This study explored the synergistic interaction of sewage sludge(SS)and automotive paint sludge(PS)during co-pyrolysis for the optimized treatment of sewage sludge in cement kiln systems,utilizing thermogravimetric an...This study explored the synergistic interaction of sewage sludge(SS)and automotive paint sludge(PS)during co-pyrolysis for the optimized treatment of sewage sludge in cement kiln systems,utilizing thermogravimetric analysis(TGA)and thermogravimetric-mass spectrometry(TGA-MS).The result reveals the coexisting synergistic and antagonistic effects in the co-pyrolysis of SS/PS.The synergistic effect arises from hydrogen free radicals in SS and catalytic components in PS,while the main source of the antagonistic effect is that,during the mechanical mixing process,the SS/PS is converted from the particulate form into a dough-like rubbery which contributes to the film-forming effect,hindering the volatilization of volatile components.SS/PS co-pyrolysis reduces the yielding of tar production while increasing coke and gas.This study will provide some in-depth insights into the co-pyrolysis of SS/PS,and offer theoretical support for the subsequent research on the collaborative disposal processes in cement kilns.展开更多
The co-pyrolysis of natural gas and coal is a promising way for the production of acetylene due to its high efficiency for energy and hydrogen utilization.This work investigated the thermodynamics for the copyrolysis ...The co-pyrolysis of natural gas and coal is a promising way for the production of acetylene due to its high efficiency for energy and hydrogen utilization.This work investigated the thermodynamics for the copyrolysis reaction of natural gas and coal using density functional theory.The favorable reaction conditions are presented in the form of phase diagrams.The calculation results show that the extra amount of methane may benefit the production of acetylene in the co-pyrolysis reaction,and the C/H ratio of 1:1,temperature around 3000 K and pressure at 0.1 MPa are most favorable.The results would provide basic data for related industrial process for the production of acetylene.展开更多
The co-pyrolysis of coal and biomass has proven to be a promising route to produce liquid and gaseous fuels as well as specific value-added chemicals while contributing to mitigating CO_(2) emissions.The interactions ...The co-pyrolysis of coal and biomass has proven to be a promising route to produce liquid and gaseous fuels as well as specific value-added chemicals while contributing to mitigating CO_(2) emissions.The interactions between the co-processed feedstocks,however,need to be elucidated to support the development of such a thermochemical conversion process.In this context,the present work covers the kinetic analysis of the co-pyrolysis of a bituminous coal with poplar wood.In this research,biomass was blended with coal at two different mass ratios(10%(mass)and 20%(mass)).Thermogravimetric analyses were carried out with pure and blended samples at four heating rates(5,10,15 and 30℃·min^(-1)).A direct comparison of experimental and theoretical results(based on a simple additivity rule)failed to yield a clear-cut conclusion regarding the existence of synergistic effects.Kinetic analyses have therefore been achieved using two model-free methods(the Ozawa-Flynn-Wall and Kissinger-Akahira-Sunose models)to estimate the rate constant parameters related to the pyrolysis process.A significant decrease of the activation energy has thus been observed when adding wood to coal(activation energies associated with the blend containing 20%(mass)of biomass being even lower than those estimated for pure wood at low conversion degrees).This trend was attributed to the possible presence of synergies whose related mechanisms are discussed.The rate constant parameters derived by means of the two tested models were finally used to simulate the evolution of the conversion degree of each sample as a function of the temperature,thus leading to a satisfying agreement between measured and simulated data.展开更多
An experimental study on co-pyrolysis of bituminous coal and biomass was performed in a pressured fluidized bed reactor.The blend ratio of biomass in the mixture was varied between 0 and 100 wt%,and the temperature wa...An experimental study on co-pyrolysis of bituminous coal and biomass was performed in a pressured fluidized bed reactor.The blend ratio of biomass in the mixture was varied between 0 and 100 wt%,and the temperature was over a range of 550–650℃ under 1.0 MPa pressure with different atmospheres.On the basis of the individual pyrolysis behavior of bituminous coal and biomass,the influences of the biomass blending ratio,temperature,pressure and atmosphere on the product distribution were investigated.The results indicated that there existed a synergetic effect in the co-pyrolysis of bituminous coal and biomass in this pressured fluidized bed reactor,especially when the condition of bituminous coal and biomass blend ratio of 70:30(w/w),600℃,and 0.3 MPa was applied.The addition of biomass influenced the tar and char yields and gas and tar composition during co-pyrolysis.The tar yields were higher than the calculated values from individual pyrolysis of each fuel,and consequently the char yields were lower.The experimental results showed that the composition of the gaseous products was not in accordance with those of their individual fuel.The improvement of composition in tar also indicated synergistic effect in the co-pyrolysis.展开更多
To reasonably utilize the coal direct liquefaction residue(DLR), contrasting research on the co-pyrolysis between different low-rank coals and DLR was investigated using a TGA coupled with an FT-IR spectrophotometer a...To reasonably utilize the coal direct liquefaction residue(DLR), contrasting research on the co-pyrolysis between different low-rank coals and DLR was investigated using a TGA coupled with an FT-IR spectrophotometer and a fixed-bed reactor. GC–MS, FTIR, and XRD were used to explore the reaction mechanisms of the various co-pyrolysis processes. Based on the TGA results, it was confirmed that the tetrahydrofuran insoluble fraction of DLR helped to catalyze the conversion reaction of lignite. Also, the addition of DLR improved the yield of tar in the fixed-bed, with altering the composition of the tar. Moreover, a kinetic analysis during the co-pyrolysis was conducted using a distributed activation energy model. The co-pyrolysis reactions showed an approximate double-Gaussian distribution.展开更多
To increase the low yield and selectivity of aromatic hydrocarbons during the biomass pyrolysis process,we torrefied the biomass and then co-pyrolyzing with plastics such as high-density polyethylene(HDPE),polystyrene...To increase the low yield and selectivity of aromatic hydrocarbons during the biomass pyrolysis process,we torrefied the biomass and then co-pyrolyzing with plastics such as high-density polyethylene(HDPE),polystyrene(PS),ethylene-vinyl acetate(EVA)and polypropylene(PP)and also single and dual catalyst layouts were investigated by Py-GC/MS.The results showed that non-catalytic fast pyrolysis(CFP)of raw bagasse(RBG)generated no aromatics.After torrefaction non-CFP of torrefied bagasse(TBG)generated low aromatic yield.Indicating that torrefaction would enhance the proportion of aromatics during the pyrolysis process.The CFP of TBG_(200℃)and TBG_(240℃)over ZSM-5 produced the total aromatic yield of 1.96 and 1.88 times higher,respectively,compared to non-CFP of TBG.Furthermore,the addition of plastic could increase H/Ceff ratio of the mixture,consequently,increase the yield of aromatic compounds.Among the various torrefied-bagasse/plastic mixtures,the CFP of TBG/EVA(7:3 ratio)mixture generated the highest the total aromatic yield of 7.7 times more than the CFP of TBG alone.The dual catalyst layout could enhance the yield of aromatics hydrocarbons.The dual-catalytic co-pyrolysis of TBG_(200℃)/plastic(1:1)ratio over USY(ultra-stable Y zeolite)/ZSM-5,improved the total aromatics yield by 4.33 times more than the catalytic pyrolysis of TBG_(200℃)alone over ZSM-5 catalyst.The above results showed that the yield and selectivities of light aromatic hydrocarbons can be improved via catalytic co-pyrolysis and dual catalytic co-pyrolysis of torrefied-biomass with plastics.展开更多
