From a chemical reaction engineering point of view,the relationship between primary pyrolysis and secondary reactions of small-size oil shale pyrolysis technologies was analyzed.A novel method was proposed to regulate pyrolysis volatiles to flow in an expected direction and to match their secondary reactions to flow/transfer fields in the reactor.A new technology of solid heat carrier pyrolysis was further developed on moving bed reactor with particularly designed internals to overcome challenges for small-size oil shale pyrolysis,including low oil yield,high contents of dust,and heavy components.In such internal-structured moving bed reactor,pyrolysis volatiles flew laterally across particle bed in order to realize in-bed dust removal via filtering and in-situ oil upgrade through ash-involved selective secondary reactions.A 10 kg·h^-1 laboratory setup built to assess the new solid heat carrier pyrolysis technology adopting internal-structured moving bed showed shale oil product at high yield and high quality from small-size oil shale.The results presented a good application prospective of the proposed pyrolysis reactor and process.

Recently,coal pyrolysis to liquid (CPTL) process and oil shale to liquid (STL) process have developed rapidly for the strategic reserve of energy.This paper reviews major technologies of CPTL and STL process,then compares the two processes from aspects of techno-economic.Result shows that CPTL process consumes 11.4 tonnes low-rank coal per tonne fuel oil while STL process needs 24.5 tonnes oil shale correspondingly;meanwhile,water consumption of CPTL process is 1.4 times than that of STL process.Economic performance shows that the total capital investment of CPTL process is 6510 CNY·t^-1 fuel oil while STL process is 5716 CNY·t^-1 fuel oil;however,the production cost of CPTL process is 3887 CNY·t^-1 fuel oil while STL process costs 4217 CNY·t^-1 fuel oil;also,calculating results indicate that the break-even crude oil price of CPTL process and STL process fluctuate at 59-68 USD·bbl^-1 and 71-76 USD·bbl^-1 separately.Generally speaking,it is necessary to improve and consummate relevant techniques or prolong downstream industrial chain,we can seek a breakthrough from retorting,system integration,comprehensive utilization and poly-generation etc.

Pyrolysis is an efficient approach for coal clean utilization.To improve the tar yield in coal pyrolysis,several processes to integrate catalytic and/or low-temperature plasma activation of methane (including partial oxidation,CO₂ reforming,steam reforming,methane aromatization and cold plasmas) with coal pyrolysis were reviewed.The results showed that all integrated processes can obviously improve the tar yield compared with the pyrolysis under N₂ or H₂,and are adaptable to different coals.These methods provide new approaches for enhancing the tar yield.The mechanism for high tar yield was analyzed by the isotopic trace techniques.The analysis of main components in the tar from the integrated process by GC-MS indicates that some free radicals (like· CH_x,·H) are formed by the catalytic activation of methane on Ni-based catalysts or the excitation by electrons with higher energy in low-temperature plasma.These active species participate in the formation of coal tar by the interaction with the free radicals cracked from coal,leading to the remarkable enhancement.The reactor designing of the integrated process and the catalyst development with good catalytic performances for methane activation are the key to the industrial utilization in the future.

To promote the development of coal-based liquid oil separation technology and maximize the utilization value of each component,the coal-based liquid oil separation methods were analyzed.Coal-based liquid oil separation can be divided into two directions:the separation of a particular component and the separation of group composition.The particular component includes phenols,heterocyclic compounds,and aromatics.The main methods to separate the particular component comprise caustic washing,solvent extraction,precipitation,complexation,liquid chromatography,liquid membrane extraction,supercritical fluid extraction,deep eutectic solvent extraction,and ionic liquid extraction.While the main methods for the separation of group composition are solvent extraction,supercritical extraction,column chromatography and high performance liquid chromatography.Each method has its advantages and disadvantages.These methods are roughly divided into four categories based on the separation mechanism between separation agent and target product:the third substance produced by chemical reaction,changing the solubility,taking advantage of the difference of adsorption capacity,forming the hydrogen bond and conjugation effect.At last,the improved proposals and prospects are suggested.

Flow and mixing characteristics of two parallel jets were studied using PIV measurements at different velocities and distances between centers of two nozzles.The results showed that absolute velocity along symmetric line rose but the point of maximum combined velocity barely changed as velocities at nozzle exits were increased.With distance increase between two nozzles,the parallel jets displayed delay in merging process,moving down of combining point,decrease of momentum transported to the symmetric line,and reduce of maximum velocity at combining point.A linear relationship was observed between the spacing ratio and the combining point.Compared to large spacing ratio,small spacing ratio had more obvious impact on the combining point and thus the slope was larger.The turbulence characteristics indicated that main momentum transfer between the two parallel jets occurred in the merging region.As the spacing between two jets was increased,the merging region moved away from nozzle exits.

