Understanding the origins of potential source rocks and unraveling the intricate connections between reservoir oils and their source formations in the Siwa Basin(Western Desert,Egypt)necessitate a thorough oil-source ...Understanding the origins of potential source rocks and unraveling the intricate connections between reservoir oils and their source formations in the Siwa Basin(Western Desert,Egypt)necessitate a thorough oil-source correlation investigation.This objective is achieved through a meticulous analysis of well-log responses,Rock-Eval pyrolysis,and biomarker data.The analysis of Total Organic Carbon across 31 samples representing Paleozoic formations in the Siwa A-1X well reveals a spectrum of organic richness ranging from 0.17 wt%to 2.04 wt%,thereby highlighting diverse levels of organic content and the presence of both Type II and Type III kerogen.Examination of the fingerprint characteristics of eight samples from the well suggests that the Dhiffah Formation comprises a blend of terrestrial and marine organic matter.Notably,a significant contribution from more oxidized residual organic matter and gas-prone Type III kerogen is observed.Contrarily,the Desouky and Zeitoun formations exhibit mixed organic matter indicative of a transitional environment,and thus featuring a pronounced marine influence within a more reducing setting,which is associated with Type II kerogen.Through analysis of five oil samples from different wells—SIWA L-1X,SIWA R-3X,SIWA D-1X,PTAH 5X,and PTAH 6X,it is evident that terrestrial organic matter,augmented by considerable marine input,was deposited in an oxidizing environment,and contains Type III kerogen.Geochemical scrutiny confirms the coexistence of mixed terrestrial organic matter within varying redox environments.Noteworthy is the uniformity of identified kerogen Types II and III across all samples,known to have potential for hydrocarbon generation.The discovery presented in this paper unveils captivating prospects concerning the genesis of oil in the Jurassic Safa reservoir,suggesting potential links to Paleozoic sources or even originating from the Safa Member itself.These revelations mark a substantial advancement in understanding source rock dynamics and their intricate relationship with reservoir oils within the Siwa Basin.By illuminating the processes of hydrocarbon genesis in the region,this study significantly enriches our knowledge base.展开更多
The Albian-Maastrichtian interval of the Ivorian sedimentary basin has been the subject of numerous sedimentological, biostratigraphic, and geophysical studies. However, its geochemical characteristics remain relative...The Albian-Maastrichtian interval of the Ivorian sedimentary basin has been the subject of numerous sedimentological, biostratigraphic, and geophysical studies. However, its geochemical characteristics remain relatively unexplored. This study aims to determine the oil potential and the nature of the organic matter it contains. It focuses on the geochemical analysis (physicochemical method) of two oil wells located in the offshore sedimentary basin of Côte d’Ivoire, specifically in the Abidjan margin. A total of 154 cuttings samples from wells TMH-1X and TMH-2X were analyzed to determine their oil potential and the nature of the organic matter (OM) they contain. The analyses were performed using Rock-Eval pyrolysis, a method that characterizes the amount of hydrocarbons generated by the organic matter present in the rocks. The key parameters measured include Total Organic Carbon (TOC), Hydrogen Index (HI), oil potential (S2), and maximum pyrolysis temperature (Tmax). These parameters are used to assess the amount of organic matter, its thermal maturity, and its potential to generate hydrocarbons in the studied wells. The results show significant variations between different stratigraphic levels. In well TMH-1X, the Cenomanian and Campanian intervals stand out with very good quantities of organic matter (OM) with good oil potential, although often immature. In contrast, other stages such as the Albian and Turonian contain organic matter in moderate to low quantities, often immature and of continental type, which limits their capacity to generate hydrocarbons. In well TMH-2X, a similar trend is observed. Despite an abundance of organic matter, the oil potential remains low in most of the studied stages. The organic matter is primarily of type III (continental origin) and thermally immature, indicating a low potential for hydrocarbon generation. The study reveals that, although some intervals exhibit high-quality organic matter, the majority of the samples show insufficient maturity for effective hydrocarbon production. Wells TMH-1X and TMH-2X offer limited oil potential, requiring more advanced maturation conditions to fully exploit the hydrocarbon resources.展开更多
How to accurately recover the hydrocarbon loss is a crucial step in reservoir evaluation by Rock-Eval pyrolysis. However, it is very difficult to determine the recovering coefficients because there are numerous factor...How to accurately recover the hydrocarbon loss is a crucial step in reservoir evaluation by Rock-Eval pyrolysis. However, it is very difficult to determine the recovering coefficients because there are numerous factors causing the hydrocarbon loss. Aiming at this problem, a new method named critical point analysis is put forward in this paper. The first step of the method is to find the critical point by drawing the scatterplot of hydrocarbon contents versus the ratio of the light component of with the heavy component of;And the second step is to calculate the recovering coefficient by contrasting the pyrolysis parameters at the critical point of different sample types. This method is not only been explained reasonably theoretically,but also has got a good application effect in Huanghua depression.展开更多
This paper focuses on the preparation of rare earth oxide products from rare earth chloride solutions during the rare earth extraction and separation processes,as well as the recycling of magnesium chloride solutions....This paper focuses on the preparation of rare earth oxide products from rare earth chloride solutions during the rare earth extraction and separation processes,as well as the recycling of magnesium chloride solutions.It proposes the idea of introducing spray pyrolysis technology into the rare earth extraction and separation processes.This paper briefly describes the development history of chloride spray pyrolysis technology,focusing on the research status and application progress of rare earth chloride solution and magnesium chloride solution spray pyrolysis technology,as well as spray pyrolysis equipment.The paper also analyzes the challenges and technical intricacies associated with applying spray pyrolysis technology to chloride solutions in the rare earth extraction and separation processes.Additionally,it explores future trends and proposes strategies to facilitate the full recycling of acids and bases,streamline the process flow,and enhance the prospects for green and low-carbon rare earth metallurgy.展开更多
It is important to understand the effects of demineralization on the reactivity of coal pyrolysis for demineralization coal in OCCSS systems.The molecular dynamics of the pyrolysis of ZD-R and ZD-D was investigated us...It is important to understand the effects of demineralization on the reactivity of coal pyrolysis for demineralization coal in OCCSS systems.The molecular dynamics of the pyrolysis of ZD-R and ZD-D was investigated using the ReaxFF MD method.It is indicated that the pyrolysis reactivity of ZD-D is enhanced.Acid demineralization treatment helps to enhance the cross-linking reaction of light tar C5-14 molecules in the main pyrolysis stage,generating light tar fragments with higher molecular mass.In the polycondensation pyrolysis stage,the acid demineralization treatment promotes the polycondensation reaction at high temperatures.The generation of H2 in ZD-R pyrolysis is primarily attributed to the N-H bond breaking in pyrrole at low temperatures.At high temperatures,it is predominantly associated with the hydrogen abstraction reaction between carboxyl functional groups and the dehydrogenation reaction of hydrogen bond breaking in the aliphatic hydrocarbon structures.H2O is primarily attributed to the reaction of the hydroxyl group on the carboxyl group.CO_(2) is always related to the carboxyl group.CO is mainly related to the reduction reaction of carbonyl group,carboxyl group,and CO_(2).During the initial pyrolysis stage of ZD-D after acid demineralization treatment,the hydrogen abstraction reaction of the carboxyl functional group and the generation of CO molecules by the methoxy group are enhanced.The generation of H2 by the aliphatic structure is enhanced in the main pyrolysis stage.The ring-opening reaction of the phenoxy group to generate CO in the polycondensation pyrolysis stage is also facilitated.展开更多