Unlike plastic,biomass can also be converted and produce high quality of biofuel.Co-pyrolysis of coconut husk(CH)and laminated plastic packaging(LPP)were done in this study.Synergy between these two feedstock was calc...Unlike plastic,biomass can also be converted and produce high quality of biofuel.Co-pyrolysis of coconut husk(CH)and laminated plastic packaging(LPP)were done in this study.Synergy between these two feedstock was calculated by using thermogravimetric(TGA)and derivative thermogravimetry(DTG)analysis.Different activation energies of the reactions in the co-pyrolysis of CH and LPP were evaluated using the Coats-Redfern method.Results showed an activation energy ranging from 8 to 37 kJ/mol in the different percentage composition of the co-pyrolysis.Also,thermal degradation happens in two-stages in the copyrolysis of CH and LPP,in which CH degrades at the temperature range of 210℃ to 390℃ while LPP degrades in temperatures 400℃-600℃.Co-pyrolysis of CH and LPP can be an alternative for biofuel production and can also reduce the waste problems in the community.展开更多
Hazardous waste stream needs to be managed so as not to exceed stock-and rate-limited properties of its recipient ecosystems.The co-pyrolysis of Chinese medicine residue(CMR)and textile dyeing sludge(TDS)and its bio-o...Hazardous waste stream needs to be managed so as not to exceed stock-and rate-limited properties of its recipient ecosystems.The co-pyrolysis of Chinese medicine residue(CMR)and textile dyeing sludge(TDS)and its bio-oil,biochar,and ash quality and quantity were characterized as a function of the immersion of K_(2)CO_(3),atmosphere type,blend ratio,and temperature.Compared to the mono-pyrolysis of TDS,its co-pyrolysis performance with CMR(the comprehensive performance index(CPI))significantly improved by 33.9%in the N_(2)atmosphere and 33.2%in the CO_(2)atmosphere.The impregnation catalyzed the co-pyrolysis at 370℃,reduced its activation energy by 77.3 kJ/mol in the N_(2)atmosphere and 134.6 kJ/mol in the CO_(2)atmosphere,and enriched the degree of coke gasification by 44.25%in the CO_(2)atmosphere.The impregnation increased the decomposition rate of the co-pyrolysis by weakening the bond energy of fatty side chains and bridge bonds,its catalytic and secondary products,and its bio-oil yield by 66.19%.Its bio-oils mainly contained olefins,aromatic structural substances,and alcohols.The immersion of K_(2)CO_(3)improved the aromaticity of the copyrolytic biochars and reduced the contact between K and Si which made it convenient for Mg to react with SiO_(2)to form magnesium-silicate.The co-pyrolytic biochar surfaces mainly included-OH,-CH_(2),C=C,and Si-O-Si.The main phases in the co-pyrolytic ash included Ca_(5)(PO_(4))_(3)(OH),Al_(2)O_(3),and magnesium-silicate.展开更多
This study utilizedathermogravimetric analyzer to assess the thermal decomposition behaviors and kinetics properties of vacuum residue(VR)and low-density polyethylene(LDPE)polymers.The kinetic parameters were calculat...This study utilizedathermogravimetric analyzer to assess the thermal decomposition behaviors and kinetics properties of vacuum residue(VR)and low-density polyethylene(LDPE)polymers.The kinetic parameters were calculated using the Friedman technique.To demonstrate the interactive effects between LDPE and VR during the co-pyrolysis process,the disparity in mass loss and mass loss rate between the experimental and calculated values was computed.The co-pyrolysis curves obtained through estimation and experimentation exhibited significantdeviations,whichwerei influencedby temperature and mixing ratio.A negative synergistic interaction was observed between LDPE and VR,although this inhibitory effect could be mitigated or eliminated by reducing the LDPE ratio in the mixture and increasing the co-pyrolysistemperature.Theco-pyrolysisprocess resulted in a reduction in carbon residue,which could be attributed to the interaction between LDPE and the heavy fractions,particularly resin and asphaltene,present in VR.These findings align with the pyrolysis behaviors exhibited by the four VR fractions.Furthermore,it was observed that the co-pyrolysis process exhibited lower activation energy as the VR ratio increased,indicating a continuous enhancement in the reactivity of the mixed samples during co-pyrolysis.展开更多
The extreme alkalinity of bauxite residue(BR)leads to difficulty with its reuse.Alkaline leachate and dust generation during the stacking process can pollute surrounding soil,air and water.In this work,co-pyrolysis of...The extreme alkalinity of bauxite residue(BR)leads to difficulty with its reuse.Alkaline leachate and dust generation during the stacking process can pollute surrounding soil,air and water.In this work,co-pyrolysis of bauxite residue and sawdust was applied to rapidly produce a soil-like matrix that met the conditions for plant growth as demonstrated by ryegrass pot experiments.The present study aimed to characterize the detailed changes in physicochemical,mineral weathering,and microbial communities of the pyrolyzed BR with different ratios of saw dust after plant colonization for 2 months.With increasing sawdust addition during co-pyrolysis,the pH of BR decreased from 11.21 to 8.16,the fraction of macro-aggregates 0.25-2 mm in the water-stable agglomerates increased by 29.3%,and the organic carbon concentration increased from 12.5 to 320 mg/kg,whilst facilitating the degree of humification,which were all beneficial to its revegetation performance.The backscattered electron-scanning electron microscope-energy-dispersive X-ray spectrometry(BSE-SEM-EDS)results confirmed the occurrence of sodalite and calcite weathering on aggregate surfaces,and X-ray photoelectron spectroscopy(XPS)results of surface Al and Si compounds identified that some weathering products were clay minerals such as kaolinite.Furthermore,bacterial community composition and structure shifted towards typical soil taxonomic groups.These results demonstrate soil development of treated BR at an early stage.The technique is a combination of alkalinity regulation and agglomerate construction,which accelerates soil formation of BR,thus proving highly promising for potential application as an artificial soil substitute.展开更多
Catalytic co-pyrolysis of biomass and plastic is an effective method to improve bio-oil produced by biomass pyrolysis.To further exploit the synergistic mechanism between biomass and plastic,co-pyrolysis of polypropyl...Catalytic co-pyrolysis of biomass and plastic is an effective method to improve bio-oil produced by biomass pyrolysis.To further exploit the synergistic mechanism between biomass and plastic,co-pyrolysis of polypropylene(PP)and deuterated glucose(G)(1:1 wt%)over mesoporous catalysts MCM-41(M)and Al-MCM-41(Al)was studied using a thermal gravimetric analyser(TGA)and pyrolysis-gas chromatography-mass spectrometry.The findings show that M and Al overlap the decomposition of PP and G,making synergy possible.With catalysts M and Al,the yield of olefins increases sharply to 36.75% and 13.66% more than the calculated value.Additionally,hydrogen transfers from G to 4C-13C olefins and aromatic products are influenced by the catalysts.Without a catalyst,there is no deuterium in all the co-pyrolytic products.However,catalysts M and Al can help transfer one to four deuterium atoms from G to the products.M and Al provide the pool for the intermediates of PP and G to form synergetic products.Additionally,Al helps break the carbon chain and transfer more deuterium into the products by reducing carbon atoms.展开更多
