With the advantages of favorable chemical stability and electrical conductivity, large specific surface area, and rich pore structure, carbon microspheres have broad application prospects in adsorption, catalysis, and other fields, which have attracted extensive attentions from researchers. As one of the preparation methods of carbon microspheres, phenolic-based carbon microspheres are obtained by high-temperature carbonization process with phenolic resin as the precursor. This preparation method has the advantages of simple process, low requirements on equipment, and high yield of the carbon microspheres. In addition, the structure and functionality of the obtained carbon microspheres can be regulated by adjusting the reactants and reaction conditions, which can be better conform to the requirements of practical applications. In this paper, recent studies of phenolic-based carbon microspheres are reviewed, which are mainly divided into three aspects: small-particle carbon microspheres preparation, porous carbon microspheres preparation, and functionalized carbon microspheres preparation, it also introduces the applications of phenolic-based carbon microspheres in the fields of energy storage, adsorption and electro-catalysis, and the future directions of their development are prospected in the end.

Ammonia is a carbon-free and hydrogen-rich energy carrier with high volumetric energy density and easy liquefaction storage. It is an ideal hydrogen storage medium. Transforming chemical energy in ammonia into electrical energy directly by ammonia oxidation reaction (AOR) in low-temperature alkaline exchange membrane fuel cells (AEMFCs) is an ideal way for efficient utilization of ammonia. However, the NH₃-AEMFCs are far away from the commercial application due to its low performance, which is limited by slow kinetics in AOR, high price of noble metals, catalyst poisoning and poor stability. It posts the significance of developing efficient, cheap and robust catalysts to achieve satisfied performance in low-temperature NH₃-AEMFCs. Herein, we firstly give a brief introduction of current status on understanding the fundamentals in AOR and then summarize the recent progress in the development of noble and non-noble metallic catalysts towards AOR. Based on the in-depth understanding of the reaction mechanism, the performance of NH₃-AEMFCs was further summarized and discussed. Finally, the R&D direction and prospect of catalyst design for AOR and NH₃-AEMFCs are proposed.

Hydrate technology has broad application prospects in the fields of energy and climate, and is expected to become a key technology for addressing energy challenges and climate change. However, the current technology has the disadvantages of slow hydrate formation rate and low gas consumption, which limits the industrial development of hydrate technology. In this paper, from the perspective of microscopic mechanism, the theoretical viewpoints on the formation mechanism of gas hydrates are reviewed and summarized, and the effects of driving force and gas solubility on the nucleation process of hydrates are briefly described. The influence mechanism of surfactants and nanoparticles on hydrate formation and the commonly used microscopic analysis techniques are introduced. It is found that the formation mechanism of gas hydrate is not yet unified, and the research on the action mechanism of accelerator is not enough. It is difficult to capture the molecular behavior of gas hydrate in micro-state by the existing micro-analysis methods. These problems limit the development of hydrate technology to be faster and more efficient. Exploring the relevant mechanism of hydrate technology, understanding the working principles of various influencing factors and exploring new analytical means will be helpful to break through the bottleneck of hydrate technology and search for an accelerator with better performance, a way to synthesize hydrates more efficiently.

Developing chemical process of uranium purification is significant to the improvement in China’s nuclear energy industry. However, it is always limited by the deficiency in fundamental thermodynamics property information. Molecular simulation methods provide an opportunity to address the above challenges due to their efficient, environmentally friendly, and economical properties for predicting properties. In this paper, firstly, various of simulation methods on thermodynamics properties are summarized, the development and advantage/disadvantage of common force-field (FF) and potential function are introduced, most importantly, their applicability on computing fluorides is discussed. Then, the progress of simulating thermodynamics properties of fluorides is summarized, and the impact on applied FF and potential function is discussed and evaluated. High computation efficiency and accuracy of temperature dependent intermolecular potential (TDIP) are found in calculating the second virial coefficient, viscosity, and vapor-liquid coexistence properties. However, the summary shows that there are lots of fundamental questions needed to be solved before further improving the accuracy of computation of fluorides. Therefore, the development of molecular simulation method of fluoride thermodynamics was prospected, hoping to provide a practical basis of design of uranium purification process.

The existence of magnesium sulfate affects the potassium salt yield and product quality of carnallite (Car) processing. In this study, the incomplete decomposition experiments of magnesium sulfate Car in Yiliping salt lake was carried out at 25℃, the decomposition and formation mechanism, and the dynamic behavior of potassium salts were studied. The results show that: (1) Magnesium sulfate type Car will decomposes rapidly when water added, and after 3—4 h of induction period, potassium chloride and magnesium sulfate will gradually converts into kainite (Kai), although there is no Kai phase area on the metastable phase diagram. When phase equilibria achieved after 50 h, nearly 55% of the total potassium converts into Kai, about 20% dissolves in decomposition solution, and only 25% exists as solid potassium chloride. (2) During the conversion process, if there is magnesium sulfate hydrate, the illusion of “metastable state with fixed solid and liquid points” will appear, In fact, it is the dynamic process of the conversion of potassium chloride and magnesium sulfate hydrate into kaleite. When the solid phase magnesium sulfate hydrate is absent, the liquid point will move to the tetrasalt co-saturation point of sodium chloride, potassium chloride, kaleite, and carnallite. (3) In the kinetic equation of Kai formation, the order of the reaction driving force (the difference between the ionic activity products at invariable point and process point) is 1.5, the influence index of the product stock is 2/3, and the reaction rate constant is 3.907×10^-4 mol^1/3·min^-1. The kinetic equation and the full-component material equation constitute a dynamic model, which can quantitatively express the state of the solid-liquid mixing system at any time during the transformation process. These results have important guiding significance for improving the utilization process of potassium resources in salt lakes.

Hydrate storage and transportation (NGH) is a natural gas storage and transportation technology developed in recent years and has the potential to realize industrialization. However, the growth of hydrate is a reaction controlled by mass and heat transfer, so there are many uncertain factors in the scale-up experiment. Based on the chemical reaction kinetic and the mass and heat transfer in porous materials, a mathematical model of methane hydrate formation and heat transfer is established in hydrate reactor for the formation and heat transfer process in porous materials, which can be used to predict the hydrate formation and heat distribution in the reactor and guide the design and optimization of hydration reactor. The reliability of the model was verified by comparing with experimental data, and the hydrate reaction process in porous materials with different thermal conductivity was numerically simulated. The results show that the AARD between the simulated value and the experimental value is less than 6%, and the heat transfer model is highly accurate. Heat transfer is one of the key factors affecting the hydrate formation rate during hydrate reaction. When the heat conduction is poor, it is easy to form local overheating in the hydrate formation center, resulting in thermal inhibition of hydrate formation. When performing scale-up experiments on hydrate formation, special attention should be paid to thermal control inside the reactor.

