CO₂ mineral curing technology is based on the carbonation reaction and product formation process between the early-formed concrete material and CO₂ to improve the mechanical strength of concrete products. The development of CO₂ mineral carbonation curing focuses on the mineralization reaction (i.e., accelerated carbonation) between the binder materials and CO₂ in the concrete after pre-curing/early hydration molding. In this process, the hydration process of the cementitious material is no longer the main reaction for the strength gain. Therefore, in order to fully realize the mineralization cementation and the CO₂ fixation, and maximize the environmental benefits, researchers have widely explored the alkali metal materials with CO₂ mineralization potential in recent years, and investigated the effect of mineralization reaction on the microstructure and properties of concrete. In this paper, the research progress of CO₂ mineral carbonation curing technology on novel concrete materials is reviewed. The hydraulic calcium silicate materials used in traditional concrete, non-hydraulic calcium silicate materials, magnesium-based cement materials and industrial solid waste materials are considered and compared. The paper introduced the latest achievements on the CO₂ reaction characteristics of different materials and the performance optimization of building materials after curing. The prospects for the future development of CO₂ mineral carbonation technology are also summarized. The main suggestions include: firstly, focusing on the microstructure reaction mechanism and mineral properties, and developing effective reaction enhancement methods; secondly, developing the non-hydraulic calcium silicate materials; thirdly, combining the industrial solid waste recycling and the CO₂ mineral carbonation processes to use solid waste and gas waste in one process, and developing the specific process and device.

The synthetic methods, purification, waste treatment and cost control of acetonitrile synthesis processes were analyzed according to the principles of green chemistry. The methods of directly synthesis of acetonitrile from ethanol, including hydrogenated ammonization and ammoxidation, were mainly introduced. The performance of the catalysts was analyzed and compared in terms of the conversion of ethanol and selectivity to acetonitrile. Two purification processes of extractive distillation and pressure-swing distillation, were discussed, and the advantages of pressure swing distillation, waste treatment methods and cost control strategies were illustrated. An acetonitrile production process was proposed based on the requirements of green chemistry. Bioethanol is a renewable and rich available source and its production technology is mature, making it an ideal synthetic substrate. The synthesis process would be better to adopt the ammonia oxidation method, with molecular oxygen as oxidant, and supported vanadium or palladium on activated zirconia as a catalyst. The ethanol conversion is close to 99%, and the selectivity of acetonitrile is 95%—99%. As for the purification process, the pressure-swing distillation was more advantageous with respect to the green chemical requirements than the extractive distillation. And the product purity could reach 99.9% without the use of additional solvent, which were beneficial to the process scale-up. The by-product treatment processes were evaluated by their effectiveness and economy. Besides, the carbon emission of the whole process is strictly controlled, which provides a new idea for the upgrading and transformation of acetonitrile factory.

The medium temperature latent heat thermal energy storage systems have extensive research and application prospects in the fields of solar heat utilization and waste heat recovery, but the low thermal conductivity of the phase change materials seriously weaken the thermal response rate and heat storage and release efficiency of the latent heat thermal energy storage systems. In order to solve this problem, this paper summarizes the heat transfer enhancement methods of medium temperature latent heat thermal energy storage systems in recent years from three aspects: increasing heat transfer coefficient, expanding heat transfer area and increasing average temperature difference. It can be seen from the analysis that the carbon-based filler has the advantages of higher thermal conductivity, lower cost and lower density than the metal-based filler. The direct latent heat thermal energy storage system is light in weight and high in heat transfer efficiency, and is suitable for use in mobile phase change heat storage vehicles. The cascade latent heat thermal energy storage system conforms to the energy cascade utilization concept and has high heat storage and release efficiency. In the future research, there is still important research potential and value in further modification of the heat conduction reinforcing filler, direct latent heat thermal energy storage system, cascade latent heat thermal energy storage system and the effect of heat transfer enhancement and the mechanism of synergistic enhancement of various heat transfer enhancement methods.

Although there are many studies on hydrate deposition in multiphase flow pipeline systems at home and abroad, the hydrate deposition mechanism remains to be further studied. According to the different conditions of hydrate deposition experiment, the multi-phase flow pipeline transportation system is divided into gas-dominated systems, oil-dominated systems, partially-dispersed systems and water-dominated systems. In this paper the main mechanism of hydrate deposition in each system is summarized and the future research direction is proposed. The hydrate deposition mechanism in the pipe transport system includes water wet deposition surface, hydrate particles aggregation, hydrate wall film growth, hydrate particles wall adhesion and hydrate particles bedding. Most scholars believe that the wall film growth of hydrate is the main mechanism of hydrate deposition in gas-dominated systems and the main mechanism of hydrate deposition in oil-dominated systems is hydrate particles bedding, while the hydrate deposition mechanism of partially-dispersed systems and water-dominated systems has not been unified and needs to be further studied. The future development direction of hydrate deposition research in the multi-phase flow tube transport systems is as follows. ① Establish a fully transparent flow loop to observe the actual formation process and deposition process of hydrate in the pipeline, and conduct in-depth research on the hydrate deposition mechanism. ② The effects of oil moisture layer, water-in-oil (or oil-in-water) emulsion, free water layer on hydrate deposition and plugging should be quantified. ③ It is necessary for the gas-dominated system to study the deposition mechanism of other common flow patterns such as slug flow and bubble flow except the annular flow and the stratified flow with the focus of developing a comprehensive model to describe hydrate deposition process. ④ For the water-dominated system, the specific mechanism of oil-water emulsion breaking in the hydrate formation process should be the direction of quantitative research on the future hydrate deposition process. ⑤ At home and abroad, there is little theoretical research on the hydrate deposition and plugging in vertical tubes, elbows and tube valves, and thus the future should emphasize this aspect.

The investigation on the flow field and dispersion characteristics of resonant sound mixing is of great significance for the dispersion mixing of heat sensitive superfine materials. In order to simulate the flow field and dispersion characteristics of resonant sound mixing, a gas-liquid-solid three-phase flow model based on CLSVOF-DPM was established, and the mixing uniformity was evaluated by the standard deviation of the number of particles in different regions. The CLSVOF model solves the gas-liquid interface and the dispersion flow field. The DPM model tracks the particle position and realizes the bidirectional coupling of the CLSVOF model and the DPM model through the momentum exchange between the continuous phase and the particles. The calculation results showed that the turbulent flow is diffused downward from the vicinity of the liquid surface when the acceleration exceeds 30g, where g is the gravitational acceleration. The liquid filling ratio and the feeding position affect the dispersion efficiency and quality. The uniform dispersion time is the shortest when the excitation acceleration is 40g. Finally, experiments were carried out using a self-made resonance acoustic hybrid prototype, and the flow field vector under different excitation accelerations was recorded using the PIV system, and the radial velocity distributions of the experiments and simulations were compared. The experimental results prove the accuracy of the simulation ones.