Sewage sludge produced by municipal sewage treatment plants can potentially be used as a biomass energy source because of its high organic content.Presently,the conversion and utilization of rapidly growing amounts of...Sewage sludge produced by municipal sewage treatment plants can potentially be used as a biomass energy source because of its high organic content.Presently,the conversion and utilization of rapidly growing amounts of sewage sludge represent an urgent challenge in China.Thermal conversion of sewage sludge to biochar through pyrolysis is a promising solution to this problem.However,biochar produced by pyrolysis of sewage sludge alone has a poor pore structure as a result of its low C content and high ash content.Furthermore,it is enriched in heavy metals that may pose high ecological risks.In this study,we addressed these issues through co-pyrolysis of sewage sludge and cotton stalks(1:1,wt./wt.)at different pyrolysis temperatures ranging from 350℃ to 750℃.The properties and surface characteristics of the biochars were investigated.Meanwhile,the transformation behavior of heavy metals during the co-pyrolysis process was studied,and the potential ecological risks of heavy metals in biochars were assessed.The results showed that elevated pyrolysis temperatures reduced the biochar yield and C content of the biochars,whereas such temperatures increased the pH value and ash content of the biochars.The biochars prepared at different pyrolysis temperatures were all mesoporous materials.The elevated temperatures promoted the transformation of heavy metals from mobile fractions to stable ones,thus resulting in a significant decrease in the ecological risks.In summary,co-pyrolysis of sewage sludge with cotton stalks proved to be a feasible method for the conversion and utilization of sewage sludge.展开更多
The present study addresses the influence of blending of waste plastics(i.e.,polystyrene,PS and waste nitrile gloves,WNG)with mahua seeds(MH)for co-pyrolytic liquid yield and its fuel properties.Various blends of wast...The present study addresses the influence of blending of waste plastics(i.e.,polystyrene,PS and waste nitrile gloves,WNG)with mahua seeds(MH)for co-pyrolytic liquid yield and its fuel properties.Various blends of waste plastics were mixed with biomass(10,20 and 30 wt%)and pyrolyzed in a semi-batch reactor at an optimized environment(550℃ temperature,80℃ min^(-1) heating rate,and 100 mL min^(-1) N_(2) flow rate).Physicochemical results displayed its ability to yield renewable fuel and valuable chemicals.Co-pyrolysis outcomes showed that blending of waste plastics at 20 wt%,yielded maximum liquid(44.18±1.2 wt%and 45.89±1.4 wt%for MH+WNG and MH+PS respectively)which was higher than thermal pyrolysis of individual MH(39.26±1.2 wt%).Further,characterization results revealed a substantial reduction in viscosity,oxygen content,moisture,and a positive increment in gross heating value,carbon content and acidity.FTIR examination exposed the attendance of mainly aromatics,acids,phenols,water,esters and ethers.Further,NMR analysis of pyrolytic oil confirmed an increase in aromaticity by blending of waste plastics(20 wt%)while there was a reduction in paraffinic compounds.GC-MS investigation revealed substantial improvement in hydrocarbons and minimization in the oxygen-rich products by blending of waste plastics at 20 wt%.展开更多
Pyrolysis is a promising technique used for treating of sewage sludge.However,the application of pyrolysis products is limited due to the presence of heavy metals.In this study,sewage sludge mixed with kaolin/zeolite ...Pyrolysis is a promising technique used for treating of sewage sludge.However,the application of pyrolysis products is limited due to the presence of heavy metals.In this study,sewage sludge mixed with kaolin/zeolite was pyrolyzed in a rotary kiln,aiming to improve the immobilization of heavy metals in pyrolytic carbon.The total concentrations,speciation distributions,leaching toxicities,and potential ecological risk indices of heavy metals in pyrolysis biochar were explored to examine the effects of kaolin/zeolite and pyrolytic temperature on immobilizing heavy metals.Further,mineral composition and surface morphology of biochar were characterized by X-ray diffraction and scanning electron microscopy to reveal the potential mechanism of immobilizing heavy metals.Increasing pyrolysis temperature facilitated the stabilization of heavy metals in pyrolysis biochar.The proportions of stable heavy metals in biochar obtained at 650℃ were 54.50%(Cu),29.73%(Zn),79.29%(Cd),68.17%(Pb)and 86.70%(Cr).Compared to sewage sludge,the potential contamination risk index of pyrolysis biochar obtained at 650℃ was reduced to 17.01,indicating a low ecological risk.The addition of 7%kaolin/zeolite further reduced the risk index of co-pyrolysis biochar prepared at 650℃ to 10.86/15.28.The characterization of biochar revealed that increase in the pyrolysis temperature and incorporation of additives are conducive to the formation of stable heavy metal-inorganics.This study demonstrates that the formation of stable mineral compounds containing heavy metals is the key to stabilizing heavy metals in pyrolysis biochar.展开更多
The addition of effective additives can effectively improve the pyrolysis performance of oil sludge(OS)and have a great potential to reduce pyrolysis costs.In the present study,co-pyrolysis performance of OS with diff...The addition of effective additives can effectively improve the pyrolysis performance of oil sludge(OS)and have a great potential to reduce pyrolysis costs.In the present study,co-pyrolysis performance of OS with different proportions of additives at a heating rate of 10°C/min was conducted in a thermal analyzer.Walnut shell,Fe_(2)O_(3),K_(2)CO_(3),PVC and the pyrolysis char produced from OS at the final pyrolysis temperature of 700℃were selected as the additives.TG results showed that the OS pyrolysis with and without additives can be divided into five reaction stages,which include volatilization of free water,the escape of light components,the cleavage of heavy components,carbon decomposition and inorganic minerals decomposition.The addition of additives decreased the maximum weight loss rate when the blending ratio was 5 wt%during OS pyrolysis.Kinetic analysis revealed that the overall activation energy of pyrolysis reaction was lower during pyrolysis of OS with the addition of walnut shells and pyrolysis char.The activation energy of three main reaction stages all decreased during co-pyrolysis of OS with K_(2)CO_(3)and PVC.展开更多
Biomass and pig manure have distinct compositions and the co-pyrolysis of them has gained much attention.However,the influence of volatiles interaction on the properties of the char was still unclear.In this study,lig...Biomass and pig manure have distinct compositions and the co-pyrolysis of them has gained much attention.However,the influence of volatiles interaction on the properties of the char was still unclear.In this study,lignin was selected as the model component of biomass with pig manure for co-pyrolysis at 600°C.The results indicate that volatiles from co-pyrolysis promoted re-condensation reaction,resulting in the higher char yield(48.0%in co-pyrolysis versus 31.0%in pyrolysis of single manure)and the formation of more aromatics in bio-oil.The co-pyrolysis also facilitated the dehydrogenation and dehydration reactions,which accounted for the elimination of oxygen and nitrogen contents and thus a higher carbon content(64.7%in the co-pyrolysis versus the averaged value of 46.4%from the pyrolysis of single feedstock),higher crystallinity and thermal stability of the char.The in-situ diffuse reflection infrared Fourier transform spectroscopy(DRIFTS)characterization results demonstrated that the functionalities abundances of char with temperature was influenced by volatiles interaction via accelerating the carbonization reaction.In addition,the high heating value(HHV)of char was obviously improved by cross-interaction of volatiles during co-pyrolysis(24.4 MJ/Kg in co-pyrolysis versus averaged value of 15.1 MJ/Kg from single pyrolysis),implying that the co-pyrolysis enhanced the energy density of the resulting char.展开更多
