Production cost can be reduced in preparation of powdered activated coke (PAC) by achieving higher SO2 adsorption capacity and lower burn-off. In this study, for the rapid preparation of PAC from pulverized coal, response surface methodology (RSM) based on central composite design (CCD) was used to develop the second order quadratic models of SO2 adsorption capacity and burn-off. Analysis of variance (ANOVA) was used to determine the effective parameters of the two models, and to explain the accuracy and fitness of them. In addition, the 3D response surface plots illustrated the influencing rules of the variables and their interactions. Further, multi-objective optimization was performed to maximize SO2 adsorption capacity and minimize burn-off using the desirability function. Optimal process parameters obtained were: reaction temperature, 923.97℃; oxygen concentration, 5.89% and vapor concentration, 20.04%; and the corresponding prediction results were: SO2 adsorption capacity, 110.31mg/g; burn-off, 47.45%. Confirmation experiment at the optimal condition was carried out, and the experimental results were consistent with the model prediction results, further verifying the accuracy and fitness of the models. The optimization results would provide guidance for the design and operation adjustment of large-scale industrial applications in the future.

De-inking sludge (DIS) is generated as a waste stream from secondary fibre paper mills during the de-inking stage of the paper pulping process; in order to ensure end of waste to landfill an alternative valorisation route is required for this waste. At the same time, an inexpensive sacrificial catalyst is essential to achieve the techno-economic feasibility of biomass gasification and pyrolysis. The present work explores the potential of DIS char as a catalyst using a 2 kg/h Thermo-Catalytic Reforming (TCR®) system, which involves intermediate pyrolysis combined with a unique integrated catalytic reforming step. Wood was used for the TCR catalytic experiments with a DIS char to biomass ratio (wt.%) of 0.3:1 and 0.65:1. Results have shown that hydrogen relative volumes and syngas yields, are positively correlated with the increase in DIS char to wood ratio. Average hydrogen relative volumes of 28.30 vol.% and syngas yields of 47.64 wt.% were achieved. Organic liquid yields were significantly reduced in favour of higher syngas yields, implying the suitability of DIS char as a tar reduction catalyst in gasification or pyrolysis. The influence of TCR DIS char is less profound on the chemical distribution in the organic phase of bio-oil; a reduction on PAHs from 38.82% to 26.70% though was determined with the use of DIS char, according to the relative abundance peak areas from the GC-MS chromatograms. The oxygen content of bio-oil was significantly reduced due to cracking of higher molecular weight organics.

Investigation on the biomass components pyrolysis behaviors in a lab-scale reactor is a necessary step before its industrialization due to the poor transportability of the findings obtained from the micro-scale pyrolyzer which often neglects the heat and mass transfer effect. In present study, the pyrolysis behavior of xylan-based hemicellulose in a fixed bed reactor was investigated. The residue evolution and bio-oil composition of xylan, xylose, arabinose and glucose show the close relationship of pyrolysis characteristics between xylan and its components. It is noteworthy that the xylan and those mono-sugar units melted during pyrolysis, and many bubbles formed. Investigation of the effect of temperature, material thickness and carrier gas flow rate on the products distribution and bio-oil composition indicates that high temperature promotes the xylan conversion and increases the yield of bio-oil, however, if the temperature is too high (> 500°C), violent decomposition of xylan occurs and leads to the formation of low molecular weight compounds (such as hydroxyl acetaldehyde, acetic acid and 1-hydroxyl-2-propaone etc.). And interestingly, the bio-oil yield increases monotonically with the material thickness, and thick material layer can increase the content of furfural in bio-oil. Carrier gas flow rate has a little influence on the xylan char yield, and relative high carrier gas flow rate (> 2.55L/min) could decrease the secondary decomposition of primary didehydrated pentose but reduce the bio-oil yield.

This study pursues the valorization of waste tires by pyrolysis using a different approach for tire parts, specifically, the tire tread rubber and side wall rubber. Tire tread rubber was used to produce hot char with the purpose of using it as cracking catalyst. Side wall rubber was valorized by pyrolysis and online catalytic pyrolysis over tire tread rubber derived hot char in two fixed bed reactor. This work aims to improve the quality of pyrolysis products using tire tread rubber derived hot char as catalyst. The thermal decomposition behavior and products characteristics were tested by means of TG-FTIR, GC, GC-MS, nitrogen adsorption and SEM. Under catalytic pyrolysis temperature of 500-550 °C, a high yield of valuable single ring aromatics (concentration in the oil of 50 %) was obtained. The yield of gas can reach 10.5 wt.% after catalytic pyrolysis, which only 3.0 wt.% without catalytic pyrolysis. The yield of undesirable byproducts as PAHs and carbon deposits was also limited. This strategy represents a novel and feasible alternative to traditional waste tire catalytic pyrolysis processes using expensive catalysts as zeolite.

