Chemical looping oxidative dehydrogenation (CL-ODH) of ethane provides a safer and potentially more energyefficient route to ethylene than conventional oxygen-fed oxidative dehydrogenation, but its performance critically depends on oxygen carriers that can simultaneously promote C-H activation and suppress deep oxidation. Here, Cobalt-doped SrCuO2 oxygen carriers were developed to regulate lattice oxygen reactivity and the distribution of oxygen species for selective ethane CL-ODH. Among the prepared materials, 10% Co-SrCuO2 exhibited the best performance at 750 degrees C, delivering 48.6% ethane conversion, 94.2% ethylene selectivity, and an ethylene yield of 45.8%, while maintaining stable reactivity over 10 redox cycles. Structural and mechanistic analyses reveal that Co incorporation induces lattice contraction, weakens Cu-O bonding, enhances reducibility, and lowers the apparent activation energy to 98.5 kJ & sdot;mol- 1. More importantly, cobalt doping increases the proportion of lattice oxygen while suppressing highly reactive electrophilic oxygen species, thereby facilitating selective C-H bond activation and inhibiting ethylene over-oxidation. This work provides mechanistic insight into oxygen-species regulation in redox catalysts and offers an effective strategy for designing oxygen carriers for selective alkane upgrading via chemical looping.

Endogenous CO2 in biomass pyrolysis volatiles is commonly treated as a diluent, although it could potentially participate in oxygen-carrier regeneration and carbon reutilization. In this work, a coupled strategy integrating endogenous CO2-assisted regeneration with chemical looping dry reforming of biomass pyrolysis volatiles was investigated. The objective was to determine whether endogenous CO2 could be converted from a limiting component into a reactive carbon source under realistic reducing atmospheres containing CH4, H2, and CO. Thermodynamic analysis showed that methane dry reforming became favorable above 650 °C, while kinetic fitting indicated that the kinetic behavior over the reduced Ni0.36Fe0.64 phase was consistent with an MvK-type contribution with an Ea of 83.66 kJ·mol−1. In situ DRIFTS and XRD results revealed that CO2 activation proceeded through a hydrogen-assisted formate route and a direct carbonate route, and that the coexisting H2/CO atmosphere suppressed surface oxidative reconstruction, shifting the active structure from a Ni-Fe3O4 interfacial state to a more reduced NiFe3-rich alloy state. This structural evolution weakened CO2 activation but favored syngas formation under strongly reducing conditions. At the process level, staged regeneration with endogenous CO2 increases syngas production by 13.99% and achieves a lattice oxygen recovery rate of 45.75%. Light volatiles do not significantly increase syngas production, and the lattice oxygen recovery rate drops to about 20%; the H2/CO in the volatiles has an inhibitory effect on oxygen carrier regeneration. The enhanced syngas production in Process 4 should be attributed to the combined effect of endogenous CO2 utilization and exogenous biomethane-assisted DRM, increasing syngas yield by 34% and reduced CO2 emissions by 10.5%. These results suggest that endogenous CO2 can be repurposed as a reactive species for oxygen-carrier regeneration and syngas coproduction, providing a feasible route for improving carbon utilization and syngas production from biomass pyrolysis volatiles.

Blast furnace slag (BFS) carries considerable high-grade sensible heat and reactive mineral phases, offering opportunities for thermochemical waste heat recovery coupled with biomass conversion. In this work, glycine (Gly) and medium-chain triglycerides (MCT) were selected as model compounds for the protein and lipid fractions of microalgae to investigate the thermal conversion behavior in BFS-assisted pyrolysis. Thermogravimetric analysis coupled with mass spectrometry was performed at different BFS blending ratios and heating rates. To bridge the gap between complex experimental data and underlying reaction mechanisms, an Enhanced PhysicsInformed Neural Network (E-PINN) was developed to reconstruct activation energy distributions with improved stability and accuracy. The results showed that BFS exerted distinct structure-dependent effects on the two substrates. For Gly, the slag lowered the average activation energy monotonically from 129.95 to 113.57 kJ & sdot;mol1 and shifted the energy distribution toward lower values, while the gas product distribution remained largely unchanged. In contrast, MCT exhibited a non-monotonic response. At 30 wt% loading, the average activation energy reached a maximum of 171.33 kJ & sdot;mol-1 with a compressed reaction interval, accompanied by a marked shift in gas distribution from CO2-dominated to CO-enriched. These converging observations suggest that BFS does not simply promote decomposition but instead redirects the reaction toward a higher-barrier pathway. The findings demonstrate that BFS can serve as both a heat carrier and a catalytic medium, with its role depending strongly on the molecular structure of the feedstock. This study provides a reliable tool for resolving complex thermal conversion kinetics and offers guidance for process design in thermochemical recovery of metallurgical waste heat.