Co-pyrolysis of coal and seaweed can not only effectively decrease the carbon footprint but also improve the quality and output of coal pyrolysis products,however,the influence of seaweed on thermal releasing behavior...Co-pyrolysis of coal and seaweed can not only effectively decrease the carbon footprint but also improve the quality and output of coal pyrolysis products,however,the influence of seaweed on thermal releasing behaviors of mercury during co-pyrolysis process are still unclear.In this work,the chlorella and Guizhou bituminous coal were mixed and used to reveal the mercury release behavior during co-pyrolysis by the temperature programmed pyrolysis experiments,thermogravimetric and differential thermogravimetric analysis(TG-DTG)and thermogravimetry-mass spectrometry(TG-MS)methods,offering a sufficient explanation on the control technology of mercury pollutants in co-pyrolysis.The results exhibited that a large amount of reducing gases such as CO,H_(2) and H_(2)O were generated in chlorella at the temperature range of 100-500℃,which was favorable for the transformation from oxidized mercury to elemental mercury,thus remarkably increased the release of elemental mercury in the raw coal sample.The mixed chlorella also significantly lowered the decomposition temperature range(from 400-600 to 300-400℃)of pyrite-bound mercury and decreased the decomposition temperatures of the pyrite-bound mercury species.Additionally,in the copyrolysis about 91.82%of mercury was released into the gas phase below 400℃ and was 13.77% higher than that of in individual pyrolysis of coal.展开更多
It has become the top priority for coking industry to rationally use and enlarge coking coal resources because of the shortage of the resources.This review focuses on the potential utilization of oil shale(OS)as a fee...It has become the top priority for coking industry to rationally use and enlarge coking coal resources because of the shortage of the resources.This review focuses on the potential utilization of oil shale(OS)as a feedstock for coal-blending coking,in which the initial and basic step is pyrolysis.However,OS has a high ash content.If such OS is directly used for coal-blending coking,the coke product will not meet market demand.Therefore,this review firstly summarizes separation and beneficiation techniques for organic matter in OS,and provides an overview on coal and OS pyrolysis through several viewpoints(e.g.,pyrolysis process,phenomena,and products).Then the exploratory studies on co-pyrolysis of coal with OS,including co-pyrolysis phenom-ena and process mechanism,are discussed.Finally,co-pyrolysis of different ranks of coals with OS in terms of coal-blending coking,where further research deserves to be performed,is suggested.展开更多
A mixture of Pingdingshan lean coal and acid-treated Huadian oil shale was co-pyrolyzed in a drop-tube fixed-bed reactor in the temperature range of 300℃–450℃.To reveal the formation mechanism of the solid co-pyrol...A mixture of Pingdingshan lean coal and acid-treated Huadian oil shale was co-pyrolyzed in a drop-tube fixed-bed reactor in the temperature range of 300℃–450℃.To reveal the formation mechanism of the solid co-pyrolysis product,changes in some physicochemical properties were investigated,using analysis by X-ray diffraction,X-ray photoelectron spectroscopy,scanning electron microscopy,pore analysis,thermogravimetry,and electron spin resonance.X-ray diffraction showed that the lattice plane spacing for the co-pyrolyzed mixture decreased from 0.357 nm to 0.346 nm and the average stacking height increased from 1.509 nm to 1.980 nm in the temperature range of 300°C–450°C,suggesting that pyrolysis treatment increased its degree of metamorphism.The amount of oxygen-containing functional groups and pore volume decreased with increasing temperature.Thermogravimetry and electron spin resonance results showed that synergistic effects occurred during the co-pyrolysis process.A formation mechanism for the solid product was proposed.Hydrogen-rich radicals generated from the pyrolysis of the oil shale were trapped by hydrogen-poor macromolecular radicals of the intermediate metaplast produced from coal pyrolysis,thereby increasing the yield of solid product.展开更多
This research effort focuses on the co-pyrolysis of cassava peels waste and some synthetic polymers towards energy conversion and reducing the volume of these waste fractions dumped on dumpsites.The co-pyrolysis behav...This research effort focuses on the co-pyrolysis of cassava peels waste and some synthetic polymers towards energy conversion and reducing the volume of these waste fractions dumped on dumpsites.The co-pyrolysis behavior and pyrolysis kinetics of various synthetic polymer wastes/cassava peel blends were investigated by blending cassava peel waste with low-density polyethylene(LDPE),polyethylene terephthalate(PET),and polystyrene(PS)at different weight ratios.The physical characteristics of each sample were investigated and the co-pyrolysis experiments were conducted at a heating rate of 10℃/min from room temperature to 800℃in N_(2)atmosphere in a thermogravimetric analyzer.Subsequent to thermal decomposition,kinetic analysis was done using the thermogravimetric data.Results from physicochemical characterization showed that cassava peel has a relatively lower calorific value of 15.92 MJ/kg compared with polystyrene(41.1 MJ/kg),low-density polyethylene(42.6 MJ/kg),and polyethylene terephthalate(21.1 MJ/kg).The thermal decomposition behavior of cassava peel was seen to be significantly different from those of the synthetic polymers.The decomposition of the biomass material such as cassava peel generally occurs in two stages while the decomposition of LDPE,PS,and PET occurred in a single stage.The activation energy required for thermal degradation in cassava peel was also found to be lower to that of the plastic material.The co-pyrolysis of cassava peel and different synthetic polymers affected the thermal and kinetic behaviors of the blends,reduce the activation energy and residue after pyrolysis.展开更多
基金Funded by National College Student Innovation and Entrepreneurship Training Program Project(No.CY202036)。
文摘This study explored the synergistic interaction of sewage sludge(SS)and automotive paint sludge(PS)during co-pyrolysis for the optimized treatment of sewage sludge in cement kiln systems,utilizing thermogravimetric analysis(TGA)and thermogravimetric-mass spectrometry(TGA-MS).The result reveals the coexisting synergistic and antagonistic effects in the co-pyrolysis of SS/PS.The synergistic effect arises from hydrogen free radicals in SS and catalytic components in PS,while the main source of the antagonistic effect is that,during the mechanical mixing process,the SS/PS is converted from the particulate form into a dough-like rubbery which contributes to the film-forming effect,hindering the volatilization of volatile components.SS/PS co-pyrolysis reduces the yielding of tar production while increasing coke and gas.This study will provide some in-depth insights into the co-pyrolysis of SS/PS,and offer theoretical support for the subsequent research on the collaborative disposal processes in cement kilns.