This paper presents findings of a study on solid wastes conversion into fuels through pyrolysis of plastic materials, presenting an alternative renewable approach for waste management. Investigations were conducted on...This paper presents findings of a study on solid wastes conversion into fuels through pyrolysis of plastic materials, presenting an alternative renewable approach for waste management. Investigations were conducted on conversion of polypropylene (PP), low-density polyethylene (LDPE) and high-density polyethylene (HDPE) under normal and catalyst mediated process conditions. Plastic wastes were collected from various dumpsites in Nairobi and segregated using plastic resin codes to various classes. Samples were cleaned, dried and shredded to 2 mm and fed into a pyrolysis reactor. The pyrolysis process was conducted at between 220˚C and 420˚C. Pyrolysis gases were condensed in a shell and coil condenser and the incondensable gases were stored in gasbags. Liquid fuels were analysed using Gas chromatograph with a mass spectroscopic detector and Fourier Transform Infrared Spectrometry. The results revealed that the most optimal process conditions were a temperature range of 220˚C - 420˚C at a heating rate of 10˚C per minute. Under these conditions, the oil yields were 53.72% for PP, 62.10% for LDPE, and 64.14% for HDPE. As the heating rate increased from 10˚C/min to 20˚C/min, gas yields increased, rising from 28.05% to 31.12% in PP, 14.96% to 30.62% in LDPE, and 18.51% to 29.49% in HDPE. The introduction of Fe2O3 and Al2O3 catalyst significantly enhanced gas production during pyrolysis, increasing yields from 18% to 61% and 47% respectively.展开更多
Sewage sludge(SS)and SS impregnated with activating agents(ZnCl_(2) and KOH)were pyrolyzed in a fixed-bed reactor to produce gaseous fuel and activated char.The effects of heating rate,pyrolysis temperature and activa...Sewage sludge(SS)and SS impregnated with activating agents(ZnCl_(2) and KOH)were pyrolyzed in a fixed-bed reactor to produce gaseous fuel and activated char.The effects of heating rate,pyrolysis temperature and activator type on gas yields,pore structure and adsorption properties of activated char were systematically studied.The results demonstrated that increasing the pyrolysis temperature from 450℃ to 850℃ propo rtionally enhanced H_(2) and CO yields from the rapid pyrolysis of SS,while CH_(4) yield showed minimal variation between 650℃ and 850℃.ZnCl_(2) notably increased the CO yield,reaching71.9 ml·g^(-1)at 850℃,but caused a marked reduction in CH_(4) yield under the tested conditions.Similarly,KOH promoted CO yield at 750℃ and 850℃,with minimal impact on CH_(4) production.Both activators facilitated higher H_(2) yields in the range of 450-550℃,while the maximum H_(2) yield(109.8 ml·g^(-1))was observed at 850℃ in the absence of activator.The activated char derived from ZnCl_(2)-assisted pyrolysis exhibited well-developed micro-and mesopore structures,with specific surface areas ranging from 188.2 to 54.1 m^(2)·g^(-1)across pyrolysis temperatures of 450-850℃.When evaluated as adsorbents for methylene blue removal,activated char with greater specific surface area and total pore volume exhibited superior adsorption capacity.The adsorption process was well-described by the pseudo-second-order kinetic model.展开更多
Polystyrene(PS)waste was depolymerized using a low-temperature pyrolysis treatment(LTPT)to increase its caking index.The mechanism of caking index modification was revealed by using Fourier transform infrared spectros...Polystyrene(PS)waste was depolymerized using a low-temperature pyrolysis treatment(LTPT)to increase its caking index.The mechanism of caking index modification was revealed by using Fourier transform infrared spectroscopy,thermogravimetric(TG)analysis,pyrolysis-gas chromatography with mass spectrometric detection,and solid-state^(13)C nuclear magnetic resonance spectroscopy.The crucible coal-blending coking tests were carried out using an industrial coal mixture and the treated-PS with the highest caking index(PS300)or raw PS.Some properties of the resultant cokes were also analyzed.It was demonstrated that the caking index of PS dramatically increased by LTPT;however,exceeding 300℃ did not yield any benefit.The caking index increased due to the formation of the caking components,whose molecules are medium in size,caused by LTPT.Additionally,the coke reactivity index of the coke obtained from the mixture containing PS300 decreased by 5.1%relative to that of the coke made from the mixture with PS and the coke strength after reaction index of the former increased by 7.3% compared with that of the latter,suggesting that the ratio of depolymerized PS used for coal-blending coking could increase relative to that of PS.展开更多
This study explores,for the first time,the influence of various C1 gases,such as methane(CH_(4)),carbon dioxide(CO_(2)),and biogas(CH4+CO_(2)),on catalytic pyrolysis of plastic waste(polypropylene)to evaluate their po...This study explores,for the first time,the influence of various C1 gases,such as methane(CH_(4)),carbon dioxide(CO_(2)),and biogas(CH4+CO_(2)),on catalytic pyrolysis of plastic waste(polypropylene)to evaluate their potential in producing aromatic hydrocarbons.Also,this study used the 0.5 wt%,1 wt%,3 wt%,and 5 wt%Ga-modified ZSM-5 catalyst and its reduction-oxidation processed catalysts owing to their promising catalytic properties.According to the results,the highest yield(39.5 wt%)of BTEX(benzene,toluene,xylene,and ethylbenzene)was achieved under CH4 over RO-GHZ(1)catalyst among all tested conditions.The reduction-oxidation process not only promotes a significant reduction of the Ga-size but also induces its diffusion inside the pore,compared to GHZ(1).This leads to the formation of highly active GaO^(+)ionic species,balancing the Lewis/Brönsted ratio,thereby accelerating the aromatization reaction.The effect of Ga loading on the RO-GHZ catalyst was also evaluated systematically,which showed a negative impact on the BTEX yield owing to the lowering in the concentration of active GaO+species.A detailed catalyst characterization supports the experimental results well.展开更多
Lignin pyrolysis leads to the formation of diverse phenolic products that bear structural similarities to natural lignin,and the related mechanism has been widely explored based on the linkage cleavageinvolved reactio...Lignin pyrolysis leads to the formation of diverse phenolic products that bear structural similarities to natural lignin,and the related mechanism has been widely explored based on the linkage cleavageinvolved reactions.However,some unusual pyrolytic products exhibiting significant structure deviations from lignin,such as aldehydes,remain obscure in mechanism due to long-standing neglect of their formation pathways.The present work found the pivotal role of aryl migration,a special radical-mediated rearrangement process,in governing the formation of these atypical products for the first time.Herein,density functional theory calculations,electronic structure analyses,and pyrolysis experiments were combined to investigate rearrangement patterns and prerequisite structural characteristics of aryl migration by employing typical radicals derived from linkages and substituents of lignin as models.The results indicate that the radical with an unpaired electron located on the second atom of the aromatic side chain can undergo three-membered aryl 1,2-migration triggered by exo cyclization with the best superiority,determining the generation of aldehydes,alkenes,and other products through subsequent cleavage reactions.A clear correlation among the initial geometric and electronic structures of lignin,the patterns and types of aryl migration,the energy barriers,and the end products was established.This study contributes to systematically elucidating rearrangement mechanisms and constructing a more comprehensive lignin pyrolysis mechanism network.展开更多