Coal occupies a large proportion of global energy consumption; improving the efficiency of its thermochemical conversion is essential for energy security, low-carbon transition, and value-added utilisation. Pyrolysis is the leading step of coal utilisation. Predicting the distribution of pyrolysis products is the basis of pyrolysis process optimisation and targeted product regulation. Traditional experimental methods are time-consuming and costly. Existing kinetic prediction models suffer from structural complexity or limited accuracy, which cannot meet the needs of industrial production and scientific research. To achieve accurate and low-cost prediction of coal pyrolysis product, an enhanced hybrid prediction model named SSA-BOA-BPNN was constructed by integrating the sparrow search algorithm (SSA) and the butterfly optimisation algorithm (BOA) with the back-propagation neural network (BPNN). The average R2 values reached 0.9508, 0.9699, 0.9294, 0.9758 for the three-phase product distribution, tar component distribution, tar fraction composition, and pyrolysis gas composition, respectively. The prediction accuracy and generalisation performance were substantially outperforming conventional BPNN, single-algorithm optimisation models and other commonly used models. To provide guidance for the regulation of pyrolysis products and process optimisation, the optimal pyrolysis conditions for typical bituminous coal and lignite corresponding to the optimal range of optimisation objectives (including tar yield and lighter tar proportion, the contents of aromatic hydrocarbon and phenolic compound in tar, gas yield and tar yield) were obtained by Multi-objective Pareto frontier optimisation. The research results realised the accurate, efficient and low-cost prediction of coal pyrolysis product distribution, which provided an important reference for promoting the development of coal thermochemical conversion technology.

To identify suitable extractants for extractive enhanced glycerol-CO2 carbonylation, liquid-liquid equilibrium data were determined for glycerol-glycerol carbonate systems with 2-pentanone, cyclohexanone, and 4-methyl-2-pentanone at 423.2, 433.2, and 443.2 K under a pressure of 1.5 MPa. The efficacy of the three extractants in the extraction of glycerol carbonate from glycerol was evaluated using distribution coefficients and extractive selectivity. Among the extractants, cyclohexanone possessed the highest distribution coefficient (>1) and superior extraction capability, while 4-methyl-2-pentanone exhibited the best selectivity for glycerol carbonate over glycerol. The liquid-liquid equilibrium data were then correlated using the Non-Random Two-Liquid (NRTL) model, and the corresponding binary interaction parameters were determined. The regressed parameters effectively reproduced the phase equilibrium trends observed for all studied systems. This work provides fundamental data and parameters for the selection of extractant to enhance the glycerol-CO2 carbonylation through extractive reactions as well as for subsequent process development and optimization for the carbonylation.

This work pursues a generalized filtered reaction rate (FRR) model for reactive gas-solid flows via fine-grid two-fluid model (TFM) simulations. The power-law kinetic with various reaction orders (n) is considered. It is well known that the solid-catalyzed reaction rate is bounded by the kinetic regime (KR) and external mass transfer-controlled regime (EMTR). It is found that the FRR model maintains excellent predictive performance both for n > 1 in two different regimes and n < 1 in the KR. However, an underprediction is observed at n < 1 within the EMTR. Thus, a modified formula for the FRR model in the EMTR is proposed. Then a generalized FRR model is derived. The assessment for the model is performed via a priori analysis and a filtered TFM simulation. The priori analysis and filtered TFM simulations quantitatively demonstrate that the model exhibits robust predictive capability.