基金supported by the National Natural Science Foundation of China(21875096)the Natural Science Foundation of Jiangxi Province,China(20181BCD40004,No.20224BAB213015)。
文摘The co-pyrolysis of natural gas and coal is a promising way for the production of acetylene due to its high efficiency for energy and hydrogen utilization.This work investigated the thermodynamics for the copyrolysis reaction of natural gas and coal using density functional theory.The favorable reaction conditions are presented in the form of phase diagrams.The calculation results show that the extra amount of methane may benefit the production of acetylene in the co-pyrolysis reaction,and the C/H ratio of 1:1,temperature around 3000 K and pressure at 0.1 MPa are most favorable.The results would provide basic data for related industrial process for the production of acetylene.
基金the support of the French Ministry of Higher Education,Research and Innovation(Ministère de l’Enseignement supérieur,de la Recherche et de l’Innovation)。
文摘The co-pyrolysis of coal and biomass has proven to be a promising route to produce liquid and gaseous fuels as well as specific value-added chemicals while contributing to mitigating CO_(2) emissions.The interactions between the co-processed feedstocks,however,need to be elucidated to support the development of such a thermochemical conversion process.In this context,the present work covers the kinetic analysis of the co-pyrolysis of a bituminous coal with poplar wood.In this research,biomass was blended with coal at two different mass ratios(10%(mass)and 20%(mass)).Thermogravimetric analyses were carried out with pure and blended samples at four heating rates(5,10,15 and 30℃·min^(-1)).A direct comparison of experimental and theoretical results(based on a simple additivity rule)failed to yield a clear-cut conclusion regarding the existence of synergistic effects.Kinetic analyses have therefore been achieved using two model-free methods(the Ozawa-Flynn-Wall and Kissinger-Akahira-Sunose models)to estimate the rate constant parameters related to the pyrolysis process.A significant decrease of the activation energy has thus been observed when adding wood to coal(activation energies associated with the blend containing 20%(mass)of biomass being even lower than those estimated for pure wood at low conversion degrees).This trend was attributed to the possible presence of synergies whose related mechanisms are discussed.The rate constant parameters derived by means of the two tested models were finally used to simulate the evolution of the conversion degree of each sample as a function of the temperature,thus leading to a satisfying agreement between measured and simulated data.
基金Supported by Hydrocarbon High-efficiency Utilization Technology Research Center of Yanchang Petroleum(Group)Co.Ltd.,China(ycsy2013ky-A-30)
文摘An experimental study on co-pyrolysis of bituminous coal and biomass was performed in a pressured fluidized bed reactor.The blend ratio of biomass in the mixture was varied between 0 and 100 wt%,and the temperature was over a range of 550–650℃ under 1.0 MPa pressure with different atmospheres.On the basis of the individual pyrolysis behavior of bituminous coal and biomass,the influences of the biomass blending ratio,temperature,pressure and atmosphere on the product distribution were investigated.The results indicated that there existed a synergetic effect in the co-pyrolysis of bituminous coal and biomass in this pressured fluidized bed reactor,especially when the condition of bituminous coal and biomass blend ratio of 70:30(w/w),600℃,and 0.3 MPa was applied.The addition of biomass influenced the tar and char yields and gas and tar composition during co-pyrolysis.The tar yields were higher than the calculated values from individual pyrolysis of each fuel,and consequently the char yields were lower.The experimental results showed that the composition of the gaseous products was not in accordance with those of their individual fuel.The improvement of composition in tar also indicated synergistic effect in the co-pyrolysis.
基金Supported by National High-tech Research and Development Program of China(2011AA05A2021)the National Natural Science Foundation of China(21536009)Science and Technology Plan Projects of Shaanxi Province(2017ZDCXL-GY-10-03).
文摘To reasonably utilize the coal direct liquefaction residue(DLR), contrasting research on the co-pyrolysis between different low-rank coals and DLR was investigated using a TGA coupled with an FT-IR spectrophotometer and a fixed-bed reactor. GC–MS, FTIR, and XRD were used to explore the reaction mechanisms of the various co-pyrolysis processes. Based on the TGA results, it was confirmed that the tetrahydrofuran insoluble fraction of DLR helped to catalyze the conversion reaction of lignite. Also, the addition of DLR improved the yield of tar in the fixed-bed, with altering the composition of the tar. Moreover, a kinetic analysis during the co-pyrolysis was conducted using a distributed activation energy model. The co-pyrolysis reactions showed an approximate double-Gaussian distribution.
基金supported by the National Natural Science Foun-dation for Excellent Young Scholar of China(51822604)the Nature Science Foundation of Jiangsu Province for Distinguished Young Scholar(BK20180014).
文摘To increase the low yield and selectivity of aromatic hydrocarbons during the biomass pyrolysis process,we torrefied the biomass and then co-pyrolyzing with plastics such as high-density polyethylene(HDPE),polystyrene(PS),ethylene-vinyl acetate(EVA)and polypropylene(PP)and also single and dual catalyst layouts were investigated by Py-GC/MS.The results showed that non-catalytic fast pyrolysis(CFP)of raw bagasse(RBG)generated no aromatics.After torrefaction non-CFP of torrefied bagasse(TBG)generated low aromatic yield.Indicating that torrefaction would enhance the proportion of aromatics during the pyrolysis process.The CFP of TBG_(200℃)and TBG_(240℃)over ZSM-5 produced the total aromatic yield of 1.96 and 1.88 times higher,respectively,compared to non-CFP of TBG.Furthermore,the addition of plastic could increase H/Ceff ratio of the mixture,consequently,increase the yield of aromatic compounds.Among the various torrefied-bagasse/plastic mixtures,the CFP of TBG/EVA(7:3 ratio)mixture generated the highest the total aromatic yield of 7.7 times more than the CFP of TBG alone.The dual catalyst layout could enhance the yield of aromatics hydrocarbons.The dual-catalytic co-pyrolysis of TBG_(200℃)/plastic(1:1)ratio over USY(ultra-stable Y zeolite)/ZSM-5,improved the total aromatics yield by 4.33 times more than the catalytic pyrolysis of TBG_(200℃)alone over ZSM-5 catalyst.The above results showed that the yield and selectivities of light aromatic hydrocarbons can be improved via catalytic co-pyrolysis and dual catalytic co-pyrolysis of torrefied-biomass with plastics.