Considering the pressing needs of developing micro fluidized bed reaction analyzer (MFBRA) suitable for analyzing chemical vapor deposition reaction,this study conducted a preliminary research on the hydrodynamics of internally circulating micro fluidized bed.It investigated the influences of central jetting tube height,in-bed draft tube diameter and initial particle bed height on the start-up gas velocity of internal particle circulation and the gas bypass into the annulus.The results showed that raising the height of jetting tube increases the start-up gas velocity for particle internal circulation.There is an existed optimal draft tube diameter (20 mm) that minimizes such a start-up gas velocity.The start-up gas velocity becomes lower with the increase of initial particle bed height.The gas bypass into the annulus was evaluated according to the mass-spectrum intensities of the tracer gas.For the tested experimental conditions,the bypass of gas from draft tube to annulus was ignorable in the bottom section but discernable at the top of the annulus.

Computational particle fluid dynamics (CPFD),a discrete element method (DEM),was utilized to simulate the lateral diffusion behavior of large solid particles in a 900 mm×100 mm×1200 mm quasi-three dimensional fluidized-bed.Before the simulating,verification had been performed in accordance with previous experimental studies to ensure the reliability of CPFD.The effects of the tracer particle diameter and the fluidizing air velocity on lateral dispersion coefficient of large solid particles in dense zone were investigated by the method of tracer particle.The results showed that the bubble behavior was the major factor of solid mixing in dense zone,which had been confirmed in many literatures.An increased gas velocity or a reduced tracer particle diameter resulted in an increased lateral dispersion coefficient.

Heat transfer test rig had been built with pure water as heat transfer medium and air as heat transfer gas.Heat transfer experimental investigation on circle tube and staggered three-dimensional externally finned tube had been carried out.The building of test rig and experimental procedure had been introduced in details accompany with the theoretical model being derived for solving heat transfer coefficients.It was found that due to the special structure of staggered three-dimensional externally finned tube,its overall heat transfer coefficient is 3.1 times bigger than that of circular tube.By a linear regressive method,the experimental data were processed.The criterion relations of heat transfer were obtained and compared with circular tube.The results could provide reference for the industrial application.Finally,the deviation of the experimental data is analyzed and the result is believable.

Methyl methoxyacetate (MMAc),an important fine chemical,is an intermediate product producing ethylene glycol from syngas.Literature reports showed that high molar ratio of CO to DMM (>100) and low CO conversions (<0.5%) were obviously beneficial for vapor-phase carbonylation of dimethoxymethane (DMM) to MMAc.Using a slurry phase reactor,this work systematically studied the effects of different solvents,sulfonic acid resin catalysts,reaction temperature,pressure,reaction time and drying temperature on DMM conversion and MMAc selectivity.The solubility of CO in liquid phase was significantly increased by sulfolane solvent,thus obviously promoting the carbonylation reaction and suppressing the hydration as well as disproportionation reactions of DMM.Comparing with H-Y,the carbonylation activity of sulfonic acid resin catalyst was higher.The high rate of DMM disproportionation for H-Y was attributed to the micropores of zeolite,which facilitated a critical initial step in the formation of DME and MF.With the increased reaction temperature,pressure or reaction time,the conversion of DMM increases,whereas the selectivity of MMAc first increased and then decreased.With increasing the drying temperature,the moisture content left in the resin gradually decreased.But higher drying temperature resulted in the collapse of pores and surface sintering.For the liquid phase carbonylation process,many complicated and unreported side reactions were accompanied.The DMM conversion can reach to about 100% with 74.32% MMAc selectivity using sulfolane as solvent and D-009B as the catalyst at 110℃ and 5 MPa for 6 h.It was anticipated that this direct carbonylation of DMM to produce MMAc process was promising for industrial manufacture.

Catalytic hydrodenitrogenation under mild conditions was improved by using modified solid catalyst coupled with[Bmim]BF₄ ionic liquid.Ni₂P/SBA-15 catalyst was modified with different Mo loadings and structures of Mo-Ni₂P/SBA-15 modified catalysts were characterized by N₂ adsorption-desorption,X-ray diffraction,and X-ray photoelectron spectroscopy.These catalysts coupled with[Bmim]BF₄ were evaluated for denitrification of pyrrolidine model compound in batch reactor at mild pressure and temperature.The results showed that Mo addition improved catalytic hydrodenitrogenation activity.At low temperature,the denitrification process was dominated by ionic liquid extraction.As temperature was increased,coupling hydrodenitrogenation was more obvious.5% Mo-25% Ni₂P/SBA-15 catalyst coupled with[Bmim]BF₄ exhibited the best hydrodenitrogenation efficiency up to 80.1% at 150℃ and 3 MPa.Furthermore,the ionic liquid did not show significant decrease in hydrogenation efficiency after four cycles.The presence of ionic liquids achieved good catalytic hydrodenitrogenation under mild conditions,which could be a new process for catalytic hydrogenation under low temperature and pressure conditions.