Pulverized coal fast pyrolysis is a key clean efficient technology, but its industrial scale up remains constrained by complex multi-physics coupling. In this study, a cross scale model integrating intrinsic reaction kinetics with realistic multiphase flow was developed to simulate an industrial entrained-flow pyrolyzer. This framework enables the simultaneous tracking of reactor-scale performance, particle-scale thermal history, and molecularscale structural evolution, with validation from multiple levels. At the reactor scale, the spatiotemporal evolution of heat-transfer mechanisms was revealed. Radiation became the dominant mode (52.4%) after approximately 1.8 s. At the particle scale, the coupling between particle trajectories and thermal history was elucidated, clarifying how injection parameters regulate heating. At the molecular scale, a clear correlation between microstructural evolution and macroscopic product was established. Early stage yields correlated strongly with bridge bonds ratio, while later stages decoupled due to structural stabilization and metaplast release. The reaction pathways for gas, metaplast, and tar increase in complexity. It led to sequentially weaker correlations with the initial structure (correlation coefficients of 0.9987, 0.9799, and 0.9424, respectively). Guided by multidimensional evaluation system, the optimal operating window was identified (velocity 15-20 m/s, horizontal opposed, height 3-4 m). A 0 degrees baffle design was further selected as the optimal configuration, raising light tar to 2.9 wt% while maintaining carbon emissions at 0.807 kg CO2/kg tar. The study provides a predictive design framework that supports the joint optimization of high-value product output and low-carbon operation for industrial pyrolysis reactors.

The challenge of hydrogen atom (H*) poisoning active sites during dehydrogenation has severely limited the application of liquid organic hydrogen carriers (LOHCs). While hydrogen spillover has been extensively studied in hydrogenation reactions, its potential to enhance dehydrogenation kinetics remains unexplored. This work demonstrates a progress by repurposing this fundamental phenomenon to address the critical bottleneck in LOHC dehydrogenation. A tungsten-doped alumina (WAlO) support was engineered to create atomic-scale spillover pathways. The Pt/WAlO catalyst achieved a remarkable dehydrogenation degree of 86.61%. Through the in situ DRIFTS and H2-TPR, tungsten doping is demonstrated to generate oxygen vacancies which act as hydrogen sinks, promoting H* migration. DFT calculations confirm a reduced energy barrier for H* migration. The generalizability of this strategy is further demonstrated across multiple LOHC substrates. This study successfully expands the application scope of hydrogen spillover beyond conventional hydrogenation processes, paving the way for designing efficient LOHC dehydrogenation catalysts.

Abstract Regeneration of oxygen carriers under realistic biomass-derived conditions is constrained by a coupled tradeoff among carbon elimination, lattice oxygen replenishment, and structural preservation. Here, NiFe2O4@SBA-15 was used to investigate regeneration under realistic microalgae-derived conditions and to develop a staged CO2–air regeneration strategy. Compared with the benchmark H2 redox cycle, the regeneration efficiency decreased from approximately 75% to 55% after real microalgae reforming. Among single-atmosphere cases, CO2 delivered the best overall regeneration performance because it promoted carbon removal while suppressing sintering and retaining the mesostructure. A staged CO2–air regeneration strategy further increased regeneration efficiency to about 70%. Multiscale characterizations, especially Mössbauer spectroscopy, showed that CO2 step mainly induced carbon removal and partial Fe reoxidation, whereas the subsequent air step near-complete lattice oxygen replenishment and NiFe2O4 spinel reconstruction. These results demonstrate that temporally separating decarbonization from deep reoxidation is an effective regeneration design principle for redox oxygen carriers.

Hydrogen production via in-situ chemical looping reforming of rapidly pyrolyzed volatiles from microalgae was investigated using a NiFe2O4@SBA-15 oxygen carrier (OC). A two-stage fixed-bed reactor system was first employed to identify optimal pyrolysis conditions for chlorella and then to systematically optimise key reforming process parameters, including the confinement strategy, temperature, OC loading, and steam addition. The reaction pathway was further clarified using ex-situ characterisation techniques, providing detailed insight into intermediate species and structural changes during the process. Results showed that hydrogen and carbon yields in the pyrolysis products increased progressively with temperature. Therefore, 600 degrees C was identified as the optimal condition, attributed to the abundance of hydrogen-rich volatile precursors, including hydrocarbons and light volatile species. During the reforming stage, the highest hydrogen production performance was achieved at 850 degrees C, with an oxygen carrier to biomass ratio of 1 g center dot g(microalgae)(-1), and a steam injection volume of 0.4 mL, maintaining excellent stability over ten redox cycles. Ex-situ characterisation revealed that the controlled lattice oxygen transfer in nickel ferrite effectively promoted the selective conversion of volatiles. However, the accumulation of aldehyde intermediates and the extensive removal of oxygenated species were identified as rate-limiting steps. This study elucidates the reaction mechanism of hydrogen production via chemical looping reforming of fast microalgae pyrolysis. It provides an important theoretical basis and technical reference for green and low-carbon production of hydrogen from algal biomass.