基金The author would like to acknowledge the big help of the Department of Science and Technology in funding this research.
文摘Unlike plastic,biomass can also be converted and produce high quality of biofuel.Co-pyrolysis of coconut husk(CH)and laminated plastic packaging(LPP)were done in this study.Synergy between these two feedstock was calculated by using thermogravimetric(TGA)and derivative thermogravimetry(DTG)analysis.Different activation energies of the reactions in the co-pyrolysis of CH and LPP were evaluated using the Coats-Redfern method.Results showed an activation energy ranging from 8 to 37 kJ/mol in the different percentage composition of the co-pyrolysis.Also,thermal degradation happens in two-stages in the copyrolysis of CH and LPP,in which CH degrades at the temperature range of 210℃ to 390℃ while LPP degrades in temperatures 400℃-600℃.Co-pyrolysis of CH and LPP can be an alternative for biofuel production and can also reduce the waste problems in the community.
基金National Natural Science Foundation of China (Nos.51978175,42177196,and 22006015)the Scientific and Technological Planning Project of Guangzhou,China (No.202103000004)+2 种基金the Guangdong Province Science and Technology Planning Project,China (No.2022A0505050076)the Dongguan Science and Technology of Social Development Program (No.20211800904662)the Dongguan Sci-tech Commissioner Program (No.20221800500282)。
文摘Hazardous waste stream needs to be managed so as not to exceed stock-and rate-limited properties of its recipient ecosystems.The co-pyrolysis of Chinese medicine residue(CMR)and textile dyeing sludge(TDS)and its bio-oil,biochar,and ash quality and quantity were characterized as a function of the immersion of K_(2)CO_(3),atmosphere type,blend ratio,and temperature.Compared to the mono-pyrolysis of TDS,its co-pyrolysis performance with CMR(the comprehensive performance index(CPI))significantly improved by 33.9%in the N_(2)atmosphere and 33.2%in the CO_(2)atmosphere.The impregnation catalyzed the co-pyrolysis at 370℃,reduced its activation energy by 77.3 kJ/mol in the N_(2)atmosphere and 134.6 kJ/mol in the CO_(2)atmosphere,and enriched the degree of coke gasification by 44.25%in the CO_(2)atmosphere.The impregnation increased the decomposition rate of the co-pyrolysis by weakening the bond energy of fatty side chains and bridge bonds,its catalytic and secondary products,and its bio-oil yield by 66.19%.Its bio-oils mainly contained olefins,aromatic structural substances,and alcohols.The immersion of K_(2)CO_(3)improved the aromaticity of the copyrolytic biochars and reduced the contact between K and Si which made it convenient for Mg to react with SiO_(2)to form magnesium-silicate.The co-pyrolytic biochar surfaces mainly included-OH,-CH_(2),C=C,and Si-O-Si.The main phases in the co-pyrolytic ash included Ca_(5)(PO_(4))_(3)(OH),Al_(2)O_(3),and magnesium-silicate.
基金The authors acknowledge the support from the National Key Research and Development Program of China(Grant No.2021YFB3801300)the National Natural Science Foundation of China(Grant No.U22B20149,22021004).
文摘This study utilizedathermogravimetric analyzer to assess the thermal decomposition behaviors and kinetics properties of vacuum residue(VR)and low-density polyethylene(LDPE)polymers.The kinetic parameters were calculated using the Friedman technique.To demonstrate the interactive effects between LDPE and VR during the co-pyrolysis process,the disparity in mass loss and mass loss rate between the experimental and calculated values was computed.The co-pyrolysis curves obtained through estimation and experimentation exhibited significantdeviations,whichwerei influencedby temperature and mixing ratio.A negative synergistic interaction was observed between LDPE and VR,although this inhibitory effect could be mitigated or eliminated by reducing the LDPE ratio in the mixture and increasing the co-pyrolysistemperature.Theco-pyrolysisprocess resulted in a reduction in carbon residue,which could be attributed to the interaction between LDPE and the heavy fractions,particularly resin and asphaltene,present in VR.These findings align with the pyrolysis behaviors exhibited by the four VR fractions.Furthermore,it was observed that the co-pyrolysis process exhibited lower activation energy as the VR ratio increased,indicating a continuous enhancement in the reactivity of the mixed samples during co-pyrolysis.
基金supported by the National Natural Science Foundation of China(Nos.42030711,42177391)the Hunan Provincial Innovation Foundation for Postgraduate(No.CX20200177).
文摘The extreme alkalinity of bauxite residue(BR)leads to difficulty with its reuse.Alkaline leachate and dust generation during the stacking process can pollute surrounding soil,air and water.In this work,co-pyrolysis of bauxite residue and sawdust was applied to rapidly produce a soil-like matrix that met the conditions for plant growth as demonstrated by ryegrass pot experiments.The present study aimed to characterize the detailed changes in physicochemical,mineral weathering,and microbial communities of the pyrolyzed BR with different ratios of saw dust after plant colonization for 2 months.With increasing sawdust addition during co-pyrolysis,the pH of BR decreased from 11.21 to 8.16,the fraction of macro-aggregates 0.25-2 mm in the water-stable agglomerates increased by 29.3%,and the organic carbon concentration increased from 12.5 to 320 mg/kg,whilst facilitating the degree of humification,which were all beneficial to its revegetation performance.The backscattered electron-scanning electron microscope-energy-dispersive X-ray spectrometry(BSE-SEM-EDS)results confirmed the occurrence of sodalite and calcite weathering on aggregate surfaces,and X-ray photoelectron spectroscopy(XPS)results of surface Al and Si compounds identified that some weathering products were clay minerals such as kaolinite.Furthermore,bacterial community composition and structure shifted towards typical soil taxonomic groups.These results demonstrate soil development of treated BR at an early stage.The technique is a combination of alkalinity regulation and agglomerate construction,which accelerates soil formation of BR,thus proving highly promising for potential application as an artificial soil substitute.
基金the funding support by the National Natural Science Foundation of China(No.51576111)Fundamental Research Funds for the Central Universities(2019MS029).
