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Investigating the oxygen bond cleavage and its migration mechanisms during the pyrolysis process of sub-bituminous coals is essential for their classification utilization. The present study employed a fixed-bed pyrolysis technique (temperature range: 350–600 °C) to explore the cleavage of oxygen-containing bonds and subsequent behavior of oxygen migration and transformation during the pyrolysis process of Naomaohu sub-bituminous coal (NSBC). X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy results reveal that the organic oxygen in NSBC predominantly exists as the form of C–O bonds, accounting for 22.81 wt% of the total composition, mainly encompassing hydroxyl, carbonyl, ester, and ether groups. The organic oxygen in the light tar is mainly in the form of phenols, reaching 1.71 wt%, of which methyl substituted phenols is predominant at a final pyrolysis temperature of 600 °C. This can be attributed to the presence of more aryl ether bonds and hydroxyl groups in NSBC, which are prone to cleavage at higher temperatures, resulting in the formation of phenoxyl radicals. Additionally, the higher temperature facilitates the weakening of hydrogen bonds between phenolic hydroxyl groups, thereby enhancing the yield of phenolic compounds. The ester compounds present a decreasing trend with increasing temperature, primarily associated with the cleavage temperature of ester linkers being 350 °C, suggesting that an increase in temperature favors the cleavage of ester bonds. In addition, the cleavage of C–O bonds begins to accelerate significantly during the pyrolysis temperature range of 450–500 °C, subsequently accounting for the pronounced proliferation of phenols within this specific thermal interval. The oxygen content in semi-coke decreased with the increase of temperature, from 85.27 wt% at 350 °C to 37.17 wt% at 600 °C, while the oxygen content in the pyrolysis gas increases from 11.63 wt% at 350 °C to 47.53 wt% at 600 °C, indicating that a significant migration of organic oxygen to the pyrolysis gas during the pyrolysis of NSBC. This study can deepen the understanding of the transformation mechanism of oxygen-containing structure in NSBC pyrolysis process, and provide a theoretical basis for high-grade utilization of low-rank coals. [Display omitted] • Elevated temperatures promote the migration of organic oxygen into volatile products. • The breaking of organic oxygen bonds depends mainly on temperature. • High temperatures favor the breaking of aryl ether bonds to form phenols. • Cleavage of aryl alkyl ethers at 350–450 °C leads to a large increase in alcohols. • The release of volatile oxygenates leads to a reduction in the oxygen content of the coke. [ABSTRACT FROM AUTHOR]

Summary: In the process of one‐step synthesis of methylal via methanol oxidation, the design and research of various dual‐function catalysts are important and studies on the influence of reaction conditions on this type of process are scarce. We explored the influence of reaction temperature, reaction space velocity, and the feed ratio of methanol to air on the catalytic effect of the process based on the Fe‐Mo‐based bifunction catalyst and discovered the most appropriate reaction conditions for the process. Results showed that excessively high reaction temperatures were not conducive to the formation of target product Dimethoxymethane (DMM) and this was verified from the perspective of thermodynamic analysis. At the same time, through Brunaure Emmett Teller (BET), X‐ray diffraction, scanning electron microscope, NH3‐temperature‐programmed chemisorption, and Pyridine Fourier Infrared (PY‐FTIR) characterization, analysis of the microstructure and surface characteristics of the catalyst showed that an excessively high reaction temperature caused accumulation of metal oxides on the catalyst surface to block pores and reduce the specific surface area. This also destroyed the active acidic sites on the catalyst surface and weakened the acidity of the catalyst, thereby reducing catalytic activity. Investigation showed that excessively high reaction space velocity caused most of the formaldehyde obtained by catalyzing the initial oxidative dehydrogenation to fail to undergo polycondensation with methanol after desorption in time to obtain DMM, leading to a significant decrease in DMM selectivity. Investigation of the methanol‐air feed ratio showed that when CH3OH:air = 1.5, the methylal selectivity was highest and catalytic activity had improved. Orthogonal experiments showed that optimal reaction conditions of the process were 663 K, 15 000 h−1 and CH3OH: air = 0.82. In addition, compared with other bifunctional catalysts of this process, the self‐made Mo:Fe(2)/HZSM‐5 bifunctional catalyst exhibited high stability and carbon deposition resistance under severe operating conditions. [ABSTRACT FROM AUTHOR]

In this study, fast pyrolysis of seawater Spirulina , is carried out to evaluate the potential of deriving valuable chemicals and fuel molecules from this seawater algae variety. The devolatilization behavior and gaseous product evolution of seawater Spirulina were carried out by TG-FTIR. Py-GC-MS was employed to investigate the composition and distribution of volatile products formed from the seawater Spirulina through high-temperature fast pyrolysis process. Finally, the seawater Spirulina char gasification reactivity and kinetic parameters were evaluated using advanced methods of volume, shrinking core and random pore. Results indicate that the thermal cracking process of seawater Spirulina mainly consisted of three reaction stages, including dehydration and drying stage, fast pyrolysis stage and residues slow decomposition stage. High heating rate has significant effect on the performance of devolatilization profiles. H 2 O, CH 4 , CO 2 , HNCO, NH 3 , HCN, CO, C–O bond and C O bond were the typical gaseous products released from the fast pyrolysis stage of seawater Spirulina. The maximum release rate of seawater Spirulina for CH 4 was located at about 450 °C, corresponding to the main pyrolysis of long-chain fatty acids from lipid fraction. The high temperature fast pyrolysis of seawater Spirulina resulted in aliphatic (alkanes, alkenes) and aromatic hydrocarbons, esters, oxygenates (carboxylic acids, aldehydes, ketones, and alcohols), phenolics, and nitrogen- and sulfur-containing organic compounds. Above 750 °C was considered as the optimum temperature, which can reduce the generation of oxygenated compounds, and the content of nitrogen and phenolic compounds were decreased, maximum yield of quantified hydrocarbons was observed. The increase of gasification temperature can obviously improve the gasification reactivity of seawater Spirulina chars. The activation energies of the VM, SCM and RPM models of seawater Spirulina chars were 187.95, 173.14 and 154.34 kJ/mol, respectively. RPM displays a significant fitness with the experimental data than those of the other two models. Image 10035 • Pyrolysis behaviors, products and char/steam gasification of seawater Spirulina were studied. • High heating rate has significant effect on the performance of devolatilization profiles. • Above 750 °C was considered as the optimum temperature in the fast pyrolysis of seawater Spirulina. • Char gasification reactivity and kinetic parameters were evaluated using advanced methods. • Gasification temperature can obviously improve the gasification reactivity of chars. [ABSTRACT FROM AUTHOR]

A simple process by slurry bed and π-complexation adsorbent was developed for separation of propylene/propane mixtures. The adsorbent, Cu(I) immobilized active carbon (AC), was prepared by the in-situ reduction of Cu(CH3COO)2. The adsorption amount of propylene and selectivity was 35.1 mL/g and 1.57, 30.4 mL/g and 1.45 for Cu(CH3COO)2-AC-N2(calcined in N2atmosphere) and Cu(CH3COO)2-AC-Air, respectively. Compared with AC, the BET surface area decreased, while the average pore diameter increased. It suggested that the metal salt deposited at the entrance of pores, blocking part of pores. According to the results from IR, XRD and TPR, Cu2O was the main copper species on the surface of the solid adsorbent. [ABSTRACT FROM AUTHOR]

The NiO/SBA-15 monolith with a three-dimensional (3D) network structure was synthesized by a facile one-pot hydrothermal method for CO 2 methanation. The results showed that the net-linked mesoporous framework of SBA-15 was well preserved after incorporation of 15 wt% NiO, and the one-pot prepared NiO/SBA-15-Op material exhibited higher surface area, larger pore volume than the NiO/SBA-15-Im synthesized by traditional impregnation method. In addition, NiO/SBA-15-Op showed higher catalytic activity and anti-sintering property of metallic Ni than NiO/SBA-15-Im for CO 2 methanation due to higher Ni dispersion and more Ni particles dispersed in the meso-channels. [ABSTRACT FROM AUTHOR]

The residues cracking gasification was performed in a dual fluidized bed reactor by using calcium aluminate as the bifunctional catalyst, which was prepared by the solid phase method. Besides, carbon black assisted could contribute to improve the specific surface area of the catalyst. The performances of the reaction temperature and hydrothermal treatment catalysts on the products distribution for vacuum residue cracking were studied. It was found that solid base catalyst could promote to produce the products of light oils and light olefins, and co-producing the H 2 -rich syngas. The results showed that the C 2 + C 3 olefinicity of higher than 58.0%, heavy oil conversion of above 92.0%, and carbon deposited of ca. 4.2 wt% were achieved by cracking over two self-made solid base catalysts at 650 °C with a catalyst-to-oil ratio 7.0. Moreover, the catalyst with higher specific surface area displayed a better cracking performance than the one with lower specific surface area. Hydrothermal treatment base catalysts indeed decreased its activity, and thus led to higher liquid yield and lower gas yield. The carbon deposited on the catalyst was well gasified at 800 °C in steam-5.0 vol% oxygen. The H 2 content and the H 2 /CO ratio were reached about 58.0 vol% and 4.5, respectively, with the CH 4 content < 0.5 vol%. Besides, in comparison with an industry solid base catalyst, the coke gasification rate was obviously accelerated over two self-made solid base catalysts. Furthermore, the cracking performance of the solid base catalysts could reach basically stable via a few cracking gasification cycles. [ABSTRACT FROM AUTHOR]