Considering the characteristics of three processes of large scale LNG tank leakage jet, pool evaporation and gas cloud dispersion in receiving terminal,combined with phase equilibrium principle and gas continuous diffusion Gauss model, Euler multiphase flow model was used to simulate the process. By studying on the effects of wind speed, spill rate and ground roughness of it, the results showed that the diffusion process of continuous leaking gas cloud in large LNG storage tank can be divided into three stages according to the form of spilling dispersion: heavy gas diffusion (heating of gas cloud), passive diffusion and dilution dissipation. The backflow and large-scale eddies in the area of 24m near the leakage hole of LNG tank were formed, and the wind speed in this area was reduced by 70%—80%. With the increase of wind speed, the 0.5LFL downwind distance of methane concentration decreased by 20%, increases by 50% and decreases by 23% in the three stages, respectively. the maximum 0.5LFL downwind distance of methane concentration and pool length expansion decreased with increase of wind speed. With increasing spill rate, the jet length, pool length and pool radius all increased and the 0.5LFL downwind distance of methane concentration increased by 42m, 33m and 45m in three stages. With the increase of surface roughness, the pool radius and length all decreased. The height of dispersion surface at the front of gas cloud increased by 15.5m, 25m and 16m. In addition, by studying the influence of wind speed, spill rate and ground roughness on LNG gas cloud dispersion, the sensitive factors in horizontal direction and altitude direction of LNG gas cloud dispersion were determined.

Di-2-ethylhexyl phosphoric acid (D2EHPA) was used as extractant for deironing from solutions. The difficulty in stripping of Fe³⁺ from D2EHPA-kerosene phase was due to the strong complexation ability between Fe³⁺and D2EHPA. The frequently-used method to strip Fe³⁺ from an organic solvent was the use of high concentrated acidic solutions. However, the use of a concentrated acidic solution would destroy the organic molecules and influence the cycling utilization of extractant. In this study, a process employing oxalic acid to increase the efficiency of Fe³⁺ stripping of Fe³⁺-D2EHPA complexes from D2EHPA-kerosene phase has been developed. The process has been studied to optimize various process variables such as shaking speed, oxalic acid concentration, temperature, equilibration time and phase ratio for effective separation of Fe³⁺. The results showed that approximate 99% of Fe³⁺ can be stripped from D2EHPA-kerosene phase loaded with 1g/L of Fe³⁺ after a two stage counter-current contact under the optimum conditions, where 0.4mol/L of oxalic acid was used to strip(Ⅲ) iron from Fe³⁺-D2EHPA complexes for 10min at 40℃ with a 1∶1 volumeric phase ratio (O/A, volume of Fe³⁺-loaded D2EHPA-kerosene phase-0.4mol/L of oxalic acid aqueous solution). According to the results, the stripping of Fe³⁺ is an endothermic reaction with the enthalpy change of 81.58kJ/mol. In addition, the reaction was found to follow pseudo first order kinetics with the activation energy of 49.5kJ/mol. The stripping method was further tested to remove Fe³⁺ from D2EHPA-kerosene phase after being used for the extraction of Fe³⁺ from Fe₂(SO₄)₃ aqueous solution. The results showed the extraction rate of Fe³⁺ remains unchanged after D2EHPA-kerosene phase being recycled for five times using 0.4mol/L of oxalic acid stripping solution, which is far more effective than high concentrated acidic solutions employed in the previous reports. The proposed stripping process could further simplify the stripping operation and reduce the extractant loss.

Experimental study on the heat transfer characteristics of supercritical carbon dioxide under transient pressure was carried out. The experiment of supercritical CO₂ heat transfer was performed in a 10.0mm inner diameter tube. The experimental conditions were: pressure, P=7.58—9.97MPa, heat flow density, q _w=64—256kW/m² and mass flow rate, G=660—893kg/(m²·s). The heat transfer characteristics during the rapid depressurization process was analyzed under normal heat transfer and heat transfer deterioration conditions. According to the experimental reaults, with the decrease of pressure，the wall temperature decreased, and heat transfer coefficients increased under normal heat transfer. The wall temperature rises rapidly in the process of pressure relief when the heat transfer deterioration occurs, and heat transfer coefficient decreases. Meanwhile, the peak point of the deteriorating wall temperature moves towards the entrance direction. Finally, the experimental phenomenon was explained. Under normal heat transfer, with the decrease of pressure, specific heat increased, and the heat transfer improved. When the heat transfer deterioration occurs, the decrease of pressure reduces the pseudo-critical enthalpy value i _pc, thus increasing supercritical “boiling” number SBO. The larger SBO indicated that the vapor expansion effect was stronger compared to the inertia effect, larger SBO expands “vapor layer” thickness to increase the heat transfer resistance lead to serious heat transfer deterioration.

Finding cost effective retrofit for heat exchanger networks remains a challenge. Traditional retrofit methods rely heavily on topological modifications, which often increase retrofit time and investment costs. Therefore, this paper focuses on the heat exchanger network retrofit with a fixed network structure, and a data-driven efficient optimization method was proposed. A performance simulation model was established to simulate the utility consumption and temperature distribution of a heat exchanger under different performance parameters, so as to obtain a large number of data for the optimization of the heat exchanger network. Then back propagation neural network prediction model and genetic algorithm were used to solve the retrofit problem with the goal of maximum energy savings. Case studies showed that the retrofitted heat exchanger network can obtain greater energy-saving benefits through smaller investment. Compared with the literature, the energy savings per unit cost increased by 51.4%. A modification scheme that cannot be obtained by the empirical rule method can be quickly obtained compared with the sensitivity analysis of the same structure. Moreover, the effectiveness and economic practicability of the proposed method were demonstrated.

In the field of industrial waste water treatment, evaporation crystallization technology can recover raw materials for industrial production while carrying out deep treatment. It can realize resource utilization of waste water. The applicability of different types of evaporators is limited in existing research. In response to the above issue, mechanical vapor recompression(MVR) parallel double-effect evaporation crystallization system was proposed, which combined a falling film evaporator with a forced circulation evaporator. After designing the process flow, thermodynamic state of medium in each pipe segment of the system was analyzed. On this basis, mathematical model of the target system was established. It can be used to calculate mass and energy balance of the whole system and related equipment. Energy analysis of the system can also be carried out. In addition to energy analysis, exergy analysis model was also established. Taking sodium sulfate solution with a concentration of 5% at atmospheric pressure as an example, the model calculation was carried out by Matlab software. A three-effect evaporation crystallization system was introduced as a reference system. Results showed that MVR parallel double-effect evaporation crystallization system is much more energy-efficient. Its coefficient of performance(COP) is 21.4 and 82.2% higher than that of the reference system under same working condition. Its unit energy consumption is only 17.6% of the reference system. Meanwhile MVR parallel double-effect evaporation crystallization system has a higher degree of thermodynamic perfection. Its exergy efficiency is 51.5% higher than that of the reference system, and exergy loss is 24.7% lower than that of the reference system. MVR parallel double-effect evaporation crystallization system has great application potential in energy saving.