The biomass and coal co-pyrolysis (BCP) technology combines the advantages of both resources, achieving efficient resource complementarity, reducing reliance on coal, and minimizing pollutant emissions. However, this ...The biomass and coal co-pyrolysis (BCP) technology combines the advantages of both resources, achieving efficient resource complementarity, reducing reliance on coal, and minimizing pollutant emissions. However, this process still encounters numerous challenges in attaining optimal economic and environmental performance. Therefore, an ensemble learning (EL) framework is proposed for the BCP process in this study to optimize the synergistic benefits while minimizing negative environmental impacts. Six different ensemble learning models are developed to investigate the impact of input features, such as biomass characteristics, coal characteristics, and pyrolysis conditions on the product profit and CO_(2) emissions of the BCP processes. The Optuna method is further employed to automatically optimize the hyperparameters of BCP process models for enhancing their predictive accuracy and robustness. The results indicate that the categorical boosting (CAB) model of the BCP process has demonstrated exceptional performance in accurately predicting its product profit and CO_(2) emission (R2>0.92) after undergoing five-fold cross-validation. To enhance the interpretability of this preferred model, the Shapley additive explanations and partial dependence plot analyses are conducted to evaluate the impact and importance of biomass characteristics, coal characteristics, and pyrolysis conditions on the product profitability and CO_(2) emissions of the BCP processes. Finally, the preferred model coupled with a reference vector guided evolutionary algorithm is carried to identify the optimal conditions for maximizing the product profit of BCP process products while minimizing CO_(2) emissions. It indicates the optimal BCP process can achieve high product profits (5290.85 CNY·t−1) and low CO_(2) emissions (7.45 kg·t^(−1)).展开更多
Hydrocarbon generation kinetics are influenced by complex factors,including temperature,reaction time,pressure,and molecular structure,which render simple modeling approaches inadequate for accurately simulating metha...Hydrocarbon generation kinetics are influenced by complex factors,including temperature,reaction time,pressure,and molecular structure,which render simple modeling approaches inadequate for accurately simulating methane generation.The closed-system pyrolysis experiment,a common method to study hydrocarbon generation,poses challenges for kinetic parameter regression due to limited data points.This limitation necessitates the application of sophisticated data analysis techniques to extract meaningful insights from sparse experimental data.This paper establishes a quantitative relationship between methane production and the thermal process through closed system pyrolysis experiments.A nonlinear regression model using multiple algorithms is established based on this quantitative relationship.Accordingly,a method that can quantitatively invert the methane generation kinetic parameters corresponding to the samples based on the experimental data is provided.Based on this theoretical model,a computer program capable of processing experimental data is designed and implemented.Practical analyses are performed using the method above for three samples:a coal sample from the Yulong,Guizhou;a solid bitumen sample from Guangyuan,Sichuan;and a marlstone sample containing type Ⅰ kerogen from Luquan,Yunnan.The results obtained agree with the qualitative estimates based on hydrocarbon generation kinetic theory using the previous method.Thus,the validity of the new data processing method,the new mathematical model,and the data processing procedures are verified.展开更多
Roasting bastnaesite concentrates is a crucial process in extracting rare earths.This study explored an efficient suspension roasting technology and investigated the bastnaesite pyrolysis and cerium(Ce)oxidation.Relev...Roasting bastnaesite concentrates is a crucial process in extracting rare earths.This study explored an efficient suspension roasting technology and investigated the bastnaesite pyrolysis and cerium(Ce)oxidation.Relevant analytical tests were applied to evaluate the phase and surface property variations of bastnaesite,and isothermal kinetic analysis of bastnaesite pyrolysis and Ce oxidation was performed.The results revealed that bastnaesite decomposed rapidly and accompanied by Ce oxidation,and the gas-solid products were identified as CO_(2),Ce_(7)O_(12),La_(2)O_(3),CeF_(3) and LaF_(3),with Ce oxidation restricted by bastnaesite pyrolysis.As roasting time prolonged,cracks and pores appeared on bastnaesite surface;the BET specific surface and pore diameter increased.In later roasting period,the pore diameter continued to increase but the specific surface decreased,assigned to particle fusion agglomeration and pore consolidation.Additionally,the surface C content reduced and Ce(Ⅳ)content increased gradually as roasting progressed.The reaction kinetics all followed Avrami-Erofeev equations,the reaction orders of bastnaesite pyrolysis and Ce oxidation decreased with decreasing reaction temperature.The calculated activation energies at lower temperatures were higher than those calculated at higher temperatures.This study analyzed the bastnaesite reaction mechanism to supply a reference for the application of suspension roasting technology in bastnaesite smelting.展开更多
High density polyethylene(HDPE)pyrolysis and in-line oxidative steam reforming was carried out in a two-step reaction system consisting of a conical spouted bed reactor and a fluidized bed reactor.Continuous plastic p...High density polyethylene(HDPE)pyrolysis and in-line oxidative steam reforming was carried out in a two-step reaction system consisting of a conical spouted bed reactor and a fluidized bed reactor.Continuous plastic pyrolysis was conducted at 550℃ and the volatiles formed were fed in-line to the oxidative steam reforming step(space-time 3.12 gcat min gHDPE−1;ER=0.2 and steam/plastic=3)operating at 700℃.The influence Ni based reforming catalyst support(Al_(2)O_(3),ZrO_(2),SiO_(2))and promoter(CeO_(2),La_(2)O_(3))have on HDPE pyrolysis volatiles conversion and H_(2) production was assessed.The catalysts were prepared by the wet impregnation and they were characterized by means of N_(2) adsorption-desorption,X-ray fluorescence,temperature-programmed reduction and X-ray powder diffraction.A preliminary study on coke deposition and the deterioration of catalysts properties was carried out,by analyzing the tested catalysts through temperature programmed oxidation of coke,transmission electron microscopy,and N_(2) adsorption-desorption.Among the supports tested,ZrO_(2) showed the best performance,attaining conversion and H_(2) production values of 92.2% and 12.8 wt%,respectively.Concerning promoted catalysts,they led to similar conversion values(around 90%),but significant differences were observed in H_(2) production.Thus,higher H_(2) productions were obtained on the Ni/La_(2)O_(3)-Al_(2)O_(3) catalyst(12.1 wt%)than on CeO_(2) promoted catalysts due to La_(2)O_(3) capability for enhancing water adsorption on the catalyst surface.展开更多