• Synergistic effect of hydrogen atmosphere and char in pyrolysis-catalytic reforming of biomass. • Synergistic of hydrogen atmosphere and biochar catalyst degrades heavy tar components. • Increased hydrogen concentration and higher reforming temperature promotes CH 4 production. • Biochar inhibited the polycondensation of macromolecular compounds in tar. • Tar conversion efficiency and the yield of CH 4 increased with increasing biochar layer height. This study investigated the synergistic effect of a hydrogen atmosphere and biochar for tar removal and CH 4 -rich gas production during the pyrolysis-catalytic reforming of biomass using a lab-scale dual-stage fixed-bed furnace. The biomass feedstock was pyrolyzed under a hydrogen atmosphere at 850 °C, and then the evolved vapors were passed to a second stage with pyrolysis gases reformed in the presence of biochar as a catalyst. The influence of reforming temperature, hydrogen concentration, and the mineral and layer height of the biochar catalyst were investigated. Using such a synergistic pattern not only effectively promoted tar decomposition but also generated methane-rich gas and continuously regenerated the biochar catalyst. In particular, the tar conversion efficiency reached 93.72 % with the use of biochar under a hydrogen concentration of 20 % at a reformer temperature of 850 °C. The CH 4 yield increased evidently with increasing hydrogen concentration and reforming temperature. The maximum CH 4 yield in producer gas of 36.52 vol% was obtained at a catalytic temperature of 850 °C and a hydrogen concentration of 100 %. The catalytic activity of minerals in biochar has a significant effect on tar decomposition and producer gas components, which was proven by the decrease in CH 4 yield when demineralized biochar was used for reforming the catalyst. The tar conversion efficiency and yield of CH 4 tended to increase with increasing biochar catalyst layer height. Finally, a hydropyrolysis-catalytic reforming mechanism of a hydrogen atmosphere and biochar catalyst in tar removal and methane-rich gas production was proposed. [ABSTRACT FROM AUTHOR]

Using small-sized fluidized bed experimental device with the vacuum residue as raw material and magnesia-alumina as catalyst, the effects on gas product distribution of heavy oil catalytic cracking under different reaction temperature, water-oil mass ratio and catalyst-loading quantity were studied. The effects of different catalysts on heavy oil catalytic cracking were also investigated. The results showed that temperature was the most influential factor to heavy oil catalytic cracking. The ethylene mass yield of vacuum residue was 11. 89%, and the total olefins mass yield was 20.19% under the optimum condition of 750 °C, water-oil mass ratio of 2, catalyst loading quantity of 40 g. Through the comparison of different catalysts, the selectivity of magnesium-aluminate was better than that of calcium-aluminate, and the yield of calcium-aluminate was higher than that of magnesium-aluminate. [ABSTRACT FROM AUTHOR]

Abstract: Powdered active carbon was converted into active carbon monoliths (ACMs) without reducing specific surface (SSA) by adding H3PO4-impregnated waste sawdust (HIWS) before extrusion. The effects of activation time on the morphologies, textural properties, and compression strength of the prepared ACMs were investigated. The HIWS could act as an easy-making binder for conversion of powdered active carbon into ACMs having a higher SSA than the powdered active carbon. The SSA and compression strength of the ACMs increased with prolonging the activation time. Monolithic active carbon with a SSA of 715m2/g and compression strength of 4.8MPa was produced by heating at 560°C for 160min. This research might lead to cost-effective conversion of powdered active carbon into ACMs without compromising SSA. [Copyright &y& Elsevier]

Aiming at the mass production of heavier and inferior crude oil and unconventional inferior quality heavy oil, such as the shale oil, oil sands, heavy (thick) oil, ultra heavy oil, deep oil, asphalt and coal tar, and discussing the motor vehicle emissions standards, the structure of he automobile fuel system, quality standards and requirements as well as the light passenger car electrifying. The objective products of crude oil to light oil is the motor gasoline gradually transiting to the kerosene and diesel fuel, and the kerosene and diesel oil with low sulfur and low aromatic hydrocarbons was also put forward. At the same time, the development direction of inferior quality heavy oil processing technology was analyzed. Emphatically, the heavy oil fluidized pyolysis process, the heavy oil coupling of fluidized pyrolysis gasification process, the heavy oil catalytic cracking process with high temperature and short contact, the heavy oil suspended bed hydrogenation cracking process and the kerosene and diesel oil saturation pyrolysis process will become important direction and hotspot of inferior quality heavy oil technology research and development in the future. [ABSTRACT FROM AUTHOR]

Summary: The recent abundance of methanol has made it an attractive raw material for chemical synthesis. This study conducts a thermodynamic analysis of the main and side reactions in a system where methanol is oxidized to methylal. A relationship between the thermodynamics and product distribution of this system is proposed. By studying the effect of reaction temperature on the catalytic activity of a Mo‐Fe/HZSM‐5 (80‐80) catalyst, the relationship between thermodynamic parameters and product distribution was further verified. Kinetic analysis of the one‐step process shows that a lower activation energy is one of the reasons for the higher catalytic activity of the iron‐molybdenum‐based bifunctional catalyst. Accordingly, it is proposed that all main and side reactions in this process are driven by two chemical adsorption reactions. The first occurs at active sites of iron and molybdenum oxidation on the catalyst surface. The adsorbed methanol and O2 obtain hydroxyl and methoxy groups linked to the iron molybdate. Subsequently, desorbed formaldehyde and methanol undergo a second chemical adsorption on the acidic active centres of the catalyst with surface carbonyl and hydroxyl groups, respectively. Formaldehyde and the adsorbed methoxy group are catalysed by the acidic sites to generate intermediates similar to the methoxy and methylene group structures. This study provides complete information on the thermodynamics, kinetics, and reaction mechanism of a one‐step process of producing methylal from methanol, thereby allowing optimization of this process. [ABSTRACT FROM AUTHOR]

Dry reforming of methane (DRM) takes advantage of greenhouse gases (CH 4 and CO 2) and mitigates their eco-environmental consequences. However, the biggest obstacle for DRM reactions has been the design of catalysts with high resistance to sintering and carbon deposition. In this paper, the embedded bimetallic nickel-cobalt@ silicalite-1 (S1) catalysts (NiCo@S1), with high resistance to sintering and lower carbon deposition, were prepared by grinding crystallization method. The physicochemical characterizations demonstrated that the embedded catalyst for NiCo@S1 could effectively control the size and dispersion of the active metal Ni–Co in the catalyst compared to the supported catalysts for 10Ni/SiO 2 and 10Ni/S1, which further enhance the interaction between the active metal phase and the carrier S1, and greatly minimize the amount of carbon accumulation on the catalysts. After being subjected to a reaction at 700 °C for 6 h, the 10Ni2.5Co@S1 exhibited a significant performance improvement. The instantaneous conversion rate of CH 4 increased from 63.17% to 86.39% (an increase of 23.22%), and the instantaneous conversion rate of CO 2 rose from 70.20% to 88.62% (an increase of 18.42%). Additionally, carbon deposition reduced from 14.58% to 0.82% (a decrease of 13.76%). Therefore, the conceptual design provided a new perspective for designing Ni-based dry reforming catalysts. • An industry-friendly grinding crystallization method has been introduced. • The grinding crystallization method can effectively promote the dispersion of active components、enhance metal-support interaction and prevent the migration of metal nanoparticles and their agglomeration, avoiding sintering, and thus reducing carbon deposition. • 10Ni2.5Co@S1 catalyst showed excellent performance in dry reforming of methane reactions. [ABSTRACT FROM AUTHOR]

• Parametric effect on biomass fast partial hydropyrolysis vapor has been carried out. • Gases yield increased from level with 0% hydrogen as the hydrogen amount increased. • A large amount of methane was produced due to the hydrogenolysis of tar. • High H 2 ratio resulting in more aromatic hydrocarbons yields. • AAEMs matters in ash that will favor the reaction of dissociate molecular hydrogen. Fast partial hydropyrolysis of biomass was carried out at the level with hydrogen concentration of 0% to 30% and temperatures ranging from 700 to 900 °C by using a downer pyrolyzer. A theoretical parametric effect on yields and properties of the hydropyrolysis products were clarified. It was found that the volatile matter evolved during pyrolysis was substantially increased in the presence of hydrogen. The yields of CH 4 , C 2 H 6 and light tar increased with increasing elevated H 2 ratio, CH 4 showed an especially large yield increase. The produced methane mainly comes from the reactions of hydropyrolysis of biomass and secondary hydrogenation of tar. Moreover, the presence of alkali and alkaline earth metals matters was significant catalyzes on both reactions. The CH 4 yield increased with elevating the operating temperature and optimal sweeping-gas flow rate is 150 mL/min. These results will be strengthening regulation of feedstocks-operating-products in the practical Biomass Fast Partial Hydropyrolysis technology. [ABSTRACT FROM AUTHOR]