In this paper we examined the effect of moisture on the solvent liquefaction of loblolly pine, cellulose, and lignin in tetralin at 280 °C and pressures ranging from 15 to 70 bar. Solvent liquefaction experiments were conducted in a quasi-batch reactor capable of continuous pressure control and external vapor condensation. Moisture was varied by the controlled addition of de-ionized water. Control over the system pressure subsequently impacted the removal of water vapor from the reactor. Liquid yield decreased by 25, 21, and 35 wt%, for pine, cellulose, and lignin, respectively, when moisture content was increased from 1 to 50 wt% at 42 bar. Humins were observed in the solid residue from liquefaction of wet cellulose. Wet lignin yielded a substantial amount of solid residue compared to dry lignin with a corresponding decrease in total phenolic monomer production. It was concluded that the ionic dissociation of water was an important factor in loss of liquid yield in the presence of water. Although water was less than 20 wt% of the solvent loading in these experiments, it strongly influenced the liquefaction of biomass and biomass components.

Poplar-derived lignin-rich feedstock (i.e. stillage) obtained from bioethanol production was subjected to fast pyrolysis in a modified fluidised bed reactor at 430 °C, 480 °C, and 530 °C. The stillage was pretreated by enzymatic digestion prior to fast pyrolysis. Pyrolysis vapors were collected by fractional condensation to separate the heavy organic and aqueous phase liquids. The intention of this study was to assess the potential utilization of lignin-rich digested stillage as a fast pyrolysis feedstock. Heavy organic and aqueous phase pyrolysis liquids were obtained in yields ranging from 15.1 to 18.1 wt.% and 9.7 to 13.4 wt.% respectively. The rest of the feedstock material was converted to char (37.1 to 44.7 wt.%) and non-condensable gases (27.1 to 31.5 wt.%). Detailed liquid analysis indicated that the heavy organic phase fractions contain compounds arising from the degradation of lignin, residual microbial biomass and remaining polysaccharides. Fast pyrolysis adds 26.8 wt.% to the conversion of this otherwise recalcitrant feedstock material, thereby reducing waste generation and enhancing the value of second-generation bioethanol production.

Catalytic cracking recovery of polyolefins is a research hotspot at present. The addition of catalyst also increases the operation cost. So, the product selectivity and stability of catalysts are very important. In this paper, the synthesis and properties of ordered mesoporous Fe-SBA-15and their applications in PP catalytic cracking have been studied. The ordered mesoporous Fe-SBA-15 has been successfully synthesized by the acidity of Fe ion hydrolysis. The specific surface area of synthesized Fe-SBA-15 was between 890 and 750 m2/g, and the average pore size was 8-10 nm. With the increase of Fe/Si ratio, the acid content of the strong acid sites of Fe-SBA-15 also increases, and the acid content of weak acid sites increases first and then decreases. Fe-SBA-15has strong catalytic cracking properties and good cyclic performance. Compared with thermal cracking, the catalytic cracking of PP can shorten the heating time, decrease the solid and gas product. With the increase of Fe/Si ratio, the catalytic activity also increases. Moreover, the cyclic performance test of the catalyst is carried out by Fe-SBA-15 with Fe/Si ratio of 0.15andthe results indicate that it has strong cycle stability.

The pyrolysis behaviors of seven kinds of polyurethane elastomers (PUEs) with different ratios between the hard segment (HS) and soft segment (SS) were investigated for both fast pyrolysis (300, 350, 450, 850 °C) and slow pyrolysis at the heating rate of 10 °C min–1 by thermogravimetric analysis (TG), pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), and evolved gas analysis-mass spectrometry (EGA-MS). These PUEs were synthesized from 4,4’-diphenylmethane diisocyanate (MDI), 1,4-butane diol (BD), and poly(oxytetramethylene glycol) (PTMG). Atomic force microscopy measurements found that the HS domains were formed in PUEs containing HS, and these domains were aggregated at extremely high HS ratio. The main pyrolysate derived from HS was MDI under all conditions. In fast pyrolysis tests, the decomposition of SS proceeded sufficiently at 450 °C, and a lot of low molecular weight compounds were produced at 850 °C. In slow pyrolysis tests, three-step degradation was observed, and this degradation behavior was influenced by the HS domain and SS matrix structures. The first step is the HS pyrolysis inside the HS domain, then the HS surrounded by SS is pyrolyzed. Finally, the SS matrix is pyrolyzed. The HS pyrolysates changed from isocyanate to amine with increasing temperature. We believe that the newly found pyrolysis behavior of PUEs with different ratios between the HS and SS will promote future studies on the characterization of PUE materials and the pyrolytic recovery of chemical feedstock from PUE wastes.

The liquefaction of corn cobs and switchgrass was studied using 1-(3-propylsulfonic)-3-methylimidazolium chloride and 1-(4-butylsulfonic)-3-methylimidazolium chloride Brønsted acidic ionic liquids as catalysts in acetone at 120 °C for 5 h. The highest biomass conversions to liquefied bio-oil for corn cobs and switchgrass are 63.4 ± 0.9 and 56.4 ± 0.9 % (w/w) respectively. The liquefied products were fractionated to polar and non-polar fractions by solvent extractions and analyzed using liquid chromatography - mass spectrometry (LC-MS) and gas chromatography - mass spectrometry (GC-MS). The weights of polar fraction : non-polar fraction was 2 : 1 for all liquefied bio-oils. Sixteen products were identified from the polar fractions of liquefied bio-oils, whereas nineteen products were identified from methylene chloride soluble non-polar fractions. The compounds formed as a result of cross aldol condensations of biomass derived furans furfural and 5-hydrxymrthylfurfural with one or more acetone molecules were identified in bio-oils. Four lignin derived compounds were also found in non-polar factions of liquefied bio-oils. Corn cobs with higher hemicellulose content produced higher liquefaction product yields indicating that hemicellulose is more easily liquefied under the conditions used. The two catalysts, 1-(3-propylsulfonic)-3-methylimidazolium chloride and 1-(4-butylsulfonic)-3-methylimidazolium chloride produced practically comparable liquefaction yields, showing that structural effect of one methylene group in the catalyst is not significant.