The kinetic characteristics of plasma-assisted oxidative pyrolysis of ammonia are studied by using the global/fluid models hybrid solution method.Firstly,the stable products of plasma-assisted oxidative pyrolysis of a...The kinetic characteristics of plasma-assisted oxidative pyrolysis of ammonia are studied by using the global/fluid models hybrid solution method.Firstly,the stable products of plasma-assisted oxidative pyrolysis of ammonia are measured.The results show that the consumption of NH_(3)/O_(2)and the production of N_(2)/H_(2)change linearly with the increase of voltage,which indicates the decoupling of nonequilibrium molecular excitation and oxidative pyrolysis of ammonia at low temperatures.Secondly,the detailed reaction kinetics mechanism of ammonia oxidative pyrolysis stimulated by a nanosecond pulse voltage at low pressure and room temperature is established.Based on the reaction path analysis,the simplified mechanism is obtained.The detailed and simplified mechanism simulation results are compared with experimental data to verify the accuracy of the simplified mechanism.Finally,based on the simplified mechanism,the fluid model of ammonia oxidative pyrolysis stimulated by the nanosecond pulse plasma is established to study the pre-sheath/sheath behavior and the resultant consumption and formation of key species.The results show that the generation,development,and propagation of the pre-sheath have a great influence on the formation and consumption of species.The consumption of NH_(3)by the cathode pre-sheath is greater than that by the anode pre-sheath,but the opposite is true for OH and O(1S).However,within the sheath,almost all reactions do not occur.Further,by changing the parameters of nanosecond pulse power supply voltage,it is found that the electron number density,electron current density,and applied peak voltages are not the direct reasons for the structural changes of the sheath and pre-sheath.Furthermore,the discharge interval has little effect on the sheath structure and gas mixture breakdown.The research results of this paper not only help to understand the kinetic promotion of non-equilibrium excitation in the process of oxidative pyrolysis but also help to explore the influence of transport and chemical reaction kinetics on the oxidative pyrolysis of ammonia.展开更多
In this paper,the pyrolysis characteristics of waste tire rubber with catalyst addition were experimentally studied.Pyrolysis experimentations of waste tire rubber with either base,acid or Zeolite catalysts were perfo...In this paper,the pyrolysis characteristics of waste tire rubber with catalyst addition were experimentally studied.Pyrolysis experimentations of waste tire rubber with either base,acid or Zeolite catalysts were performed in a Thermal Gravimetric Analyzer,a one-stage test rig and a two-stage test rig respectively.This is followed by analysis into the rates of pyrolysis reactions and the yields and distribution of the three-phase products using thermogravimetric infrared spectroscopy(TG-IR)and gas chromatographymass spectrometry(GC-MS).Results indicated that the transition metal chloride catalysts improved the reaction rate and were overall effective than the solid acid-base catalysts.Benzene and toluene yields were improved by all three catalysts in the primary pyrolysis,and the best performance was achieved at 550℃ and 600℃ with 30%NaOH.With ZSM-5 in the secondary pyrolysis,proportion of high calorific gases components as H2 and CH4 were increased,and the arylation and isomerization reactions were also promoted.The optimum aromatics yield was achieved at 600℃ and 50%ZSM condition.This study would provide a reference for resourceful utilization of waste tires.展开更多
Utilizing calcium aluminate(CaAlO)as a catalyst in lignocellulosic biomass pyrolysis offers dual advantages of cost saving and mitigating environmental pollution from industrial waste.This study employs kinetic analys...Utilizing calcium aluminate(CaAlO)as a catalyst in lignocellulosic biomass pyrolysis offers dual advantages of cost saving and mitigating environmental pollution from industrial waste.This study employs kinetic analysis to validate the catalytic effect of CaAlO on biomass pyrolysis.Thermalgravimetric analysis of walnut shell pyrolysis was conducted,incorporating CaAlO,CaO,and Al_(2)O_(3) additives to examine catalytic pyrolysis and gas release characteristics.The results reveal that CaAlO exhibits a catalytic effect similar to that of CaO and Al_(2)O_(3),suggesting its potential as an effective catalyst.Activation energies obtained without additive and with CaAlO,CaO,and Al_(2)O_(3) by Friedman method are 184,178,158,and 176 kJ·mol^(-1),while by Flynn-Wall-Ozawa(FWO)method are 186,179,160,177 kJ·mol^(-1).Finally,distributed activation energy model(DAEM)analysis was performed,and the obtained parameters were successfully coupled into three-dimensional numerical simulation with some simplifications in the DAEM integration to reduce calculation cost,showing its potential applicability in biomass pyrolysis investigation.展开更多
Coal pillars are critical supporting structures between underground coal gasification gasifiers.Its bearing capacity and structural stability are severely threatened by high-temperature environments.To elucidate the h...Coal pillars are critical supporting structures between underground coal gasification gasifiers.Its bearing capacity and structural stability are severely threatened by high-temperature environments.To elucidate the high-temperature deterioration mechanism of coal pillars at multiple scales,coal strength features as a function of temperature were investigated via uniaxial compression and acoustic emission equipment.The pyrolysis reaction process and microstructure evolution were characterized via X-ray diffractometer(XRD),scanning electron microscope(SEM),thermogravimetric(TG),Fourier transform infrared spectroscopy(FTIR),and computed tomography(CT)tests.Experimental results reveal a critical temperature threshold of 500℃for severe degradation of the coal bearing capacity.Specifically,both the strength and elastic modulus exhibit accelerated degradation above this temperature,with maximum reductions of 45.53%and 61.34%,respectively.Above 500℃,coal essentially undergoes a pyrolysis reaction under N_(2)and CO_(2)atmospheres.High temperatures decrease the quantity of O_(2)-based functional groups,growing aromaticity and the degree of graphitization.These changes induce dislocation and slip inside the coal crystal nucleus and then lead to deformation of the coal molecular structural units and strain energy generation.This process results in a great increase in porosity.Consequently,the stress deformation of coal increases,transforming the type of failure from brittle to ductile failure.These findings are expected to provide scientific support for UCG rock strata control.展开更多
To address the issue of uneven temperature distribution in shale gas oil-based drill cuttings pyrolysis furnaces,a numerical model was developed using Fluent software.The effects of nitrogen flow rate,heating tube spa...To address the issue of uneven temperature distribution in shale gas oil-based drill cuttings pyrolysis furnaces,a numerical model was developed using Fluent software.The effects of nitrogen flow rate,heating tube spacing,and furnace dimensions on the internal temperature field were thoroughly analyzed from a mechanistic perspective.The results indicated that non-uniform radiation from the heating tubes and flow disturbances induced by the nitrogen stream were the primary causes of localized heat concentration.Under no-load conditions,the maximum deviation between simulated and on-site measured temperatures was 1.5%,validating the model’s accuracy.Further-more,this study investigated the trade-offs between temperature uniformity,energy consumption,and construction costs.The findings provide a crucial design basis and a reliable simulation platform for developing and optimizing pyrolysis equipment.展开更多