文摘Catalytic co-pyrolysis of biomass and plastic is an effective method to improve bio-oil produced by biomass pyrolysis.To further exploit the synergistic mechanism between biomass and plastic,co-pyrolysis of polypropylene(PP)and deuterated glucose(G)(1:1 wt%)over mesoporous catalysts MCM-41(M)and Al-MCM-41(Al)was studied using a thermal gravimetric analyser(TGA)and pyrolysis-gas chromatography-mass spectrometry.The findings show that M and Al overlap the decomposition of PP and G,making synergy possible.With catalysts M and Al,the yield of olefins increases sharply to 36.75% and 13.66% more than the calculated value.Additionally,hydrogen transfers from G to 4C-13C olefins and aromatic products are influenced by the catalysts.Without a catalyst,there is no deuterium in all the co-pyrolytic products.However,catalysts M and Al can help transfer one to four deuterium atoms from G to the products.M and Al provide the pool for the intermediates of PP and G to form synergetic products.Additionally,Al helps break the carbon chain and transfer more deuterium into the products by reducing carbon atoms.
基金supported by the National Key Research&Development Program of China(Grant NO.2017YFC0504400-1)the National Natural Science Foundation of China(Grants NO.51074170,51704016)
文摘Sewage sludge produced by municipal sewage treatment plants can potentially be used as a biomass energy source because of its high organic content.Presently,the conversion and utilization of rapidly growing amounts of sewage sludge represent an urgent challenge in China.Thermal conversion of sewage sludge to biochar through pyrolysis is a promising solution to this problem.However,biochar produced by pyrolysis of sewage sludge alone has a poor pore structure as a result of its low C content and high ash content.Furthermore,it is enriched in heavy metals that may pose high ecological risks.In this study,we addressed these issues through co-pyrolysis of sewage sludge and cotton stalks(1:1,wt./wt.)at different pyrolysis temperatures ranging from 350℃ to 750℃.The properties and surface characteristics of the biochars were investigated.Meanwhile,the transformation behavior of heavy metals during the co-pyrolysis process was studied,and the potential ecological risks of heavy metals in biochars were assessed.The results showed that elevated pyrolysis temperatures reduced the biochar yield and C content of the biochars,whereas such temperatures increased the pH value and ash content of the biochars.The biochars prepared at different pyrolysis temperatures were all mesoporous materials.The elevated temperatures promoted the transformation of heavy metals from mobile fractions to stable ones,thus resulting in a significant decrease in the ecological risks.In summary,co-pyrolysis of sewage sludge with cotton stalks proved to be a feasible method for the conversion and utilization of sewage sludge.
文摘The present study addresses the influence of blending of waste plastics(i.e.,polystyrene,PS and waste nitrile gloves,WNG)with mahua seeds(MH)for co-pyrolytic liquid yield and its fuel properties.Various blends of waste plastics were mixed with biomass(10,20 and 30 wt%)and pyrolyzed in a semi-batch reactor at an optimized environment(550℃ temperature,80℃ min^(-1) heating rate,and 100 mL min^(-1) N_(2) flow rate).Physicochemical results displayed its ability to yield renewable fuel and valuable chemicals.Co-pyrolysis outcomes showed that blending of waste plastics at 20 wt%,yielded maximum liquid(44.18±1.2 wt%and 45.89±1.4 wt%for MH+WNG and MH+PS respectively)which was higher than thermal pyrolysis of individual MH(39.26±1.2 wt%).Further,characterization results revealed a substantial reduction in viscosity,oxygen content,moisture,and a positive increment in gross heating value,carbon content and acidity.FTIR examination exposed the attendance of mainly aromatics,acids,phenols,water,esters and ethers.Further,NMR analysis of pyrolytic oil confirmed an increase in aromaticity by blending of waste plastics(20 wt%)while there was a reduction in paraffinic compounds.GC-MS investigation revealed substantial improvement in hydrocarbons and minimization in the oxygen-rich products by blending of waste plastics at 20 wt%.
基金funded by National Key Research and Development Program of China(No.2018YFC1901202).
文摘Pyrolysis is a promising technique used for treating of sewage sludge.However,the application of pyrolysis products is limited due to the presence of heavy metals.In this study,sewage sludge mixed with kaolin/zeolite was pyrolyzed in a rotary kiln,aiming to improve the immobilization of heavy metals in pyrolytic carbon.The total concentrations,speciation distributions,leaching toxicities,and potential ecological risk indices of heavy metals in pyrolysis biochar were explored to examine the effects of kaolin/zeolite and pyrolytic temperature on immobilizing heavy metals.Further,mineral composition and surface morphology of biochar were characterized by X-ray diffraction and scanning electron microscopy to reveal the potential mechanism of immobilizing heavy metals.Increasing pyrolysis temperature facilitated the stabilization of heavy metals in pyrolysis biochar.The proportions of stable heavy metals in biochar obtained at 650℃ were 54.50%(Cu),29.73%(Zn),79.29%(Cd),68.17%(Pb)and 86.70%(Cr).Compared to sewage sludge,the potential contamination risk index of pyrolysis biochar obtained at 650℃ was reduced to 17.01,indicating a low ecological risk.The addition of 7%kaolin/zeolite further reduced the risk index of co-pyrolysis biochar prepared at 650℃ to 10.86/15.28.The characterization of biochar revealed that increase in the pyrolysis temperature and incorporation of additives are conducive to the formation of stable heavy metal-inorganics.This study demonstrates that the formation of stable mineral compounds containing heavy metals is the key to stabilizing heavy metals in pyrolysis biochar.
基金supported by Natural Science Foundation of Shandong Province(ZR2020QE199)State Key Laboratory of Pollution Control and Resource Utilization research(No.PCRRF19023)Key Research and Development Program of Liaoning Province(No.2020JH2/10300099)。
文摘The addition of effective additives can effectively improve the pyrolysis performance of oil sludge(OS)and have a great potential to reduce pyrolysis costs.In the present study,co-pyrolysis performance of OS with different proportions of additives at a heating rate of 10°C/min was conducted in a thermal analyzer.Walnut shell,Fe_(2)O_(3),K_(2)CO_(3),PVC and the pyrolysis char produced from OS at the final pyrolysis temperature of 700℃were selected as the additives.TG results showed that the OS pyrolysis with and without additives can be divided into five reaction stages,which include volatilization of free water,the escape of light components,the cleavage of heavy components,carbon decomposition and inorganic minerals decomposition.The addition of additives decreased the maximum weight loss rate when the blending ratio was 5 wt%during OS pyrolysis.Kinetic analysis revealed that the overall activation energy of pyrolysis reaction was lower during pyrolysis of OS with the addition of walnut shells and pyrolysis char.The activation energy of three main reaction stages all decreased during co-pyrolysis of OS with K_(2)CO_(3)and PVC.
基金This work was supported by National Natural Science Foundation of China(No.51876080)the Program for Taishan Scholars of Shandong Province Government,the Agricultural Innovation Program of Shandong Province(SD2019NJ015)the R&D program of Shandong Basan Graphite New Material Plant.