Pyrolytic products have been historically used as a therapeutic treatment for psoriasis, a dermatological inflammatory disease. However, little is known about the mechanisms involved in their pharmacological activity. The main goals of this work were to characterize pyrolytic fractions derived from Amphipterygium adstringens bark, a plant used in Mexican traditional medicine, and to study the effects of pyrolytic oils as anti-IL-17 agents on HaCaT keratinocytes. A. adstringens biomass and pyrolytic fractions were first characterized by proximate, elemental analysis, FTIR, Py-GC-MS, GC-MS, UV-fluorescence and HPLC-DAD to determine its physicochemical composition. Toxicity of pyrolytic oils was further assessed on HaCaT keratinocytes by the MTT method and the non-cytotoxic concentrations were used to determine their effects on IL-8 production of IL-17-stimulated HaCaT keratinocytes. The result obtained show that pyrolytic oils are very rich in phenols, some of them recognized by their anti-inflammatory properties. Pyrolytic oils showed significant inhibitory effects on IL-8 production, suggesting that they could be potentially explored for treating IL-17 driven dermatological diseases such as psoriasis.

The pyrolytic behaviour of two oligosaccharides – cellobiose and cellohexose – was studied using reactive pyrolysis-GC/MS with in situ hexamethyldisilazane derivatisation. Pyrolysis was conducted in a sealed vessel at various times ranging from 0.2 to 60 min. Semi-quantitative calculations were carried out on integrated peak areas to obtain information on derivatisation efficiency and composition of the pyrolysate as a function of pyrolysis time. The results were compared with a previous work by us in which glucose and cellulose were studied with the same procedure. The relative areas of anhydrosugars were found to decrease with the increase of the degree of polymerisation of the substrate, while the derivatisation efficiency showed an opposite trend. The results were explained by considering the role of both the sealed environment and free water molecules released during the pyrolysis process. We hypothesised that higher amounts of water were released from glucans with low degrees of polymerization, hindering both secondary pyrolysis reactions and derivatisation efficiency. Glucans with high degrees of polymerization, on the contrary, showed high signals of secondary pyrolysis products, consistent with a lower amount of water and the formation of a liquid phase.

O2/H2O oxy-fuel combustion, as one of the most promising combustion technologies for CO2 reduction, has become a hot spot around the world. In oxyfuel combustion, H2O gasification has an important effect on the overall reaction process. This paper used Chinese Shenhua coal as raw material to decouple the effect of H2O on the whole process of raw coal-H2O gasification reaction. At 800 °C in 15 vol.% H2O, the changes of gas-liquid-solid phase product concentration and the development of char structure in the coal-H2O gasification were investigated. The MFBRA was used to analyze the rapid coal-H2O gasification reaction, while the slow-heating-rate gasification of coal was analyzed by TG-FTIR-MS. The results show that in the rapid single-particle reaction at 800 °C, H2O promotes the whole devolatilization of coal, with a certain inhibitory effect on the secondary gas-phase reaction, especially for the H2 release. H2O increases the oxygen-containing functional groups on the char surface and increases the structural defects in char. H2O would increase the -COO- groups, and promotes the consumption of C = C on the surface. H2O has an obvious etching effect on the char surface. For slow-heating-rate gasification of coal, the reaction has obvious secondary weightlessness, and H2O promotes initial devolatilization, but has an inhibitory effect on the secondary one. At >700 °C, the H2O gasification is more pronounced than that of a single-particle rapid reaction. H2O reduces the activation energy of the initial stage and increases the reaction activation energy of the secondary one during devolatilization. H2O can promote the consumption of aromatic liquid-phase products such as toluene and phenol during devolatilization of pulverized coal under the slow-heating condition.

In this paper, pyrolysis behaviors of oxygen-containing structures of Xilinhaote (XLHT) lignite in hydrogen donor solvent (HDS) were investigated to reveal the effect of HDS on the pyrolysis sequence characteristics of XLHT and the difference of the pyrolysis behaviors of oxygen-containing structures in the presence or absence of HDS. Results showed that coal conversion was closely associated to the decomposition of oxygen-containing structures of lignite, and HDS could promote the cleavage of oxygen-containing groups and inhibit the resolidification of decomposed products, while its effect on the pyrolysis sequence of different structures of lignite was tiny. Thermal cleavage of weak aryl-alkyl ether bonds and carbonyl groups of lignite at relatively low temperatures of 280-380 °C contributed to the depolymerization of XLHT lignite to form preashphaltene (PA) with coal conversion and PA yield increasing from 12.85% and 1.98% to 64.58% and 13.08%, respectively. As the temperature rose to 430 °C, coal conversion was up to 84.13%, and HDS could promote the cleavage of relatively stable oxygen-containing groups, aryl-aryl ethers, and methylene structures, which was the major contributor to increase coal conversion at relatively high temperatures during liquefaction. Besides, C-O and C = O moieties retained on the surface of LR at 430 °C, which netted 12.54% and 3.52% of carbon single bond forms, respectively.