Highlights • The fast thermal-cracking experiments were performed by Py-GC/TOF-MS and a fluidized bed reactor. • Five styles of compounds were contained in volatile products of OSB. • Relative content distribution of volatile products with temperature/carbon number was discussed. • Effect of temperature on yield and distribution of products for OSB was revealed. • Chemical structures of liquid products remarkably changed compared to OSB. Abstract In order to obtain a deep insight into the upgrade of oil sand bitumen (OSB), the composition, distribution and chemical structure of products obtained from the fast thermal cracking of the OSB were investigated via Py-GC/TOF-MS and a laboratory-scale fluidized bed reactor. A detail composition information of fast thermal-cracking products of the OSB was determined by Py-GC/TOF-MS, which mainly contained alkenes (1-alkenes, iso-alkenes and cycloalkenes), alkanes (n-alkanes, iso-alkanes and cycloalkanes), diolefins, aromatics and sulfur-containing compounds. The distribution of fast thermal-cracking products varied under different temperature. Alkenes were the uppermost style in volatile products at the temperature ranging from 500 °C to 700 °C, whereas with the temperature further rising to 800 °C, aromatics products became predominant and were mainly generated from the deep cleavage of alkyl substituent groups and the secondary reactions to form aromatics. Moreover, the relative content and carbon number distribution of volatile products along with various temperature were summarized. The thermal cracking experiments of the OSB over silica sand in a laboratory-scale fluidized bed reactor showed that the gas products had a remarkable increase in yield as the temperature increase, which was connected with the increase in methane and ethylene of dry gas as well as propylene and butenes of LPG. The coke yield also exhibited an increase tendency with the enhancement of temperature, while this variation was slighter in comparison to that of gases. Conversely, the yield of liquid products gradually decreased with the temperature, which was closely related to the significant decrease of VGO and heavy oil fractions due to the coke formation of polyaromatics and the intensive rupture of alkyl side chains. Nevertheless, the light oil fraction (diesel and gasoline) displayed the different variation along with the temperature, which increased firstly and then decreased as a result of the decomposition of heavy fractions and secondary cracking of light oil itself. Compared to the native OSB, there was a slight difference in functional group distribution for liquid products which was concerned with the formation of olefins, whereas the average structural parameters of the liquid products changed dramatically after the fast thermal cracking of the OSB. Furthermore, the effects of the reaction temperature on the chemical structures were significant due to the decomposition, condensation and secondary reactions proceeded during the fast thermal cracking process. [ABSTRACT FROM AUTHOR]

Gas-solid fluidized bed usually forms wet particle fluidization system due to a small amount of liquid on the particle surface, resulting in the cohesive effects and agglomeration behavior which makes its fluidization characteristics significantly different with that of the dry particle system. In this study, based on the two-fluid model (TFM) with variable restitution coefficient model describing the cohesive effects, a particle diameter model of agglomerate was developed to account the agglomeration behavior by replacing the initial particle diameter. Therefore, the TFM with variable restitution coefficient and diameter was successfully established and applied to predict the hydrodynamics of a wet spouted fluidized bed, in which the variation of restitution coefficient and particle diameter were captured simultaneously for the first time. The agglomeration behavior of wet particles was reproduced and analyzed, and the simulation results were compared with the experimental and CFD-DEM results reported. The effects of liquid viscosity and layer thickness on the hydrodynamics of wet particles were also investigated. [ABSTRACT FROM AUTHOR]

• The activation energy of basic catalytic dehydrogenation cracking of VR is calculated. • The optimal reaction conditions for catalytic dehydrogenation cracking of VR are obtained. • A new mechanism is constructed to explain the catalytic dehydrogenation cracking process. The basic calcium aluminate with appropriate catalytic cracking activity, excellent anti-coking performance, and hydrothermal stability is of great potential for the utilization of heavy oil. However, there is a lack of systematic research on the catalytic dehydrogenation cracking characteristics of vacuum residue (VR) over solid basic catalyst. Thus, by combining the TG and Py-GC/MS methods, the dehydrogenation cracking behavior of S-VR was investigated. The results indicated that S-VR cracking on calcium aluminate leads to less coking and higher olefin content in liquid products compared with FCC catalyst and quartz sand. Then, the activation energy E a is computed from the catalytic dehydrogenation cracking of S-VR on calcium aluminate. The results show that the E a values from Friedman and OFW methods range from 68 to 143 kJ∙mol−1 and 114 to 192 kJ∙mol−1, respectively. After that, the molecular-level carbon number distributions of the products obtained from cracking S-VR on different reaction conditions are investigated, and the optimal reaction temperature and the heating rate are 650 °C and 1000 °C/s, respectively. Finally, the free radical regulation theory was constructed to explain the catalytic dehydrogenation cracking mechanism of basic calcium aluminate catalyst. [ABSTRACT FROM AUTHOR]

The study was devoted to exploring the fundamental study on the upgrading of Buton oil sand bitumen (OSB) via fast alkaline catalytic pyrolysis based on the fluid pyrolysis technology. The effect of fast heating rate on the composition and molecular distribution of volatile products from the high-temperature fast pyrolysis of OSB was investigated by Py-GC/TOF-MS that could simulate the fast heating rate of industrial fluid pyrolysis process. The results showed that the volatile products of OSB under heating rates ranging from 10 to 1000 °C/s had the similar species composition. It was found that there were the highest relative content of low-carbon alkenes (C 2 -C 4) and light aromatics (C 6 -C 8) in volatile products under the 1000 °C/s, indicating that the fast heating rate favored the production of light alkenes and aromatics. Subsequently, a laboratory-scale fluidized bed apparatus was employed to further gain insight into fast alkaline catalytic pyrolysis behaviors of OSB. The investigation on the yield distribution, fractional- and molecular-level chemical characteristic of volatile products obtained from the fast alkaline catalytic upgrading of OSB over calcium aluminate was carried out with the aid of the comparison with that over Y zeolite-based FCC catalyst and silica sand. The results revealed that three-phase products over calcium aluminate possessed the larger selectivity of C 2 −C 4 alkenes, larger yield of light oil and the lower coke output, which were 51.88%, 45.49% and 7.96%, respectively. On basis of the chemical structure analysis of liquid products, the alkaline catalytic upgrading of OSB over calcium aluminate could heighten the content of chain alkyl structures as well as alkyl-substituents attached to aromatic ring in liquid products. This indicated that the fast heating rate and alkaline catalyst that adopted in catalytic upgrading process of OSB could play an energetic role in optimizing the composition of volatile products. The alkaline catalytic upgrading of OSB based on fluid pyrolysis technology with the fast heating rate could heighten the yield of low-carbon olefins and light oil and lessen coke yield, meanwhile modify the chemical structure characteristics of liquid products that were conducive to the generation of valuable chemicals (light alkanes and BTX) during secondary processing of liquid products. [Display omitted] • The fast alkaline catalytic pyrolysis was used to upgrade Buton oil sand bitumen (OSB). • Fast heating rate favored the production of light alkenes and aromatics. • Calcium aluminate had the moderate cracking activity and the ability to attenuate coke. • The alkaline catalytic upgrading ensured high yield and modified chemical characteristic of liquids products. [ABSTRACT FROM AUTHOR]

[Display omitted] • CaO-Ca 12 Al 14 O 33 has better deoxygenation activity and structural stability among solid base catalysts. • Zn/ZSM-5 has the highest deoxidation capacity and aromatics selectivity among metal-modified ZSM-5 catalysts. • CaO-Ca 12 Al 14 O 33 &Zn/ZSM-5 tandem catalysis can promote the formation of BTX while inhibiting the formation of PAHs. Catalytic pyrolysis is an effective means for high-value utilization of biomass. This study investigated the effect of solid base catalysts (CaO, calcium aluminate catalysts CaAl-1, CaAl-2, CaAl-3), acid zeolite catalysts (ZSM-5, Fe/ZSM-5, Co/ZSM-5, Ni/ZSM-5, Cu/ZSM-5, Zn/ZSM-5) and base-acid tandem catalysts on pine sawdust pyrolysis using Py-GC/MS. Acid zeolite catalysts exhibited robust deoxidation and aromatization capabilities, favoring aromatics, while solid base catalysts yielded more phenols and ketones. Among the solid base catalysts, CaAl-3 (CaO-Ca 12 Al 14 O 33) showed comparable deoxygenation activity to CaO and optimal aromatic selectivity with structural stability. Zn/ZSM-5 excelled in deoxygenation and aromatic selectivity (70.42%) among metal-modified ZSM-5 catalysts. Base-acid tandem catalysis promoted the formation of aliphatics and BTX (benzene, toluene, xylene) while suppressing polycyclic aromatics. The highest BTX content (44.35%) was achieved with CaO-Ca 12 Al 14 O 33 &Zn/ZSM-5 tandem catalysts in a 1:3 ratio. This work demonstrates base-acid tandem catalysis as a promising approach for converting pine sawdust into valuable chemicals. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ca 12 Al 14 O 33 -Ca 2 Fe 2 O 5 framework improved the stability of CaO. • Ca 2 Fe 2 O 5 combined with Co3+/Co2+ enhanced CO 2 activation. • Same CO 2 adsorption and in situ conversion temperature can be operated at 610 °C for low CO 2 concentration flue gas. • Stable CO 2 capture capacity, over 98% CO 2 conversion rate and close to 100% CO selectivity still can be achieved after 100 cycles. Integrating CO 2 capture and in-situ conversion is a promising means of processing low concentration CO 2 in flue gas. The development of a low cost, highly stable catalyst to reduce the running cost is key to the development of this technology. The ultrastable bifunctional multi-stage active metal catalysts (Ca 12 Al 14 O 33 - y (Ca 2 Fe 2 O 5)-Co x CaO) were synthesized by the solid phase synthesis method with low cost industrial powder raw materials. The catalyst was stabilized with calcium aluminate (Ca 12 Al 14 O 33) and calcium ferrite (Ca 2 Fe 2 O 5) as a substrate structural framework for CaO and enhanced the dispersion of CaO. It not only solved the problem of CaO deactivation due to sintering, pore collapse, and agglomeration in the continuous high-temperature reaction, but also showed excellent catalytic performance for reverse-water–gas-shift (RWGS) reaction. On the basis of calcium-looping and RWGS reaction, the high temperature CO 2 capture and in-situ conversion process is realized in the same fixed-bed reactor for processing simulated flue gas with 16.7 vol% CO 2. The results showed that at the optimum operating temperature of 610 °C, the catalyst still maintains a stable CO 2 capture capacity, over 98% CO 2 conversion rate and close to 100% CO selectivity after 100 cycles. The multi-stage active metal structure catalysts provided a unique construction idea for designing ultrastable catalysts for low concentration CO 2 capture and in-situ conversion with great potential for industrial application. [ABSTRACT FROM AUTHOR]