基金the research project is funded by Abdullah Alrushaid Chair for Earth Science Remote Sensing Research at King Saud University,Riyadh,Saudi Arabia.。
文摘Understanding the origins of potential source rocks and unraveling the intricate connections between reservoir oils and their source formations in the Siwa Basin(Western Desert,Egypt)necessitate a thorough oil-source correlation investigation.This objective is achieved through a meticulous analysis of well-log responses,Rock-Eval pyrolysis,and biomarker data.The analysis of Total Organic Carbon across 31 samples representing Paleozoic formations in the Siwa A-1X well reveals a spectrum of organic richness ranging from 0.17 wt%to 2.04 wt%,thereby highlighting diverse levels of organic content and the presence of both Type II and Type III kerogen.Examination of the fingerprint characteristics of eight samples from the well suggests that the Dhiffah Formation comprises a blend of terrestrial and marine organic matter.Notably,a significant contribution from more oxidized residual organic matter and gas-prone Type III kerogen is observed.Contrarily,the Desouky and Zeitoun formations exhibit mixed organic matter indicative of a transitional environment,and thus featuring a pronounced marine influence within a more reducing setting,which is associated with Type II kerogen.Through analysis of five oil samples from different wells—SIWA L-1X,SIWA R-3X,SIWA D-1X,PTAH 5X,and PTAH 6X,it is evident that terrestrial organic matter,augmented by considerable marine input,was deposited in an oxidizing environment,and contains Type III kerogen.Geochemical scrutiny confirms the coexistence of mixed terrestrial organic matter within varying redox environments.Noteworthy is the uniformity of identified kerogen Types II and III across all samples,known to have potential for hydrocarbon generation.The discovery presented in this paper unveils captivating prospects concerning the genesis of oil in the Jurassic Safa reservoir,suggesting potential links to Paleozoic sources or even originating from the Safa Member itself.These revelations mark a substantial advancement in understanding source rock dynamics and their intricate relationship with reservoir oils within the Siwa Basin.By illuminating the processes of hydrocarbon genesis in the region,this study significantly enriches our knowledge base.
文摘The Albian-Maastrichtian interval of the Ivorian sedimentary basin has been the subject of numerous sedimentological, biostratigraphic, and geophysical studies. However, its geochemical characteristics remain relatively unexplored. This study aims to determine the oil potential and the nature of the organic matter it contains. It focuses on the geochemical analysis (physicochemical method) of two oil wells located in the offshore sedimentary basin of Côte d’Ivoire, specifically in the Abidjan margin. A total of 154 cuttings samples from wells TMH-1X and TMH-2X were analyzed to determine their oil potential and the nature of the organic matter (OM) they contain. The analyses were performed using Rock-Eval pyrolysis, a method that characterizes the amount of hydrocarbons generated by the organic matter present in the rocks. The key parameters measured include Total Organic Carbon (TOC), Hydrogen Index (HI), oil potential (S2), and maximum pyrolysis temperature (Tmax). These parameters are used to assess the amount of organic matter, its thermal maturity, and its potential to generate hydrocarbons in the studied wells. The results show significant variations between different stratigraphic levels. In well TMH-1X, the Cenomanian and Campanian intervals stand out with very good quantities of organic matter (OM) with good oil potential, although often immature. In contrast, other stages such as the Albian and Turonian contain organic matter in moderate to low quantities, often immature and of continental type, which limits their capacity to generate hydrocarbons. In well TMH-2X, a similar trend is observed. Despite an abundance of organic matter, the oil potential remains low in most of the studied stages. The organic matter is primarily of type III (continental origin) and thermally immature, indicating a low potential for hydrocarbon generation. The study reveals that, although some intervals exhibit high-quality organic matter, the majority of the samples show insufficient maturity for effective hydrocarbon production. Wells TMH-1X and TMH-2X offer limited oil potential, requiring more advanced maturation conditions to fully exploit the hydrocarbon resources.
文摘How to accurately recover the hydrocarbon loss is a crucial step in reservoir evaluation by Rock-Eval pyrolysis. However, it is very difficult to determine the recovering coefficients because there are numerous factors causing the hydrocarbon loss. Aiming at this problem, a new method named critical point analysis is put forward in this paper. The first step of the method is to find the critical point by drawing the scatterplot of hydrocarbon contents versus the ratio of the light component of with the heavy component of;And the second step is to calculate the recovering coefficient by contrasting the pyrolysis parameters at the critical point of different sample types. This method is not only been explained reasonably theoretically,but also has got a good application effect in Huanghua depression.
基金supported by the National Key Research and Development Program of China(2022YFB3504501)the National Natural Science Foundation of China(52274355)。
文摘This paper focuses on the preparation of rare earth oxide products from rare earth chloride solutions during the rare earth extraction and separation processes,as well as the recycling of magnesium chloride solutions.It proposes the idea of introducing spray pyrolysis technology into the rare earth extraction and separation processes.This paper briefly describes the development history of chloride spray pyrolysis technology,focusing on the research status and application progress of rare earth chloride solution and magnesium chloride solution spray pyrolysis technology,as well as spray pyrolysis equipment.The paper also analyzes the challenges and technical intricacies associated with applying spray pyrolysis technology to chloride solutions in the rare earth extraction and separation processes.Additionally,it explores future trends and proposes strategies to facilitate the full recycling of acids and bases,streamline the process flow,and enhance the prospects for green and low-carbon rare earth metallurgy.
文摘It is important to understand the effects of demineralization on the reactivity of coal pyrolysis for demineralization coal in OCCSS systems.The molecular dynamics of the pyrolysis of ZD-R and ZD-D was investigated using the ReaxFF MD method.It is indicated that the pyrolysis reactivity of ZD-D is enhanced.Acid demineralization treatment helps to enhance the cross-linking reaction of light tar C5-14 molecules in the main pyrolysis stage,generating light tar fragments with higher molecular mass.In the polycondensation pyrolysis stage,the acid demineralization treatment promotes the polycondensation reaction at high temperatures.The generation of H2 in ZD-R pyrolysis is primarily attributed to the N-H bond breaking in pyrrole at low temperatures.At high temperatures,it is predominantly associated with the hydrogen abstraction reaction between carboxyl functional groups and the dehydrogenation reaction of hydrogen bond breaking in the aliphatic hydrocarbon structures.H2O is primarily attributed to the reaction of the hydroxyl group on the carboxyl group.CO_(2) is always related to the carboxyl group.CO is mainly related to the reduction reaction of carbonyl group,carboxyl group,and CO_(2).During the initial pyrolysis stage of ZD-D after acid demineralization treatment,the hydrogen abstraction reaction of the carboxyl functional group and the generation of CO molecules by the methoxy group are enhanced.The generation of H2 by the aliphatic structure is enhanced in the main pyrolysis stage.The ring-opening reaction of the phenoxy group to generate CO in the polycondensation pyrolysis stage is also facilitated.