Co-pyrolysis behaviors of MLS with Hami sub-bituminous coal (HM) were examined by a thermogravimetric analyzer coupled with a mass spectrometer and the kinetic characteristics were interpreted with simplified distributed activation energy model, aiming at understanding the co-pyrolysis characteristics and interactions between MLS and coal, and providing some useful guidance for the efficient utilize of MLS. Two special crucible reactors with or without a vertical baffle were made to investigate the interactions between MLS and HM during co-pyrolysis. Results show that the amount of C-H bonds in MLS is more abundant, but the oxygen-containing functional groups are less compared with HM. The pyrolysis reactivity of MLS is higher than that of HM, and that of blends increases with the MLS dosage increasing. The co-pyrolysis behaviors including weight loss, weight loss rate and the gas emission characteristics of MLS and HM in the two crucibles were compared, and it is found that the different results are related to pyrolysis temperature and MLS dosage. The role of promoting release of volatiles is mainly caused by the hydrogen supply from MLS and the opposite effect is mainly ascribed to the heat and mass transfer caused by low softening point and strong cohesiveness of MLS. In addition, the activation energies of co-pyrolysis of the blends significantly decrease with the increase of MLS dosage.

This paper reports the enhanced production of hydrogen gas and polyaromatics during lignite pyrolysis using a pressurized entrained-flow reactor. The pyrolysis temperature and pressure ranged between 600-900 °C and 0.1-4.0 MPa, respectively. Both pyrolysis temperature and pressure were found to greatly influence the yield and composition of pyrolysis products. The results showed that the yield of H2 in the light gas fraction drastically increased with pyrolysis temperature and pressure, reaching 91.69 vol% at 900 °C and 4.0 MPa, which corresponded to H2 generation of 1.49 m3/kg coal. The yields of polycyclic aromatic hydrocarbons (PAHs) such as naphthalene, biphenylene, fluorene, phenanthrene, pyrene, and fluoranthene were promoted at elevated pyrolysis temperatures and pressures. The highest PAHs concentration of 90.4 area% was also obtained at 900 °C and 4.0 MPa. It was also found that the changes in hydrogen distribution under pressurized entrained-flow conditions mainly took place during the secondary pyrolysis reactions. It was postulated that hydrogen was formed via aromatization, condensation, and direct cleavage reactions. The findings of this study showed that lignite could be efficiently converted to hydrogen-rich gas, PAHs as selective chemical raw materials, and energy-dense lignite char via a novel poly-generation system based on pressurized entrained-flow pyrolysis.

Thermochemolysis-GC-MS was used to characterize Methicillin resistant Staphylococcus aureus (MRSA) and a predatory actinobacteria isolated from Moroccan marine water through their membrane fatty acids released as methyl esters (FAMEs). FAMEs from MRSA were dominated by branched iso and anteiso C15, straight C18 and C20 whereas the predatory actinobacteria was dominated by branched C14, iso and anteiso C15, and straight C16. The iso to anteiso C15 ratio was 0.44 for MRSA and 0.9 for the actinomycete. A co-culture of actinomycetes and bacteria was conducted during 15 days. An increase in the iso to anteiso ratio, a decrease in C18 and C20 FAMEs and an increase in branched C14 and C16 FAMEs demonstrated the predation of MRSA by the actinomycete. The total amount of FAMEs which was significantly higher in the studied actinobacteria (83 mg/g) compared to MRSA (17 mg/g) increased during the co-culture demonstrating the predation. Principal Component (PCA) and Hierarchical Cluster Analysis (HCA) were used to correlate fatty acids (FA) distributions with the strains. HCA allowed to discriminate between MRSA and the actinobacteria. With PCA, long chained (>C18) FAMEs correlated with MRSA whereas short branched-chained FAMEs correlated with the actinobacteria and T15. Consequently, a clear distinction in the chemotaxonomy of MRSA and actinobacteria was established by PCA. Additionally, PCA highlighted the predation of MRSA by the actinobacteria through dissimilarity between MRSA and T15 and similarity between actinobacteria and T15.

Temperature rise characteristics of subbituminous coal impregnated with KOH in a wide range of KOH/coal ratio (w/w, 0.25∼2) under microwave (MW) heating were investigated and the catalytic performance in methane decomposition (CMD) over the resultant activated carbon (AC) was measured. The results showed that with the increase of KOH content, the temperature rise ability of the coal-KOH adduct under MW-field increases gradually, and the maximum temperature that can be increased from 170℃ to 880℃. The increase of aromaticity due to the structural rearrangement of the coal aromatic layers during KOH impregnation and the release of volatiles during MW-heating provides the main driving force for the continuous increase of temperature. When KOH/coal ratio is 1.5, it took 224 seconds for coal-KOH adduct to rise from room temperature to 800℃, with the development of specific surface area ( SBET) and pore volume to the maximum of 661.8 m2/g and 0.512 cm3/g, respectively. However, the catalytic activity of AC with the largest SBET for CMD is not the highest. At 800℃ and higher temperatures, the increase of active site number on the surface by the potassium intercalation mechanism promotes the catalytic activity of AC. Therefore, the research core of carbon-based catalysts from coal is to increase the number of active site, not the SBET alone.