Two-phase boiling heat transfer can improve the performance of array jet cooling in higher heat flux density heat dissipation situations. Based on the promotion of phase transformation by ribbed structure, two kinds of ribbed surfaces were proposed. Related experimental research on the heat transfer and flow characteristics of the optimized heat sink were carried out. The two ribbed surface structures are: smooth cutting pin fins (SL1), rough needle ribs coated with sintered porous layer (SL2). The pin fins are all 0.6mm×0.6mm×1mm (length× width × height), and for SL2 the particle sizes ranging between 120μm and 150μm with a thickness of about 2 times the particle diameter. The distributed array orifice plate constitutes a 5×5 jet unit,each unit corresponding to a 4×4 pin fin array. The total heat source area is 30mm×30mm and the total number of pin fins is 400. Anhydrous ethanol was used as the working fluid. The boiling curves and heat transfer curves of the heat sink were obtained at the fluid flow rate of 2.6—12.7mL/s and the inlet temperature of 283—313K. The results showed that the two pin-finned structures can effectively realize the transition from single-phase forced convection heat transfer to two-phase boiling heat transfer. Increasing the inlet temperature or reducing the fluid flow rate can effectively promote the phase transition. When using the same fluid flow rate and temperature, SL1 has better single-phase heat transfer performance than SL2. With the increase of heating heat flux density, SL2 can achieve subcooled boiling at lower wall superheat and better heat transfer characteristics, but SL1 achieves higher critical heat flux.

The experimental study method was used to construct a multi-component liquid stratification system in a visual rectangular container. The effects of initial buoyancy ratio (R_ρ) on the instability pattern, the moving speed of the interface, energy accumulated during instability and the stability of the stratified system were studied by analyzing the stratification evolution and temperature response under different mass fraction differences and sidewall leakage. The study showed that with the increase of the initial buoyancy ratio, the instability pattern and the moving speed of the interface exhibit different laws, and the critical initial buoyancy ratio (R_ρc) keep the system stable. When the initial buoyancy was low (R_ρ≤0.35), the boundary floating flow could reach the liquid surface after penetrating the interface, the mixing area was located in the upper part of the upper liquid. The downward velocity of the interface was generally faster, but gradually slowed down later. When the initial buoyancy was high (0.47≤R_ρ≤R_ρc), the boundary floating flow could not reach the liquid surface, the mixing area was mainly located at the side of the upper liquid. The downward velocity of the interface was generally slower, but gradually accelerated later. Finally, it was found that with the increase of the initial buoyancy ratio, the interface penetration time was delayed, and the energy accumulated during instability was more. When the heat leakage rate was the same, a situation with the large initial mass fraction difference was more dangerous. When the mass fraction difference was the same, there may be a case with the low heat leak rate was more dangerous.

Ejector is a common fluid supercharging equipment, and its mixing efficiency is low. To solve this problem, a new type of swirling ejector was proposed, which adds three-dimensional disturbing elements to the ejector driving nozzle to enhance momentum exchange efficiency. As a research object, its performance in air condition was studied experimentally and numerically. Compared with the traditional ejector, it can significantly improve the performance of ejector equipment. Under the sup-sonic condition, the three-dimensional disturbing elements cannot affect the mass flow of driving fluid, and the experimental measurement of the critical pressure point (P_RC) is unchanged, so that the boosting performance is guaranteed. The entrainment ratio (E_R) of the critical region increased to 5%. The numerical calculation results are in good agreement with the experimental ones. The flow field analysis of the numerical calculation shows that the spoiler elements installed at the tail of the ejector driving nozzle is useful. On the one hand, it can make the fluid mixing boundary increase. The petal-shaped fold appears, and the increase of the number of teeth can make more area of fluid mixing increases. On the other hand, the thickness of mixing area increases to 39.28%, the disturbing elements can make the axial velocity of driving fluid change into circumferential and radial velocity, the peak value of circumferential velocity changes from 0 to 5.5—20m/s, and the radial velocity increases from 25m/s to 30—47m/s. Swirling flow and radial turbulence make the ejector into three-dimensional momentum exchange. Under the sub-sonic condition of the momentum-enhanced elements, the entrainment ratio decreases, but the critical pressure point decreases, so that the supercharging capacity loses.

The synthesis of anhydrous ethanol from syngas via carbonylation of dimethyl ether and hydrogenation of methyl acetate has attracted much market attention due to its many advantages. The key reaction mechanism and recent research progress of this process were reviewed in this paper. The effects of 8-membered and 12-membered rings of mordenite on carbonylation were discussed. How to improve the activity and stability of carbonylation catalysts by modifying the active sites of 8-membered and 12-membered rings of mordenite was described. The effects of particle size, dispersion and distribution of Cu⁺ and Cu⁰ on the catalytic activity of copper-based catalysts for hydrogenation were reviewed. Improvement of ethanol selectivity and catalyst stability is the focus and difficult point of this study. The optimization of carbonylation catalysts focuses on adjusting the pore structure of mordenite, and the development direction of hydrogenation catalysts is to construct highly dispersed copper nanoparticles and maintain stability in the reaction process is pointed.

The objective of this study was to research the effect of Alternaria alternata on the total acid value and other properties of stock jet fuel during growth. With the dry weight of mycelium as the index, the optimal culture conditions of Alternaria alternata were selected by three-factor and three-level orthogonal experiments. The jet fuel, medium and fungus culture system were constructed to study the effects of Alternaria alternata growth and proliferation on the total acid value of jet fuel, the silver sheet corrosion test, water reaction test, and surface tension, etc. The culture system with dodecane as the sole carbon source was constructed and the residual rate of dodecane was detected by gas chromatography to study the growth and reproduction of Alternaria alternata and the degradation characteristics of dodecane. The optimal culture conditions of Alternaria alternata were 30℃, the initial pH was 8, and the sodium concentration was 0mg/L. With acidic substances and surface-active substances produced, the total acid value of jet fuel was increased, and the aqueous pH, the surface tension of jet fuel and water were reduced during Alternaria alternata growth and reproduction. Alternaria alternata could grow and multiply with dodecane as the sole carbon source. It was concluded that in the process of growth and reproduction, Alternaria alternata could increase the total acid value of jet fuel, reduce the surface tension of jet fuel, water phase and the aqueous pH.