文摘This paper presents findings of a study on solid wastes conversion into fuels through pyrolysis of plastic materials, presenting an alternative renewable approach for waste management. Investigations were conducted on conversion of polypropylene (PP), low-density polyethylene (LDPE) and high-density polyethylene (HDPE) under normal and catalyst mediated process conditions. Plastic wastes were collected from various dumpsites in Nairobi and segregated using plastic resin codes to various classes. Samples were cleaned, dried and shredded to 2 mm and fed into a pyrolysis reactor. The pyrolysis process was conducted at between 220˚C and 420˚C. Pyrolysis gases were condensed in a shell and coil condenser and the incondensable gases were stored in gasbags. Liquid fuels were analysed using Gas chromatograph with a mass spectroscopic detector and Fourier Transform Infrared Spectrometry. The results revealed that the most optimal process conditions were a temperature range of 220˚C - 420˚C at a heating rate of 10˚C per minute. Under these conditions, the oil yields were 53.72% for PP, 62.10% for LDPE, and 64.14% for HDPE. As the heating rate increased from 10˚C/min to 20˚C/min, gas yields increased, rising from 28.05% to 31.12% in PP, 14.96% to 30.62% in LDPE, and 18.51% to 29.49% in HDPE. The introduction of Fe2O3 and Al2O3 catalyst significantly enhanced gas production during pyrolysis, increasing yields from 18% to 61% and 47% respectively.
基金financially supported by the National Natural Science Foundation of China(U21A2062)National innovative training program for college students of China(202410792014)。
文摘Sewage sludge(SS)and SS impregnated with activating agents(ZnCl_(2) and KOH)were pyrolyzed in a fixed-bed reactor to produce gaseous fuel and activated char.The effects of heating rate,pyrolysis temperature and activator type on gas yields,pore structure and adsorption properties of activated char were systematically studied.The results demonstrated that increasing the pyrolysis temperature from 450℃ to 850℃ propo rtionally enhanced H_(2) and CO yields from the rapid pyrolysis of SS,while CH_(4) yield showed minimal variation between 650℃ and 850℃.ZnCl_(2) notably increased the CO yield,reaching71.9 ml·g^(-1)at 850℃,but caused a marked reduction in CH_(4) yield under the tested conditions.Similarly,KOH promoted CO yield at 750℃ and 850℃,with minimal impact on CH_(4) production.Both activators facilitated higher H_(2) yields in the range of 450-550℃,while the maximum H_(2) yield(109.8 ml·g^(-1))was observed at 850℃ in the absence of activator.The activated char derived from ZnCl_(2)-assisted pyrolysis exhibited well-developed micro-and mesopore structures,with specific surface areas ranging from 188.2 to 54.1 m^(2)·g^(-1)across pyrolysis temperatures of 450-850℃.When evaluated as adsorbents for methylene blue removal,activated char with greater specific surface area and total pore volume exhibited superior adsorption capacity.The adsorption process was well-described by the pseudo-second-order kinetic model.
基金supported by the National Natural Science Foundation of China(22308006 and 22278001)the Natural Science Foundation of Anhui Provincial Education Department(KJ2021A0407).
文摘Polystyrene(PS)waste was depolymerized using a low-temperature pyrolysis treatment(LTPT)to increase its caking index.The mechanism of caking index modification was revealed by using Fourier transform infrared spectroscopy,thermogravimetric(TG)analysis,pyrolysis-gas chromatography with mass spectrometric detection,and solid-state^(13)C nuclear magnetic resonance spectroscopy.The crucible coal-blending coking tests were carried out using an industrial coal mixture and the treated-PS with the highest caking index(PS300)or raw PS.Some properties of the resultant cokes were also analyzed.It was demonstrated that the caking index of PS dramatically increased by LTPT;however,exceeding 300℃ did not yield any benefit.The caking index increased due to the formation of the caking components,whose molecules are medium in size,caused by LTPT.Additionally,the coke reactivity index of the coke obtained from the mixture containing PS300 decreased by 5.1%relative to that of the coke made from the mixture with PS and the coke strength after reaction index of the former increased by 7.3% compared with that of the latter,suggesting that the ratio of depolymerized PS used for coal-blending coking could increase relative to that of PS.
文摘This study explores,for the first time,the influence of various C1 gases,such as methane(CH_(4)),carbon dioxide(CO_(2)),and biogas(CH4+CO_(2)),on catalytic pyrolysis of plastic waste(polypropylene)to evaluate their potential in producing aromatic hydrocarbons.Also,this study used the 0.5 wt%,1 wt%,3 wt%,and 5 wt%Ga-modified ZSM-5 catalyst and its reduction-oxidation processed catalysts owing to their promising catalytic properties.According to the results,the highest yield(39.5 wt%)of BTEX(benzene,toluene,xylene,and ethylbenzene)was achieved under CH4 over RO-GHZ(1)catalyst among all tested conditions.The reduction-oxidation process not only promotes a significant reduction of the Ga-size but also induces its diffusion inside the pore,compared to GHZ(1).This leads to the formation of highly active GaO^(+)ionic species,balancing the Lewis/Brönsted ratio,thereby accelerating the aromatization reaction.The effect of Ga loading on the RO-GHZ catalyst was also evaluated systematically,which showed a negative impact on the BTEX yield owing to the lowering in the concentration of active GaO+species.A detailed catalyst characterization supports the experimental results well.
基金supported by the National Natural Science Foundation of China,China(52436009,52276189)the Postdoctoral Fellowship Program of CPSF,China(GZB20230207)the Fundamental Research Funds for the Central Universities,China(2024JC001,2024MS087)。
文摘Lignin pyrolysis leads to the formation of diverse phenolic products that bear structural similarities to natural lignin,and the related mechanism has been widely explored based on the linkage cleavageinvolved reactions.However,some unusual pyrolytic products exhibiting significant structure deviations from lignin,such as aldehydes,remain obscure in mechanism due to long-standing neglect of their formation pathways.The present work found the pivotal role of aryl migration,a special radical-mediated rearrangement process,in governing the formation of these atypical products for the first time.Herein,density functional theory calculations,electronic structure analyses,and pyrolysis experiments were combined to investigate rearrangement patterns and prerequisite structural characteristics of aryl migration by employing typical radicals derived from linkages and substituents of lignin as models.The results indicate that the radical with an unpaired electron located on the second atom of the aromatic side chain can undergo three-membered aryl 1,2-migration triggered by exo cyclization with the best superiority,determining the generation of aldehydes,alkenes,and other products through subsequent cleavage reactions.A clear correlation among the initial geometric and electronic structures of lignin,the patterns and types of aryl migration,the energy barriers,and the end products was established.This study contributes to systematically elucidating rearrangement mechanisms and constructing a more comprehensive lignin pyrolysis mechanism network.
