(mass ratio), reaction for 3 hours at 90℃ in water.

Ozonation can effectively remove emerging pollutants, such as pharmaceuticals and personal care products(PPCPs). However, the effectiveness may be affected by the matrix of wastewater effluent. In this study, the influence of effluent organic matter(EfOM)on the ozonation of sulpiride(SP), a regularly utilized antipsychotic drug, was investigate at two aspects of degradation and mineralization. And three representative model compounds, humic acid(HA), bovine serum albumin(BSA), and sodium alginate(AGS), were used to simulate the main constituents in EfOM. The results showed that ozonation can effectively remove SP concentration from aqueous solution, with the removal efficiency > 85% within 8 min. However, SP couldn't be mineralized completely, and TOC removal efficiency was < 10% after 25min. The ozonation of SP was hindered by the added HA and BSA. With increasing concentrations of HA and BSA, the reaction rate of SP decreased and the mineralization of SP solution was enhanced. However, the influence of AGS on the ozonation of SP was minor at AGS concentrations of 0-3.0mg/(L TOC).

The H₄SiW₁₂O₄₀@C photocatalysts synthesized in situ from silicadodecatungstic acid (SiW12) and soluble starch were studied and characterized by SEM, EDX, XRD, FTIR, UV-vis and BET in this research. The degradation of Rhodamine B (RhB) wastewater with H₄SiW₁₂O₄₀@C photocatalysts and hydrogen peroxide was investigated under ultraviolet irradiation. The effects of different factors and synergetic effects on the degradation of RhB were investigated and the mechanism of catalytic oxidation of RhB was discussed. The results showed that the RhB was degraded efficiently. The decoloration efficiency of the RhB was up to 95.78% with the initial pH value of 3 and RhB concentration of 100mg/L under optimal reaction conditions (i.e. SiW20@C of 0.15g, dose of hydrogen peroxide concentration of 14mmol/L, reaction temperature of 25℃, the high pressure mercury lamp power of 500W, the radiation time of 70min). Degradation process of RhB wastewater by ultraviolet, hydrogen peroxide and SiW20@C had synergetic effects. UV-vis spectroscopy and HPLC results of the wastewater showed that the conjugating structure of RhB was destroyed, phenylcontained and small molecular compounds were included in the solution. In addition, the SiW20@C photocatalyst also showed good reusability.

The main method of leaching of lead, tin, antimony from waste printing circuit board is traditional heating assisted hydrometallurgy, but long time and low efficiency limit its application. In order to solve this problem, this paper proposed a microwave-assisted hydrometallurgy in metal leaching. The research adopted microwave radiation waste circuit board powder and explored effects of several factors on the metals leaching rate, including NaNO₃ and NaOH dosage, microwave capacity and microwave time in the oxidizing leaching process, water dosage, microwave time in the Na₂S leaching process. The experimental results showed that the optimum reaction conditions were:mass ratio of NaNO₃ and NaOH to metal powder was 3:5, radiation for 6min under microwave power was 800W in the oxidizing leaching process;liquid-solid ratio was 3, and radiation time for Na₂S leaching process was 20s. The leaching rate of Pb, Sn and Sb was 92.37%, 94.4%, 88.13% respectively. Compared with the traditional oxidation smelting technology, this new method had high reaction speed and leaching rate, produced less waste liquor, convenient and efficient, environmental friendly.

This paper described the current commonly e-waste gold leaching methods, their advantages and disadvantages, and analyzed research status of e-waste thiosulfate gold leaching. Gold leaching from waste integrated circuit (IC) using the alkaline sodium thiosulfate solution with copper iron was investigated. Through the mechanical pretreatment, particle size analysis, dissociate-ion analysis, chemical pretreatment and gold leaching experiments, the effects on gold leaching rate of Na₂S₂O₃ concentration, Cu²⁺ concentration, NH₃ concentration, temperature, leaching time and liquid to solid ratio were discussed, and optimum gold leaching conditions were obtained:0.3mol/L of Na₂S₂O₃, 0.03mol/L of Cu²⁺, 0.5mol/L of NH₃, 3.5g/L of Na₂SO₃ as the stabilizer, leaching temperature of 50℃, leaching time of 2.5h, liquid to solid ratio of 10:1. Under these conditions, the highest rate of gold leaching was 92.25%. Compared with traditional methods, the new method had advantages of fast leaching speed, non-toxic leachate and easy operation.