Efficient and resource- abundant heterogeneous catalysts for formic acid (FA) dehydrogenation are essential for realizing a sustainable hydrogen energy cycle. However, earth-abundant non-noble metal catalysts are severely limited by intrinsically sluggish C–H activation, acid-induced metal leaching and rapid CO poisoning from the competing dehydration pathway. To address these challenges, we propose a synergistic strategy integrating spatial confinement with alloy electronic modulation to synthesize a series of bimetallic nanoparticles encapsulated within biocarbon shells (NiM@BC). Among the synthesized catalysts, NiCo@BC exhibits outstanding catalytic performance, achieving a gas generation rate of 634 mL·g−1·h−1 at 95 °C (nearly twice that of monometallic Ni@BC) and drastically reducing the CO concentration from 8350 to 1240 ppm, along with excellent durability over multiple cycles. Structural characterizations confirm that NiCo alloy nanoparticles are uniformly encapsulated within a robust graphitic carbon shell, which prevents metal leaching and suppresses aggregation. Kinetic analysis and density functional theory calculations reveal that Co incorporation moderately shifts the Ni d-band center to an optimal position. The electronic modulation lowers the energy barrier of the rate-determining C–H bond cleavage, while simultaneously raising the dehydration barrier significantly, thereby widening the energetic gap between dehydrogenation and CO-forming pathways. This work provides a systematic theoretical foundation for the high-value utilization of biomass and the development of CO-resistant, durable, and precious-metal-free catalytic systems for FA dehydrogenation

The tar-rich coal pyrolysis atmosphere is crucial for in-situ pyrolysis and oil recovery, as it directly impacts tar recovery efficiency and product quality. CO2 emerges as a highly promising medium that not only reduces tar viscosity to boost its flowability and recovery efficiency in underground reservoirs, but also actively interacts with pyrolysis products to improve tar quality. In order to clarify the role of CO2 systematically, this study combines ReaxFF molecular dynamics (ReaxFF MD) simulations and experimental analyses. Thermogravimetric experiments were performed under Ar (inert reference) and CO2 atmospheres. In contrast, ReaxFF MD simulations were performed on tar-rich coal-CO2 systems with varying CO2 ratios (0%, 10%, 30%, and 50%) at 1500 to 3000 K. By analyzing activation energy changes, product evolution, chemical bond breaking/recombination and key reaction pathways, the study elucidated CO2 ' s regulatory effect on pyrolysis characteristics. Results confirm that CO2 lowers the pyrolysis activation energy of tar-rich coal from 225.66 to 218.51 kJ & sdot;mol- 1 in experiments and from 320.22 to 192.20 kJ & sdot;mol- 1 in simulations. The simulation results of ReaxFF MD show that the yield of semi-coke decreased from 73.13% to 50.25%, while yields of heavy oil, light oil and gas increased to 20.55%, 7.91% and 21.29% respectively under the atmosphere of 2500 K CO2. Reaction pathway analysis reveals that CO2 promotes hydrogen radical generation, which induces C-C bond cleavage in char and heavy oil to produce light oil. Simultaneously, CO2 converts CH4 and H2O into CO and H2 via double reforming, enhancing syngas yield. This work clarifies the micro-mechanism of CO2, providing a basis for optimizing in-situ pyrolysis parameters and coal resource carbon conversion.