The fluidized bed (FB) two-stage gasification process has recently been proposed to produce clean fuel.Catalytic tar removal in a mini FB two-stage apparatus was studied by char catalytic reforming technique.It was found that tar removal was strongly related to reaction temperature,gas residence time in tar reformer,and char specific surface area and porous structure.In the range of experimental conditions,increasing reaction temperature and residence time effectively promoted catalytic reforming of tar and generated more useful gas components.Larger specific surface area and more advanced porous structures of char catalysts delivered better effects on catalytic tar removal.Compared to thermal cracking,char catalytic reforming of tar was more effective in tar removal,production of more useful gas components,and better inhabitation of carbon deposition.The study showed that the suitable operational condition for tar removal by char catalyst in FB two-stage gasification process was temperature of 1000℃ and gas residence time above 0.9 s.

Secondary catalytic reactions of primary volatiles from oil shale pyrolysis were characterized by using a two-stage reactor to study the effects of different catalytic materials,reaction atmospheres and residence time on oil/gas yield and quality.The results showed that comparison with FCC catalyst as bed materials in the 2nd stage,the shale ash possessed relatively moderate activity for adjusting the secondary reaction of pyrolysis volatiles in the applied range of residence time.Using steam as the reaction atmosphere could further enhance the liquid yield by 5% and suppress the C₂-C₃ hydrocarbons in the cracked gas.The heavy oil fractions,such as vacuum gas oil (VGO,>350℃),could be converted into light oil fractions by the catalytic effects of shale ash,and correspondingly the boiling range of pyrolysis oil tended to be lighter with higher residence time.Oil components analyzed with GC-MS demonstrated that steam could effectively inhibit the over-cracking of aliphatic hydrocarbons at shorter residence time (<3 s),and thus increase the gasoline and diesel fractions by over 20% compared with the N₂ atmosphere.However,at higher residence time (3-5 s) the VGO fractions were prone to be condensed as coke,and as a result profoundly decreased the pyrolysis oil yield.

To obtain high-quality bio-syngas with low tar content from sorghum straw,two-stage prolysis (prolysis+cracking) was performed in a two-stage fixed bed reactor based on the research on its one-stage prolysis characteristics,and the catalytic effects of oil shale ash on cracking the volatile products from pyrolysis were investigated.The results showed that compared to the one-stage prolysis,the two-stage prolysis strengthened the correlation between water vapor with volatiles (above all pyrolysis gas).High cracking temperatures facilitated cracking and reforming of tar,resulting in generation of more gas products and also enhancements in the bio-syngas (H₂+CO) yield and the H₂/CO volumetric ratio.The oil shale ash significantly promoted gasification of tar.With the oil shale ash added for cracking volatiles at the moderate temperature of 850℃(pyrolysis at 450℃),the gas yield surpassed 40%(mass) with such a low tar yield as 1.0%(mass).Meanwhile,the yield of bio-syngas reached up to 186 ml·g^-1 with its highest content of 64%(vol) in gas products,and the H₂/CO volumetric ratio was above 0.5.The oil shale ash facilitated H₂ generation mainly due to its ferric component capable of catalyzing water-gas shift reaction.

The catalytic effects of N-hydroxyl phthalimide combined with various transition metal salts on the oxidative breakage of C-C bond of lignin by O₂ under mild conditions were studied.1,2-diphenylethane was adopted as the model compound of lignin C-C bond.It was found that Mn (OAc)₂ showed the highest promotion effect on the catalytic activity of NHPI among the soluble cobaltous,manganous and cupric salts.The oxidative breakage of C-C bonds led to the production of benzyl aldehyde and benzoic acid with high selectivity.1,2-Diphenyl ethanone was found to be the primary product.Either increase the reaction temperature,Mn (OAc)₂ amount as well as the reaction time favored the C-C bond cleavage.Total selectivity of benzyl aldehyde and benzoic acid up to 76.5% was achieved in acetic acid under the conditions of 90℃ and 1.0 MPa O₂ for 8 h by using 10% NHPI and 1% Mn (OAc)₂ with respect to the amount of benzyl phenyl ether as the catalyst.