To investigate the polarization dynamic characteristics of bubbles under a non-uniform electric field, the evolution and dispersion of bubbles in heptane solution are visualized by using high-speed photography. Combined with dimensionless numbers, the effects of gas flow and applied voltage on bubble characteristics and the bubble motion law dominated by polarization force are discussed. The results show that increasing the electric field strength can significantly reduce the growth period and size of the bubbles, and accelerate their generation frequency. Under the action of a weak electric field, the bubble motion is dominated by hydrodynamics and influenced by the wake induction, as the height of its trajectory decreases as the Bo_E increases. In contrast, the effects of a strong electric field cause the bubble movement to be first dominated by the polarization force and exhibits electrohydrodynamic (EHD) properties, and the bubble trajectory extends upward with increasing Bo_E. However, with the vertical decay of the electric field intensity and the influence of the liquid phase resistance, the velocity of the bubbles decreases continuously. When the bubbles leave the region dominated by the polarization force, their motion again exhibits hydrodynamic characteristics, then the bubbles disperse in the liquid phase impacting by the bubble wake and interactions between bubbles.

Noncondensable gas restricts the safety of heat exchange equipment and system efficiency. To study the mechanism and characteristics of free convective condensation of steam in the presence of noncondensable gas on horizontal tube, this paper experimentally studied steam condensation on horizontal tube in presence of noncondensable gas with mass fraction of He, N₂ and CO₂ changing of 1.16%—18.18%, 7.56%—60.86% and 11.39%—70.95%, respectively. Horizontal tube surface wall subcooling ranged of 5—25 K. The total pressure varied with 5—101 kPa. The condensation characteristics Q/Q_Nu of H₂O-He, H₂O-N₂, and H₂O-CO₂ for different noncondensable gas mass fraction, surface subcoolings and pressures were analyzed and compared. When pressure and surface subcooling are constant, for the same mass fraction of noncondensable gas the order of Q/Q_Nu from large to small is H₂O-CO₂, H₂O-N₂, H₂O-He, but for the same mole fraction the order of from large to small is H₂O-He, H₂O-N₂, H₂O-CO₂. For the same total pressure and noncondensable gas mass fraction, Q/Q_Nu of H₂O-He decreased most slowly with the increase of surface subcooling. For the same noncondensable gas mass fraction and surface subcooling, the value of Q/Q_Nu of H₂O-He is the smallest, and it is most significantly affected by pressure.

In order to make the ionic liquids (ILs) easier to separate and recycle while maintaining the catalytic activity, and to reduce the corrosion, a variety of supported ILs were prepared to catalyze the esterification for the synthesis of ethyl acetate (EtAc). The supported ILs are analyzed and characterization by infrared spectroscopy, thermogravimetric, nitrogen adsorption-desorption and scanning electron microscopy. It is found that sol-gel method can immobilize ILs on SiO₂ more effectively than impregnation. In the conditions of R⁰_A∶E = 1, T in the range of 323.15—338.15 K, and x_cat∶HAc in the range of 5%—15%, the supported IL [HSO₃-BMIM][HSO₄]/SiO₂ which prepare by sol-gel method shows fast reaction rate, the conversion of acetic acid (X_HAc) exceeds 50% at the first 30 min, which achieves 70% of the equilibrium conversion (X_HAc = 68%). The LHHW model was used to fit the rate of [HSO₃-BMIM][HSO₄]/SiO₂-catalyzed esterification reaction, and the results showed that the model predicted accurately. The repeatability experimental result showed that X_HAc (t = 4 h) of [HSO₃-BMIM][HSO₄]/SiO₂ in the third run exceeded 60%, which decreased at the 6th run. The catalytic activity and stability of supported IL prepared by sol-gel method are better than that of impregnation. These results show that sol-gel method is more suitable for the preparation of supported ILs.

Slurry bed hydrotreating process can treat inferior heavy oil and residual oil from different sources. Therefore, compared with other processes, the process is characterized by strong adaptability of raw materials. One of the main reactions of heavy oil hydrotreating is the activation of hydrogen. Molybdenum-based dispersed catalyst is widely used as an efficient hydrogenation catalyst in the slurry bed hydrogenation process. One of the key factors affecting the hydrogenation activity of heavy oil is the dispersion of molybdenum-based catalysts. Therefore, it is meaningful to explore the dispersion of the catalyst for hydrogen activation. In this paper, Mo₇S_15, Mo₁₂S₂₆, Mo₁₈S₃₉, Mo₂₅S₅₄ and Mo₃₃S₇₁ clusters were built and their structure is optimized. On the basis of stable structure, the stability and activity of clusters with different sizes were studied, and the adsorption dissociation process of hydrogen on Mo _x S _y clusters with different sizes was discussed, including the stability of hydrogen molecules at different adsorption sites, the adsorption dissociation process of hydrogen molecules on Mo _x S _y clusters with different sizes, and the changes with the size of Mo _x S _y clusters. According to the calculation results, it is found that the currently established clusters with smaller size have the lower binding energy, the smaller HOMO-LUMO energy gap value, the weaker stability and the stronger activity. During the adsorption and dissociation of H₂ above the cluster, it is found that hydrogen is more easily adsorbed at the edge position. With the increase of cluster size, the adsorption energy was -64.25, -34.60, -34.14, -7.20 and -6.82 kJ/mol; the absolute value of the adsorption energy decreased; the interaction between hydrogen molecules and the cluster was weaker; the dissociation energy gradually increased, and were 13.76, 33.14, 53.64, 60.75 and 64.47 kJ/mol, respectively. The current results show that the smaller the cluster size, the easier it is for hydrogen to adsorb/ dissociate and the cluster shows higher activity.

To achieve the CO₂ efficient separation in mixed matrix membranes (MMMs), a dual-filler (CM) of carboxyl modified multi-walled carbon nanotubes (CNT) and amino modified β-cyclodextrin metal organic framework (β-CD MOF) was designed and introduced to sulfonated poly(ether ether ketone) (SPEEK) to construct both CO₂ diffusion channels and affinity sites within the membranes, which enhanced the separation performance of MMMs. The chemical and pore structures of the dual-filler were characterized by FTIR and BET, and the filler-polymer interfacial interactions were verified by SEM, FTIR and mechanical properties of the membranes. The effects of the proportion, content, pressure, temperature and mixed gas on the separation performance of MMMs were investigated. The results showed that CM was compatible with SPEEK and provided fast transport channels for gas molecules. The SPEEK/CM-7 MMMs with mass ratio of 5∶5 displayed the optimal separation performance with a CO₂ permeability of 844 Barrer and a CO₂/N₂ selectivity of 84 at 0.1 MPa and 25℃, which were 178% and 163% higher than those of the pristine SPEEK membrane, respectively, surpassing the 2019 upper bound. The straight pore channels of functional CNT shortened the CO₂ diffusion path, while the amino carriers on the surface of modified MOF enhanced the CO₂ dissolution, which synergistically improved the separation performance of MMMs. Moreover, the membranes loaded with dual-filler had preferable separation performance than those loaded with the same amount of carboxyl modified CNT or amino modified MOF alone. During 360 h testing, the SPEEK/CM-7 MMMs remained good stability.