基金support from the National Natural Science Foundation of China(22108052).
文摘The biomass and coal co-pyrolysis (BCP) technology combines the advantages of both resources, achieving efficient resource complementarity, reducing reliance on coal, and minimizing pollutant emissions. However, this process still encounters numerous challenges in attaining optimal economic and environmental performance. Therefore, an ensemble learning (EL) framework is proposed for the BCP process in this study to optimize the synergistic benefits while minimizing negative environmental impacts. Six different ensemble learning models are developed to investigate the impact of input features, such as biomass characteristics, coal characteristics, and pyrolysis conditions on the product profit and CO_(2) emissions of the BCP processes. The Optuna method is further employed to automatically optimize the hyperparameters of BCP process models for enhancing their predictive accuracy and robustness. The results indicate that the categorical boosting (CAB) model of the BCP process has demonstrated exceptional performance in accurately predicting its product profit and CO_(2) emission (R2>0.92) after undergoing five-fold cross-validation. To enhance the interpretability of this preferred model, the Shapley additive explanations and partial dependence plot analyses are conducted to evaluate the impact and importance of biomass characteristics, coal characteristics, and pyrolysis conditions on the product profitability and CO_(2) emissions of the BCP processes. Finally, the preferred model coupled with a reference vector guided evolutionary algorithm is carried to identify the optimal conditions for maximizing the product profit of BCP process products while minimizing CO_(2) emissions. It indicates the optimal BCP process can achieve high product profits (5290.85 CNY·t−1) and low CO_(2) emissions (7.45 kg·t^(−1)).
文摘Hydrocarbon generation kinetics are influenced by complex factors,including temperature,reaction time,pressure,and molecular structure,which render simple modeling approaches inadequate for accurately simulating methane generation.The closed-system pyrolysis experiment,a common method to study hydrocarbon generation,poses challenges for kinetic parameter regression due to limited data points.This limitation necessitates the application of sophisticated data analysis techniques to extract meaningful insights from sparse experimental data.This paper establishes a quantitative relationship between methane production and the thermal process through closed system pyrolysis experiments.A nonlinear regression model using multiple algorithms is established based on this quantitative relationship.Accordingly,a method that can quantitatively invert the methane generation kinetic parameters corresponding to the samples based on the experimental data is provided.Based on this theoretical model,a computer program capable of processing experimental data is designed and implemented.Practical analyses are performed using the method above for three samples:a coal sample from the Yulong,Guizhou;a solid bitumen sample from Guangyuan,Sichuan;and a marlstone sample containing type Ⅰ kerogen from Luquan,Yunnan.The results obtained agree with the qualitative estimates based on hydrocarbon generation kinetic theory using the previous method.Thus,the validity of the new data processing method,the new mathematical model,and the data processing procedures are verified.
基金Projects(2022YFC2905800,2021YFC2901000)supported by the National Key R&D Program of ChinaProject(52174242)supported by the National Science and Technology of ChinaProject(52130406)supported by the National Science and Technology Major Project of China。
文摘Roasting bastnaesite concentrates is a crucial process in extracting rare earths.This study explored an efficient suspension roasting technology and investigated the bastnaesite pyrolysis and cerium(Ce)oxidation.Relevant analytical tests were applied to evaluate the phase and surface property variations of bastnaesite,and isothermal kinetic analysis of bastnaesite pyrolysis and Ce oxidation was performed.The results revealed that bastnaesite decomposed rapidly and accompanied by Ce oxidation,and the gas-solid products were identified as CO_(2),Ce_(7)O_(12),La_(2)O_(3),CeF_(3) and LaF_(3),with Ce oxidation restricted by bastnaesite pyrolysis.As roasting time prolonged,cracks and pores appeared on bastnaesite surface;the BET specific surface and pore diameter increased.In later roasting period,the pore diameter continued to increase but the specific surface decreased,assigned to particle fusion agglomeration and pore consolidation.Additionally,the surface C content reduced and Ce(Ⅳ)content increased gradually as roasting progressed.The reaction kinetics all followed Avrami-Erofeev equations,the reaction orders of bastnaesite pyrolysis and Ce oxidation decreased with decreasing reaction temperature.The calculated activation energies at lower temperatures were higher than those calculated at higher temperatures.This study analyzed the bastnaesite reaction mechanism to supply a reference for the application of suspension roasting technology in bastnaesite smelting.
文摘High density polyethylene(HDPE)pyrolysis and in-line oxidative steam reforming was carried out in a two-step reaction system consisting of a conical spouted bed reactor and a fluidized bed reactor.Continuous plastic pyrolysis was conducted at 550℃ and the volatiles formed were fed in-line to the oxidative steam reforming step(space-time 3.12 gcat min gHDPE−1;ER=0.2 and steam/plastic=3)operating at 700℃.The influence Ni based reforming catalyst support(Al_(2)O_(3),ZrO_(2),SiO_(2))and promoter(CeO_(2),La_(2)O_(3))have on HDPE pyrolysis volatiles conversion and H_(2) production was assessed.The catalysts were prepared by the wet impregnation and they were characterized by means of N_(2) adsorption-desorption,X-ray fluorescence,temperature-programmed reduction and X-ray powder diffraction.A preliminary study on coke deposition and the deterioration of catalysts properties was carried out,by analyzing the tested catalysts through temperature programmed oxidation of coke,transmission electron microscopy,and N_(2) adsorption-desorption.Among the supports tested,ZrO_(2) showed the best performance,attaining conversion and H_(2) production values of 92.2% and 12.8 wt%,respectively.Concerning promoted catalysts,they led to similar conversion values(around 90%),but significant differences were observed in H_(2) production.Thus,higher H_(2) productions were obtained on the Ni/La_(2)O_(3)-Al_(2)O_(3) catalyst(12.1 wt%)than on CeO_(2) promoted catalysts due to La_(2)O_(3) capability for enhancing water adsorption on the catalyst surface.