The influence of two typical alkali and alkaline earth metal (AAEM),sodium and magnesium,on the gas releasing kinetics during rice husk high-temperature pyrolysis was investigated in a micro-fluidized bed reactor (MFBRA).Reaction kinetics for generating four main gases (H₂,CO,CH₄ and CO₂) was deduced based on universal integral method.Results indicated that different gas components had different times to start and end the gas releasing process,indicating different evolution routes and mechanics for generating these gas species.The conversion rate of four gases could be promoted at higher temperature or with the presence of AAEM.The gas releasing process was calculated by linear fitting method based on typical gas-solid reaction models and the most probable mechanism functions of four gas components were obtained at different conditions.The kinetic parameters of gaseous products calculated by most probable mechanism functions indicated that the resulting apparent activation energies for four gases decreased in presence of sodium and magnesium.Particularly,the effect of the two metal irons on the formation of CO was more obvious compared with the other gas species.From this study,the influence of two metal ions on biomass pyrolysis characteristics was confirmed on the basis of the variation of the activation energy.

Four nickel based catalysts were prepared by mechanical chemical method,Al₂O₃ as carrier,Ce,Co and Fe as additives.The catalysts were characterized using XRD,H₂-TPR,BET and NH₃-TPD.The catalytic effects on cracking behavior of coal tar model compounds toluene and pyrene were investigated in a fixed-bed reactor under carrier gas flow rate of 50 ml·min^-1 and cracking temperature of 750℃.The experimental results showed that all four catalysts have higher ordered mesoporous structure and active species Ni mainly exists as NiAl₂O₄ spinel in the catalysts.In addition,acidic strength of catalyst with Fe additive was higher than that of Ni/Al₂O₃,while the opposite trend was observed in catalysts with Ce and Co additives.The cracking evaluation results showed that these additives have little effect on the cracking rate of heavy component pyrene,about 67% for all catalysts.However,Ce and Co additives were beneficial to carbon deposition resistance of catalysts,which carbon deposition,compared to none additive catalyst,was reduced by 28.8% and 18.0%,respectively.

The H-MOR zeolite catalysts were prepared by hydrothermal synthesis.An inactivated catalyst which was used in dimthyl ether carbonylaiton was regenerated.The effects of gas,coke-burning temperature,O₂ volume fraction and heating rate on the coke-burning process were investigated.The results of TPO and XRD analysis showed that there was different property coke on the inactivated catalyst.In the optimum conditions for the coke-burning of the inactivated catalyst,temperature 550℃,heating rate of 2℃·min^-1 and O₂ volume fraction of 3%,the catalyst activity was almost completely restored.The fresh and regenerated catalysts were characterized by means of NH₃-TPD and N₂ adsorption-desorption.The results showed that the coke was removed cleanly and channels were protected in the optimum condition.

CO methanation plays an important role in production of synthetic natural gas from coal.Application of Ni-based catalysts was restricted due to poor activity at low temperature,coke forming and Ni particle sintering at high temperature.A series of Nd-decorated Ni-Nd-Al ordered mesoporous methanation catalysts were synthesized by improved solvent evaporation-induced self-assembly method,and their catalytic performances for CO methanation were investigated.N₂ adsorption,X-ray diffraction (XRD),X-ray photoelectron spectroscopy (XPS),field emission scanning electron microscopy (SEM),bright-field transmission electron microscopy (TEM) were used to characterize structure and morphology of both fresh and used catalysts.The results showed that all Ni-Nd-Al catalysts had ordered mesoporous structures,in which Ni particles were anchored but Nd species were dispersed in the ordered mesoporous alumina channels.Addition of appropriate Nd contributed to size reduction and dispersion improvement of Ni particles,and adsorption enhancement of H₂,such that catalytic performance was promoted.The confinement effect of ordered mesoporous channels attributed to better anti-coking and anti-sintering properties of catalysts.

In order to explore the feasibility of strengthening the synergistic effect during the aromatic hydrocarbon from catalytic pyrolysis of biomass and plastic wastes,three series tests about catalytic pyrolysis of cellulose and high-density polyethylene (HDPE) were carried out by the two stage fix-bed reactor.Some parameters,such as product characteristics,yield and selectivity of aromatics and carbon deposition of catalyst,were compared among the catalytic pyrolysis of single material,physical mixture (cellulose:HDPE=1:1) and stage pyrolysis.The results indicated that the obvious synergistic effect was observed during the catalytic co-pyrolysis of cellulose and HDPE (including physical mixture catalytic pyrolysis and stage catalytic pyrolysis).What's more,the stage catalytic pyrolysis had more obvious synergistic effects than simple mixture catalytic pyrolysis,which would be reflected by following indicators:① increasing the yield and selectivity of aromatics;② facilitating deoxygenation from cellulose in the form of water;③ increasing conversion of cellulose;and ④ decreasing the carbon deposit amount of catalyst.The synergies existed in the co-pyrolysis of cellulose and HDPE can be explained by Diels-Alder reaction theory.In addition,an enhancing synergistic mechanism for the stage catalytic pyrolysis of cellulose and HDPE was proposed based on the verification test of catalytic pyrolysis of HDPE in this work.