The efficient separation of phenolic compounds from low-temperature coal tar is of great industrial significance. 40 deep eutectic solvents (DESs) were screened for m-cresol-cumene separation by conductor-like screening model for real solvents (COSMO-RS). The indexes of screening process included capacity, selectivity, and performance index at infinite dilution. In addition, the σ-profile and σ-potential of m-cresol, cumene, and the screened DESs were used to analyze the molecular interactions, which could interpret the high extraction performance of the screened DESs. The screening results were verified by liquid-liquid equilibrium (LLE) experiments, and the extraction process conditions were optimized. The results show that choline chloride (ChCl)∶ethylene glycol (EG) (1∶2), ChCl∶glycerol (Gly) (1∶2), ChCl∶lactic acid (LA) (1∶2) demonstrate the higher performance index and are preliminarily screened as extractants. There is a strong hydrogen bond between 3 screened DESs and m-cresol, as well as a repulsive interaction between 3 screened DESs and cumene. Both COSMO-RS calculation and LLE experimental results show that ChCl∶EG (1∶2) presents the highest distribution coefficient and selectivity. Moreover, ChCl∶EG (1∶2) has the lowest viscosity, which is selected as the most suitable extractant for m-cresol-cumene separation. When the temperature and the mass ratio of ChCl∶EG (1∶2) to model oil are 25℃ and 1∶1, respectively, the ChCl∶EG (1∶2) can extract 98.41% of the m-cresol with only 8.41% entrained cumene, and ChCl∶EG (1∶2) has good recycling performance.

Lanthanum hydroxide [La(OH)₃] cross-linked chitosan (CS) microspheres (La-CS-M) were prepared based on microfluidic technology. The compositions and structures of La-CS-M were characterized by various means. The performance and mechanism of its adsorption and removal of phosphate in water were explored. The results showed that La(OH)₃ was successfully loaded within La-CS-M. Compared with the cross-linked chitosan spheres (La-CS) prepared by traditional dropping method, the surface and interior of La-CS-M were porous with an volumetric mean particle size of 415.8 μm, porosity of 89.22%, average pore size of 960.0 nm, and pH_pzc of about 6.5. La-CS-M maintained a high adsorption capacity in a wide pH range from 3.0 to 10.0, and the presence of \mathrm{C}{\mathrm{O}}_{\mathrm{3}}^{\mathrm{2}-} had a more negative effect on phosphate adsorption compared to Cl^-, \mathrm{N}{\mathrm{O}}_{\mathrm{3}}^{-}, \mathrm{S}{\mathrm{O}}_{\mathrm{4}}^{\mathrm{2}-} and humic acid (HA). The adsorption kinetic data and isotherm results were well fitted with pseudo-second-order model and Langmuir model, achieving a maximum adsorption capacity of 56.48 mg/g at pH 6.0. Combined with XPS characterization and adsorption data, it could be deducted that the adsorption mechanism of La-CS-M involved electrostatic adsorption and formation of inner sphere complex (through coordination exchange or Lewis acid-base interaction). After phosphate adsorption, La-CS-M could be desorbed by 2.5 mol/L NaOH solution, exhibiting good reproducibility and adsorption stability.

Efficient separation of CH₄/N₂ mixture is one of the keys to realize the utilization of low concentration coalbed methane. Based on the in-situ encapsulation strategy, FeTPPs were successfully encapsulated into the pores of CuBTC by one-pot method, and the purpose of enhancing the adsorption and separation of CH₄/N₂ mixed gas was achieved through the synergistic effect of the two. As a result, encapsulation of FeTPPs enhanced the interactions between CH₄ and adsorbent, while the interactions between N₂ and adsorbent were weakened. Therefore, the encapsulation of FeTPPs is beneficial for the CH₄/N₂ mixture separation. Based on the calculation of ideal adsorption solution theory (IAST), it was found that the selectivity of FeTPPs@CuBTC reached 5.4 under normal temperature and pressure without loss of CH₄ adsorption capacity, which is 1.28 times that of CuBTC and higher than most reported zeotile and MOFs. The study confirms the potential application of FeTPPs packaging strategy for low concentration coalbed methane, and also provides a new design idea for the development of new adsorbent materials.

Aiming at the problem that the fault data generated by the chiller is insufficient and the quantity of normal data and fault data in the historical data set is unbalanced, which leads to the decline of the fault diagnosis accuracy. In this paper, a fault diagnosis method based on central loss conditional generative adversarial network (CLCGAN) and support vector machine (SVM) were proposed. Firstly, CLCGAN generates new fault data from a small amount of real fault data. Then, the generated fault data was mixed with the initial data set to balance the amount of normal data and fault data. Finally, the SVM model was constructed by using the balanced data set for fault diagnosis. When GAN generates chiller fault data, the dynamic center loss term was constructed and added into the objective function. Through the dynamic center loss term, the intra-class distance of various fault data generated by the chiller was reduced, so that the overlapping degree of each fault generated data was reduced and the reliability of generated data was increased. Before generating fault data, configure fault labels and input them into CLCGAN to guide the data generation process. In this way, the generated fault data can be evenly distributed among different fault types. The proposed method was validated on ASHRAE 1043-RP project data set, and the results show that the proposed method has higher fault diagnosis accuracy than other fault diagnosis methods that solve the problem of data imbalance.

Canonical variable dissimilarity analysis (CVDA) is a new dynamic process monitoring method proposed in recent years, which has been successfully applied in the field of incipient fault detection. To solve the problem that traditional CVDA method neglects the probability information mining of features, one novel method based on weighted probability CVDA (WPCVDA) is proposed for incipient fault detection of dynamic chemical system. On the one hand, based on the basic CVDA model features, Wasserstein distance (WD) is introduced to measure the change of feature probability distribution to construct probability-related WD features to improve the sensitivity of CVDA model to incipient faults. On the other hand, further considering the difference of fault information carried by different WD feature components, an adaptive weight calculation strategy is designed to set large weights for key fault-sensitive feature components, so as to highlight their roles in the monitoring statistics. The validation results on a standard chemical process show that the proposed WPCVDA method has better performance than the traditional CVDA method in incipient fault detection.