Formaldehyde is a dangerous chemical present in many industrial waste gases. It can be recovered via catalytic processes; however, many of these require costly precious metals operating under limited reaction temperatures, making their industrialization difficult. This paper proposes a novel method of formaldehyde recovery. A sulfonation catalyst is used to promote a condensation reaction of methanol and formaldehyde to form methylal. Hence, a valuable chemical product is obtained while removing formaldehyde. A series of Al 2 O 3 -xSO 3 H catalysts were designed and the effects of surface acidity and hydroxyl groups on catalytic activity were explored by varying the activation temperature and sulfonation ratio. At an activation temperature of 60 °C, the yield of formaldehyde reaches 78.62% and the selectivity to methylal reaches 80.11%. This recovery rate is much higher than those reported in other studies. Through a series of characterizations, it was found that when the content of –SO 3 H groups is low, the hydroxyl content increases, which provides more activation centers for the formation of by-product formic acid from formaldehyde, and for the dehydration and condensation of formic acid and methanol to form methyl formate. At the same time, when the content of –SO 3 H groups is too high, side reactions of methanol and formaldehyde occur preferentially. Therefore, the synergistic effect of the contents of –SO 3 H and hydroxyl groups is the fundamental cause of the excellent catalytic performance. Based on in-situ infrared research, a possible mechanism of the reaction between methanol and formaldehyde on sulfonated silica gel is proposed, which also verifies the characterization of the catalyst. This research presents new possibilities for solving the problem of formaldehyde pollution. • Researched a new concept of formaldehyde recovery that "turns waste into treasure". • The recovery effect of formaldehyde is much higher than other studies. • Discovered the root cause that affects the catalytic activity of sulfonation catalysts. • Through in-situ infrared research, the reaction mechanism was proposed. [ABSTRACT FROM AUTHOR]

Active carbons simultaneously possessing large surface area (>2000 m2/g) and high pore volume (>2.0 cm3/g) are pretty promising electrode materials for capacitive desalination. However, it is challenging to find a simple, cheap, and scalable method for preparing such materials. In this research, H 3 PO 4 -loaded coconut shell was fast heated in steam flow to yield active carbon for capacitive desalination. The as-yielded active carbon simultaneously displayed large specific surface area (2869 m2/g), high pore volume (2.26 cm3/g), and big micropore volume (0.83 cm3/g). Because of these characteristics, the carbon showed an electrosorption capacity of 64.1 mg/g in a membrane capacitive deionization (MCDI) configuration at 1.2 V in 500 mg/L NaCl solution. The capacity ranked among the highest values ever reported for C-based materials. The capacity retention exceeded 86 % after 20 adsorption/desorption cycles. Besides, the carbon showed high charge efficiency (92.4 %) and desalination rate. This research was beneficial for scalable synthesis of carbon materials for CDI. [Display omitted] • Use of steam activation to reduce production cost and environment hazard. • The carbon shows high surface area (2869 m2/g) and big pore volume (2.26 cm3/g) • It has high electroadsorption capacity (64.1 mg/g) and charge efficiency (92.4 %). [ABSTRACT FROM AUTHOR]

An environmentally friendly lignin-based composite (Lignin-PEI) was facilely prepared via cross-linking enzymatic hydrolysis lignin matrix and branched poly (ethylene imine). The specific physicochemical and structural properties of lignin-PEI were characterized by elemental analysis, N 2 physisorption, GPC, TG, SEM, FT-IR and XPS. The nitrogen content of lignin-PEI was 9.02%, and the BET surface area was 20.32 m2/g. The synthetic composite showed high capacity and selectivity of Cr(VI) adsorption. The influence of solution pH, contact time, initial Cr(VI) concentration, and coexisting ions on Cr(VI) adsorption on lignin-PEI was systemically studied. The Cr(VI) adsorption on lignin-PEI was well described by the Langmuir model. According to the Langmuir model, the Cr(VI) adsorption capacity on lignin-PEI was as high as 898.2 mg/g at 318 K and pH 2.0. The calculated thermodynamic parameters, such as Δ G , Δ H , and Δ S , indicated the spontaneous and endothermic adsorption of Cr(VI) on lignin-PEI. The adsorption of Cr(VI) by lignin-PEI was following the pseudo-second-order kinetic model, indicating that it was a chemisorption process. The uptake mechanism was demonstrated to be electrostatic attraction, ion exchange, complexation and partial reduction. This work provided a promising candidate for Cr(VI) uptake with lignin-based biosorbents. Unlabelled Image • An eco-friendly lignin-based biosorbent was prepared by grafting PEI. • The maximum adsorption capacity of Cr(VI) was 898.2 mg/g. • Lignin-PEI had an excellent selectivity for Cr(VI). • The adsorption mechanism was proposed. [ABSTRACT FROM AUTHOR]

• Biomass components were classified into starch, cellulose, hemicellulose, lignin, protein and oil. • The devolatilization sensitivity was the order of hemicellulose > starch > oil > cellulose ≈ protein > lignin. • The E a was in the order of starch > oil > lignin > Hem > protein > cellulose. • Oil-rich biomass was a potential material for alkene. Pyrolysis of more biomass group components should be studied in order to obtain a more comprehensive understanding of various biomass pyrolysis. In this study, chemical properties of six biomass group components, namely, starch, cellulose, Hemicellulose (Hem), lignin, protein and oil, were evaluated and their pyrolysis behavior, gaseous product evolution, kinetics and product distributions were investigated using TG-FTIR and Py-GC/MS. The results indicated that their devolatilization sensitivity to heating rate followed the order of Hem > starch > oil > cellulose ≈ protein > lignin. Kinetic results revealed that it was difficult to pyrolyze for biomass rich in oil and lignin but easy to pyrolyze for biomass rich in cellulose, starch, Hem and protein. During their pyrolysis, polysaccharides (starch, cellulose and Hem) mainly generated oxygen-containing components such as C O and O-heterocycles; lignin mainly contributed to the formation of phenols (up to 81.4%); protein produced nitrogen-containing components (up to 52.71%), including N-heterocycles, pyrroles, pyridines, nitriles, and amines/amides; oil generated large quantities of alkenes (46.48%). Finally, this research would serve to gain further insight into biomass pyrolysis containing different group components. [ABSTRACT FROM AUTHOR]

• Tar catalytic reforming behaviors of biochar catalysts were critically compared. • The tar conversion efficiency could reach about 94.6% by Re-char catalyst. • The yield and compositions of gas products also changed markedly. • Attempt to propose the mechanism of tar reduction process over biochar catalysts. • The increase in temperature can promotes the polymerization of some tar components. The catalytic activity of biochar for tar removal was evaluated in a bench-scale combined fixed bed reactor by comparison of gaseous tar catalytic cracking behaviors over land (Corn stalks, Cs), coastal (Reed, Re) and marine (Sargassum horneri , Sh) char catalyst. The experiments demonstrated that the tar yield after addition of the biochar was reduced significantly; the tar conversion efficiency reached to 94.6% for catalytic at 850 °C with 50 mm char bed length using Re char. And the yield and composition of gas also changed markedly. The percentage of H 2 and CO in the product gas were obviously increased. Sh has a higher H 2 content (49.3% of the total gas content), whereas, CO dominated in the gas products for Cs (45.4%) and Re (48.1%). The results from GC–MS analysis illustrated that the increase in temperature promoted the tar cracking and also promotes the polymerization of some tar components. [ABSTRACT FROM AUTHOR]