The influences of superficial velocity (u) and granular layer thickness (L) on the granular bed filtration performances were investigated in a cold-state experimental apparatus using two kinds of filter media.Combined with the macroscopic model of granular bed filtration,the effects of the specific mass deposit (σ) on the deviation degree (F and G) of dust collecting ability and pressure drop with initial values under different operation conditions were analyzed.On this basis,the prediction of filter efficiency and pressure drop was performed.The results revealed that F increased at first and then decreased with increasing of σ,while G presented a linearly increase trend.The functional relationship between F(G) and σ was established by combination with experimental data under the condition of u=0.2~0.6 m·s^-1 and L=0.11~0.2 m.The calculations of the proposed formulas were in a good agreement with experiments,which were better than the formulas provided in the literature,and thus could provide some guidance for the prediction of performances of granular bed filters.

The basic reservoir physical parameters of Silurian shale samples in Sichuan Basin including total organic carbon,clay mineral content and vitrinite reflectance were represented.Pore structure was characterized by field emission scanning electron microscope and low temperature nitrogen adsorption methods.Based on these characterizations,shale samples have well-developed pore structure,with micropores predominantly comprising the pore structure.It is also found that the micropore is the major contributor to the overall specific surface area,whereas most of the pore volume is occupied by mesopores.The adsorption capacity of pure methane and carbon dioxide were performed using a setup of the manometric method.The factors affecting the adsorption capacity of shale gas were investigated,and the selectivity of CO₂/CH₄ adsorption on shale samples was studied.The results show that the adsorption capacity of CO₂ on shale is higher than that of CH₄.TOC and pore structure have a great influence on shale adsorption,which is positively correlated.Meantime,a high temperature is unfavorable to shale gas adsorption and the influence of unit pressure on the adsorption decreases with the increase of pressure.In the study of competitive adsorption,shale has higher selectivity to CO₂.

The molar ratio of H₂/CO required is around 2.1 for the methanol synthesis of the coal-to-methanol (CTM) process.However,the H₂ to CO ratio of the crude syngas is only about 0.7.It is necessary to convert part of CO and H₂O into H₂ and CO₂ by water gas shift reaction.While mixing of the shifted syngas and the unshifted syngas results in reduction of CO₂ concentration,this leads to the high energy consumption for CO₂ capture.A coal based methanol and power cogeneration process with low energy consumption for CO₂ capture is proposed.The CO of the crude syngas is partly converted into CO₂ and H₂,and the shifted syngas does not mix with the unshifted syngas.The CO₂ concentration in the shifted syngas is thus relatively high compared to conventional CTM process.The energy consumption for CO₂ capture is reduced as a result.The H₂ rich syngas after CO₂ capture is partly mixed with the unshifted syngas to adjust the composition of methanol feed gas.System analyses are made based on process modeling and simulation.The energy saving ratio of the proposed process reaches 16.5%,and energy consumption for CO₂ capture is reduced by 30.3%.

The devolatilization of oil shale during retort process would cause significant changes to the pore structure of oil shale semi coke,which would have important effects on the semi coke combustion and ash formation.The pore structures of oil shale semi coke prepared at different retorting temperatures and different residue times were analyzed by SEM and nitrogen adsorption and desorption.The results were discussed with the combustion results of the same samples which conducted by other researchers.The results show that,the pore specific area and volume of oil shale semi coke would initially increase and then decrease with the increase of retorting temperature within experimental parameters range,which might be explained by coke blocking pore.With the increase of residue time,pore coalescence would happen.So the pore specific area of oil shale semi coke would initially increase and then decrease,while the pore specific volume would increase.

The viscosity of molten slags is one of the most significant parameters to predict the flow properties of ash in coal gasification process.To estimate the viscosity of molten slags,a model based on the structure of slags was established.NBO/T (number of non-bridging oxygen/tetragonally-bonded oxygen) and P/M (polymer/modifier),as the structural parameters of slags,provide description of the polymerization and bond strengths of molten slags,respectively.The model presented the dependency on both temperature and structural parameters with the viscosity in the SiO₂-Al₂O₃-CaO-MgO-Fe₂O₃-K₂O-Na₂O-TiO₂ slag systems.The accuracy of the model was verified by the experimental data of literatures.The results indicate that the viscosity decreases with the increase of NBO/T due to the reduction of polymerization in the molten slags,whereas the viscosity rises with the increase of P/M because of the strength weaken of molten slags.A good agreement is obtained from the calculated and measured values of the viscosity within a certain range.The deviation between the prediction and experiment results is within 10% when NBO/T < 0.5 and 25% when NBO/T > 0.5.