The thesis is to explore the effects of two different metal introduction methods on the catalytic pyrolysis product distribution of Shendong coal by introducing 5% transition metal Ni into the all-silicon ZSM-5 catalyst respectively with in-situ synthesis and equal volume impregnation. The synthesized catalysts are characterized by XRD, SEM, ICP and NH₃-TPD, etc. The results show that catalysts have little effect on the semi coke yield, but observable effect on the liquid yield and the gas yield. In comparison with the non-catalytic process, the all-silicon ZSM-5 catalyst reduces the liquid yield by 13.2%, while it increases the relative content of aliphatic hydrocarbons and monocyclic aromatic hydrocarbons in tar. Compared with the all-silicon ZSM-5 catalyst, the catalyst after equal volume impregnation significantly increases the production of H₂, CO in gas product, meanwhile increases the relative content of aliphatic hydrocarbons by 31.5% in tar; the in-situ synthesis of the metal-incorporated catalyst reduces the relative content of phenolic compounds, increases the relative content of naphthalene compounds and enriches the aromatic hydrocarbons in tar.

Electric thermostatic water bath and high-low temperature alternating test chamber were used to build a heat storage and release platform. Influence of 9 thickeners on the heat storage and release performance of NH₄Al(SO₄)₂·12H₂O was researched and the cycle stability of the modified NH₄Al(SO₄)₂·12H₂O was tested and analyzed. The results showed that the heat release performance of NH₄Al(SO₄)₂·12H₂O with addition of 2% xanthan gum, 1% guar gum or 1% hydroxyethylcellulose was improved respectively, and the reduction of latent heat was not significant. Under these three addition ratios, the melting point of NH₄Al(SO₄)₂·12H₂O was decreased by 1.0℃, 1.3℃, 1.3℃, respectively,the time of heat storage was increased by 94%, 35%, 9%, respectively, the time of phase change of heat storage was increased by 125%, 63%, 5%, respectively, the undercooling was decreased by 43%, 45%, 34%, respectively, the temperature variation during crystallization process was decreased by 84%, 87%, 73%, respectively, the time of heat release was increased by 27%, 11%, 50%, respectively, and the latent heat was decreased by 5.8%, 8.3%, 4.1%, respectively. The modification effect of thickener on the heat release performance of NH₄Al(SO₄)₂·12H₂O was affected by the degradation reaction, while the modification effect of 2% xanthan gum was better than the other two thickeners since the temperature variation during crystallization process of corresponding modified NH₄Al(SO₄)₂·12H₂O was always maintained above 60℃. After 60 cycles, compared with pure NH₄Al(SO₄)₂·12H₂O, the main parameters of modified NH₄Al(SO₄)₂·12H₂O changed as follows: the melting point was decreased by 0.2℃, the time of phase change of heat storage was decreased by 15%, the time of heat storage was increased by 13%, the temperature variation during crystallization process was decreased by 87%, the undercooling was decreased by 42%, the time of heat release was increased by 36%, and the latent heat was decreased by 1.6%.

Desulfurization solvent with high performance is required in order to effectively remove the high-content organosulfide compounds from the associated natural gas of Tahe Oilfield. Based on the original composition of UDS-2 solvent which had been developed and commercially applied in natural gas purification, optimum component with excellent removing efficiency for MeSH was screened via quantum calculation coupled with solubility predication using COSMO-RS model to enhance the performance of UDS-2 for MeSH removal. In addition, the purification performance of different solvents for simulated Tahe oilfield associated natural gas was evaluated under atmospheric and high pressure absorption conditions, respectively. PEGDME-3 having degree of polymerization of 5 showed the strongest intermolecular interaction with MeSH, which contributed to the highest solubility and the smallest Henry constant of 14.9 MPa·L/mol at 40℃. As compared to the parent UDS-2 solvent, the modified UDS solvent with the addition of PEGDME-3 was found to have 10.1—11.4 percentage points and 7.2—8.5 percentage points higher removal efficiencies for MeSH and total organosulfide respectively. As a result, the modified UDS solvent with largely enhanced removal efficiencies for organosulfides can be promising desulfurization solvent for the purification of Tahe associated natural gas containing high content of organosulfur compounds.

Since the catalyst and the product are not easily separated, the research on the immobilization of the hydroformylation catalyst has been widely concerned. This paper reviews the results of related research over the past 10 years from the perspective of molecular sieves, silica, carbon materials, metal oxides, magnetic nanoparticles, organic polymers and ionic liquids, and the advantages and disadvantages of different carriers and their development prospects are brief analyzed. The immobilized catalyst is divided into three different construction modes: the carrier is connected to the ligand, the carrier is connected to the metal, and the carrier is simultaneously connected to the ligand and the metal. The catalyst prepared by the third construction method is more stable, and is often used with silica as a carrier. The first construction method provides versatility for catalyst preparation and is widely used with inorganic and organic materials as a carrier. Among them, the phosphorus-containing organic polymer improves the stability of the catalyst while providing a good catalyst effect, which provides a certain guiding significance for the future research direction.

Methanol can be selectively transformed into light olefins, gasoline, aromatics and other products under the catalysis of ZSM-5 zeolite, which is an important technical route of modern coal chemical industry. ZSM-5 zeolite with regular and ordered structure, strong acidity, good hydrothermal stability and excellent shape-selectivity effect is extensively applied in the conversion of methanol to hydrocarbons. However, the product molecules cannot rapidly diffuse out of the microporous channels due to the transition limitation caused by the purely microporous structure of ZSM-5, and tend to form coke, leading to the reduction of catalyst activity and rapid deactivation. Therefore, reducing the length of microporous channels and improving the product diffusion performance become the key issues in the research of catalysts for directional methanol conversion. In this paper, the latest research on the control of microporous channels of ZSM-5 catalysts in the last decade is summarized, and the means of controlling the grain size, morphology and mesoporous structure of ZSM-5 to regulate the length of its microporous channel and improve the diffusion performance of reactive molecules are generalized. Typically, the key regulatory mechanism of the above control factors is analyzed. It is proposed that the further precise construction of mesoporous structure of nano-scale ZSM-5 is an important way to obtain highly stable catalysts in methanol to hydrocarbon(MTH) process. On the basis of controlling the porous structure, the selectivity of methanol to hydrocarbon is expected to be improved by accurately optimizing the surface acidity. This review is expected to provide a theoretical basis for the study of methanol to hydrocarbon.

The catalysts and the catalytic mechanisms are the keys to the direct catalytic oxidation of methane to methanol. In this paper, platinum catalyst, palladium catalyst, rhodium catalyst, Fe-modified zeolite catalyst, Cu-modified zeolite catalyst and modified metal-organic framework catalyst for methane to methanol as well as the corresponding catalytic mechanism were reviewed. The results showed that methane to methanol catalyzed by platinum catalysts of K₂PtCl₄, Pt(bpym)Cl₂ and Pt(bipy)Cl₂ is electrophilic substitution reaction, while that by Pd(OAc)₂ of palladium catalyst system in aqueous solution of CF₃COOH is through multi-step electron transport chain and that by Pd/C in acetic acid aqueous solution is the result of the interaction of electrophilic substitution and oxidation of reactive oxygen species. Through the interaction of monovalent Rh anchored in the carrier channel with CO, H₂O and O₂, Rh/ZSM-5 and Rh/TiO₂ in rhodium catalyst system converts methane into methanol. Regarding the Fe-modified zeolite catalyst, Cu-modified zeolite catalyst and modified metal-organic framework material catalyst, free radical reactions such as homolysis and heterolysis works. Design and preparation of catalysts for highly activating methane molecule and inhibiting deep oxidation of methanol and in-depth study of its catalytic mechanism are still the focus of future research.