To achieve efficient utilization of waste resources and promote energy transition, this study selected reed, reed leaves and reed stems as raw materials and utilized pyrolysis series chemical looping reforming (CLR) technology to produce green hydrogen. The optimal pyrolysis conditions (pyrolysis raw materials, temperature) and the feasible region of products were explored. The result shows that the optimal pyrolysis raw material is the mixed reed, with a temperature of 600 degrees C (volatiles content of 76.29 % and hydrogen production of 1.73 mg center dot greed NiFe2O4 oxygen carrier (OC) was used to explore the optimal operating conditions (temperature, OC dosage and steam addition amounts) for the pyrolysis and volatiles series CLR of reed. This study demonstrates that the volatiles conversion reached 95.83 % at 700 degrees C with a steam input of 0.6 ml, achieving a maximum hydrogen yield of 47.7 mg center dot greed-1 . In-situ diffuse reflection infrared spectroscopy and thermogravimetric infrared analysis revealed that the dissociation of methane and the further conversion of ketone products might be the ratelimiting steps of the reaction. Furthermore, this study counted and speculated the possibility of hydrogen production from reed in the world. This study provides essential data support for the green and low-carbon hydrogen production from waste resources.

In the context of the"double carbon"goals and global energy structure adjustments,underground in-situ pyrolysis technology for tar-rich coal has become an important direction for alleviating China's dependence on foreign tar and gas due to its high efficiency and low carbon footprint.To address the challenges posed by complex underground in-situ conditions,difficult pyrolysis process intensifica-tion and optimization of process parameters,this study takes tar-rich coal from Yulin in northern Shaanxi as the research object.A multi-field coupled numerical model integrating thermal,flow and chemical reaction processes was constructed based on Darcy's seepage law and pyrolysis reaction kinetics equations,and the dynamic evolution of temperature field,pressure field,fluid seepage field and product generation was systematically simulated.The influence of heat carrier temperature(550-800℃),injection pressure(4-8 MPa),coal seam permeability(50-300 mD,4.94×10-14-2.96×10-13 m2)and wellhead deployment schemes(single well,double well and four well heat in-jection)on pyrolysis process was systematically studied by combining multi-field coupled numerical simulation with random forest ma-chine learning,and an intelligent optimization model was constructed to minimize operating cost and reach the standard of conversion rate.The results indicate that an optimal efficiency range exists at pyrolysis temperatures of 650-700℃,with a conversion rate of 92.88%achieved after heating at 700℃for 100 days.The energy consumption increases gradually.The injection pressure of 8 MPa can expand the high-concentration area of light tar and gas products by 30%compared to that of 4 MPa,and the uniformity of the temperature field is significantly improved.Under the condition of 300 mD(2.96×10-13 m2)permeability,the heat transfer efficiency of the pyrolysis reaction zone extending to the deep part of the coal seam is obviously enhanced.In the multi-well heat injection scheme,the deployment of four wells can significantly improve the uniformity of the pyrolysis temperature field for 150 days,and the distribution range of products is more obvious than that of a single well.Based on 820 sets of simulation data,the predictive determination coefficients of the random forest model for temperature and conversion rate are 0.988 8 and 0.997 3,respectively.The combination of injection temperature of 589.47℃,injection pressure of 4.0 MPa,permeability of 76.3 mD(7.53×10-14 m2)and heating time of 189.5 days can be optimized,and the cooper-ative optimization of 90.47%conversion rate and operating cost can be realized.The research results provide a theoretical basis for pro-cess parameter design of tar-rich coal in-situ pyrolysis,and establish a data-driven optimization framework for engineering decision-mak-ing.