Co-pyrolysis characteristics of cornstalk with two types of coal (lignite, bituminous coal) were investigated using thermogravimetry coupled with Fourier transform infrared spectrometry (TG-FTIR). Pyrolysis thermal behaviors of biomass and coal samples and their blends in different blending ratios were revealed by TG and DTG profiles, and an online monitoring of gas products evolved was realized by FTIR measurement. In order to explore potential synergistic effect, characteristic values of TG and DTG curves were identified for all blended and parent samples. In the meantime, evolution characteristics of CO2, CO, CH4, H2O and formic acid were identified by FTIR profiles against temperature. Slight synergistic effects were approved by both TG and FTIR analysis, which resulted in higher char yields and influences on volatile evolution during co-pyrolysis. 0.3∼7.4 % higher final residual yields than expected were confirmed in co-pyrolysis. TG results showed that thermal behavior of biomass was remarkably influenced with the presence of coal in blended samples at 286–306 °C. FTIR profiles also indicated that the evolution of formic acid was affected according to the releasing characteristics of CO and C–O groups at the same temperature region. SEM images and BET analysis of residual char provided further information about synergy. Disparity of thermal behaviors and void spaces between parent biomass and coal brought favorable conditions for adsorption and coking of both biomass and coal volatiles, which led to different gas-solid interactions and significantly changed the surface morphology and porous structure of co-pyrolyzed char particles.

In this work, a new potential route to convert free fatty acids to long chain nitriles and fuel gas (H2/hydrocarbon) intermediated by Fe nitrate is proposed. Precursors based on Fe3+/RCOO-/NO3- were prepared by mixing Fe nitrate and oleic acid at the molar ratios 1:1 and 1:3. After pyrolytic decomposition at 550 °C, these precursors yielded three fractions, i.e. solid (8-27 wt%), liquid (22-51 wt%) and gaseous (41-51 wt%). TG, XRD, SEM, Raman, Mössbauer, CHN analyses of the solid products showed the presence of 25-52% carbon with reduced iron oxides (Fe3O4 and FeO). Analyses of the liquid fraction by GCMS, 1H/13C-NMR, CHN and FTIR clearly indicated the formation of nitriles as the main products, with selectivity of ca. 80% and small amounts of hydrocarbons and ketones. A large gas fraction composed mainly by hydrogen and hydrocarbons (especially C3) was also formed.

In this study, experiments were conducted to systematically determine how the surface morphology, microcrystalline and thermal transformation characteristics of coal change during acid treatment. HCl-HF acid washing was applied to pretreat the raw coal. The effects of the demineralization treatment on the carbonaceous structure and functional groups were first tested using X-ray diffraction (XRD), Raman spectroscopy and Fourier transform infrared spectroscopy (FTIR). The results show that the demineralization treatment significantly removes the peaks of inherent mineral matter (based on XRD), enhances the disorder in the structure of the coal (based on Raman spectroscopy), and changes the structure of C = O, the aromatic structure and the aliphatic side chains (based on FTIR). The surface morphologies of the raw coal and demineralized coal were then studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results show that the demineralized coal has a greater surface roughness than the raw coal. The surface morphology of the macerals show that the demineralization treatment transforms the vitrinite peaks to valleys and increases the depths of the valleys; furthermore, the demineralization treatment cause the peaks and valleys of the surface roughness to interchange. Finally, pyrolysis experiments of the raw coal and demineralized coal were conducted with thermogravimetric analysis (TGA) and a fixed-bed reactor, and the subsequent gas and tar compositions were characterized by gas chromatography (GC) and gas chromatography–mass spectrometry (GC-MS). The results show that the pyrolysis reactivity of coal is decreased by demineralization treatment. The pyrolysis experiments in the fixed-bed reactor indicate that the pyrolysis conversion rate increases with the base-acid ratio of the inherent mineral matter. The pyrolysis products show that the amounts of H2 and CH4 increases due to the presence of the inherent mineral matter. The inherent mineral matter can also promote the cracking of aliphatic hydrocarbons, polycyclic aromatic hydrocarbons and oxygen-containing compounds in the pyrolysis tar.

Ethylcyclohexane is a representative component of endothermic hydrocarbon fuel. The present work involved a comprehensive investigation of the pyrolysis process of ethylcyclohexane at different temperatures and times as well as its kinetics. At the test temperature T ranges from 683 to 723 K, the pyrolysis process of ethylcyclohexane conformed to the first-order kinetics. The apparent rate constants at different test temperatures were obtained, along with the corresponding Arrhenius parameters of pre-exponential factor A = 1.14×1015 s-1 and apparent activation energy Ea = 270 kJ/mol. The kinetics parameters for the pyrolysis of ethylcyclohexane were compared with those of several typical hydrocarbon compounds, and the results showed that thermal stabilities at given temperatures were arranged with the following order: 1,3,5-triisopropylcyclohexane < bicyclohexyl < n-propylcyclohexane < ethylcyclohexane ≈ decalin. The total heat sink of ethylcyclohexane, including the physical and chemical heat sink, was then calculated. Thermal decomposition led to an increase of heat sink by approximately 17 percent. Furthermore, based on the result of product distribution and quantum calculation result, we proposed a mechanism to clarify the pyrolysis process of ethylcyclohexane.