Polytetrafluoroethylene (PTFE) batch polymerization production mode can meet the market demand of small batch, multi-purpose and high quality products. Aiming at the strong nonlinearity and large time delay in the PTFE polymerization process, a dynamic economic optimization control method based on free terminal is proposed in this paper. Firstly, the dynamic economic optimization problem is established by integrating the production cycle as a degree of freedom into the optimization variable. The control inputs are discretized into piece-wise sequences by using improved control variable parameterization method, and the dynamic economic optimization problem can be transformed into a nonlinear programming (NLP) problem. Then, the NLP problem is solved based on the penalty function method of gradient descent, and the rolling optimization control method in the free prediction time domain is used to optimize the control input and terminal time. Finally, compared with PI control and nonlinear model predictive control, the simulation results show that free terminal dynamic economic optimization control method has higher economic benefit and shorter production cycle, which highlights the flexibility of batch production.

In order to carry out fault diagnosis for proton exchange membrane fuel cell (PEMFC) system to improve the safety and reliability of the system, aiming at the strong nonlinearity of the PEMFC system, a sliding mode observer is proposed based on the ninth-order state space model to generate residuals in real time, and the fault threshold detection method is used to establish a fault feature matrix to detect faults. In order to isolate faults, a relative fault sensitivity function is introduced to establish a theoretical relative fault sensitivity matrix, and the relative faults of each fault are calculated in real time when the system is running. The Euclidean distance between the sensitivity and the theoretical relative fault sensitivity, the fault corresponding to the minimum Euclidean distance is the fault that occurs in the system. The results verify the effectiveness of the proposed model-based fault diagnosis method, and the constructed observer can estimate the state variables that are difficult to measure directly in the PEMFC system, the average relative error is within 6%.

Intermittent process monitoring is of great importance to ensure the stable operation during the process running. However, it is difficult for traditional process monitoring methods to extract the structure-related and nonlinear dynamic time-varying features of batch process data. To solve this problem, this paper proposes a canonical correlation analysis method combining graph sample aggregate network and long-short term memory network (GSA-LSTM) for batch process monitoring. First, the K-nearest neighbor method is utilized to convert batch data into graph-structured form, and graph sample aggregate network (GraphSAGE) is used to extract the structure features of process data. Then, long-short term memory (LSTM) is used to extract the nonlinear time-varying feature of data at the same time. By integrating them with structure features through weight coefficients, the more representative batch process data features are obtained. After that, canonical correlation analysis method is utilized to carry out process monitoring. Finally, the proposed method is applied to numerical examples and injection molding process monitoring, and the results are analyzed to verify the effectiveness of the proposed method.

Oilfield wastewater containing compound surfactants is a multi-component complex system, and the study of molecular interaction is helpful to determine the subsequent wastewater treatment plan. An interface model was established by using molecular dynamics (MD) simulation method. A series of calculations of interfacial properties and the experiment of interfacial tension were performed to examine the effects of two types of anionic/cationic surfactant mixtures on oil/water interfacial property with this model. In particular, this paper defines the concepts of the twist points of surfactants, molecular angles and synergistic energy. The results demonstrated that, compared with the single-component surfactant, the electrostatic attraction between the polar head groups with opposite charges present in mixed surfactants could induce these mixtures to improve the oil/water interface stability. In oil-water systems consisting of mixed surfactants, the intermolecular synergy of sodium dodecyl sulfate/cetyltrimethyl ammonium bromide (SDS/CTAB) mixtures can better enhance the stability of the system compared to sodium dodecyl sulfonate/cetyltrimethyl ammonium bromide (SLS/CTAB) mixtures. The compounding ratio range of SDS/CTAB mixtures that could better stabilize the oil-water interface was from 8/10 to 12/6, with 12/6 being the best. The results could provide programmatic guidance for crude oil extraction and oily wastewater treatment.

Daidzein is a phytoestrogen with various biological activities, but its total biosynthesis in Escherichia coli has not been reported. The biosynthetic pathway of daidzein was divided into three modules, namely, the p-coumaric acid, liquiritigenin, and daidzein modules to engineer coculture systems for the biosynthesis of daidzein. First, to synthesize the precursor liquiritigenin, the p-coumaric acid and liquiritigenin modules were distributed into two E. coli strains to construct a two-strain coculture. Based on this, three coculture patterns were explored for the biosynthesis of daidzein. The results showed that the three-strain coculture produced 27.8 mg/L daidzein, which was superior to the other two two-strain coculture systems. Commensalism of the engineered strains was established through a unidirectional flow of phenylalanine, which benefited the pathway balance and daidzein production. The coculture system in this study realized the de novo biosynthesis of daidzein in engineered E. coli, and provided a plug-and-play platform for the biosynthesis of other flavonoids.

Aiming at the pollution of the polycyclic aromatic hydrocarbons (PAHs) in soil in China, the self-developed dielectric barrier pulse reactor was used to treat pyrene in soil, and the effects of discharge voltage, discharge frequency, soil moisture, soil thickness, air velocity and soil pH on the degradation effect were studied. The results showed that the degradation rate of pyrene increased with the increase of discharge voltage and discharge frequency, and the air flow rate and soil moisture were favorable for the degradation of pyrene. The degradation rate of pyrene decreased with the increase of soil thickness and the decrease of pH. The optimal degradation conditions are as follows: discharge voltage 12.6 kV, discharge frequency 1.0 kHz, soil moisture 3.0%, soil thickness 1 mm, air flow rate 2 L/min, pH≥7. The degradation rate was 97.04%. According to the analysis of HPLC-MS and FT-IR, it was indirectly proved that the active substances such as O₃, ·OH, NO _x produced by the discharge were beneficial to the degradation of pyrene, and the possible degradation pathway of pyrene is proposed.

The experimental research on phosphorus leaching and recovery performance of sludge smoldering treatment ash was carried out, and the phosphorus leaching and recovery performance of incineration ash and pyrolysis coke produced by traditional incineration and pyrolysis treatment processes was analyzed and compared. The results showed that phosphorus content in thermal products was influenced by their residue carbon content, while phosphorus retention rate of thermal treatments was associated with their reaction violence and so on. Thermal treatment would decrease bio-availability of phosphorus in sewage sludge, especially incineration. The phosphorus leaching process of sludge smoldering ash, incineration ash and pyrolysis coke is mainly controlled by reactant concentration and product layer diffusion, and the leaching time should not exceed 8 h. Based on sulfuric acid leaching method, phosphorus leaching amount of unit mass thermal products reached 25.72—34.42 mg/g, which meant about 59.30%—84.21% of phosphorus in sewage sludge could be recovered. By further optimizing the working conditions of the leaching process, the unit consumption of sulfuric acid can be greatly reduced while maintaining a high sludge phosphorus recovery rate.