[Background]Tar-rich coals serve as an important coal-based oil and gas resource in China,while their pyro-lysis product distribution is governed by the coupling effects of coal properties and reaction conditions.Therefore,rap-idly identifying the pyrolysis product distribution patterns holds great significance for the resource evaluation and exper-imental design of tar-rich coals.[Methods]Existing studies on tar-rich coals suffer from the insufficient integration of exclusive data and limited synergistic prediction capacities for multiple products.To address these issues,this study con-structed a dedicated dataset involving proximate analysis,ultimate analysis,elemental molar ratios,maceral composi-tion,and pyrolysis conditions by systematically collecting experimental data from associated literature.Subsequently,a feedforward neural network model for multi-target regression was established for the basic prediction of pyrolysis product yields.Accordingly,this study identified primary factors controlling the pyrolysis product distribution of tar-rich coals by combining Van Krevelen diagrams,Spearman correlation analysis,and feature contribution analysis based on SHapley Additive exPlanations(SHAP)values.Finally,through pyrolysis experiments under 400-600 ℃,this study val-idated the model's capability to reproduce the major temperature response patterns of the pyrolysis products of the tar-rich coals.[Results and Conclusions]The established feedforward neural network model effectively reproduced the typical temperature response patterns of the pyrolysis products of tar-rich coals.Specifically,with an increase in the pyrolysis temperature,the char yield decreased,the gas yield increased,the water yield increased overall,and the tar yield increased initially and then decreased.This model exhibited an average coefficient of determination(R2)of 0.89 and an average root mean square error(RMSE)of 1.53 on the testing set.Among primary influencing factors,coal prop-erties,particularly carbon content,vitrinite content,and volatile constituent content,generally produced more significant impacts on the product distribution than external operating parameters like heating rate and particle size.Experimental validation demonstrates that good agreement existed between predicted and experimental gas and char yields,while the tar yield was slightly overestimated under high-temperature conditions.Therefore,future improvement should focus on sample coverage and secondary pyrolysis under high-temperature conditions.The results of this study reveal the basic distribution patterns of the pyrolysis products of tar-rich coals and verify the capability of the established feedforward neural network model to reproduce the major temperature response trends of the pyrolysis products of tar-rich coals.These results will provide references for the resource evaluation,pyrolysis experimental design,and product control re-search of tar-rich coals.

As an important chemical raw material, the traditional preparation method of ethylene has the problems of high energy consumption and low selectivity. The chemical looping oxidative dehydrogenation process is promising to solve the problem. However, the oxygen carrier used in this process has the problems of low ethane cracking efficiency and selectivity due to excessive oxidation. Combining this process with catalytic dehydrogenation is a new approach. This study synthesized the Fe2O3/SiO2-0.6 oxygen carrier (A) and prepared Co-ZSM-5 (B) catalyst by in situ synthesis and then investigated six combination strategies: alternately packing two, four, and six layers of the oxygen carrier and catalyst; physically mixing the particles at the particle level; physically mixing via co-grinding of fine powders; and the impregnation-calcination method. The results showed that the six-layer alternating (ABABAB) arrangement achieved a 49.5% ethane conversion and 79.3% ethylene selectivity at 700 degrees C and that the first three cycles maintained a high ethylene yield. The series connection mode with different site proximity and nanoscale site contact significantly improved the ethylene selectivity and yield. The introduction of SiO2 resulted in a smaller grain size and better dispersion of Fe2O3, enhancing the gas diffusion performance. The synergistic effect of the composite catalyst combined the advantages of active oxygen and stable oxygen species, and the optimization of site proximity promoted the rapid release and oxygen transfer of lattice oxygen.

Large-scale deployment of green hydrogen is essential to reduce global CO2 emissions. Biomass pyrolysis coupled with chemical looping reforming offers a potentially low-cost route to green-hydrogen production. In this process, the molecular composition of pyrolysis volatiles and its compatibility with downstream reforming critically determine hydrogen yields. A multi-scale co-optimization strategy that couples biomass pyrolysis with chemical looping reforming is proposed and validated. Specifically, a novel molecular-mediated physics-informed neural network (MMPINN) framework was developed, trained on pyrolysis experimental data, and endowed with physical constraints at both molecular and macroscopic scales to predict macroscopic product properties and detailed molecular compositions. The molecular slate predicted by the MMPINN was used as a bridge to integrate the data-driven model with a mechanistic chemical looping reforming process model, thereby enabling joint optimization of pyrolysis and reforming operating parameters so that pyrolysis products are tailored at the molecular level to the reforming chemistry and green-hydrogen yield is maximized. An average R2 of 0.89 was achieved by the MMPINN across diverse biomass types for product prediction; physical consistency degrees of 0.97 and 0.98 were obtained at the molecular and macroscopic scales, respectively, indicating both strong statistical accuracy and physical self-consistency. Under optimized conditions, the green-hydrogen yield from wheat straw was increased by 40.31% relative to the baseline case. Overall, the hybrid data-driven–mechanistic approach demonstrated high accuracy and effectiveness in predicting volatile compositions and optimizing process parameters, leading to marked improvements in system hydrogen-production efficiency.

