The pyrolysis of propylene carbonate (PC), a cyclic carbonate solvent widely used in lithium-ion batteries, was investigated to enhance the understanding of thermal runaway mechanisms in these batteries. Experiments were conducted in a jet-stirred reactor (JSR) coupled with synchrotron vacuum ultraviolet photoionization mass spectrometry (SVUV-PIMS) at 1 atm, across a temperature range of 800–1140 K. Mole fraction profiles for PC and 15 product species were quantified, where photoionization efficiency (PIE) analysis identified propanal and acetone as the predominant oxygenated intermediates. High-level theoretical calculations were performed to characterize the potential energy surface (PES) and determine rate coefficients via RRKM/master equation analysis. The results indicate that CO₂ elimination is the most energetically favorable unimolecular decomposition pathway, with propanal (activation barrier: 63.8 kcal/mol) and acetone (66.7 kcal/mol) being the primary products. A comprehensive kinetic model including 504 species and 2793 reactions was developed and validated. Both experiments and modeling revealed that PC pyrolysis is characterized by the near-simultaneous consumption of fuel and formation of CO₂, maintaining a CO₂ molar yield near unity throughout the process. This differentiates PC from other oxygenated fuels where CO is typically a key initial intermediate. Reaction pathway analysis highlights that the subsequent decomposition of propanal and acetone governs the formation of small-molecule hydrocarbons and soot precursors. This work provides valuable insights into the pyrolysis chemistry of PC and contributes to a more comprehensive understanding of thermal runaway in lithium-ion batteries by pinpointing the role and specific reactions of this cyclic carbonate during thermal decomposition. Novelty and significance statement While linear carbonates and ethylene carbonate have been extensively studied, the thermal decomposition kinetics of propylene carbonate (PC) remains largely unexplored. This research addresses this gap by combining SVUV-PIMS experiments with high-level CCSD(T) theoretical calculations to develop and validate the first comprehensive kinetic model for PC. We discovered a distinctive pyrolytic signature where a dominant CO₂ elimination pathway (>95% flux) triggers fuel consumption and gas release near-simultaneously, fundamentally differing from other oxygenated fuels. This study provides an essential predictive tool for modeling battery thermal runaway, offering foundational insights required to design safer electrolytes and effective fire suppression systems for energy storage.

The alkylation of unsaturated organic and aromatic hydrocarbons represents a pivotal class of synthetic reactions with significant implications in both industrial and academic research. Furthermore, cyclohexylbenzene, synthesized via the alkylation of benzene with cyclohexene, represents a high-value-added fuel additive owing to its exceptionally high cetane number. However, it still remains challenging due to the insufficient activation of double bond-containing organic substrate over traditional phosphotungstate catalysts. In this study, we develop a single Pt atom doped phosphotungstate, as Pt1-NH4-PW catalyst, through a coprecipitation method, for the alkylation of cyclohexene with benzene. Compared to pristine NH4-PW, Pt1-NH4-PW catalyst consists of the electronic reconstructed Pt1-O pair coordinated with [PW12O40]3- . Such structure shows a typical synergistic interaction characteristic, where the Pt atom of the Pt1-O structure serves as a Lewis acid site to accept the electron from the C=C bond, and the nearby O functions as hydrogen acceptors to promote C-H bond activation of benzene. Consequently, the Pt1-NH4-PW catalyst demonstrates a threefold enhancement in catalytic activity compared to NH4-PW for the alkylation of cyclohexene with benzene. The catalytic system further demonstrated exceptional performance in diverse transformations, including alkylation of benzene with either 1-hexene or 1dodecene, and conversion of biomass-derived methyl oleate into high-value chemicals through alkylation.