Dielectric barrier discharge (DBD) is a typical low-temperature gas discharge plasma method, which can generate a large area of ​​discharge plasma under mild conditions for nitrogen fixation, and has the characteristics of green environmental protection, high efficiency and energy saving. The energy consumption for nitrogen fixation of DBD on the high side, however, has a large optimization space. The influence of regulated voltage and gas flow rate on performance of DBD nitrogen fixation was explored to investigate the variation of total nitrogen concentration (TNC) and energy consumption (EC) in the form of liquid nitrogen fixation. Besides, the reaction mechanism of DBD nitrogen fixation was revealed by analyzing the variation rule of DBD gas phase products. It was found that DBD gaseous phase products under different conditions were in one of the three modes of ozone mode, transition mode and nitrogen oxide mode, and the minimum EC of each experimental group were all in transition mode. The reason was analyzed that NO₂ and N₂O₅ could be effectively generated under this mode, which improved the proportion of soluble nitrogen and thus promoted the nitrogen fixation effect. The minimum value of EC is 31.69 MJ/mol when the voltage is 18 kV and the gas flow is 8 L/min.

This work simulated the reaction process of CH₄ on the surface of Al₂O₃ supported Fe₂O₃ oxygen carrier (denoted as: Fe₂O₃/Al₂O₃) in chemical looping combustion (CLC) by using ReaxFF-MD method, and explored the regulation mechanism of Al₂O₃ inert support on the combustion process of Fe₂O₃/Al₂O₃-CH₄ system. It was found that the addition of Al₂O₃ inert carrier changed the reactivity of Fe₂O₃ oxygen carrier and the thermodynamic and kinetic behaviors of Fe₂O₃/Al₂O₃-CH₄ reaction system during CLC. The main purpose is to promote the oxidation of CH₄ on the surface of Fe₂O₃ oxygen carrier, and to significantly promote and regulate the CH₄ reaction process, intermediates, products and their reaction rates and heat release. ReaxFF-MD simulation showed that the activation effects of Al₂O₃ inert support on the lattice oxygen in Fe₂O₃ active phase facilitated the migration-diffusion-release of the lattice oxygen. These findings show that the addition of inert support can enhance the lattice oxygen release of the Fe₂O₃ oxygen carriers in CLC, and favor the efficient and clean conversion of CH₄ to the syngas, and strengthen the CLC process, as well as satisfy the goals of the current energy efficient conversion and carbon emission reduction targets.

Hydroxyethylidene diphosphonic acid (HEDP) is a typical organic phosphine corrosion and scale inhibitor. It widely exists in industrial water treatment system. Its conventional biodegradation rate is less than 5%. It has become a restrictive factor for industrial wastewater treatment, reuse and efflux. The degradation efficiency of HEDP by electrochemical advanced oxidation method was explored, and the effects of key parameters such as current density, Na₂SO₄ concentration, pH, temperature and solution flow rate on the degradation rate of HEDP were investigated. The degradation mechanism of HEDP was explored by electron spin resonance test, radical quenching method and kinetic experiment. The results showed that the degradation rate of HEDP was the highest when the current density was 30 mA/cm², the concentration of electrolyte Na₂SO₄ was 0.1 mol/L, pH=11, the temperature was 30℃, the solution flow rate was 500 ml/min, and it could reach 99.7% in 90 min. The electrochemical advanced oxidation system used in the study mainly produces hydroxyl radical (·OH) and sulfate radical (SO{}_{\mathrm{4}}^{-}·). Only ·OH can degrade HEDP. The reaction rate constant of ·OH and HEDP is (4.28±0.24)×10⁸ L/(mol·s)。

Based on the defects of high oxygen content and poor quality of biomass tar, this paper proposes a method for co-conversion and utilization of biomass and heavy oil. The distribution of co-pyrolysis products of FCC slurry (FCC), rice husk (RH) and wood chip (PS) was studied by fixed bed pyrolysis at low temperature. The results show that the co-pyrolysis process is not conducive to the formation of tar in general, and the polymerization reaction in the system is strong, which promotes the increase of char yield. However, under the action of hydrogen supply by FCC, co-pyrolysis is beneficial to the removal of oxygen-containing compounds in tar. With the increase of biomass ratio, decarboxylation and decarbonylation reactions were weaken and dehydroxyl reaction was strengthen in the reaction process, and the increase of CO and CO₂ in the product decreases compared with the calculated value, while the yield of water gradually increases compared with the calculated value. The increase of hydrocarbons in tar is dominated by the increase of two-rings aromatic and four-rings aromatic in aromatic hydrocarbons and the increase of C₁₃-C₂₀ in aliphatic hydrocarbons. The quality of tar was improved after co-pyrolysis.

Chemical by-product gas is a flammable and complex gas with a certain calorific value, but its purification and reuse have always been low in economic benefits, and most of them are treated by direct combustion. In respond to the current demand for chemical industry to carry out green and low-carbon transition, this paper investigates the performance of solid oxide fuel cell (SOFC) to generate electricity using by-product gas from chemical industry. B-site cobalt doped Sr_0.95Ti_0.33Fe_0.6Co_0.07O_3-δ (STFC) perovskite oxide anode is prepared by high-temperature solid-phase synthesis method which based on SrTi_0.3Fe_0.7O_3-δ (STF) perovskite oxide with high mixed oxygen ion and electron conduction capacity. STFC anode structure, electrochemical performance and durability are systematically characterized by using different types and ratios of simulated chemical by-product gases as a fuel. The results show that Co_0.28Fe_0.72 nanoparticles were in situ precipitated after reduction of STFC perovskite oxide in humidified hydrogen. The electrochemical performance test in different types of simulated chemical by-product gases showed that, the small polarization impedance and high output power density are obtained for STFC anode. And the single cell operates for excellent long-term stability under complex fuels with rich hydrocarbon components.

To study the flame stability and NO emission characteristics of lean premixed ammonia/methane turbulent swirling flame, a visual swirling turbulent combustion device was designed and built, and a series of experimental measurements was carried out. The results show that the range of stable combustion of ammonia flame became wider with the increase of equivalence ratio, but when the ammonia mixing ratio was greater than 0.60, the flame oscillated up and down in the chamber and finally blow out; with the increase of equivalence ratio, the NO emission increased; under the same equivalence ratio, NO emission first increased and then decreased with the increase of ammonia mixing ratio. In addition, the chemical reactor network (CRN) method and the one-dimensional laminar flow premixed flame calculation method were used to numerically analyze the corresponding flame states. Although there was a large deviation between the calculated results and the experimental results, the predicted variation trend of NO emission with the ammonia mixing ratio and equivalence ratio was consistent with the experimental results. The sources of the deviation among the three results were analyzed.