An iron-based multifunctional proppant was developed to enable in-situ pyrolysis of tar-rich coal underground. Thermogravimetric experiments were conducted to deeply explore the influence mechanism of the multifunctional proppants on the pyrolysis of tar-rich coal. By calculating the comprehensive pyrolysis index, it is found that the comprehensive pyrolysis index is increased from 1.13 x 10-8/%2 & sdot;min-2 & sdot;degrees C-3 to 1.309 x 10-8/ %2 & sdot;min-2 & sdot;degrees C-3 by multifunctional proppants. The macro activation energy of pyrolysis weight loss of tar-rich coal is calculated by KAS model and DAEM model. Experimental findings reveal a reduction in activation energy enabled by multifunctional proppants. In addition, the distribution of pyrolysis products and tar components was analyzed through pyrolysis experiments in the tube furnace. Experimental results revealed a 10.5 % enhancement in the light fraction content of tar following the addition of multifunctional proppants. DTG curves peak fitting revealed the action mechanism of multifunctional proppants during pyrolysis reaction stages. Pyrolysis reaction pathways for tar-rich coal in the presence of multifunctional proppants were analyzed. Catalysis of tar upgrading by multifunctional proppants during tar-rich coal pyrolysis is supported by experimental findings. In particular, the Fe2O3-loaded multifunctional proppants hold significant potential for underground in-situ pyrolysis of tar-rich coal.

Different moisture content is an important aspect of underground coal seam heterogeneity, which would affect the underground in-situ pyrolysis of tar-rich coal. The pyrolysis characteristics and product distribution of water-bearing tar-rich coal were investigated by the fixed bed pyrolysis experiments. Based on the ReaxFF MD simulation, the pyrolysis characteristics and reaction mechanism were explored from a microscopic perspective. The results showed that the pyrolysis characteristic index (D-i) continued to decrease with increasing moisture content, indicating that H2O could increase the release difficulty of pyrolysis volatiles. As the moisture content increased from 1 wt% to 15 wt%, the tar yield and lighter tar proportion increased from 4.39 wt% and 49.75 % to 11.95 wt% and 61.25 %. Therefore, the two obtained with higher moisture content would be also higher. The above results showed that H2O could promote the pyrolysis of coal. The tar yield and lighter tar proportion obtained under the CO2 atmosphere were further improved. The results of the ReaxFF MD simulation showed that the changing trends of pyrolysis product distribution were consistent with experimental results. The statistical results of chemical bonds showed that H2O could promote the cracking of C-C and C-O bonds within the pyrolysis system. By analyzing the typical pyrolysis reaction mechanism, the results of pyrolysis experiment and ReaxFF MD simulation were further confirmed. Based on the comprehensive analysis of the above results, it could be concluded that the most suitable reaction conditions for water-bearing tar-rich coal pyrolysis were moisture content: 5 wt%similar to 10 wt%, N-2 atmosphere.

To realize the clean and efficient utilisation of coke oven gas, the chemical looping steam reforming technology was used to co-produce high purity H2 and syngas. Fe-Ni-based perovskite oxygen carriers with excellent partial oxidation performance were selected in this paper, through the strategies of B-site doping and A-site defect, the lattice oxygen transport was facilitated, which enhanced the anti-carbon deposition ability and reforming performance. The results indicated that La0.7Cu0.15Ni0.1Fe0.75O3-lambda had a favorable oxygen supply capacity for partial methane oxidation in coke oven gas. At 850 degrees C, using La0.7Cu0.15Ni0.1Fe0.75O3-lambda, the methane conversion could reach 67 %, and the hydrogen production and purity in the steam regeneration stage could reach 3.56 mmol g-1 and 99.90 %, respectively. Simultaneously, La0.7Cu0.15Ni0.1Fe0.75O3-lambda demonstrated excellent reaction performance and cycle stability. This research established an experimental foundation for designing oxygen carriers tailored for hydrogen production through the chemical looping steam reforming of coke oven gas.