基金Fundamental Research Funds for the Central Universities(M23JBZY00050)National Natural Science Foundation of China(22278032)。
文摘The kinetic characteristics of plasma-assisted oxidative pyrolysis of ammonia are studied by using the global/fluid models hybrid solution method.Firstly,the stable products of plasma-assisted oxidative pyrolysis of ammonia are measured.The results show that the consumption of NH_(3)/O_(2)and the production of N_(2)/H_(2)change linearly with the increase of voltage,which indicates the decoupling of nonequilibrium molecular excitation and oxidative pyrolysis of ammonia at low temperatures.Secondly,the detailed reaction kinetics mechanism of ammonia oxidative pyrolysis stimulated by a nanosecond pulse voltage at low pressure and room temperature is established.Based on the reaction path analysis,the simplified mechanism is obtained.The detailed and simplified mechanism simulation results are compared with experimental data to verify the accuracy of the simplified mechanism.Finally,based on the simplified mechanism,the fluid model of ammonia oxidative pyrolysis stimulated by the nanosecond pulse plasma is established to study the pre-sheath/sheath behavior and the resultant consumption and formation of key species.The results show that the generation,development,and propagation of the pre-sheath have a great influence on the formation and consumption of species.The consumption of NH_(3)by the cathode pre-sheath is greater than that by the anode pre-sheath,but the opposite is true for OH and O(1S).However,within the sheath,almost all reactions do not occur.Further,by changing the parameters of nanosecond pulse power supply voltage,it is found that the electron number density,electron current density,and applied peak voltages are not the direct reasons for the structural changes of the sheath and pre-sheath.Furthermore,the discharge interval has little effect on the sheath structure and gas mixture breakdown.The research results of this paper not only help to understand the kinetic promotion of non-equilibrium excitation in the process of oxidative pyrolysis but also help to explore the influence of transport and chemical reaction kinetics on the oxidative pyrolysis of ammonia.
基金the Chongqing Municipal Education Commission Research Project(KJZD-K202401502)Chongqing Municipal Science&Technology Commission Research Project(CSTB2022NSCQ-LZX0071)to the research work.
文摘In this paper,the pyrolysis characteristics of waste tire rubber with catalyst addition were experimentally studied.Pyrolysis experimentations of waste tire rubber with either base,acid or Zeolite catalysts were performed in a Thermal Gravimetric Analyzer,a one-stage test rig and a two-stage test rig respectively.This is followed by analysis into the rates of pyrolysis reactions and the yields and distribution of the three-phase products using thermogravimetric infrared spectroscopy(TG-IR)and gas chromatographymass spectrometry(GC-MS).Results indicated that the transition metal chloride catalysts improved the reaction rate and were overall effective than the solid acid-base catalysts.Benzene and toluene yields were improved by all three catalysts in the primary pyrolysis,and the best performance was achieved at 550℃ and 600℃ with 30%NaOH.With ZSM-5 in the secondary pyrolysis,proportion of high calorific gases components as H2 and CH4 were increased,and the arylation and isomerization reactions were also promoted.The optimum aromatics yield was achieved at 600℃ and 50%ZSM condition.This study would provide a reference for resourceful utilization of waste tires.
基金the financial support of the National Natural Science Foundation of China(22278432)National Key Research&Development Program of China(2022YFB3805602)Science Foundation of China University of Petroleum-Beijing(2462021BJRC001,2462021QNXZ007)。
文摘Utilizing calcium aluminate(CaAlO)as a catalyst in lignocellulosic biomass pyrolysis offers dual advantages of cost saving and mitigating environmental pollution from industrial waste.This study employs kinetic analysis to validate the catalytic effect of CaAlO on biomass pyrolysis.Thermalgravimetric analysis of walnut shell pyrolysis was conducted,incorporating CaAlO,CaO,and Al_(2)O_(3) additives to examine catalytic pyrolysis and gas release characteristics.The results reveal that CaAlO exhibits a catalytic effect similar to that of CaO and Al_(2)O_(3),suggesting its potential as an effective catalyst.Activation energies obtained without additive and with CaAlO,CaO,and Al_(2)O_(3) by Friedman method are 184,178,158,and 176 kJ·mol^(-1),while by Flynn-Wall-Ozawa(FWO)method are 186,179,160,177 kJ·mol^(-1).Finally,distributed activation energy model(DAEM)analysis was performed,and the obtained parameters were successfully coupled into three-dimensional numerical simulation with some simplifications in the DAEM integration to reduce calculation cost,showing its potential applicability in biomass pyrolysis investigation.
基金supported by Young Scholar Program(Category A Continuation Funding)of National Natural Science Foundation of China(No.52525401)General Program of National Natural Science Foundation of China(No.52174125)+4 种基金Outstanding Youth Cultivation Project in Shanxi Province(No.202103021222008)Major Program of National Natural Science Foundation of China(No.52334005)New Cornerstone Science Foundation through the XPLORER PRIZEShanxi-Zheda Institute of Advanced Materials and Chemical Engineering(No.2022SX-TD010)Shanxi Science and Technology Major Project(No.20201102004).
文摘Coal pillars are critical supporting structures between underground coal gasification gasifiers.Its bearing capacity and structural stability are severely threatened by high-temperature environments.To elucidate the high-temperature deterioration mechanism of coal pillars at multiple scales,coal strength features as a function of temperature were investigated via uniaxial compression and acoustic emission equipment.The pyrolysis reaction process and microstructure evolution were characterized via X-ray diffractometer(XRD),scanning electron microscope(SEM),thermogravimetric(TG),Fourier transform infrared spectroscopy(FTIR),and computed tomography(CT)tests.Experimental results reveal a critical temperature threshold of 500℃for severe degradation of the coal bearing capacity.Specifically,both the strength and elastic modulus exhibit accelerated degradation above this temperature,with maximum reductions of 45.53%and 61.34%,respectively.Above 500℃,coal essentially undergoes a pyrolysis reaction under N_(2)and CO_(2)atmospheres.High temperatures decrease the quantity of O_(2)-based functional groups,growing aromaticity and the degree of graphitization.These changes induce dislocation and slip inside the coal crystal nucleus and then lead to deformation of the coal molecular structural units and strain energy generation.This process results in a great increase in porosity.Consequently,the stress deformation of coal increases,transforming the type of failure from brittle to ductile failure.These findings are expected to provide scientific support for UCG rock strata control.
基金funded by the key research on industrialization technologies of low-cost highenergy-density cathode materials(project number:2023GY008)the Sichuan Provincial Science and Technology Program(project number:2024NSFSC1406).
文摘To address the issue of uneven temperature distribution in shale gas oil-based drill cuttings pyrolysis furnaces,a numerical model was developed using Fluent software.The effects of nitrogen flow rate,heating tube spacing,and furnace dimensions on the internal temperature field were thoroughly analyzed from a mechanistic perspective.The results indicated that non-uniform radiation from the heating tubes and flow disturbances induced by the nitrogen stream were the primary causes of localized heat concentration.Under no-load conditions,the maximum deviation between simulated and on-site measured temperatures was 1.5%,validating the model’s accuracy.Further-more,this study investigated the trade-offs between temperature uniformity,energy consumption,and construction costs.The findings provide a crucial design basis and a reliable simulation platform for developing and optimizing pyrolysis equipment.