In order to explore the synergistic oil displacement mechanism of endogenous and exogenous bacteria in the process of heavy oil recovery, the hydrocarbon-philic emulsification bacteria Geobacillus stearothermophilus SL-1 was used as the exogenous bacteria to investigate the synergistic viscosity reduction and hydrocarbon reduction performance of the bacteria and endogenous flora. The efficacy of the indigenous and exogenous bacteria to reduce crude oil viscosity and degrade hydrocarbons of heavy oil were investigated. The structural characteristics of the bacterial community were analyzed by using high-throughput sequencing of 16S rDNA, and the synergistic relationship between indigenous and exogenous bacteria was evaluated. The results showed that long-chain alkanes in heavy oil were degraded significantly and the viscosity of heavy oil decreased by approximately 79.5% under the synergistic effect of strain SL-1 and the endogenous bacteria. Hydrocarbon degrading bacteria and hydrogen producing bacteria, such as Desulfomicrobium, Rhizobium, Legionella, Coprothermobacter, and Gelria, were activated after the addition of strain SL-1, and gas production and methane content increased. The stability of the microbial community was enhanced, which improved the oil recovery performance of the functional bacteria. A species correlation analysis showed that strain SL-1 was positively correlated with Pseudothermotoga, Coprothermobacter and Gelria. The synergy between these species can promote the process of hydrocarbon degradation and methane production, which will improve the process of heavy oil recovery. This study provides theoretical support for the field application of strain SL-1.

Fossil fuel combustion flue gas contains a lot of moisture and latent heat, and the direct emission of high-humidity flue gas causes great waste of resources and environmental problems. Ceramic membrane is currently regarded as one of the most promising technologies for water and heat recovery from flue gas. A quantitative description of the water recovery process is needed for the development and optimized design for the technology. This paper analyzes the mass transfer mechanism of water vapor on the surface and inside the nano-porous ceramic membrane, and a comprehensive set of model for water recovery from flue gas is proposed. Firstly, a thermodynamic model of water vapor recovery based on the kelvin capillary condensation theory in the nano pores is developed, the critical radius where capillary condensation occurred for water vapor from flue gas under different temperature and humidity is predicted. The condensation water amount and the working pore-volume ratio of different ceramic membranes under different conditions are revealed. Secondly, a mass transfer model by combining the surface mass transfer of capillary condensation and Hagen-Poiseuille equation for viscous flow in pores is developed. The mass transfer rates of different ceramic membranes under different conditions are studied and compared. The calculated results show that the capillary condensation occurred in nano-pores greatly enhances the water recovery rates from flue gas, and the smaller the pore size, the greater the mass transfer rate. However, a much high pressure drop may be needed when the pore size is very small. The ceramic membrane with the pore size of 20.0 nm is recommended for the cases studied in this paper.

The UV-LED/NaClO process was adopted to degrade methylparaben (MeP) in aqueous solution, the second-order rate constants of HO· and \mathrm{C}{\mathrm{O}}_{\mathrm{3}}^{-}· with MeP were determined by competitive kinetics, and the contributions of different contributions in the reaction system under different oxidant dosage, pH, HA were calculated. The mineralization rate, disinfection by-products (DBPs) formation and the alteration of acute toxicity during the degradation of MeP were investigated capered in the presence of bromine. The results showed that the synergistic effect of NaClO and UV-LED is better than other oxidants, the pseudo-first-order kinetic rate constants of UV-LED/NaClO processes under experimental conditions was 0.0854 min^-1. The second-order rate constants of HO· and \mathrm{C}{\mathrm{O}}_{\mathrm{3}}^{-}· with MeP were calculated to be 4.00×10⁹ L/(mol·s) and 5.56×10⁸ L/(mol·s), respectively. The contribution rate of each reactive species in the degradation of MeP by UV-LED/NaClO process is in order as follows: active chlorine radical (RCS)>HO·>NaClO>UV-LED. Weak acidic and neutral conditions were conducive to the degradation of MeP. HA significantly inhibited the degradation of MeP. The addition of \mathrm{N}{\mathrm{O}}_{\mathrm{3}}^{-}, \mathrm{H}\mathrm{C}{\mathrm{O}}_{\mathrm{3}}^{-}^{and Br- promoted the degradation of MEP in varying degrees. Br- can enhance the mineralization of MeP, but will lead to more DBPs generation and increase the acute toxicity of the reaction solution.}

The effect of ammonium polyacrylate (PAAA), anionic polyacrylamide (APAM) and hydroxamic acid flocculant (HPAM/HCPAM) on the settling performance of hematite and goethite by simulating the Bayer red mud settlement was studied, and the particle size distribution and fractal dimension of flocs as well as the flocculation mechanism were analyzed by Fourier transform infrared spectroscopy. Among the different types of flocculants, the iron ore phase sedimentation rate is the fastest with the addition of hydroxamic acid flocculant, and the higher the hydroxamic acid content, the better the sedimentation performance; the ammonium polyacrylate and anionic polyacrylamide flocculants have little effect on the settling performance of iron-bearing minerals; under the same conditions, the settling velocity of hematite is much higher than that of goethite, and increasing the amount of flocculant helps to improve the settling velocity of goethite. Among the hematite flocs, the PAAA flocs have the largest particle size, while the HPAM flocs have the largest fractal dimension and the best compactness; among the goethite flocs, the APAM flocs have the largest particle size, while the HCPAM flocs have the largest fractal dimension and the best compactness. The hydroxamic acid flocculant forms a five membered ring chelate with a stable structure and strong adsorption capacity with hematite and goethite, which enhances the flocculation performance of hematite and goethite; PAAA is adsorbed with hematite through bidentate bridging, and adsorbed with goethite through monodentate coordination, the adsorption capacity of which is weaker than five-membered ring; APAM adopts the chemical adsorption with hematite and goethite with a poor settling performance.

Coal-burning organic pollutants have serious harm to human health and ecological environment, and O₂ has a significant regulatory effect on the formation of organic products in flames. In view of the fact that coal volatiles combustion is a crucial part of coal combustion, the effect of O₂ concentration on hydrocarbon formation characteristics and mechanisms in counterflow diffusion flame was studied by numerical simulation using coal pyrolysis gas as fuel. The results showed that the increase of O₂ concentration promoted the formation of O and OH, which in turn increased H concentration, highlighting the importance of reactions involving H and OH. In addition, concentrations of acetylene (C₂H₂), propyne (PC₃H₄), propargyl (C₃H₃), vinylacetylene (C₄H₄), benzene (C₆H₆) and naphthalene (C₁₀H₈) all increased. Increasing O₂ concentration promoted the conversion from C₂H₂ to PC₃H₄, and made C₃H₃ more inclined to convert to butadiene (C₄H₆), while fulvene was more inclined to generate C₆H₆ through phenyl (C₆H₅). Therefore, the status of C₆H₅ as a precursor of C₆H₆ was strengthened.