The pyrolysis reactions of hardwood and softwood were investigated using evolved gas analysis and mass spectrometry (EGA-MS) and by treating the experimental data with isoconversional methods to obtain kinetic information. Mass spectrometric detection allowed the identification of the pyrolysis products to be performed and component-specific thermograms were obtained by the extraction of appropriate m/z values without the need of peak-fitting. Finally, isoconversional methods, both an integral and a differential method, were used on compound-specific thermograms to calculate apparent activation energies of the carbohydrate and lignin fractions separately. The results showed that the two isoconversional methods provide comparable results, and that there are significant differences between the activation energies of the holocellulose and lignin fractions. This work shows that EGA-MS can provide reliable kinetic data for multi-component samples without the need of chemical pre-treatments or signal deconvolution.

An on-probe pyrolyzer has been constructed and interfaced with Desorption Electrospray Ionization (DESI) Mass Spectrometry (MS) for the rapid analysis of non-volatile pyrolysis products. The detection and analysis of non-volatile pyrolysis products of peptides, proteins and the synthetic polymer poly(ethylene glycol) are demonstrated with this instrument. The on-probe pyrolyzer can be operated off-line or on-line with the DESI source and was interfaced with a tandem MS (MS/MS) instrument, which allowed for structure characterization of the non-volatile pyrolytic products. Advantages of this system are its simplicity and speed of analysis since the pyrolysis is performed in situ on the DESI source probe and hence, it avoids extraction steps and/or the use of matrices (e.g., as in MALDI-MS analyses).

Photochemical degradation of commercial polyvinyl acetate (PVAc) homopolymer and PVAc paints mixed with burnt umber, cobalt blue, cadmium red dark, nickel azo yellow and titanium white commonly used for artworks were studied by pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and Fourier transform infrared spectroscopy-attenuated total reflectance (FTIR-ATR). Py-GC/MS with single-shot technique was used for the characterization of the thermal degradation of PVAc at different temperatures, while the double-shot technique of Py-GC/MS was used to reveal the differences in the specimens before and after UV ageing, including the changes of detectable amounts of deacetylation product - acetic acid and plasticizers such as diethyl phthalate (DEP). Furthermore, the relative concentration of the pyrolysis products of the paint samples could be measured and compared in the second step of the double-shot Py-GC/MS, which are highly dependent on the presence of pigments and the ageing status of PVAc paints.

The experimental results on detection and identification of intermediate radicals and molecular products from gas-phase pyrolysis of cinnamyl alcohol (CnA), the simplest non-phenolic lignin model compound, over the temperature range of 400-800 °C are reported. The low temperature matrix isolation - electron paramagnetic resonance (LTMI-EPR) experiments along with the theoretical calculations, provided evidences on the generation of the intermediate carbon and oxygen centered as well as oxygen-linked, conjugated radicals. A mechanistic analysis is performed based on density functional theory to explain formation of the major products from CnA pyrolysis; cinnamaldehyde, indene, styrene, benzaldehyde, 1-propynyl benzene, and 2-propenyl benzene. The evaluated bond dissociation patterns and unimolecular decomposition pathways involve dehydrogenation, dehydration, 1,3-sigmatropic H-migration, 1,2-hydrogen shift, C-O and C-C bond cleavage processes.

The effect of pyrolysis rate on the properties of alginic acid-derived carbonaceous materials, termed Starbon®, was investigated. Thermal Gravimetry-IR was used to prepare porous carbons up to 800 °C at several rates and highlighted increased CO2 production at higher pyrolysis rates. N2 porosimetry of the resultant carbons shows how pyrolysis rate affects both the mesopore structure and thus surface area and surface energy. Surface capacity of these carbons was analysed by methylene blue dye adsorption. In general, as the rate of pyrolysis increased, the mesopore content and adsorbent capacity decreased. It is considered here that the rapid production of volatiles at these higher rates causes structural collapse of the non-templated pore network. The work here demonstrates that pyrolysis rate is a key variable which needs to be controlled to maximise the textural properties of Starbon® required for adsorption applications.

Mixtures of carbon nanotubes (CNTs) and activated carbon (AC) were obtained from bituminous coal via the potassium hydroxide catalytic pyrolysis method. Scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Raman spectroscopy, X-ray Diffraction (XRD), and nitrogen adsorption measurements were used to investigate the characteristics of the samples and the effects of the final pyrolysis temperature and time on the structure of the carbon materials. The results indicated that the optimal range for the pyrolysis temperature and time for CNT growth were 900–950 °C and 45–90 min, respectively. The diameters of the as-prepared CNTs were in the range of 50–250 nm and their lengths were ∼15 μm. During the pyrolysis process, potassium hydroxide not only acted as the catalytic precursor to catalyze the CNT growth but also reacted with carbon to produce abundant micropores. Furthermore, the content of CNTs in the product after demineralization was significantly reduced. It was further confirmed by Inductively Coupled Plasma (ICP) analysis that the content of Fe, Co, and Ni decreased after demineralization, indicating that minerals in coal play an important role in the growth of coal-based CNTs.