• SPORL pretreatment by product was used to prepare lignosulfonate/N-methylaniline composite (LSMA). • LSMA represented prominent Cr(VI) removal performance. • Only 10 min was needed for fully removal of Cr(VI) with initial concentration below 100 mg/L. • Maximum adsorption capacity of 1264.8 mg/g of Cr(VI) was obtained by LSMA. • LSMA showed a good selectivity of Cr(VI). A lignin-based biosorbent (LSMA) was prepared by cross-linking lignosulfonate and N-methylaniline with the aid of ammonium persulfate for efficient removal of Cr(VI) from aqueous solution. Since LSMA possessed both amino groups and oxygen-containing functional groups, such as phenolic, carboxyl, and sulfonic groups, the maximum adsorption capacity of 1264.8 mg/g was achieved at 318 K according to the Langmuir isotherm. LSMA also showed excellent performance at low Cr(VI) concentration solution. The hazardous Cr(VI) solution of 50 mg/L can be fully removed within 10 min. The adsorption process of LSMA fitted the pseudo-second-order kinetic model, suggesting the chemical adsorption characteristics. Moreover, the adsorption process was spontaneous and endothermic. LSMA worked very well even with high content of competing anions. The removal mechanism was demonstrated to be the adsorption of Cr(VI) anions on LSMA with abundant functional groups, and reduction of Cr(VI) to less toxic Cr(III) by the adjacent electron donor groups. The generated Cr(III) was immobilized on LSMA by surface complexation and precipitation. LSMA composite has a great potential for the treatment of Cr(VI)-contaminated water. [ABSTRACT FROM AUTHOR]

1.5 wt. % Au/Al2O3 catalysts were prepared using the deposition‐precipitation or colloid‐deposition method and calcined at different temperatures for the selective oxidative esterification reaction of 1,3‐propanediol and methanol to form methyl 3‐hydroxypropionate (3‐HPM). The catalysts were characterized by nitrogen adsorption, transmission electron microscopy (TEM), X‐ray diffraction (XRD), UV‐Vis diffuse reflectance spectroscopy, X‐ray photoelectron spectra (XPS), CO2 temperature‐programmed desorption (CO2‐TPD) and NH3 temperature‐programmed desorption (NH3‐TPD). The effect of the calcination temperature of the catalyst prepared by the deposition‐precipitation method on the catalytic performance for the selective oxidative esterification of 1,3‐propanediol was studied. The results showed that the conversion of 1,3‐propanediol and the selectivity of 3‐HPM increased at first and then decreased with the increase of the calcination temperature of catalyst. The highest conversion of 1,3‐propanediol and selectivity of 3‐HPM at the optimal calcination temperature of 350 °C were 92.0% and 88.5%, respectively. Considering the effects of preparation method and calcination temperature, it could be concluded that the metallic Au nanoparticles with appropriate particle size in coordination with the suitable amount of weak and middle acid and base sites, were favorable to the oxidative esterification of 1,3‐propanediol and methanol to 3‐HPM. Moreover, we found that the 1.5 wt. % Au/Al2O3 catalyst could be effectively recovered without obvious decline of the catalytic properties. [ABSTRACT FROM AUTHOR]

Furfural residue (FR) is utilized directly for bioethanol production without any pretreatment and detoxification. With only 10 FPU g−1 cellulase loading, the glucose yield of FR reached 86.4, 84.6 and 80.5% at solid loadings of 2, 10 and 20%, respectively. When FR is directly used for fermentation, the terminal ethanol concentration achieved at 41 and 57 g L−1 at solid loadings of 20% and 30% (w v−1), respectively. Washing with water enhanced the enzymatic hydrolysis and fermentation of FR. The terminal ethanol of furfural residue washed by 5 times water (WFR‐5) was 48 and 66 g L−1, higher than that from FR. The enhancement is mainly due to the removal of chemical inhibitors and increase of specific surface area. The scanning electron microscope (SEM) showed that FR contained fragmental structure, coarse surface and porous areas. Therefore, FR substrates represented good cellulase accessibility. It indicated that FR could be directly used for glucose and ethanol production without any further treatment. In addition, the quasi‐simultaneous enzymatic saccharification and combined fermentation (Q‐SSF) residues are characterized by fourier transform infrared spectroscopy (FTIR) and thermogravimetry (TG). [ABSTRACT FROM AUTHOR]

• Fast pyrolysis behavior of typical coastal zone plants were critically compared. • High heating rates were chosen to simulating free-fall processes in TGA. • Down-tube reactor has been designed to investigate fast pyrolysis products. • Covalent bonds degradation rapidly in certain temperature under fast pyrolysis. • Temperature gave profound on the products distribution in a down tube unit. This study aimed at investigating fast pyrolysis behavior and products distribution of two typical coastal zone biomass fuels (Jerusalem artichoke stalk (JAS) and reeds (Re) by TGA and a homemade down tube reactor. The kinetic analysis with different ramping rates was conducted by FWO and DAEM models. The liquid, gaseous and solid products are characterized to study the influence of temperature. Results indicate that high heating rates may be overcome some resistances to mass or heat transfer inside the particles of biomass, and lead to a higher conversion rates and Re species is preferable to JAs in terms of thermochemical conversion because of the lower apparent activation energy for total conversion. Moreover, the pyrolysis conditions - temperature under fast pyrolysis in a down tube pyrolysis unit will make the covalent bonds in the biomass degradation more rapidly, gave significant influence on the yields and properties of liquid, gaseous and solid products. [ABSTRACT FROM AUTHOR]

Abstract ZSM-5 zeolite was an excellent shape-selectivity catalyst, but its micropore structure, high hydrogen transfer activity and acid strength limited its application in the processing of heavy oil. This study put forward to adding solid base calcium aluminate into ZSM-5 to crack the large-molecule oil, while the ZSM-5 was used to convert the small-molecule gas-oil into light olefins. The experiments of catalytic pyrolysis of vacuum residue (VR) over calcium aluminate and ZSM-5 mixed catalysts were investigated by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The results showed that the maximum light olefin relative content of 26.99% obtained with 50% calcium aluminate/50% ZSM-5, which was higher than that obtained with pure ZSM-5. Besides, the calcium aluminate/ZSM-5 catalyst (acid-base mixed catalyst) was more favorable to the formation of olefins compared with FCC/ZSM-5 catalyst (acid-acid mixed catalyst). To further study the cracking of VR over acid-base mixed catalyst, the catalytic characteristics of its eight group-fractions were analyzed. The saturate fraction contributed to the formation of light olefins, while the highest relative content of aromatic compounds was obtained from light aromatic fraction. The various fractions showed different yields of hydrocarbons due to their different composition and structure and the interactions among them affected the product compositions of VR. Highlights • Catalytic pyrolysis of VR and its fractions was conducted in Py-GC/MS. • The combination of calcium aluminate and ZSM-5 catalyst was used. • The maximum light olefins yield was obtained with 50% calcium aluminate/50% ZSM-5. [ABSTRACT FROM AUTHOR]

Highlights • Six compounds were selected as model compounds of biomass composition. • Pyrolysis experiments were performed under heating rate >100 °C min−1. • Castor oil had the highest E a whereas xylan had the lowest E a. • Biomass rich in lipids and cellulose was more suitable to produce energy. Abstract The aim of this work was to study the pyrolysis behavior of castor oil, corn starch, soy protein, lignin, xylan, and cellulose. The pyrolysis behavior, gaseous product evolution, kinetics and thermodynamics of these model compounds were investigated via TG-FTIR under high heating rates. The TG/DTG curves showed that castor oil had the widest pyrolysis temperature zone and lignin had the highest residual rate. The apparent activation energy of these model compounds was calculated by Kissinger-Akahira-Sunose method. The kinetic results revealed that the average bond energy of chemical compositions was in the order of lipid > lignin > starch > cellulose > protein > hemicellulose. The pre-exponential factor analysis showed that there were a large number of surface reactions for soy protein and xylan during pyrolysis, however other model compounds were not surface controlled. The thermodynamic parameters including G, Δ S, Δ H for six model compounds were also calculated. [ABSTRACT FROM AUTHOR]

Abstract In this work, the effects of heating rate on fast pyrolysis behavior and product distribution of Jerusalem artichoke stalk (JAS) were investigated fist by TG-FTIR (heating rates: 20, 30, 50, 100, 300, 500 °C/min) and then via Py-GC/MS (heating rates: 100, 1000, 5000 10000 °C/s). The results showed that with the heating rate increased, TG and DTG curves obviously shifted toward the high-temperature range, and the number of peaks in DTG curves reduced from three to two. The model-free method indicated that the apparent activation energy of JAS pyrolysis was 286 kJ/mol at the low heating rate and increased to 351 kJ/mol at the high heating rate. The distributed activation energy model showed that the value of pre-exponential factor increased with the heating rate increased and the kinetic compensation effect was obvious during the conversion from 0.3 to 0.7. Total 44 compounds were identified by GC/MS. Acid, phenol and carbonyl compounds were the major products groups. With the heating rate increased, the relative contents of acid increased whereas the relative contents of phenolic substance decreased. The yield of carbonyl compounds was maximum at the heating rate of 5000 °C/s. Highlights • The TG-FTIR experiment is conducted at a heating rate of 20–500 °C/min. • The activation energy is calculated without any mechanism assumptions. • Values of activation energy increase with increasing heating rate. • The heating rate of fast pyrolysis experiment reaches 10000 °C/s. • Increase heating rate improves acids productions while reduces phenols. [ABSTRACT FROM AUTHOR]