Manual-based peak-shaving operation has been adopted for Liquefied natural gas (LNG) regasification system to save electricity. However, this approach faces challenges of low efficiency and high randomness. In this research, it is tried to use intelligent optimal scheduling strategy in such a way that the electricity consumption costs are optimized. The proposed scheduling strategy classifies into two main parts. The first part employs the prediction models of both Kriging model and artificial neural network (ANN) for the forecast of electricity costs. The result shows that the Kriging model yields a lower relative error than that of ANN approach. The second part develops a novel improved geyser inspired algorithm (IGEA) with a chaotic mutation method, aiming to solve the electricity cost predictive model and obtain the optimal scheduling scheme. The proposed IGEA is evaluated on 18 benchmark functions, and is compared with other four popular optimization algorithms. Simulation results indicate the superior performance of the tent map on balancing the exploration and the exploitation. Furthermore, IGEA is implemented to solve the optimal scheduling problem of LNG regasification. The experimental results suggest that IGEA can benefit the scheduling scheme by reducing electricity costs of $4.63 \% \sim 15.81 \%$, compared with manual-based strategies. Therefore, we can conclude that IGEA is a promising and effective tool to solve the optimal scheduling problems and guide the manual operation for LNG regasification.

CO2 hydrogenation into methanol suffers from a huge obstacle of low methanol yield due to the leverage effect of CO2 conversion and methanol selectivity. Here, we report an In2O3-MnCO3 catalyst consisting of In2O3 covalently linked to MnCO3 for efficiently photothermal CO2 hydrogenation into methanol. Covalent linkage, the O atoms of In2O3 occupy the oxygen vacancies of MnCO3, enables the formation of In-O-Mn Lewis acid-base pairs at the In2O3-MnCO3 interface. Both light irradiations and heatings improve the electron excitations and transfers from In to O, promoting CO2 activation and methanol production. The In2O3-MnCO3 containing 30 mol.% In achieves 67.5% methanol selectivity and 13.5% CO2 conversion at 150 °C, 4.0 MPa, and 14400 mL·h-1·g-1 with a high stability for at least 500 h on stream. This study provides a serial In-Mn catalyst design and understanding of the molecular-level structure-mediated photothermal catalytic hydrogenation.

The complex conditions of methanol production from coke-oven gas have brought challenges to the copper-based methanol synthesis catalyst. In this work, a series of zinc-malachite samples with different Mg contents were prepared. The zinc-malachite and calcined samples were characterized by in-situ X-ray diffraction (XRD), thermogravimetry-mass spectrometry (TG-MS), N2 physical adsorption, H2 programmed temperature reduction (H2-TPR), CO2 programmed temperature desorption (CO2-TPD) and other methods. The effects of Mg addition on the structure of zinc-malachite and its catalytic performance of methanol synthesis were investigated. The results showed that the addition of Mg increased the degree of Cu substitution inside the zinc-malachite structure and promoted the formation of high temperature carbonates in the catalyst after roasting. With the increase of Mg content, the specific surface area of the calcined catalyst increased gradually, and the Cu grain size decreased simultaneously. In-situ XRD results showed that a small amount of Mg could effectively inhibit the growth of copper grain size during the heat treatment. The evaluation showed that the initial activity of the catalyst increased first and then decreased with Mg addition, and the activity of the Mg-doped catalyst remained at a relatively high level after heat treatment. The appropriate Mg addition is beneficial to the initial activity and thermal stability of Cu-based methanol synthesis catalyst.

Catalysts can significantly affect the pyrolysis characteristics and products of oil sludge (OS). In this paper, we used TGA, a fixed-bed reactor, GC and GC-MS to obtain information. We found that the addition of catalyst (CaO) significantly promoted the pyrolysis transformation of OS. The analysis of pyrolysis products showed that the addition of catalyst decreased the contents of high-carbon compounds and oxygen-containing functional groups, thus promoting the quality of the pyrolysis tar. Gas composition analysis showed that the addition of catalyst increased the contents of H-2, CH(4)and CO but decreased the CO(2)content.

In order to ensure the normal operation of OBD (On Board Diagnostics) system, manufacturers are required to conduct self-examination and supervision of OBD system, which is the performance evaluation of production vehicles. Multi-objective GA (Genetic Algorithm) simulates the process of biological evolution, dealing with a population, and can generate a large number of non-inferior solutions in one optimization process, so it can search the approximate Pareto optimal solution set of multi-objective optimization problems. In this paper, a fault diagnosis model based on multi-objective GA is proposed to diagnose the faults of automobile engines. The main idea is to use advanced multi-objective GA NSGA-II to adjust the parameters of the production car performance. The simulation results show that the fault samples can be completely and accurately identified by the established model, and the identification rate reaches 91.27%. Therefore, the fault diagnosis model based on multi-objective GA proposed in this paper can be used for fault diagnosis of automobile engine.