Series of Pd/Al₂O₃ catalysts were prepared by equal volume impregnation method. The effects of different Pd loadings on the catalytic activity of chlorobenzene were investigated. The results showed that the activity of 0.75% Pd/Al₂O₃ catalyst was the highest. Based on the purpose of reducing the amount of precious metals by introducing rare earth metal to improve the performance of the catalyst, Ce was introduced into the catalyst of 0.5% Pd/Al₂O₃, and the optimal ratio of Pd/Ce catalyst was obtained. It was found that the activity was best when the Ce amount was 2.5% by weight. The characterizations of the catalyst by BET, H₂-TPR, SEM, etc. confirmed that the oxidation capacity was enhanced and the catalytic oxidation efficiency was improved through the addition of Ce. In addition, the catalytic products were analyzed with ion chromatography and GC-MS. The results showed that a small amount of benzene was formed at 350℃. At the same time, the effects of calcination temperature, chlorobenzene concentration and space velocity on the catalytic activity were investigated. The results showed that the calcination temperature greatly affected the activity of the catalyst. The activity of the catalyst calcined at 550℃ was the best, and the CB conversion was 96% when calcination temperature was 400℃. When the concentration of chlorobenzene was 1500—6000mg/m³, the activity of chlorobenzene decreased with the concentration. When the space velocity was in the range of 15000—30000h^-1, it had little effect on the catalytic activity of chlorobenzene.

SiO₂ （silica gel) supported cobalt oxide catalysts with different loadings were prepared by sedimentation precipitation method. The catalyst was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), N₂ adsorption and desorption. The results showed that the cobalt-based oxide was Co₃O₄, and the cobalt oxide was uniformly distributed on the SiO₂ support. The particle size of most active component was between 2－10nm. The prepared catalyst is then used for the epoxidation of cyclohexene with cyclohexene and molecular oxygen as raw materials, isobutyraldehyde as catalytic auxiliary, and N,N-dimethylformamide (DMF) as reaction solvent . The reaction was carried out in an autoclave and the performance of the Co₃O₄/SiO₂ catalyst was compared with that of the cobalt catalysts supported on two different supports(ZrO₂ or Al₂O₃). The conversion of cyclohexene and the selectivity reached 66.56% and 71.03% under the experimental conditions of 0.20g 3% Co₃O₄/SiO₂, cyclohexene 2g, 50℃ and 4MPa.

Monolithic catalysts are widely applied in various fields, and exploration on preparation methods for monolithic catalysts is critical for industrial applications. A series of Mn-Co monolithic catalysts of Mn/Co with different molar ratios immobilized on carbon fiber cloth substrate were prepared by electrodeposition method, and their NO oxidation activities were evaluated. Raman, XRD, SEM and other techniques were used to characterize the catalysts. The results showed that the Mn-Co binary catalyst prepared by electrodeposition method had a smaller particle size than cobalt oxide or manganese oxide unary catalyst by same method, and the minimum particle size was 3—4nm. Different Mn/Co molar ratios affected the catalyst particle size and phases a lot. The main substance after calcination of the catalyst with the highest manganese content was Mn₃O₄. With the cobalt content increasing, the main phase changed to Co₃O₄, but when Mn/Co=2, the phase of the catalyst was (CoMn)(CoMn)₂O₄. Co/Mn-based catalysts prepared by electrodeposition had much better NO catalytic activity than manganese oxide catalyst prepared by same method, its conversion was closed to 100% at 50℃.

It has become an important direction for the development of bone tissue engineering to produce organic-inorganic composite bone repair scaffolds by imitating the precise structure of natural bone. Biomass materials such as collagen, gelatin, chitosan and silk fibroin are attracting more and more attention due to their excellent biological properties. On the other hand, silicon-containing bioactive materials are becoming important inorganic components in the preparation of bone repair scaffolds due to their favorable bone conductivity and bone inductivity. In this text, we introduced primarily two kinds of complex technology of components for manufacturing bone scaffolds, including the powder complex technology and in-situ complex technology, and strategies of fabricating structure of bone scaffolds, such as the freeze drying, electrostatic spinning, biomimetic mineralization and the 3D printing technology. We emphatically summarized the research progress of biomass-based bone repair scaffolds containing silicon materials, and elucidated that the current challenges were to prepare a bone scaffold possessing the appropriate mechanical properties, the favorable porous structure, and the matching performance of its biodegradation behavior with the new bone formation rate. Finally, the development trend of bone scaffold materials was discussed as well.

The existing immobilized enzyme technologies (mainly the ill-developed carriers) have limitations of low stability and/or low recovery rate. Metal-organic frameworks (MOFs) are considered as the most promising carriers for enzyme immobilization due to their unique properties such as specific host-guest interaction and confinement effect, which can greatly keep enzymes with high loading, low leaching and comparable catalytic efficiency under harsh conditions. In this review, four kinds of efficient synthesis strategies including surfaces adsorption, covalent binding, cage inclusion and in-situ synthesis are introduced and compared. Moreover, the potential applications of enzyme-MOF composites in micro-reactor design, cascade reaction and other fields are discussed. The research progresses indicate that the huge merits of MOFs carriers will synergistically promote the development of enzyme-MOF composites as catalyst and bio-sensor in multi-disciplinary fields.

UiO-66 is a typical Zr-based metal-organic framework with large surface area, high porosity, and adjustable micro-pore size and is easily functionalized. Unlike most MOFs, UiO-66 exhibits excellent chemical stability, mechanical stability, thermal stability and water resistance, indicating great application prospect in the fields of adsorption and catalysis. In this paper, the synthesis methods of UiO-66 were introduced in detail, including solvothermal, mechanochemical, microwave-assisted, continuous flow and dry-gel conversion methods. The dry-gel conversion method has the advantages of high yield, simple purification & activation process and no organic waste production, showing great potential in commercialization. Progress on modified UiO-66 materials in the field of adsorption of toxic industrial chemicals and catalytic degradation of chemical warfare agents has been reviewed, and an outlook on the development trend of electrospun nanofiber supported UiO-66 in the field of chemical protection was made.