Highlights • Effect of alkali activation temperature on densities of ACs was reported. • Effect of alkali activation temperature on ACs' volumetric CO 2 capture capacity was studied. • ACs' true density was dominated by atomic carbon ratio, not by graphitization degree. • ACs fit for practical CO 2 capture should be judged by volumetric capture performance. Abstract Activated carbons (ACs) prepared by chemical activation were promising materials for CO 2 capture, but how to adjust their densities and volumetric CO 2 adsorption performance is unclear. We prepared ACs from petroleum coke by KOH activation to study impacts of activation temperature (540–820 °C) on densities and volumetric CO 2 adsorption performance of ACs. As the activation temperature increased, the true density rose whereas the apparent density and tap density decreased. The true density of ACs was dominated by aromatic-carbon ratio, not by the previously-believed graphitization degree. The activation temperature required to achieve the maximum volumetric low-pressure CO 2 uptake was lower than that needed to attain the highest gravimetric value (540 °C < 610 °C). When an AC was expected to display a high volumetric CO 2 adsorption capacity, its tap density and gravimetric CO 2 uptake should be moderate at least. The volumetric CO 2 /N 2 selectivity decreased with increasing activation temperature, mainly because of widening of micropore size distribution. This study provided new insights into ACs' densities, and highlighted judging ACs for CO2 capture by the previously-overlooked volumetric adsorption performance rather than only by the commonly-used gravimetric performance. [ABSTRACT FROM AUTHOR]

Highlights • A novel hierarchical millisecond gas-phase catalytic cracking process was proposed. • Five catalysts were compared to study the selectivity of C 2 -C 4 hydrocarbons and BTX. • The maximum light olefins yield was obtained with 30% calcium aluminat/70% ZSM-5. • A bench-scale was used to verify the potential application of VR to chemicals. Abstract In order to enhance the production of light olefins from vacuum residue (VR), a novel hierarchical millisecond gas-phase catalytic cracking (HM-GCC) process was proposed. The process integrated the pyrolysis of VR and the catalytic cracking of the pyrolysis oil in the gas phase. Firstly, the effects of reaction temperature on the millisecond pyrolysis behavior of VR were investigated, and the results showed that the increase of C 2 -C 4 hydrocarbons content was not obvious when increasing the temperature from 600 to 750 °C. However, the thermal cracking as a pretreatment process converted the VR macromolecule into the low molecular pyrolysis oil. After that, five different catalysts calcium aluminate, FCC catalyst, and ZSM-5 zeolites (Z-40, Z-80, and Z-200) were investigated to evaluate their activities in catalytic cracking of pyrolysis oil, and among them Z-40 showed the highest selectivity for C 2 -C 4 hydrocarbons and BTX. For further study, the relative contents of C 2 -C 4 hydrocarbons were higher for the combination of calcium aluminate and Z-40 (Z + C-cat) than that of the pure Z-40 catalyst. This result was attributed to the fact that Z + C-cat facilitated the cracking of macromolecules and inhibited hydrogen transfer reactions. Finally, the conversion of VR and pyrolysis oil was studied in the bench scales with calcium aluminate and Z-40 catalyst. The yield of ethylene, propylene and butenes increased by 4.69, 7.87 and 3.37 wt% respectively in the presence of Z-40. [ABSTRACT FROM AUTHOR]

Highlights • TG experiments are operated at a heating rate of 100–500 °C/min. • High heating rates promote the occurrence of devolatilization reaction. • Fast pyrolysis is carried out at a heating rate of 100–3000 °C/s. • The content of aromatics is increasing at final temperature of 500–1000 °C. • The content of alkanes reaches the maximum (37.03%) under residence time of 1 s. Abstract The chemical properties, pyrolysis behaviors and pyrolysis product distributions of Shenmu (SM) coal were investigated by proximate and ultimate analysis, thermogravimetric analyzer coupled with Fourier transform infrared spectroscopy (TG-FTIR) and Pyrolyzer coupled with gas chromatography/mass spectrometry (Py-GC/MS). The results of the proximate and ultimate analysis indicated that SM coal had less saturated aliphatic structures and more polar components. The coke yield for SM coal during pyrolysis process at 100 °C/min, 300 °C/min, and 500 °C/min was 65.60%, 64.19%, and 63.15%, respectively, which indicating that the increment in heating rates could promote the production of volatile substances. Moreover, there was a lateral shift to high temperature of TG/DTG curves when the heating rates increasing. The main volatile species detected from FTIR in the pyrolysis of SM coal were CO 2 , CO, CH 4 , C 2 H 4 , C2+ aliphatics, light arenes, C O bond containing species and C O bond containing species. Since the difference in the temperature intervals of those volatile species released, the sources of cleavage or chain scission during pyrolysis process were not the same. According to the fast pyrolysis by Py GC/MS, the volatile species could be divided into eleven species including alkenes, cycloalkenes, alkanes, cycloalkanes, aromatics, phenols, ethers, ketones, alcohols, N-containing species, and other species. The relative contents of alkenes and alkanes were dominant regardless of the variegation of heating rate, residence time and pyrolysis final temperature. Furthermore, the trend of each species under different influence factor conditions achieved different tunes rendered with equal skill. [ABSTRACT FROM AUTHOR]

Highlights • The reactivity of eight group-fractions can well reflect the reactivity of VR. • Activation energy values from the various fractions reveal their nature. • The release of gaseous products for saturates, aromatics and VR is similar. Abstract This study investigates the pyrolysis behaviors and kinetics of vacuum residue (VR) and its eight group-fractions using TG-FTIR. The weight loss properties of the fractions of VR suggest that each fraction has individual cracking pathways which are determined by the chemical nature of the constituents. The Friedman and Ozawa-Flynn-Wall (OFW) methods were used to calculate the reaction kinetic parameters of VR and its fractions, at heating rates of 10, 30, 50, and 100 °C/min. The activation energies of saturates and aromatics increased with the increase of conversion rates, whereas that for resins, asphaltenes and VR increased initially and then decreased. The on-line FTIR analysis of the gaseous products showed that the different structure of VR and its fractions leaded to the discrepancy of the release curves. Saturates and aromatics had significant release peaks at 530 − 750 °C, indicating they were the major contributors of methane, ethylene and light aromatics during the pyrolysis of VR within the temperature range of this study. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Collagens from tilapia skin were extracted and proved as type I collagen. • Yield of PSC are higher than ASC, opposite for thermal denaturation temperature. • Tilapia collagen microfiber matrix scaffolds with thermal stability were developed. • Tilapia collagen microfiber matrix scaffolds could accelerate skin wound healing rapidly and effectively in the rat model. Abstract Aquatic origin collagen (Aqua-collagen) has been pursued as an alternative to mammalian origins. Acid-soluble collagen (ASC) and pepsin-soluble collagen (PSC) were successfully extracted from the skin of tilapia with the yield about 19–20% (basis of lyophilized dry weight), and examined for their physico-functional and structural properties. Both ASC and PSC containing α 1 , α 2 chains were characterized to be type I collagen and had lower denaturation temperature compared to mammalian origins. PSC (low telopeptides collagen) was selected for biomedical scaffolds construction due to its low immunogenicity. SEM analysis of fish collagen scaffolds showed a wide range of pore size distribution, high porosity, and high surface area-to-volume ratios. The tilapia collagen microfiber matrix scaffolds were grafted beneath the dorsal skin in 96 mice towards tissue regeneration, with bovine collagen microfiber matrix scaffolds (Avitene™ UltraFoam™ sponge) serving as control. Biocompatibility evaluation in the dorsal tissue showed that implanted scaffolds degraded completely after 20 days with no pathological inflammatory tissue responses. These findings indicated that aqua-collagens microfiber matrix scaffolds were highly biocompatible in nature, exploring its feasibility for the development of scaffolds in tissue engineering. [ABSTRACT FROM AUTHOR]

Highlights • Two main pyrolysis stage of waste bicycle tire can be observed from TG. • The release characteristics of volatiles was consistent with pyrolysis behavior. • FTIR spectrum at different temperature indicated two main pyrolysis stages. • Pyrolysis mechanism of waste bicycle tire was free radical mechanism. Abstract Pyrolysis of waste tire is attracting widespread interest recently because of the great potential in waste valorization treatment. In this study, the thermal decomposition behavior, pyrolysis mechanism and products distribution of waste bicycle tire were investigated by means of TG-FTIR and Py-GC/MS. According to the TG results, two main pyrolysis stages of waste bicycle tire were observed, which were considered as the decomposition of rubber (285–531 °C) and further pyrolysis of pyrolytic products (663–847 °C), respectively. The volatiles release characteristics and FTIR spectrum at different temperatures exhibited good consistency with pyrolysis behavior. A detail information of pyrolysis products was analyzed by Py-GC/MS, which mainly include gaseous, alkenes and aromatics. The pyrolysis mechanism of waste bicycle tire was belong to free radical reaction, and the possible further pyrolysis pathway of D-limonene and styrene was also presented. Moreover, the products distribution under different pyrolysis final temperatures and heating rates conditions were summarized. Thus, this study could enhance our understanding on more specific details for the pyrolysis process of waste tire to some extent. [ABSTRACT FROM AUTHOR]