To facilitate reduction and resource recovery from excess sludge, thickened sludge was conditioned with free ammonia conditioning (200-800 mg·L^-1, 24 h). The results demonstrate that the methanogenesis was promoted by release of micro-molecules organics through the cell membrane. The accumulated methane production and biochemical methane potential was promoted by 34.6% and 23.3%, respectively. The soluble organic matters was released as soluble chemical oxygen demand (SCOD), including soluble protein, and soluble carbohydrate which were promoted by 5.19%-23.81%, 1.47%-14.55%, and -0.64%-14.63%, respectively. Hydrolysis of the released organic matters was further enhanced by 34.2%-62.24% in form of SCOD. The first methane production peak (0-5 d) and the secondary peak (9-12 d) was improved by 21.04%, 120.39%, respectively. Parallel factor analysis (PARAFAC) based on 3-D fluorescence spectroscopy (3D-EEM) indicated that the refractory organic matter converted to biodegradable tryptophan. The above results show that free ammonia conditioning strengthens the initial release and later conversion of organic matter in the thickened sludge, thereby improving the methane yield, which is a green and low-consumption sludge resource technology.

Microfluidic fuel cell is a kind of new micro-power supply devices. The CO₂ bubbles generated during the operation of the battery in an acidic system will seriously affect the performance and stability of the battery. Studying the dynamic behaviors of bubbles during cell operation is great significance in weakening the impact of bubbles. In this paper, air-breathing microfluidic fuel cells with flow-through anode were constructed, and we studied the effect of the anode catalyst distribution on the cell performance and the CO₂ dynamic behaviors. The results showed that the catalyst distributed on both sides of the anode performed the best performance but poor stability. When the catalysts were distributed on one side, the cell operated stably and the bubbles were mainly formed in the electrolyte flow channel.

To solve the balance between proton conductivity and ion selectivity and the balance between power density and capacity decay in vanadium flow battery (VFB), a series of continuous covalent organic framework/ polyether sulfone (COF/PES) composite membrane with size-sieving effect were designed and prepared. The COF nanosheets synthesized by interfacial polymerization were fabricated into continuous proton/vanadium ion sieving COF layers on the PES support layer by vacuum assisted self-assembly. The regular rigid skeleton of COF layer endows the composite membrane with extremely low swelling ratio, and the uniform sub-nanoscale ion transport channel (pore size is about 0.6 nm) constructed by orderly staggered stacking of nanosheets has accurate size-sieving effect on H⁺/V ⁿ⁺ ions. The vanadium permeability of COF/PES composite membrane is only 0.61 × 10^-8 cm^-2·s^-1, and the ion selectivity is 4.0 times that of Nafion 212. At 80 mA·cm^-2, the energy efficiency of composite membrane reaches 82.9%, which is better than Nafion 212 (81.2%). In the long cycle test at 100 mA·cm^-2, the capacity retention rate of the VFB equipped with composite membrane was 16.2% higher than that of the battery equipped with Nafion 212, indicating that the continuous COF/PES size-sieving composite membrane has broad application prospect in vanadium flow battery.

At room temperature, the differences in the reactivity of thiol-acrylate and thiol-epoxy catalyzed by tertiary amines are obvious and have controlled sequential curing characteristics. In this paper, a thiol-acrylate-epoxy sequential dual thermal curing system was constructed with pentaerythritol tetra(3-mercaptopropionate) (SH4), 1,4-bis[(2-oxiranylmethoxy)-methyl]-benzene (BOB) or 2,5-bis[(2-oxiranylmethoxy)-methyl]-furan (BOF), and 1,4-cyclohexanediylbis(methylene) diacrylate (CHDMDA), and the effect of hydrogen bonding on the curing process and properties of the system was investigated. FTIR, rheological analysis, DSC, DMA, universal material testing machine and hardness tester were used to characterize the thermal properties, rheological properties, mechanical properties and ambient temperature service period of the intermediate material after the first stage curing and the final material after the second stage curing. The results show that the presence of hydrogen bonding delays the dual curing reaction and improves the mechanical properties of final material. In addition, the rheological, thermal and mechanical properties of the two-stage materials produced by this sequential dual thermal curing system can be regulated, and the intermediate materials can maintain stable properties at room temperature for 24 h. Controlled sequential dual curing gives thermoset polymers easy complex shape processing molding, high performance, and a broader range of applications such as shape memory actuators and pressure sensitive adhesive films, breaking the limitations of thermoset plastics in shape design and processing.

A dithiosalicylic acid derivative (MAPBS) was designed and synthesized. The effects of MAPBS on the photopolymerization kinetics of methacrylate monomers, and the volume shrinkage, thermostability and hardness of polymer films were investigated in detail. The results show that MAPBS can initiate the polymerization of methacrylate monomers and reduce the volume shrinkage of polymer films under 365 nm LED irradiation. With the increase of MAPBS content, the double bond conversion and photopolymerization rate are increased to 64.9% and 1.19%/s, respectively, while the volume shrinkage is decreased initially and followed by an increase. Furthermore, the thermostability of polymer films is slightly reduced, while their hardness is increased a little. MAPBS has the dual functions of initiating polymerization and reducing volume shrinkage, and certain application potential in LED photopolymerization system.

Using cotton cellulose as raw material, the hierarchical porous carbon (HPC) samples were prepared by pyrolyzing the mixture of magnesium nitrate, urea and cellulose. The specific surface area and pore structure of porous carbon were regulated by changing the calcination temperature and KOH activation treatment. By comparing the cyclic voltammetry curve, galvanostatic charge-discharge curve, specific capacity and other electrochemical parameters of the activated samples which were pre-calcined at three different temperatures, the results showed that 4AC@HPC800 sample had excellent electrochemical performance as the working electrode of supercapacitor, and its specific surface area reached 2433.8 m²·g^-1. The specific capacitance was as high as 234.7 F·g^-1 at the current density of 1 A·g^-1, and 207.6 F·g^-1 at the high current density of 10 A·g^-1, indicating that it had good rate performance. The electrode still presented a capacity of 196.1 F·g^-1 after 10000 cycles at the current density of 2 A·g^-1, indicating that it can work for a long time.