Hydrothermal liquefaction (HTL) is an effective way of converting biomass into fuels and chemicals. Recently, the addition of catalysts in the HTL has been investigated to improve the yield and quality of bio-oil. We previously reported that metallic-Fe-promoted HTL of lignocellulosic biomass affords a water-soluble (WS) fraction that furnishes light olefins and aromatic hydrocarbons upon catalytic cracking over a solid acid catalyst. We demonstrated that the Fe-assisted HTL of cellulose in the presence of a hydrogenation catalyst results in a superior yield and quality of the WS fraction, thereby enhancing the hydrocarbon yield in the catalytic cracking of the WS fraction. When the HTL of cellulose was performed in the presence of Fe and Pd/Al2O3 at 250 °C for 1 h, the WS fraction yield reached 73%. The addition of hydrogenation catalysts led to higher hydrogen-to-effective-carbon ratios (up to 1.33) and proportions of the volatile light WS fraction (up to 63%) than those obtained by Fe-assisted HTL. This improved performance was attributed to the synergistic acceleration by metallic Fe and the hydrogenation catalyst, which particularly hydrogenates ketones to alcohols. Finally, a plausible mechanism that explains the effect of the hydrogenation catalyst was proposed.

Large amounts of lignin are produced in the pulp and paper industry and are still not used in a more valuable way. Lignin has great potential as a renewable raw material for the production of biofuels and high value chemical products. The aim of the present work was to study the hydropyrolysis process of two industrial kraft lignin types and evaluate the influence of operating temperature and the addition of two acid catalysts: a widely known commercial zeolite (ZSM-5) and niobic acid (HY-340), which has been poorly explored as a catalyst applied to biomass. HY-340, Nb2O5⋅nH2O, as well as commercial zeolites, has desirable acidic properties, and a low cost compared to traditional catalysts employed in catalytic pyrolysis. The composition of the vapors produced in a micropyrolyzer (CDS-5200) was analyzed in an online gas chromatograph coupled to a mass spectrometer (PY-GC/MS). The effects of operational parameters, such as reaction temperature and catalyst concentration added to lignins, were also investigated. The results showed that the use of ZSM-5 as a catalyst in hydropyrolysis reactions of both lignins promotes a significant increase in the formation of aromatic hydrocarbons. In the tests performed, the increase in selectivity for aromatic hydrocarbons reached a maximum of 98% of the area for lignin 1 and 99% for lignin 2. The addition of HY-340 in the reactions of catalytic hydropyrolysis of the industrial lignins resulted in an increase in the selectivity of open chain or aliphatic hydrocarbons, mainly n-alkanes, which reached a maximum value of 93% of area for lignin 1 and 92% for lignin 2.

Catalytic treating of biomass fast pyrolysis vapors offers a promising route to convert many different types of lignocellulosic biomass into biofuels. Considerable research efforts have focused on using zeolite catalysts, especially the microporous HZSM-5 zeolite. Unfortunately, the zeolite’s initial high activity in forming coke and light gases reduces the overall oil yield. In this contribution, we synthesized conventional HZSM-5 zeolite, mesoporous HZSM-5 zeolite, and a core-shell catalyst consisting of mesoporous HZSM-5 zeolite coated with a thin layer (<20 nm) of silicalite-1 zeolite. The catalysts were characterized by inductively coupled plasma optical emission spectroscopy (ICP-OES), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2 and Ar physisorption, temperature programmed desorption of ammonia (NH3-TPD), diffuse reflectance infrared fourier transform spectroscopy (DRIFT) spectra, and 27Al nuclear magnetic resonance (NMR). The catalysts were tested in a tandem micro-pyrolyzer system for deoxygenation of wheat straw derived fast pyrolysis vapors in a downstream catalytic fixed bed reactor and the quantitative product analysis was performed with GC-MS/FID/TCD and TGA-MS. The change in yields of different product groups was monitored during catalyst deactivation for an increasing number of pyrolysis vapor pulses and the cumulative carbon recoveries of all product streams (char, vapors, gas, and coke) were compared at different biomass-to-catalyst ratios (∼4 and ∼1) for catalyst loadings of 2 and 8 mg, respectively. In addition, the yields were compared for the same number of zeolitic acid sites. Even though the coking propensity was highest for the mesoporous HZSM-5 (5.1% carbon recovery of fed biomass at B:C = 1), it showed improved conversion of oxygenates (wt% O of vapors = 15) and a higher tolerance towards deactivation by coking compared to the conventional HZSM-5 (wt% O of vapors = 20). Coating of mesoporous HZSM-5 with silicalite-1 reduced the number of acid sites per mass of catalyst by ∼20%, which is attributed to the addition of the inert silicalite-1 layer and passivation of the external acid sites of the mesoporous HZSM-5. Compared to mesoporous HZSM-5, the added silicalite-1 shell reduced the coke yield by 43% (from 5.1 to 2.9 wt% of fed biomass carbon) for the same catalyst mass and by 8% (4.7 wt% of fed biomass carbon) for the same total number of acid sites. Furthermore, the tolerance towards deactivation observed for the mesoporous HZSM-5 core was largely preserved—especially for conversion of small oxygenates like acids, alcohols and aldehydes, resulting in vapors with 14 wt% O.