Steelmaking contributes 8% to the total CO2 emissions globally, primarily due to coal-based iron ore reduction. Clean hydrogen-based ironmaking has variable performance because the dominant gas-solid reduction mechanism is set by the defects and pores inside the mm-nm sized oxide particles that change significantly as the reaction progresses. While these governing dynamics are essential to establish continuous flow of iron and its ores through reactors, the direct link between agglomeration and chemistry is still contested due to missing measurements. In this work, we directly measure the connection between chemistry and agglomeration in the smallest iron oxides relevant to magnetite ores. Using synthesized spherical 10-nm magnetite particles reacting in H2, we resolve the formation and consumption of w\"ustite (FeO) - the step most commonly attributed to agglomeration. Using X-ray scattering and microscopy, we resolve crystallographic anisotropy in the rate of the initial reaction, which becomes isotropic as the material sinters. Complementing with imaging, we demonstrate how the particles self-assemble, subsequently react and sinter into ~100x oblong grains. Our insights into how morphologically uniform iron oxide particles react and agglomerate H2 reduction enable future size-dependent models to effectively describe the multiscale iron ore reduction.

Methanol,a versatile chemical,fuel additive and potential H2 carrier,has attracted great attention.Despite of the wide industrialization,improvement of Cu-based methanol-synthesis catalysts is highly anticipated.Accordingly,a series of Cu/ZnO/Al2O3 with designed precursor structures were prepared,and its structure-function relationship was investigated to make progress on this area.Results showed the catalyst derived from highly zinc-substituted malachite demonstrated the best catalytic performance in this work.It was found that the well-behaved catalyst possessed relatively high Cu specific surface area and exposed Cu concentration,and the well Cu/ZnO synergy.CuZn alloy was found by In-situ XRD tests,and its effect on the catalyst's thermostability was discussed.Fractional precipitation,which facilitated the Cu2+sub-stitution by Zn2+in malachite lattice,could be an efficient preparation method of the Cu/ZnO/Al2O3 catalyst.

Reactivity of oxygen carriers (OCs) is a key issue in chemical looping technology. Exploring spatial evolution characteristics of active components and lattice oxygen migration during reduction reaction is of great importance in improving the reactivity of OCs. In this study, thermogravimetric analyzer (TGA) is used to control the reduction degree of OCs. Oxygen migration to the surface of CuFe2O4 (100) and CuO (111) is studied based on density functional theory (DFT). X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) are used to investigate phase change and valence evolution of active components of the oxygen carriers. The results show that the ratios of lattice oxygen, chemical adsorbed oxygen and physical adsorbed oxygen at three points are very close in OCfresh. As the reduction reaction progresses, lattice oxygen is gradually consumed and the content of Cu-0 and Fe2+ is increased. The closer to the edge point, the more lattice oxygen is consumed and the larger ratio of Cu-0 and Fe2+. Moreover, there is no Fe-0 in sample OC6.24% or OC9.19%, which is caused by the rapid migration and replenishment of lattice oxygen. The calculation results show that bulk oxygen migration to the surfaces of the OCs is exothermic and has a certain energy barrier.

Direct methane decomposition for hydrogen production is considered a clean technology with limited CO2 emission. However, catalysts usually suffer from deactivation due to carbon deposition. This study reported a method of improving the catalyst stability by using a trace amount of H2S which naturally exists in natural gas, and the action mechanism of H2S was discussed. Coconut shell activated carbon (AC) was used as the catalyst, the pure methane was mixed with 100, 200, and 300 ppm H2S and decomposed at high temperature. Results show that adding different concentrations of H2S can increase the methane conversion and delay the deactivation time of the AC catalyst. Through scanning electron microscopy characterization and Brunauer-Emmet-Teller analysis, it was found that the positive effect of H2S is achieved by changing the carbon deposition morphology which in turn changes the AC pore width distribution and the specific surface area. Under the action of H2S, AC has a relatively large number of micropores during the reaction, promoting the adsorption of methane molecules on AC. First-principles calculations show that H2S changes the reaction pathway of methane dehydrogenation and promotes methane decomposition.