Traditional supercapacitors cannot meet the needs of wearable electronic products because of their poor flexibility and low safety. Therefore, solid-state flexible supercapacitors emerge and attract many researchers’ attention due to their unique flexibility, ductility and high security. In this paper, the research significance and the main structures of solid-state flexible supercapacitors are introduced. Besides, this paper points out that two-dimensional interdigital supercapacitors are suitable for micro-electronic devices, and one-dimensional linear ones have better flexibility and adaptability. After that, the research progress of electrodes and electrolytes for solid-state flexible supercapacitors is summarized, and the existing problems are also discussed. It is concluded that the key to further development in this field is to improve the capacity performance and cycle stability of electrodes, as well as the strength, conductivity and electrochemical stability of electrolytes.

Polycarbonate (PC） is synthesized from isosorbide (IS） and dimethyl carbonate (DMC）through transesterification and polycondensation reactions catalyzed by rubidium carbonate (Rb₂CO₃）and lithium acetylacetonate (LiAcac）. The reaction conditions in both steps were fully optimized including the amount of the catalysts, ratio of the raw materials, polycondensation temperature, and the polycondensation residence time. Moreover, FTIR, ¹H NMR, ¹³C NMR, and TGA technologies were used to characterize both transesterification and polycarbonate products. The optimum conditions were obtained as follows: the amount of Rb₂CO₃ 1×10^-3mol/mol_IS, the molar ratio of DMC/IS 14, the amount of LiAcac 2×10^-3mol/mol_IS, polycondensation temperature of 225℃ and polycondensation retention time of 4h. And the intrinsic viscosity, chromatic aberration, T_g of polymer PC could be up to 36.55mL/g, 6.92, 155.6℃, respectively. The M_n of PC is 30659 and M_w is 42551 with M_w/M_n of 1.39, respectively.

Button batteries (OB-1, OB-2) and full batteries (FB-1, FB-2, mass production) of LiFePO₄ were prepared by using ordinary aluminum foil and carbon coated aluminum as current collector, respectively. The properties of the foils and batteries were characterized with scanning electron microscope, X-ray photoelectron spectroscopy and electrochemical impedance spectroscopy, and the electrochemical performance was investigated with electrochemical impedance spectroscopy and galvanostatic charge-discharge tests. The performance at different conditions was used to investigate the influence of carbon coated aluminum. The results show that the property of foil affected the Li⁺ transfer rate and the electrochemical performance. However, the influence at low temperature is greater than that at room temperature. The use of carbon coated aluminum foil is beneficial to decreasing the internal resistance of batteries, and to improving the charge-discharge performance at low temperature. The transfer rate of Li⁺ and the discharging capacity of OB-2 at -20℃ was 1.1×10^-12m²/s and 92.7mA·h/g, respectively. In addition, the capacity of FB-2 at -20℃ was still 72.2% after 100 cycles.

Efficient oxygen evolution reaction (OER) catalysts are essential for efficient energy storage and conversion. In this paper, nickel-iron alloy with nickel ferrite composite nanofibers (NiFe/NiFe₂O₄) were successfully prepared by electrospinning combined with one-step calcination. The conditions of the calcination atmosphere, temperature and element ratio were modulated. X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical methods were used to characterize and analyze these samples. Significantly, the electrochemical test results showed that the material had a high electrocatalytic activity for oxygen evolution reaction in alkaline medium (1mol/L KOH). The optimum sample required a overpotential of 380mV at 10mA/cm², which exhibited excellent stability after chronopotentiometry for 10h.

Peppermint oil microcapsules finishing on PET (polyester) fabric would improve its comfortability and coolness, while the stable chemical properties and smooth surface of PET fibers make the fabric difficult to combine with the finishing agent. In order to improve the modification effect, alkali and plasma pretreatments were used and their effects on modification were studied by testing the comfort and cool properties of the following PET fabrics: without any treatments, microcapsule finishing without pretreatments, microcapsule finishing with alkali pretreatment and with plasma pretreatment in this paper. The results showed that plasma pretreatment was more effective on the moisture permeability, water transmission, wettability, quick-drying and contact cool feeling while alkali pretreatment was more effective on the air permeability and water absorption of PET fabrics. Compared with the microcapsules finishing PET fabric without pretreatments, the water-vapor transmission rate, warp and weft wicking height, drip diffusion time, evaporation rate and contact cool feeling coefficient of the finishing fabric with plasma treatment were improved by 3.32%, 40.24%, 27.25%, 80.39%, 21.21% and 5.59%: Respectively, and the air permeability and water absorption rate of the fabric with alkali pretreatment were improved by 43.43% and 13.03%. Therefore, plasma and alkali pretreatments before the microcapsule finishing on PET fabric could significantly improve its modification effect on comfortability and coolness.

Lithium titanate (LTO) samples were prepared by solid phase method, and then LTO and graphene oxide were treated by hydro-thermal method to prepare lithium titanate/graphene oxide composite (LTO-RGO). The structure and morphology of the material were characterized by XRD, SEM and TEM, and its electrochemical properties were tested by charge-discharge performance test and AC impedance test. The results showed that the graphene coating treatment of lithium titanate had no effect on the crystal structure of lithium titanate and no impurities appeared. LTO-RGO exhibited excellent electrochemical performance. The discharge specific capacity at 0.2C ratio was 208.7mA·h/g, the capacity retention rate after 50 cycles was 98.10%, and the discharge specific capacity at 20C ratio was 136.1 mA·h/g.

Composite particles of cerium oxdie/nickel tungstate (CeO₂/NiWO₄) with different mass ratios were prepared by hydrothermal method, and the composite particles were modified by silane coupling agent KH560. The structure，morphology and properties of the composite materials were characterized by SEM, FTIR and XRD. The modified composite particles were dispersed in epoxy resin (EP), and the CeO₂/NiWO₄/EP composite coating was prepared on the carbon steel substrate by spraying method. The anti-corrosion and wear resistance studies were tested by electrochemical impendence spectroscopy (EIS), accelerated soaking test and friction-wear test. The results showed that the anti-corrosion effect of CeO₂/NiWO₄ composite coating was improved greatly. The composite coating exhibited the best anti-corrosion and wear-resisting properties when the mass ratio of CeO₂/NiWO₄ was 4∶3．The composite coating maintained a high impedance modulus (7.36 × 10⁸ Ω/cm²) immersed in 3.5% NaCl anqeous solution in the late immersion period (45 days), which was an order of magnitude higher than that of a pure epoxy coating. Meanwhile, After 10000 cycles’ rubbing, the friction mass loss of this composit coating was reduced by 56% compared with the EP and the thickness loss was only 50% of CeO₂/EP, showing the best corrosion resistance and wear resistance.