文摘Biomass and pig manure have distinct compositions and the co-pyrolysis of them has gained much attention.However,the influence of volatiles interaction on the properties of the char was still unclear.In this study,lignin was selected as the model component of biomass with pig manure for co-pyrolysis at 600°C.The results indicate that volatiles from co-pyrolysis promoted re-condensation reaction,resulting in the higher char yield(48.0%in co-pyrolysis versus 31.0%in pyrolysis of single manure)and the formation of more aromatics in bio-oil.The co-pyrolysis also facilitated the dehydrogenation and dehydration reactions,which accounted for the elimination of oxygen and nitrogen contents and thus a higher carbon content(64.7%in the co-pyrolysis versus the averaged value of 46.4%from the pyrolysis of single feedstock),higher crystallinity and thermal stability of the char.The in-situ diffuse reflection infrared Fourier transform spectroscopy(DRIFTS)characterization results demonstrated that the functionalities abundances of char with temperature was influenced by volatiles interaction via accelerating the carbonization reaction.In addition,the high heating value(HHV)of char was obviously improved by cross-interaction of volatiles during co-pyrolysis(24.4 MJ/Kg in co-pyrolysis versus averaged value of 15.1 MJ/Kg from single pyrolysis),implying that the co-pyrolysis enhanced the energy density of the resulting char.
基金supported by the Natural Science Foundation of Shandong Province (No. ZR2019MEE023)the Qingchuang Science and Technology Program of Shandong Province University (No. 2019KJD004)the National Natural Science Foundation of China (Nos. 22078168 and 21776164)。
文摘Co-pyrolysis of coal and seaweed can not only effectively decrease the carbon footprint but also improve the quality and output of coal pyrolysis products,however,the influence of seaweed on thermal releasing behaviors of mercury during co-pyrolysis process are still unclear.In this work,the chlorella and Guizhou bituminous coal were mixed and used to reveal the mercury release behavior during co-pyrolysis by the temperature programmed pyrolysis experiments,thermogravimetric and differential thermogravimetric analysis(TG-DTG)and thermogravimetry-mass spectrometry(TG-MS)methods,offering a sufficient explanation on the control technology of mercury pollutants in co-pyrolysis.The results exhibited that a large amount of reducing gases such as CO,H_(2) and H_(2)O were generated in chlorella at the temperature range of 100-500℃,which was favorable for the transformation from oxidized mercury to elemental mercury,thus remarkably increased the release of elemental mercury in the raw coal sample.The mixed chlorella also significantly lowered the decomposition temperature range(from 400-600 to 300-400℃)of pyrite-bound mercury and decreased the decomposition temperatures of the pyrite-bound mercury species.Additionally,in the copyrolysis about 91.82%of mercury was released into the gas phase below 400℃ and was 13.77% higher than that of in individual pyrolysis of coal.
基金supported by the National Natural Science Foundation of China(Grant No.21776002)Natural Science Foundation of Anhui Provincial Education Department(Nos.KJ2016A097,KJ2017A056,and KJ2019A0076)+1 种基金Innovation Project of Overscas People of Anhui Province,Scie nce and Technology Major Projects of Anhui Province(No.17030901086)Natural Science Foundation of Anhui Province(No.1708085QB33).
文摘It has become the top priority for coking industry to rationally use and enlarge coking coal resources because of the shortage of the resources.This review focuses on the potential utilization of oil shale(OS)as a feedstock for coal-blending coking,in which the initial and basic step is pyrolysis.However,OS has a high ash content.If such OS is directly used for coal-blending coking,the coke product will not meet market demand.Therefore,this review firstly summarizes separation and beneficiation techniques for organic matter in OS,and provides an overview on coal and OS pyrolysis through several viewpoints(e.g.,pyrolysis process,phenomena,and products).Then the exploratory studies on co-pyrolysis of coal with OS,including co-pyrolysis phenom-ena and process mechanism,are discussed.Finally,co-pyrolysis of different ranks of coals with OS in terms of coal-blending coking,where further research deserves to be performed,is suggested.
基金This work was supported by the National Natural Science Foundation of China(Grant No.21776002)the Natural Science Foundation of Anhui Provincial Education Department(Grant Nos.KJ2016A097,KJ2017A056,and KJ2019A0076)+1 种基金the Innovation Project of Overseas People of Anhui Province,the Science and Technology Major Projects of Anhui Province(Grant Nos.17030901086)the Natural Science Foundation of Anhui Province(Grant Nos.1708085QB33 and 2008085QB87).
文摘A mixture of Pingdingshan lean coal and acid-treated Huadian oil shale was co-pyrolyzed in a drop-tube fixed-bed reactor in the temperature range of 300℃–450℃.To reveal the formation mechanism of the solid co-pyrolysis product,changes in some physicochemical properties were investigated,using analysis by X-ray diffraction,X-ray photoelectron spectroscopy,scanning electron microscopy,pore analysis,thermogravimetry,and electron spin resonance.X-ray diffraction showed that the lattice plane spacing for the co-pyrolyzed mixture decreased from 0.357 nm to 0.346 nm and the average stacking height increased from 1.509 nm to 1.980 nm in the temperature range of 300°C–450°C,suggesting that pyrolysis treatment increased its degree of metamorphism.The amount of oxygen-containing functional groups and pore volume decreased with increasing temperature.Thermogravimetry and electron spin resonance results showed that synergistic effects occurred during the co-pyrolysis process.A formation mechanism for the solid product was proposed.Hydrogen-rich radicals generated from the pyrolysis of the oil shale were trapped by hydrogen-poor macromolecular radicals of the intermediate metaplast produced from coal pyrolysis,thereby increasing the yield of solid product.
文摘This research effort focuses on the co-pyrolysis of cassava peels waste and some synthetic polymers towards energy conversion and reducing the volume of these waste fractions dumped on dumpsites.The co-pyrolysis behavior and pyrolysis kinetics of various synthetic polymer wastes/cassava peel blends were investigated by blending cassava peel waste with low-density polyethylene(LDPE),polyethylene terephthalate(PET),and polystyrene(PS)at different weight ratios.The physical characteristics of each sample were investigated and the co-pyrolysis experiments were conducted at a heating rate of 10℃/min from room temperature to 800℃in N_(2)atmosphere in a thermogravimetric analyzer.Subsequent to thermal decomposition,kinetic analysis was done using the thermogravimetric data.Results from physicochemical characterization showed that cassava peel has a relatively lower calorific value of 15.92 MJ/kg compared with polystyrene(41.1 MJ/kg),low-density polyethylene(42.6 MJ/kg),and polyethylene terephthalate(21.1 MJ/kg).The thermal decomposition behavior of cassava peel was seen to be significantly different from those of the synthetic polymers.The decomposition of the biomass material such as cassava peel generally occurs in two stages while the decomposition of LDPE,PS,and PET occurred in a single stage.The activation energy required for thermal degradation in cassava peel was also found to be lower to that of the plastic material.The co-pyrolysis of cassava peel and different synthetic polymers affected the thermal and kinetic behaviors of the blends,reduce the activation energy and residue after pyrolysis.