为了研究钢渣对油泥热解产物的影响,以京津冀地区典型罐底油泥为研究对象,利用固定床反应器、热重分析仪对油泥热解条件及反应特性进行研究,通过单因素实验和响应面实验设计考察了热解终温、升温速率、停留时间和钢渣添加量等对热解产物产率的影响,采用气相色谱(GC)、气质联用(GC-MS)、扫描电镜(SEM)、红外光谱(FTIR)等对热解气体、热解回收油和热解焦表征,并对反应后固体残渣采用磁选的方式回收钢渣及分析物相组成(XRD).热重分析(TG)表明:添加钢渣有利于油泥失重率增加.热解动力学计算表明,油泥单独热解和添加钢渣的反应的表观活化能分别为8.32,7.43 kJ/mol.固定床实验表明:当热解温度为550℃,升温速率为40℃/min,停留时间为30 min时,钢渣添加量为15％时,油泥热解回收油产率最高,达到16.03％.通过17组响应面实验设计,预测回收油产率最高可达16.12％.热解产物分析表明,添加钢渣提高了气体中H2和CH4产量增加,降低了CO2产量.焦油的GC-MS分析表明,添加钢渣提高了焦油中低碳原子数成分含量.这证明了油泥和钢渣协同处置的可行性,可为热态钢渣与油泥的协同处置研究提供数据支撑.

This research is designed to make progress in overcoming the challenges through the development of a two-stage coal processing. Specifically, a two-stage process was used to maximize the use of the carbon in coal or increase the carbon monoxide yield or lower carbon dioxide and methane yields. Carbon dioxide-char gasification in the absence of water can generate carbon monoxide with near-zero methane, which is desired to produce high-carbon and low-hydrogen chemicals such as oxalic acid through catalytic carbon monoxide coupling and hydrolysis. The technology is applicable to any coal, although Power River Basin (PRB) coal is used as an example feedstock in this research Also, the sodium-iron catalyst can accelerate not only the reaction kinetics in both stages but also increase the hydrogen/carbon monoxide ratio in the syngas produced in the second stage. In other words, the catalyst is a multifunctional agent, which can not only intensify the overall coal process efficiency but also improve the qualities of the desired syngas products and reduce carbon dioxide emission. Thus, In the 1st stage, the catalysts can significantly reduce the CO2-char gasification by as high as 75.00%. In the 2nd stage, the H2/CO ratio of ideal syngas is ∼2:1 with near-0 CH4 generation and the CH4 production can be reduced as high as 61.29% for the CO2–H2O-Char coal gasification. The activation energy for the 2nd stage is reduced by as high as 35.43% than that of raw coal without use Na–Fe catalyst. The overall carbon footprint reduction for the study is reduced by 87.33% in the 1st stage and 96.77% compared to the direct coal combustion.

In this study, a strategy of combining oil sludge with steel slag to improve the quality of tar resulting from oil sludge pyrolysis and steel slag recycling is proposed. Oil sludge pyrolysis with the addition of different amounts of steel slag at different temperatures was conducted by employing a continuous pyrolysis-magnetic separation (CPM) process. The characteristics of oil pyrolysis were characterized by thermogravimetric analysis (TG), the compositions of the non-condensable gas and tar were characterized by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The effect of steel slag on the tar composition and char surface morphology was analysed. The recovered steel slag concentrate was measured by a magnetic separation method. The results indicated that steel slag addition caused the weight loss rate of oil sludge to increase. The yield of tar reached a maximum of 10.63% at 550 degrees C, and the increase in temperature intensified the secondary thermal cracking of the volatile fraction and decreased the tar yield. The gas composition analysis indicated that steel slag could act as a catalyst in improving the H-2 content during the pyrolysis process of oil sludge. The addition of steel slag significantly increased the content of short alkanes and increased the C-5 similar to C-10 fraction by improving the decomposition of the C-15 similar to C-20 fraction. The recovery of steel slag from the solid pyrolysis products of oil sludge containing steel slag was conducted in a magnetic separator, and the maximum recovery rate could reach 55.03%. It was concluded that the integration of oil sludge pyrolysis with steel slag and the recovery of steel slag from the solid pyrolysis products of oil sludge containing steel slag could be feasible.