Carbon nanotubes (CNTs) composites filled with sulfurized isobutylene(T321) were synthesized, by which the cutting nanofluids used for machining were prepared. The dispersion stability, thermal conductivity and rheological property of the nanofluids were studied, and the effects of acidification time, nanoparticle type and content, surfactant and test conditions on these properties were analyzed. The results showed that the filling rate of the composites was about 25%, and the optimal ratio of the two combined surfactants of SDBS and TW-80 was 3∶7 for preparing the stably dispersed nanofluids, and the optimal ratio of the combined surfactant to the composite was 5∶1. When the acidification time of CNTs was about 9 hours and under fully and stable dispersed conditions, the heat conductivity of the base solution could be increased by 110% by the composite, and the shape factor of CNTs had a most significant influence on the heat conductivity. The nanofluid was a non-newtonian fluid, and its viscosity was the smallest when the content of the combined surfactant was about 0.5%. Compared with the nanofluid prepared by the ordinary CNTs, the thermal conductivity and viscosity of the composite nanofluid were higher and smaller mainly due to that the surface of the composite was chemically modified in the end opening and filling process, leading to the better dispersion stability of the composite in the base solution.

The two step surfactant-free emulsion polymerization method was used to synthesis nanoparticles (PSS) with different sulfonic acid groups by changing the amount of sodium styrene sulfonate added in the second step. The particles were applied to prepare forward osmosis (FO) membranes. The particles compositions were characterized by FTIR and XPS. The morphology of the surface and inner structure, porosity, water contact angle of the synthesized FO membranes were characterized. The effects of polymer particles with different sulfonic radicals on the structure and properties of the membranes were investigated. The results showed that the introduction of PSS can improve the porosity and hydrophilicity of the membranes, and the more sulfonic acid contents were carried on the surface of the particles, the higher the porosity and hydrophilicity of the membranes were. This is because PSS particles can support the internal channels, and the hydrophilic groups -SO₃Na carried on the surface can improve the hydrophilicity of the membrane, affecting the formation of the active layer. The performances of the prepared FO membrane were also improved. The water flux of the membranes reached 61.1 L/(m²·h) with the salt rejection of 93.2%, and the J_s/J_v value was only 0.31g/L.

In order to achieve the excellent electrochemical performance of sodium-ion battery, apart from the improvement on the combination of electrode materials, as a key material to maintain the stability of the electrode structure, the choice of binder is also crucial. In this paper, the main effects and performance requirements of binder are discussed. The research progress of binder for the high performance sodium-ion battery in recent years is systematically reviewed. The properties of five kinds of binder, such as polyvinylidene fluoride, carboxymethyl cellulose, sodium alginate, polyacrylic acid, crosslinked polymer, are described respectively: polyvinylidene fluoride has good chemical stability and adhesion, but has a problem of large swelling ratio; carboxymethyl cellulose has good dispersibility and mechanical strength, because of the large brittleness, it needs to be used together with polymerized styrene butadiene rubber; sodium alginate is environmentally friendly and cheap, with good shape retention, but poor stability; polyacrylic acid has high elasticity modulus and tensile strength, but poor mechanical properties; the mechanical strength and elasticity of crosslinked polymer are high, and there may be network defects. Combined with the existing research reports, the application of these binders in sodium-ion battery system is discussed. It is expected that the binder will broaden the source field, match the suitable electrode materials and eliminate the negative impact of the water-based binder on battery performance.

The abundant pore structure and the large number of oxygen-containing groups cause the high water content of lignite, which limits its efficient utilization. A cationic alkyl ketene dimer (AKD) emulsion was prepared by using cationic surfactant cetyltrimethylammonium bromide (CTAB) as emulsifier. Then the AKD emulsion was coated on the surface of lignite particles after microwave dehydration to improve the hydrophobic properties of coal particles. The action mechanism of AKD and coal surface was investigated by utilizing specific surface area analyzer (BET), X-ray photoelectron spectroscopy (XPS) and chemical titration. The zeta potential of coal water system and the wettability of coal water interface were also determined. The results showed that AKD had physical and chemical adsorption on the surface of the coal when the amount of the cationic AKD emulsion was 1.5%, the absolute value of zeta potential on the surface of the modified coal particle reached the maximum, and the contact angle of the lignite and water was increased from 50.92° to 121.10°. After adding polynaphthalene sulfonate dispersant, the concentration of coal water slurry prepared by modified coal particles was higher. When the viscosity of coal water slurry was 1000mPa·s, the maximum concentration of coal water slurry increased from 56.6% to 61.2%. And the viscosity of coal water slurry remained stable with the prolongation of storage time.

Due to the metal ion-centered structural features, the metal-organic frameworks(MOFs) and their derivatives can be used to construct heterogeneous persulfate catalytic oxidation system. The heterogeneous persulfate activated process with low energy consumption and high efficiency has a good application prospect in water treatment. In this review, the activation of persulfate by MOFs and their derivatives to degrade refractory organic pollutants including organic dyes, environmental endocrine disruptors and antibiotics in aqueous solution were systematically presented. The effects of MOFs‘ and MOFs derivatives’ structure and composition on the catalytic degradation of organic pollutants were discussed. It was demonstrated that the rational structure design, synthesis strategy, unsaturated metal active sites of catalysts and active species in the catalytic oxidation system played a critical role in the degradation of organic pollutants. Finally, the problems existed in the MOFs-based heterogeneous persulfate activated system were summarized and it was proposed that the construction of a new high-efficiency combined activation system and the in-depth mechanism exploration and improvement would be the focus of future research.

With the increasing discharge of sewage sludge in China, sludge treatment and disposal has drawn more and more attention. Dewatering is the bottleneck that restricts sludge disposal. A review on sludge deep dewatering technology was thus studied in this work. Firstly, the classification and characteristics of sludge were reviewed and introduced. Secondly, different sludge deep dewatering techniques were reviewed and the mechanism of these techniques were analyzed. The dewatering performance, advantages and disadvantages of these techniques were also analyzed. The results showed that the hydrothermal pretreatment in the physical method improves the sludge dewatering performance to the maximum. Ultrasonic treatment with lower intensity and short time can improve the sludge dewatering performance obviously. The chemical method has great advantages in sludge filtration performance and dewatering rate. After the acid/alkali treatment, the zeta potential of the sludge increased, the sludge filtration performance, and dewatering rate were improved. Compared to acid/alkali treatment, the dewatering performance of sludge treated by advanced oxidation method is better. The sludge microbial cells are dissolved and organic matter is released during advanced oxidation treatment. The sludge dewater ability is thus improved. Biological treatment can also improve sludge dewatering performance. It is environmentally friendly but time-consuming. Finally, common follow-up sludge dewatering processes and systems were introduced, i.e., mechanical pressure-filter technology, thermal drying technology, hydrothermal technology. Based on different sludge subsequent utilization methods, the optimized sludge pretreatment method was recommended and proposed.