Highlights • Gasification reactivity of five different MSW chars with steam was discussed. • The main influence factors of gasification behavior were studied. • Kinetics parameters were calculated by three kinetic models. • RPM model performed best in most conditions of the gasification of MSW chars. Abstract Municipal solid waste treatment has been and will continue to be a major issue facing countries worldwide, and gasification has recently gained more attention as an efficient and clean technology. The steam gasification characteristics and kinetics of five different municipal solid waste chars had been investigated by the method of isothermal thermogravimetric analysis. The results showed that the gasification reactivity increased with gasification temperature. Effect of H/C and O/C ratios, ash composition and particle pore structure of chars on gasification reactivity were studied, which illustrated that the H/C and O/C ratios and ash composition had great influence on gasification reactivity and the pore structure cannot explain well in this study. A homogeneous model, unreacted shrinking core model and random pore model were employed to describe the kinetic behavior of different chars, and the kinetic parameters were also obtained. Finally, through the evaluation of the three kinetic models by comparing the experimental data with the fitted results, the random pore model was determined to perform best. This study should, therefore, be of some value to solid waste gasification industrialization. [ABSTRACT FROM AUTHOR]

Volatile compositions of coals during fast pyrolysis are principally governed by their bond structures and establishing the relationships between them is vital for deep understanding the pyrolysis mechanism. The structural features and bond information of Jining bituminous coal (JBC) were evaluated first by the combined advanced analytical tools. Subsequently, thermogravimetry coupled with pyrolysis-gas chromatography/time of flight mass spectrometry analysis were used to capture pyrolysis behavior and volatile species of JBC. The results showed that C O bond containing species were rich in JBC and mainly in the form of aryl ethers. Therefore, phenolic compounds were the most abundant species in volatiles during fast pyrolysis and C 6 C 9 phenols were the major constituent of this group. Average number of aromatic rings per cluster, number of substituents on each aromatic ring, and length of methylene chain in JBC were 3, 3–4, and 1.36, respectively. However, the three parameters calculated from the aryl-containing species in volatiles were all smaller than those of JBC. Cleavages of C al O, C al C al , C ar C al , and C ar O greatly contributed to volatile release and 67% of the mass loss during pyrolysis of JBC was caused by breakage of aliphatic C C and C H. Furthermore, pyrrolic nitrogen was found to be the most abundant form of organically bound nitrogen, but the pyrolysis volatiles contained more pyridine-N. [ABSTRACT FROM AUTHOR]

Pyrolysis of plastics has gained more attention recently due to the advantages of environmental protection and energy conversion. In this study, low-density polyethylene (LDPE), polypropylene (PP) and polyvinyl chloride (PVC) were studied under high heating rate conditions to investigate pyrolysis behaviors and find the most suitable kinetic reaction mechanisms. The TG and DTG curves for LDPE were similar to those for PP, but different from those for PVC. It was found that high heating rate led to the shifting of initial, end and peak temperatures to higher values. The FTIR results showed the main products of LDPE and PP were alkanes and alkenes, and the major products of PVC were HCl, alkenes and a small number of aromatic compounds. A comparative study of model-free methods like Ozawa-Flynn-Wall (OFW), Kissinger-Akahira-Sunose (KAS) and Friedman method were discussed to calculate activation energy. Kinetic reaction mechanisms were predicted by using model-fitting methods including Coats-Redfern and Criado method. The pyrolysis reaction mechanism of LDPE was summarized as contracting sphere model, PP was summarized as contracting cylinder model, whereas that of PVC was concluded that two-dimension nucleation for the first stage and three-dimension diffusion (Jander) for the second stage. [ABSTRACT FROM AUTHOR]

To enhance the performance of anti-coking and anti-sintering of the Ni-based catalysts during the reaction process of CO methanation, we synthesized a group of catalysts denoted as “Ni-xMgAl2O4” via the modified co-precipitation method utilizing carbon black as hard template. The addition of carbon black could significantly improve the specific surface area of MgAl2O4 to 235.8 m2 g−1. The Ni catalysts supported on high-surface-area MgAl2O4 (Ni-0.25MA) exhibited enhanced catalytic performance and hydrothermal stability in comparison with the conventional Ni-based magnesia alumina spinel catalysts with the same NiO content. In the process of 120-h stability test, the Ni-0.25MA catalyst exhibited remarkable improvement in both anti-sintering and anti-coking. After a series of characterizations, we found that the addition of carbon black could make more pores over MgAl2O4, resulting in the supported Ni particles being anchored in the pore rather than on the outside surface of support. This structure enhanced the dispersion of nickel nanoparticles, thus strengthening the interaction between nickel species and the MgAl2O4 support, which led to the promotion in catalytic activity and stability of high-surface-area Ni/MgAl2O4. [ABSTRACT FROM AUTHOR]

The ordered mesoporous NiRu-doped CaO-Al 2 O 3 nanocomposites were synthesized via a facile evaporation-induced self-assembly method for CO 2 methanation. Metallic Ni and Ru species retained the single-component heterostructure rather than NiRu alloy over the 600 °C-reduced catalysts. Owing to the synergistic effect of bimetallic Ni–Ru as well as the improved H 2 and CO 2 chemisorption capacities after the addition of Ru and CaO promoters, the ordered mesoporous 10N1R2C-OMA catalyst exhibited enhanced catalytic activity and selectivity, which achieved the maximum CO 2 conversion of 83.8% and CH 4 selectivity of 100% at 380 °C, 0.1 MPa, 30000 mL g −1 h −1 . In a 550 °C-109 h-lifetime test, the ordered mesoporous 10N1R2C-OMA catalyst showed high stability and superior anti-sintering property due to the confinement effect of the ordered mesostructure. [ABSTRACT FROM AUTHOR]

The Chemical structures of oil sand bitumen (OSB) derived from Buton and Xinjiang oil sands were determined by elemental analysis, FTIR and 1 H NMR. The thermal cracking behaviors and evolving characteristics of gaseous products of Buton and Xinjiang OSBs were investigated by using thermogravimetric analyzer coupled with Fourier transform infrared spectroscopy (TG-FTIR). Additionally, the composition and distribution of volatile products formed from the fast thermal cracking process of these two OSBs were evaluated via pyrolysis gas chromatography-time of flight mass spectrometry (Py-GC/TOF-MS). Results indicated that Xinjiang OSB featured stronger polarity and contained more aliphatic structures with shorter chain length and larger branching degree compared to Buton OSB. Whereas Buton OSB possessed a larger amount of aromatic structures and its condensation degree was lower than that of Xinjiang OSB. The thermal cracking process of these two OSBs were both mainly consisted of two reaction stages, including volatilization stage and main reaction stage. The coke yields for Buton and Xinjiang OSBs were 15.51% and 16.76%, respectively. CO 2 , CO, CH 4 , C 2 H 4 , light C 2+ aliphatic hydrocarbons and light aromatics were the typical gaseous products released from the main reaction stages of both two OSBs. The evolving behavior of each of the typical gaseous products except for CO 2 and light aromatics during the thermal cracking process of Buton and Xinjiang OSB featured good similarity. The volatile products formed during the fast thermal cracking process of Buton and Xinjiang OSBs were mainly divided into five types of compounds, including alkenes (1-alkenes, iso-alkenes and cycloalkenes), alkanes (n-alkanes, iso-alkanes and cycloalkanes), diolefins, aromatics and sulfur compounds. Among of them, alkenes was the most predominant type in volatile products and 1-alkenes were the most abundant products for both two OSB. Furthermore, Buton OSB has higher selectivities of 1-alkenes and n-alkanes compared to Xinjiang OSB. [ABSTRACT FROM AUTHOR]

A fixed-bed reactor was used to study the effect of water vapor on the efficiency of Hg 0 removal over CeO 2 -modified semi-coke. Adsorption experiments showed that the oxidation activity, and therefore, the mercury adsorption efficiency decreased with increasing water vapor concentrations. Hydrogen temperature-programmed reduction (H 2 -TPR) indicated that the oxidation activity of CeO 2 decreased after water vapor treatment. Fourier-transform infrared (FT-IR) studies revealed that CeO 2 -H 2 O showed new bending vibration peaks at 1110 cm −1 ascribed to Ce–OH groups. X-ray photoelectron spectroscopy (XPS) results showed that the content of Ce–OH increased from 20.85% to 39.99%, while the lattice oxygen content decreased from 68.21% to 45.83% after water vapor treatment. Density functional theory (DFT) calculations revealed that H 2 O can be dissociated on clean and oxygen-defective CeO 2 (1 1 1) surfaces to form H atoms and OH fragments. The H atoms associated with the adjacent oxygen atoms of CeO 2 , and the OH fragments were bound directly with Ce atoms to form Ce–OH for the clean CeO 2 surface; or occupied the oxygen vacancies and were surrounded by three Ce atoms via van der Waals forces, without additional bond formation for the oxygen-defective CeO 2 surface. Thus, the formation of Ce–OH groups and the consumption of lattice oxygens reduced the Hg 0 removal efficiency. [ABSTRACT FROM AUTHOR]