In the solid-solid mixing pyrolytic process,the ash or bed material may influence the pyrolytic behaviors of the oil shale.Thus,pyrolysis of oil shale mixed with four metal oxides Al₂O₃,MgO,CaO and Fe₂O₃ were investigated.The results showed that CaO had a strong influence to the yields of products,and particularly promotes the formations of shale oil and char,while decreases the yield of gas product.On the contrary,Al₂O₃ in acidic property can most distinctly promote the devolatilization of oil shale with an augmented yields of shale oil,water and gas products.Comparatively,the effects of MgO and Fe₂O₃ to product yields were much weaker.All of the four metal oxides can promote the formation of H₂,CH₄ and C₂ hydrocarbons.The content of CO₂ decreased extremely for CaO,while all other metal oxides played promoting role to the formation of CO₂.H₂ and CH₄ can be most distinctly increased for Fe₂O₃ and Al₂O₃,respectively.The content of aromatics in shale oil can be augmented by all of the four metal oxides and the effect of Fe₂O₃ was most significant.For the components of chain hydrocarbons,the short-chain (C₆-C₁₂) alkanes and alkenes were promoted for both of CaO and MgO,while only the short-chain alkanes were increased under the effect of Al₂O₃.It was deduced that the alkalinic CaO and MgO firstly reacted with the fatty acids of the organic matters,forming a fatty acid salt.Then,a decarboxylating step was followed in the way of releasing CaCO₃,simultaneously generating intermediates that could be converted to both of alkanes and alkenes.However,under the acidic Al₂O₃,the decarboxylation product was CO₂,determined a prevalent alkane product.

The pore change and the volatile matter release of Shenmu coal and Huadian oil shale during thermal pretreatment at 150-400℃ were investigated.The effect of the pretreatment on the successive slow pyrolysis of the coal and oil shale was studied.The results showed that,after the thermal pretreatment,the pore structure of oil shale significantly increased and the specific surface area increased by more than 4 times and pore volume increased by more than 5 times.In contrast,the pore structure of Shenmu coal significantly reduced,in particular,for the pore larger than 1 nm,its pore volume reduced by nearly 60% and the surface area reduced by nearly 80%.However,the pore below 1 nm is relatively stable,and the pore volume and specific surface area reduced by only about 10%.When the thermal pretreatment temperature is below 400℃,in addition to the removal of adsorbed water,other volatile components,mainly CO₂,and a small amount of CO,also were released,but the total mass loss caused by volatile release is not more than 5%.The slow pyrolysis experiments with a fixed bed reactor showed that,after the thermal pretreatment,the oil yield of oil shale increased by 22.7%,the yield of water and gas products reduced,and the content of H₂ in the gas decreased while CH₄ increased.The thermal pretreatment had no obvious influence on the oil yield of coal pyrolysis,while increased the yield of the gas product and CH₄ content in the gas and decreased H₂ content.

The carbon,hydrogen,oxygen are the majornitrogen and sulfur atoms,mostly in the form of C-X (X=N,S),still play a nonnegligible role in the structure and application of coal and oil shale.The homolytic bond dissociation enthalpies (BDE) of C-X for model compounds that are representative of the functionalities present in coal and kerogen were computed by using a double-hybrid method mPW2PLYP.The studies will be helpful for people to construct the transfer model of N and S in pyrolysis,and enrich the knowledge of chemical reaction of typical bonds in coal and kerogen.The BDE for C-N and C-S cover a range from 154.1-55.7 kcal·mol^-1 and 83.0-56.6 kcal·mol^-1,respectively.The results suggest that the thiophenyl radical or phenylamino radical are the most favorable intermediates in the early pyrolytic stage.With the increase of temperature,the loss of sulfydryl and amidogen groups become feasible,and the ring cleavage reaction of five-membered ring (pyrrole and thiophene) through homolysis of C-N and C-S bond can also occur.The phenyl radical is the most difficult to form,and the directly bond dissociation of C-N bond in pyridine with six-membered ring is extremely unfavorable in the pyrolysis of coal and kerogen.Compared to other types of bonds,C-S bond has the lowest general BDE range.The order of the lowest BDE for various bonds is O-H > C-H > C-C > C-N > C-S > C-O.The bond dissociation of C-O to generate PhOx radical is easier than to generate PhSx radical through homolysis of C-S,otherwise the BDE of C-O is higher than C-S.

Sequential extraction was employed to determine the modes of occurrence of calcium in Zhundong coal.The samples from Zhundong coals before and after extraction were ashed in a high temperature atmosphere furnace.The calcium content of the coal and ash samples and the calcium-contained minerals in the samples were determined using an inductively coupled plasma atomic emission spectroscopy and X-ray diffraction analysis.The results indicated that the calcium contained in Zhundong coal was in the forms of water-soluble,ammonium acetate-soluble,hydrochloric acid-soluble and insoluble species,and the main calcium modes were the ammonium acetate-soluble and hydrochloric acid-soluble species,while the proportions of the water-soluble and insoluble-calcium were low.During the combustion process,the chemical reactions among the calcium-containing minerals,the silicon-containing minerals and aluminum-containing minerals in Zhundong coal occurred to form fukalite,mayenite,kilchoanite and rankinite.The base/acid ratio decreased and the ash melting temperature increased after water extraction.The hydrochloric acid-soluble calcium species reacted with the silicon-containing and aluminum-containing minerals,leading to form mayenite,kilchoanite and rankinite.The insoluble-calcium species existed in the form of margarite was stable in the coal during combustion process.