Heavy trivalent lanthanides and yttrium picolinates were synthesized by complexation of basic rare-earth metal carbonates with an aqueous solution of picolinic acid. The novel compounds were obtained with the general formula Ln(L)3∙nH2O, where L is picolinate and n = 1.5 H2O (Dy, Ho, Yb, Lu and Y), 2 H2O (Tb and Tm) and 2.5 H2O (Er). The stoichiometry of the complexes was calculated through mass losses found in the thermogravimetry (TG) curves, complexometry, and elemental analysis (EA). The thermal behavior in oxidative and pyrolytic atmospheres of the compounds were analyzed by simultaneous thermogravimetry differential scanning calorimetry (TG-DSC). The gaseous products of the pyrolysis were determined throughout by monitoring the evolved species using the techniques: TG-DSC Fourier transform infrared spectroscopy (TG-DSC-FTIR), hot-stage microscopy mass spectrometry (HSM-MS), and gas chromatography mass spectrometry (GC-MS). The obtained results validated mass loss assignments made using the TG curves, however, gaseous product analysis indicates the degradation processes are more complex than the thermoanalytical techniques suggest alone. This study used a GC-MS technique to identify the condensed gaseous products obtained during the second step of thermal degradation of the picolinate complexes. The analysis of the symmetric and asymmetric stretching frequencies of the carboxylate group in the FTIR spectra showed a monodentate bonding mode. The compounds were obtained in the amorphous state, as suggested by the powder x-ray diffractometry (PXRD) data.

The structural and magnetic properties of NixZn1-xFe2O4/SiO2 nanocomposites (NCs) synthetized using a modified sol-gel method were investigated. The formation of Ni-, Zn- and Fe-succinate precursors (<200 °C) and their decomposition into ferrites (<400 °C) was confirmed by the thermal analysis and Fourier transformed infrared spectroscopy. The transmission electron microscopy images revealed spherical shape nanoparticles of size increasing with the annealing temperature. According to X-ray diffraction, by annealing at 1200 °C, highly crystalline single-phase ferrite in samples with high Ni content and crystalline ferrite together with SiO2 in samples with low Ni and high Zn content were evidenced. A linear dependence of crystallite size, lattice parameter, X-ray density and porosity on the Ni content of NCs was observed. The magnetic properties such as saturation magnetization (Ms), remanent magnetization (Mr), coercivity (Hc) and anisotropy (K), also were found to be dependent on the Ni content in NCs. The shape of hysteresis loops indicated a superparamagnetic and ferromagnetic behavior of the obtained NCs.

Shales in the early maturity and oil window stages contain a considerable amount of heavy hydrocarbons (S2oil) having strong interactions with kerogen/rock that make the accurate measurement of total oil (total extractable organic matter) more difficult from the routine Rock-Eval experiment. In this study, a fast method for evaluating the total oil yield using a single routine Rock-Eval experiment on as-received shales is proposed. First, the temperature threshold (TOK) of the S2oil and cracking hydrocarbons were determined by combining the pyrograms of the as-received shale with a solvent-extracted replicate. Then, the total oil yield was directly derived from the hydrocarbons evaporate at a temperature below than TOK in a routine Rock-Eval experiment. The results show that the TOK value is controlled by the sample’s maturity and pore structure. The higher the maturity, the larger the specific surface area and the smaller the pore size, the greater the TOK. A prediction model of TOK was proposed based on the sample’s production index (PI). The total oil yields estimated by the two methods of both the TOK prediction model and the average TOK value (465 °C) are consistent with those obtained by Jarvie (2012) using the thermal-extraction method with correlation coefficients of 0.983 and 0.9548, respectively. Compared with the previous methods, the single routine Rock-Eval experiment method proposed in this study is convenient and not requires an extraction experiment. In addition, there are archived routine pyrolysis data available that can be used to directly calculate the total oil yield based on the temperature threshold.

Palm kernel cake (PKC) was pyrolyzed in a bench-scale pyrolysis plant equipped with a bubbling fluidized bed reactor, char separation system, and bio-oil recovery system under various reaction temperatures. Experiments were conducted to evaluate the effects of reaction temperature and observe the behavior of nitrogen in pyrolysis products. The maximum yield of bio-oil from PKC was approximately 63 wt.% at a reaction temperature of 401 °C. The main chemical compounds of bio-oils obtained from PKC were acetic acid, levoglucosan, nitrogen-containing compounds, and fatty acids such as dodecanoic acid, octanoic acid, tetradecanoic acid, and oleic acid. At reaction temperatures above 401 °C, the nitrogen content of bio-oils does not depend on reaction temperature. It is suggested that the resulting bio-oil requires additional treatment for use as a clean fuel.

Whereas increasing plastic solid waste production constitutes one of the main challenges of modern society, mainly due to the lack of suitable recycling technologies, chemical recycling represents an attractive solution for the conversion of plastic solid waste into valuable chemical intermediates. Herein, a kinetic model for the pyrolysis of a dental industry waste, ethylene glycol dimethacrylate (EGDMA) crosslinked poly (methyl methacrylate) (PMMA), is presented for the first time. Kinetics parameters and their statistical significance have been estimated from eight non-isothermal thermogravimetric analysis (TGA) experiments with heating rates varying between 5 and 50 °C·min-1 by using nonlinear regression. Our analysis indicates that the mechanism of depolymerisation of EGDMA crosslinked PMMA is likely to involve a consecutive reaction pathway involving two steps. The developed kinetic model - containing five kinetic parameters only - was able to predict well all non-isothermal TGA runs, and was validated against isothermal TGA experiments at 400 °C.