Production of hydrogen-rich syngas from sludge steam gasification based on calcium-based sorbents is an efficient and environmental friendly sludge treatment method. In this paper, a series of calcium-based sorbents were prepared by sol-gel method, using Al₂O₃ as support and Co as catalytic active ingredient. The CO₂ capture capacity and cyclic stability of calcium-based sorbents in multiple carbonation and decarbonization cycles were measured by thermogravimetric analyzer, and sludge steam gasfication experiments were carried out on a fixed bed reactor. The results show that Al₂O₃ and CaO in calcium-based sorbents supported with Al₂O₃ form mayenite (Ca₁₂A_l4O₃₃). The calcium-based sorbents have great pore structure and CO₂ adsorption capacity. The carbonation conversion of sorbents with 10% Co content was stable at about 70% in 30 cycles. Increase of gasification temperature and the addition of Co in calcium-based sorbents promote tar cracking and methane reforming, and significantly increases H₂ yield and syngas concentration and cold gas efficiency of sludge gasification. Compared to pure CaO, H₂ yield increases by 102% and H₂ concentration reaches 85% in syngas when sorbents with 15% Co content is applied at 650℃.

Diesel engines are still widely used as main power equipment for trucks, heavy machinery and ships. The technologies of nitrogen oxides removal from diesel exhaust are hot research topics. This paper sets up a gas supply system that simulates the diesel exhaust, and uses a dielectric barrier discharger (DBD) to generate non-thermal plasma (NTP) to investigate the removal of nitrogen oxides. The experimental results showed that the power efficiency and energy density increase with the input voltage for this system. The power efficiency is above 90% when the input voltage is higher than 60V. In the O₂/N₂ system, NO generation increases with the O₂ concentration and energy density, while NO₂ increases first, then decreases and stabilizes. The removal rate of NO is close to 100% by NTP in NO/N₂ system. For the NO/O₂/N₂ system, the critical O₂ concentration increases with NO concentration. With the increase of energy density, the denitrification efficiency is above 90% at 1% O₂ volume fraction and negative when O₂ volume fraction is higher than 14%. The O₂ concentration plays a decisive role in the denitration performance of the NTP. NH₃ improves the denitration rate at low energy density while slightly reduces the denitration rate at high energy density. The denitration rate is 40.6% at simulating real diesel exhaust conditions when H₂O and ammonia is added.

The treatment of magnesium-based desulfurization products was concentrated on wet magnesium-based desulfurization products, and few reported on the treatment and utilization of semi-dry magnesium-based desulfurization products. In order to solve this problem, the semi-dry magnesium-based desulfurization product was soaked in water. The effects of soaking times, soaking temperature and soaking time on the desulfurization products were studied. The products were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray fluorescence spectrometer (XRF).The results showed that the desulfurization products were divided into three parts after water immersion: aqueous solution, solid mass and sediment. The solute is magnesium chloride and magnesium sulfate in the solution, magnesium sulfate and magnesium chloride obtained in the first soaking account for 8.85% of the solution mass, which is much higher than 2.33% of the second soaking. When the immersion temperature is 70℃, the obtained magnesium sulfate and magnesium chloride are 0.14 to 3% more than room temperature and 50℃, there is almost no change in the density of the solution after soaking for three days. The solid mass is composed of Mg(OH)₂ and a small amount of sulfate and chloride. The component of the sediment is Mg(OH)₂. The water soaking treatment can complete the reuse of the desulfurization products.

A novel technology of froth flotation coupled ultrafiltration has been developed for recovering nano-sized TiO₂ photocatalyst from its organic wastewater. First, the ultrafiltration efficiency for the recovery of nano-sized TiO₂ photocatalyst was evaluated according to the permeate flux and the rejecting ratio. Second, in order to reduce the concentration of the feeding solution, froth flotation was performed with cetyltrimethylammonium bromide (CTAB) as the collector. The effects of CTAB concentration, volumetric air flow rate and pore diameter of gas distributor on the performance of froth flotation were investigated. Finally, the suitable operation conditions of the proposed technology were determined. The experimental result showed that under the suitable operation conditions of pH 7.0, CTAB concentration 0.20g/L, volumetric air flow rate 15mL/min, and pore diameter of gas distributor 180μm, the enrichment ratio and the recovery percentage of nano-sized TiO₂ photocatalyst reached 22.52 and 99%, respectively. Meanwhile, the operating time of the membrane increased by 133% compared to that in ultrafiltration only operation.

A double bins pneumatic feeding device for biomass pyrolysis was designed and manufactured. The feeding rate of the biomass power was studied at the different fluidization gas velocity, injection gas velocity, effective injection distance（s=50mm,100mm,150mm,200mm）, inner diameter of conveying pipe（d ₁=21mm,24mm,29mm） and biomass particle size. The experimental results showed that the feeding rate increased with the increase of fluidization gas velocity, injection gas velocity, inner diameter of conveying pipe and biomass particle size. When the effective injection distance was 100mm, the feeding rate was the highest. The solid-gas ratio firstly increased and then decreased with the increase of fluidization gas velocity or injection gas velocity. Under the combined action of fluidization gas and injection gas, the solid-gas ratio decreased with the increase of gas flow velocity. To describe the link of the feeding rate with the fluidization flow velocity, injection flow velocity, effective injection distance, inner diameter of conveying pipe and biomass particle size, a multivariate linear regression model was established by using multivariate linear regression analysis. Extra experiments were carried out to verify the accuracy of the model. The results showed that the error between the experimental value and the predicted value was within ±10.2%, which indicated that the model was reliable and could be used to predict the conveying efficiency of the feeder.

The removal of NO and SO₂ in simulated flue gas was studied by self-designed dielectric barrier - corona discharge plasma reactor. The effects of gas composition such as O₂ concentration, CO₂ concentration and water vapor on the removal of NO and SO₂ were investigated. The effect of additive CH₃COONH₄ on NO and SO₂ removal and its mechanism of action were also discussed. Experimental results showed that the increase of O₂ concentration, CO₂ concentration and H₂O vapor concentration would inhibit the removal of NO. After the introduction of CH₃COONH₄, these inhibitory effects would be weakened and the removal rate of NO would be greatly increased, but its inhibitory effects would not be completely eliminated. After the introduction of CH₃COONH₄ into N₂/O₂/SO₂ system, the influence of gas composition and input current on SO₂ removal was not obvious, and the removal rate of SO₂ could reach about 94%. When 0.27%CH₃COONH₄ was added into N₂/O₂/CO₂/H₂O/NO/SO₂ system, under the initial concentration of NO was constant, When the content of SO₂ was low, the effect on NO removal was not obvious, the removal rate of NO decreased with the increase of SO₂ concentration, the effect of SO₂ could be eliminated by increasing the addition of CH₃COONH₄. On the other hand, under the condition of constant initial concentration of SO₂, with the increase of NO content, the removal rate of SO₂ remained around 94%. When 0.51%CH₃COONH₄ was added into N₂/O₂/CO₂/H₂O/NO/SO₂ system, the removal rate of NO reached 72% when the input current was 2.5A.