In order to examine the effective exploitation of high ash and high nitrogen content biomass, the fast pyrolysis behavior of mushroom bran (MB) and corn straw (CS) was studied utilizing high heating rate TG-FTIR and Py-GC/MS. TG was used to study the pyrolysis behavior of MB and CS under low and high heating rates followed by a seven-stage pyrolysis studies using Py-GC/MS. The results showed that at higher heating rates, there is an overlap of the decomposition of starch and hemicellulose, potentially leading to synergistic effects that would promote the formation of furan and furfural. At heating rates greater than 200 °C/min, nitrogen has a tendency to migrate from hydrogen cyanide to NH 3 before 450 °C. Deoxidation and denitrification mainly occurred between the pyrolysis temperature range of 300 °C to 350 °C, which merits further research. Staged pyrolysis interrupts the oil's continuous deoxidation process in comparison to direct pyrolysis, and it reduces the selectivity of aldehydes and ketones in MB and CS pyrolysis by 12.57% and 12.25%, respectively. More importantly, the study of staged pyrolysis in this work provides detailed pyrolysis characteristics for high nitrogen and ash content biomass, allowing for a better understanding of the pyrolysis behavior of such biomass. • Potential synergies were found via fast pyrolysis. • The staged pyrolysis process of MB and CS were analyzed and summarized. • 350 °C stage is the main deoxidation and nitrogen removal stage for MB and CS. • Staged pyrolysis can reduce the selectivity of oxygenated compounds in volatiles. [ABSTRACT FROM AUTHOR]

• Metal/acid catalysts with different structure and basicity/acidity were prepared. • Catalytic cracking conversion of crude oil to light olefins was conducted by Py-GC/MS and a fluidized bed reactor. • The coupling mechanism between metals and acid catalysts to form bifunctional catalysts was investigated. • Cracking characteristics, apparent kinetics, and product adjustment mechanism of crude oil were analyzed by TG-FTIR. Catalytic dehydrogenation cracking of crude oil to light olefins (CTO) was carried out by pyrolysis gas chromatography-mass spectrometry (Py-GC/MS) and a fluidized bed reactor. Cracking characteristics, apparent kinetics, and product release rules of CTO were analyzed by the thermogravimetric analyzer coupled with Fourier transform infrared spectroscopy (TG-FTIR). Results showed that dehydrogenation-cracking bifunctional catalysts could be obtained only when the properties of metals matched with acid catalysts. The bifunctional 1%Ca/ZSM-5 (1Ca/ZSM-5) catalysts can increase dehydrogenation, attenuate hydrogen transfer, and inhibit coking. Consequently, light (C 2 -C 4) olefins produced from 1Ca/ZSM-5 catalyst were enhanced significantly. There were mainly-two stages of pyrolysis and catalytic dehydrogenation cracking in the catalytic conversion of crude oil. The activation energy of bifunctional 1Ca/ZSM-5 catalyst decreased in the pyrolysis stage. The product adjustment mechanism by bifunctional catalysts was proposed from the perspective of structure and basicity/acidity, which would guide the maximization production of light olefins. [ABSTRACT FROM AUTHOR]

• Metal/acid catalysts with different structure and basicity/acidity were prepared. • Catalytic cracking conversion of crude oil to light olefins was conducted by Py-GC/MS and a fluidized bed reactor. • The coupling mechanism between metals and acid catalysts to form bifunctional catalysts was investigated. • Cracking characteristics, apparent kinetics, and product adjustment mechanism of crude oil were analyzed by TG-FTIR. Catalytic dehydrogenation cracking of crude oil to light olefins (CTO) was carried out by pyrolysis gas chromatography-mass spectrometry (Py-GC/MS) and a fluidized bed reactor. Cracking characteristics, apparent kinetics, and product release rules of CTO were analyzed by the thermogravimetric analyzer coupled with Fourier transform infrared spectroscopy (TG-FTIR). Results showed that dehydrogenation-cracking bifunctional catalysts could be obtained only when the properties of metals matched with acid catalysts. The bifunctional 1%Ca/ZSM-5 (1Ca/ZSM-5) catalysts can increase dehydrogenation, attenuate hydrogen transfer, and inhibit coking. Consequently, light (C 2 -C 4) olefins produced from 1Ca/ZSM-5 catalyst were enhanced significantly. There were mainly-two stages of pyrolysis and catalytic dehydrogenation cracking in the catalytic conversion of crude oil. The activation energy of bifunctional 1Ca/ZSM-5 catalyst decreased in the pyrolysis stage. The product adjustment mechanism by bifunctional catalysts was proposed from the perspective of structure and basicity/acidity, which would guide the maximization production of light olefins. [ABSTRACT FROM AUTHOR]

[Display omitted] • Longan shell and seed showed differences in several aspects. • Longan seed was easy to decompose and showed a lower E a of 160 kJ/mol. • Longan shell could produce more H 2 , CH 4 , HCHO, phenols, and aldehydes. • Longan seed char contained more Ca and Mg and had larger surface area. • Longan waste is a very favourable feedstock compared with other biomass waste. Longan waste (shell and seed) is a by-product of longan processing industry and accounts for near 90 % of the total fruit weight, which is a most promising renewable energy and can be converted into value-added chemicals and carbon materials by pyrolysis. However, detailed pyrolysis characteristics, kinetics, product formation mechanism, and char properties of longan waste were never studied. This work provided the first comprehensive investigations on the thermal decomposition of longan waste based on the combined pyrolysis method. The results showed that longan shell and seed were different in chemical compositions, pyrolysis characteristics, and product distributions. Longan seed was easy to decompose at a low temperature and showed a smaller E a of about 160 kJ/mol. However, longan shell could produce more H 2 , CH 4 , HCHO, phenols, and aldehydes compared with longan seed. The formation mechanisms of 6 gases and 33 condensable compounds were deeply discussed. In addition, longan shell char was rich in Ca/Mg-containing minerals, whereas longan seed char had a higher graphitization degree and a larger surface area of 236.4 m2/g. On the whole, the longan waste is a very potential feedstock for the productions of energy, value-added chemicals, and carbon materials in an efficient and environmentally sustainable way. [ABSTRACT FROM AUTHOR]

• Kinetics of pine and LDPE co-pyrolysis over basic and acidic catalysts were studied. • Co-pyrolysis of pine and LDPE showed a positive synergistic effect. • Catalytic co-pyrolysis can reduce the energy input and increase desired products. • The optimal base and acid catalysts are calcium aluminate and ZSM-5 (Si/Al = 40). • Base-acid tandem catalyst gave the maximum light olefins and BTX yield. Co-pyrolysis of pine and LDPE over basic catalysts (calcium oxide, calcium aluminate, and calcium ferrite), acidic catalysts (ZSM-5 with Si/Al ratios of 40, 80 and 200, commercial FCC and ZSM-5 based catalysts), and acid-base tandem catalysts were investigated by TG-FTIR and Py-GC/MS to improve light olefins and aromatics production. Research found that co-pyrolysis of pine and LDPE showed a positive synergistic effect and the addition of catalyst could reduce the average apparent activation energy of co-pyrolysis significantly. The optimal base and acid catalysts are calcium aluminate (CaAl) and ZSM-5 with Si/Al ratios of 40 (Z40), respectively. The highest content of light olefins and BTX (69.45 %) can be obtained over base-acid (CaAl-Z40) tandem catalyst at 600 °C, with CaAl to Z40 ratio of 1:1. This work will serve as a relevant reference for production of light olefins and BTX from the catalytic co-pyrolysis of biomass and plastics over base-acid tandem catalysts. [ABSTRACT FROM AUTHOR]

To convert the Xinjiang low temperature coal tar (XJ-CT) into high value-added chemicals, the coupling process of fast pyrolysis and catalytic cracking (FP-CC process) is proposed, and the related fundamental data is collected in this research. First, the composition of XJ-CT is analyzed by GC-GC/MS, and the result shows that the relative contents of alkanes, alkenes, aromatics, and the oxygen compound are 13.16%, 4.85%, 48.38%, and 29.29%, respectively. Then, the performance of XJ-CT fast pyrolysis is evaluated under different reaction temperature. The results show that aromatics is predominant among the pyrolysis vapor, whereas the yield of aliphatic products enhances with the increase of temperature. And the aliphatic products are mainly formed from the deep cleavage of long-chain aliphatics and alkyl side chains (alkyl bridge chain) of aromatics. Meanwhile, the relative content of oxygen-containing compounds decrease with the increase of temperature. Furthermore, molecular distributions of the major groups in pyrolysis vapor with different temperatures are summarized to gain insight into the pyrolysis process. Finally, the ZSM-5 (40), ZSM-5 (200), and USY zeolite are used to catalyze the pyrolysis vapor. It is demonstrated that the maximum light olefin yield of 31.79% is obtained over ZSM-5 (40), while converting XJ-CT to liquid fuels can be realized on USY zeolite. • A novel fast pyrolysis and catalytic cracking (FP-CC) coupling process is proposed. • Effect of temperature on molecular distribution of pyrolysis vapor for XJ-CT is revealed. • The maximum light olefin yield of 31.79% is obtained over ZSM-5 (40). [ABSTRACT FROM AUTHOR]