Coal is a rich-in-C and poor-in-H material. How should we maximize uses of C and H in coal for producing desired gases eventually converted to liquid chemicals with minimal CO2 emission? This research is designed to make progress in overcoming the challenges through development of a two-stage coal processing. The technology is applicable to any coal, although Power River Basin (PRB) coal is used as an example feedstock in this research. In the 1st stage or pyrolysis process of the low-carbon-footprint technology, a Na-Fe bimetallic catalyst was found to be able to not only enhance the yield of CO and ratio of H2/CO but also lower CH4 and CO2 yields with the presences of the Na-Fe catalyst, which are desired because the produced gas is an ideal syngas. In the 2nd stage or gasification of the char obtained from pyrolysis stage with CO2 for producing almost 100%-purity CO without presence of H2O. The CO2 as the major byproduct of the 1st stage could be used as a raw material in the 2nd stage, which is an ideal process integration for significant reduction in CO2 emission. Also, the Na-Fe catalyst can accelerate not only the reaction kinetics in both stages but also increase the H¬2/CO ratio in the syngas produced in the 2nd stage. In other words, the catalyst is a multifunctional agent, which can not only intensify the overall coal process efficiency but also improve the qualities of the products and reduce CO2 emission.

反相微乳液法是一种合成金属纳米颗粒的有效方法,以十六烷基三甲基溴化铵(CTAB)、正戊醇、环己烷、金属盐溶液构建反相微乳液体系,制备了一系列用于合成甲醇的纳米铜基催化剂,并分别对其结构、形貌和活性进行了表征.结果 表明,催化剂制备过程中的老化温度、碱浓度、H2O/CTAB的摩尔比以及盐溶液的浓度对催化剂的粒径和活性均有一定的影响,为甲醇合成催化剂的新型制备方法提供了借鉴.

CO2 capture and utilization caused more and more public attention because of its environmental impact. The objective of this work was to study the catalytic gasification of a sub-bituminous coal from the Powder River Basin (PRB) using a CO2 and H2O mixture as the gasifying agent. Sodium and iron, in the form of inexpensive compounds, were chosen to catalyze the coal gasification. The experiments were conducted between 700 and 900 °C in a fixed-bed laboratory gasifier under the atmospheric pressure. Results show that the added catalysts had an effect on the composition of gas products in a way different from it in pure steam gasification. Fitting models for kinetic data were examined and the results show that addition of 3 wt% Na or 3 wt% iron led to a 28.0% or a 19.5% reduction in the activation energy of the gasification reaction, respectively. The sodium and iron in the coal char were characterized and the results show that sodium is more evenly distributed than iron during gasification. Suggestions for improving the catalysts' performance in coal gasification were proposed accordingly.

Humic acids obtained from a Chinese lignite via alkali treatment were analyzed using Fourier transform infrared spectroscopy and Orbitrap mass spectrometry coupled with an electrospray ion source (ESI-Orbitrap-MS).

Coal is the most abundant fossil energy, however, coal industry is threatened by its environmental problems caused by the traditional way of utilization. In recent years, China has developed a series of clean coal technologies to transform black-dirty coal into clean fuels and chemicals. Shenhua Group, the largest coal company in China is leading the commercialization of modern clean-coal technologies for value-added chemicals and clean transportation fuels, in which CO2 is captured in the process and ready for carbon capture, utilization and storage (CCUS). Industrial plants for coal based methanol production and conversion are flourishing in last decade. With the development of renewable H-2, methanol production could be realized by CO2 hydrogenation to transform into "Methanol Economy", the sustainable energy development system. This paper will focus on the overview of research and development of methanol-based coal conversion technologies in China, such as methanol synthesis, methanol to olefins (MTO), chemicals (formaldehyde, acetic acid, aromatics, ethanol, ethylene glycol, etc.), gasoline (MTG), dimethyl ether (DME), polyoxymethylene dimethyl ethers (DMMn), methyl tertbutyl ether (MTBE), direct combustion (DMFC), and as energy carrier. Commercial and successfully demonstrated units in China on both the synthesis of methanol and its utilization are discussed in detail.