Inductively coupled plasma mass spectrometer (ICP-MS) has been used to determine the concentration of Li,V,Cr,Co,Ni,Cu,Zn,Sr,Mo,Cd,Sb,Ba,and Pb in oil shale samples and semi-cokes pyrolyzed at different final temperatures.The results show that Balikun oil shale contains more trace elements,especially Ba,Cd,Li,V and Sb,compared with Longkou oil shale which is only rich in Ba and Cd,and that most trace elements volatilize at around 500℃.In addition,the influence of trace elements on kerogen pyrolysis was studied.Thermogravimetric analyzer was used to investigate pyrolysis kinetics of kerogen with trace elements in different forms.The kinetic parameters (apparent activation energy E and frequency factor A) were calculated using overall n order reaction procedure.The relative content of alkane products was characterized by pyrolysis-gas chromatography/mass spectrometer (PY-GC/MS).The results indicate that Ni (NO₃)₂ can catalyse kerogen pyrolysis by increasing its conversion,rate and yields of light alkane products and decreasing yields of heavy alkane products.

The releasing characteristics of gas species during isothermal co-pyrolysis of pine sawdust (PS) and coal slime (CS) were studied in a micro fluidized bed reactor.Four main pyrolysis gaseous products,CH₄,CO,CO₂ and H₂,were investigated under different temperature and blending ratios.The kinetic parameters were calculated employing the universal integral method to examine the interaction of PS and CS during co-pyrolysis.It was observed by FT-IR that CS mainly contained aromatic compounds carrying C-O and C==O,while the PS was mainly consist of long-chain aliphatic hydrocarbon with-OH.The gas forming reaction rate of PS was higher than that of CS,and its value increased in a certain extent with the increase of biomass blending ratio.The kinetic parameters of pyrolysis gas formation of PS,CS and their blends were obtained by the mechanism function models,and the most probable mechanism function was determined by comparing the experimental and calculated values.The effect of blending PS and CS on the forming activations of the four gas species varied obviously.The activation energies of CO were significantly lower than the calculated ones,indicating that a positive synergistic effect existed between PS and CS.The co-pyrolysis reaction led to a negative effect on the formation of H₂ at a PS blending ratio of 75% as the activation energy was obviously higher than the calculated one.In comparison,biomass blending showed relatively small positive synergistic effect on the formation of CH₄,while that of CO₂ depended upon the blending ratio significantly.

The influence of multiple process factors affecting the oil shale particles size distribution and the degree of fragmentation/pulverization was studied in fixed-bed during thermal effect.The results show that with the temperature increasing from 120℃ to 900℃,the fraction of retention particles (25-13 mm) is decreased from 96.54% to 82.69%.The fragmentation particles group (13-1 mm) are increased from 2.01% to 10.63%(13-6 mm grain size increased the highest rate);The pulverization particles group (less than 1 mm) are increased from 1.45% to 6.68%(the fractions of particles less than 0.075mm are significantly changed).The degree of fragmentation and pulverization are increased with particles size and holding time as well.Impact of multi-factor on fragmentation is revealed using gray relational analysis method as follows:temperature > size > time,and the impact on pulverization is:temperature > time > size.Through the analysis of TGA,XRF,XRD,SEM-EDS,the internal incentives affecting fragmentation/pulverization are revealed:vapor-volatile arising,calcite decomposition behavior,indirect reinforcement with time,and internal air resistance/particle material resistance.The descriptive model of oil shale fragmentation-pulverization in fixed-bed during thermal effect is built based on these factors.

Yilan oil shale organic matter was depolymerized by sequential thermal dissolution in tetralin.The soluble portions (SP) were analyzed by GC-MS and classified into different components,and the residues were analyzed by FT-IR and ¹³C NMR.Based on the above information,Yilan oil shale organic molecular structure was revealed at a molecular level.The results indicated that Yilan oil shale organic matter could be depolymerized by sequential thermal dissolution from 200℃ to 400℃,the yields of soluble portions at 200,300,350,375 and 400℃ were 8.8%,9.9%,18.5%,19.2% and 23.4%,respectively,and the total yield was 79.8%.In the total soluble fraction,aliphatic hydrocarbon compounds accounted for more than 36.9%(including 27.4%n-alkanes and 8.7% branched alkanes),alcohols/phenol 5.5%,aromatic hydrocarbon 32.0%,ketones 12.7%,ether/ester 5.4%,and the other compounds 7.5%.The order of yield of compounds is as follow:aliphatic hydrocarbons > aromatic compounds > ketones > phenols > alcohols/esters.The identified n-alkanes in soluble portions have a distribution range from C₁₄ to C₃₀ with two maximum values at C₁₆ and C₂₆.