In order to study the suppression characteristics and mechanism of oxalate and bicarbonate on the explosion flame of polyethylene dust, two kinds of bicarbonate powders ( NaHCO₃, KHCO₃ ) and two kinds of oxalate powders ( Na₂C₂O₄, K₂C₂O₄ ) were selected. The inhibition performance of oxalate and bicarbonate on flame propagation of polyethylene dust explosion was analyzed from two aspects of flame structure and flame propagation velocity. Combined with the physical and chemical properties of four kinds of explosion suppression powders, the mechanism of inhibiting polyethylene dust explosion was analyzed. The results show that all four kinds of explosion suppression powder can inhibit the flame propagation of polyethylene dust explosion, and the inhibition effect increases with the increase of the concentration of explosion suppression powder. Under the same explosion inhibitor concentration, KHCO₃ had the best explosion suppression performance, followed by NaHCO₃, and then K₂C₂O₄ and Na₂C₂O₄. That is, the explosion suppression performance of potassium salt powder was better than that of sodium salt with the same acid radical ion, and the explosion suppression performance of bicarbonate powder was better than that of oxalate with the same metal ion. The four kinds of explosion suppression powders all have physical and chemical explosion suppression properties. In terms of physics, bicarbonate powder mainly has the functions of thermal desorption, dilution of oxygen and thermal shielding, while oxalate only has the functions of dilution of oxygen and thermal shielding. In terms of chemical, four kinds of explosion suppression powders can be pyrolyzed to produce active free radicals Na· and K·, and react with the high active radicals H· and OH· produced by polyethylene dust explosion to form Na·⇔NaOH and K·⇔KOH cyclic reaction, and then play an explosion suppression role by interrupting the chain reaction.

By changing the speed of the emulsification disperser, the mixed emulsion explosive matrix samples with different internal phase particle sizes were prepared on site. Phase particle size, microstructure, ammonium nitrate precipitation, and viscosity changes were used to evaluate the effect of internal phase particle size on the vibration resistance of the field-mixed emulsion explosive matrix. The experimental results show that the anti-vibration performance of the emulsified explosive matrix weakened as the particle size of the internal phase droplets increased, and the matrix with the internal phase particle size larger than 5.00 μm was more susceptible to the vibration effect of emulsion breakage and crystal precipitation. The poly dispersion index (PDI) of 1^# matrix with the internal phase particle size of 9.47 μm was 2.78, and the emulsion was obviously broken and destabilized after 1 vibration cycle, and the crystallization amount increased by 143% and viscosity increased by 1.4 times after 3 vibration cycles, so the emulsion was broken seriously and the viscosity was too large for pumping. The PDI of 5^# matrix with the internal phase particle size of 3.97 μm was 1.88, and the crystallization amount increased by 52% and viscosity increased by 1.07 times after 3 vibration cycles, but it still maintained the form of the emulsion explosive matrix and had good stability. The emulsion explosive with too large internal phase particle size is easy to crystallize after being vibrated, which leads to the decrease of performance. In actual production, the internal phase particle size during the preparation of the explosive matrix should be controlled to be less than 5.00 μm.

For the vertical upward barrier jet fire, the predecessors mostly studied the ceiling jet, but there were very few studies on the vertical upward jet fire plume impinging on the pipeline. In order to study the evolution behavior characteristics of the vertical upward jet fire plume hitting the pipeline, based on the basic principles of combustion and fluid mechanics, the influence of different heat release rates, diameters of the obstacle pipelines and the distance between the pipe wall and the fire source were investigated by using the Fluent software. It is concluded that the diameter of the obstacle pipe and the distance between the pipe wall and the fire source have a certain degree of influence on the flame height and width, and a dimensionless flame height representation model based on Froude number is obtained.

In response to the existing fluorocarbon foam extinguishing agent key component PFOS is restricted due to international environmental conventions for environmental protection and health reasons, and the existing foam extinguishing agent still has the problem that the rapid sedimentation rate affects the fire extinguishing energy efficiency, on the basis of previous research and team’s exploration of fluorine-free foam compounding scheme, based on the theory of fire chemistry and surfactant technology, hydrocarbon/silicone surfactant (LS-99/SDS) was selected as the basic agent of the foam composite system, and the foam foaming multiple and 25% drainage time were adjusted by introducing low-carbon alcohol (ethanol, n-propanol and isobutanol) which can improve foam aggregation. The comparative experiments of foam extinguishing with and without low-carbon alcohol were conducted to investigate the energy efficiency of foam extinguishing after introducing low-carbon alcohols. The results showed that the introduction of low-carbon alcohol could significantly increased the foaming multiple and 25% drainage time of LS-99/SDS binary composite foam system. Compared with ethanol and n-propanol, when the addition of isobutanol was 0.1%, the precipitation process of alcohol-containing foam system can be effectively delayed and the precipitation rate can be reduced. Through the flame temperature measurement in the fire extinguishing process, it was found that the flame cooling rate at the height of 10 cm and 20 cm under the action of foam extinguishing agent containing alcohol system was 20.1℃·s^-1 and 11.2℃·s^-1, and the cooling increase was 39.58% and 14.29% respectively compared with the alcohol-free system, with significant cooling effect. The fire extinguishing time of the foam containing alcohol system was shortened by 3.6 s compared with that of the alcohol-free system, with a reduction of 37.5%. It can effectively delay the process of foam liquid separation, improve the bubbling times and foam stability of the foam system with the introduction of appropriate concentration of isobutanol into the fluorine-free foam system. And this can provide a new path for the optimal design of fluorine-free foam. A fire extinguishing effect evaluation method based on comprehensive indicators such as 25% drainage time, average drainage speed, the maximum cooling rate and fire-extinguishing time was established, which provided a reference base for evaluation of foam extinguishing efficiency.

To reduce the impact of methane explosion, polydopamine self-polymerization reaction was studied to synthesize polydopamine, which was coated on the surface of silica and calcium carbonate mixed powder, and methane explosion experiment was carried out on the independently developed acrylic pipeline experimental platform. The explosion suppression comparison experiment of mixed powder coated with different concentrations of dopamine was carried out to explore the effect of dopamine concentration on methane explosion. Particle size analysis, scanning electron microscopy, thermogravimetric analysis and other techniques were used to characterize the polydopamine coated mixed powder. The experimental results show that polydopamine coated mixed powder accords with the characteristics of general explosive suppression powder. Combined with the analysis of the maximum explosion overpressure and flame propagation characteristic images, the methane explosion suppression performance was explored. The explosive overpressure was analyzed, when the concentration of dopamine was 0.6 g/L, the polydopamine coated mixed powder had the best explosive suppression performance. Compared with the condition without powder spraying, the maximum explosive overpressure decreased by 32.31%. Finally, the chemical and physical analysis of the mechanism of explosion suppression was carried out in combination with related characterization analysis, and the complex mechanism of explosion suppression was discussed.