A multi-particle characterization index describing the degree of fragmentation was proposed.Thermal fragmentation and pulverization properties of Huadian oil shale under different pyrolysis conditions were systematically investigated using the self-designed drum pyrolysis reactor,and the fragmentation mechanism was analyzed.The results showed that in thermo-mechanical force coupled loading mode,the rate of pulverization was 3.96 times of the sum of the individual loading modes,which indicated the synergistic effect of the coupled loading mode.The thermal force was the main influencing factor,its essence was the evolution of the internal pore structure,and the mechanical force was to enhance the phenomenon of fragmentation.The relative breakage rate and the pulverization rate were consistent with the change trend of pore structure.The smaller the feeding particle size,the smaller the overall degree of fragmentation.The higher the oil content,the greater the degree of fragmentation.The pulverization rate of the lean sample is lowest due to the higher content of calcite which was difficult to decompose into fine particles.Fragmentation and pulverization were two relatively independent concepts;there was no correlation between them.

The difference of spontaneous combustion liability of fresh samples (SA) and pre-oxidation samples (SB) of lignite upgraded at different temperature,were tested by the experiment equipment of temperature programming.Free radicals in situ were dynamically analyzed by X-band electron spin resonance spectroscopy (ESR) and the effect of pre-oxidation on spontaneous combustion liability was surveyed.The results showed that the spontaneous combustion liability of SA reduced with rising upgrading temperature.With the storage time extension in natural environment,lignite upgraded at 105-500℃ was effected by pre-oxidation.The spontaneous combustion liability increased in varying degrees,and lignite upgraded at 400℃ became easy to spontaneous combustion as well as raw lignite.During the oxidation process of spontaneous combustion,being different from fresh samples,the free radical concentration for pre-oxidation samples increased with increasing adsorbed oxygen amount.Pre-oxidation not only improved the free radical amount of upgraded lignite,but also made the continuous generation of new free radical and kept the self-heating and temperature rising in the later part of accelerating oxidation phase.But micromolecule free radicals were rapidly consumed and loss 80% for the fresh sample upgraded at 400℃,which made it could not provide new free radicals and maintain oxidation reaction.

Synthesis of high purity TiO₂ powder by fluidized gas hydrolysis method is investigated.To tackle the problem of high Cl content remained in the TiO₂ powder,the hydrolysis reaction conditions and subsequently calcination at air,steam and H₂ are mainly investigated for dechlorination.The results show that the structure and phase transition of TiO₂ are two key factors that affect the efficiency of dechlorination.With the increase of the calcination temperature,the internal structure of TiO₂ is changed from porous to dense structure,and the crystalline structure is transformed from anatase to rutile.The structure and phase transition of TiO₂ are beneficial to increasing the removal rate of Cl.Compared with the air calcination,the dechlorination efficiency in water vapor atmosphere is obviously improved,which is attributed to the further reaction of water vapor and the multi hydroxyl chloride in the TiO₂ particles.Compared with air and steam calcination,the removal rate of Cl can be further improved up to 95% under the atmosphere of hydrogen at 800℃ for 2h,which is mainly attributed to the reduction of TiO₂ structure by hydrogen reduction.

The magnesium hydroxide crystals were prepared by ammonia circulation method,using light burning powder,ammonium chloride,ammonium nitrate,ammonium acetate and ammonium sulfate as raw materials and ammonia gas as precipitant.X-ray diffraction (XRD) and scanning electron microscopy (SEM) have been employed to characterize these products.The effects of Cl^-,NO₃^- and CH₃COO^- on the growth of (001) and (101) crystal planes of magnesium hydroxide crystals were calculated by the CASTEP module in the Materials Studio molecular simulation software.The results showed that magnesium hydroxide crystals with different morphologies were obtained by different magnesium salts.The larger the anionic electronegativity was,the smaller the effect on the crystal morphology.The (001) and (101) crystal face energy and population analysis of Mg (OH)₂ crystals showed that the surface energy increased and Fermi energy decreased of (001) and (101) planes of the crystals with Cl^-,NO₃^- and CH₃COO^-.New ionic bond with weak covalency was formed between anion and the (001) and (101) planes which affected the growth of the crystal plane.The theoretical calculations explained the formation of magnesium hydroxide crystals with different morphologies.