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Production of high-grade bio-oil through catalytic pyrolysis technology was of great significance for alleviating the current energy shortage problem. This study synthesized a series of carbon-supported transition metal catalysts and their catalytic influence on the product distribution, behavior and liquid component during cellulose pyrolysis in N 2 and CO 2 atmosphere were analyzed. The obtained results indicated that the unique flower-like structure of carbon significantly elevated strengths to generate gaseous products and the enrichment of furan compounds during pyrolysis. The inclusion of CO 2 further enhanced the secondary reaction of liquid product, and the maximum increment of syngas yield was 14.50 wt% after adding Ni/Co–C catalyst. Moreover, CO 2 participated in thermal conversion process of biomass as an oxygen source and thus more sugars were converted into furans. The Ni/Co–C catalyst and CO 2 produced favorable synergistic effect during cellulose pyrolysis, which resulted in the highest relative content of furans, with the value of 26.77%. Therefore, this study presented an efficient means to access to furan-rich bio-oil via catalytic pyrolysis of biomass. • The flower-like carbon-based catalysts that improve yield of furans are synthesized. • A 15.31% increase in furans is obtained by adding Ni/Co loaded carbon catalyst in CO 2. • The prepared catalysts promote the secondary reaction for generation of syngas. • The mechanism of flower-like carbon catalyst for component variation is given. [ABSTRACT FROM AUTHOR]

In this work, the Zr-Mg bimetallic catalyst is prepared and used to facilitate the conversion of the waste mask to hydrocarbon-rich fuels. The effects of the catalyst and the reaction atmosphere on pyrolysis behaviors of different layers of the mask are discussed, and the interactions between CO 2 and the catalyst are analyzed. The results showed that the synthesized catalyst significantly promoted the conversion of long-chain hydrocarbons to short-chain hydrocarbons. Compared with pyrolysis alone under N 2 atmosphere, the relative contents of hydrocarbon compounds obtained by catalytic pyrolysis in the inner layer and middle layer increased by 12.21% and 16.24%, respectively. Additionally, the relative content of olefins in the liquid product increased by 9.62%. When the pyrolysis atmosphere was changed from N 2 to CO 2 , the selectivity of the cycloalkanes was significantly enhanced. Also, the interactions between CO 2 and the catalyst improved the selectivity of C 2 H 6. These works provide important support for the effective disposal of masks and an in-depth understanding of the CO 2 -assisted pyrolysis process. • A catalyst that promotes the generation of hydrocarbon-rich fuels is synthesized. • The selectivity of short-chained liquid hydrocarbons is increased by 13.87%. • The CO 2 promotes the generation of C 3 H 6 in gaseous hydrocarbon products. • Effects of CO 2 and catalyst converting mask into hydrocarbon-rich fuels are given. [ABSTRACT FROM AUTHOR]

• Catalysts that can effectively promote cellulose decomposition are synthesized. • CO 2 -assisted cobalt-based Ce/Fe/Mg catalyst enhances furans and ketones. • The synthesized catalyst has good oxygen transfer ability. • The performance of catalyst in improving the selectivity of compound is given. The production of high value-added liquid products by catalytic pyrolysis of cellulose has become an effective way to realize the efficient utilization of biomass. This work synthesized a series of Co-Ce, Co-Fe and Co-Mg composite metal catalysts and used them to obtain furans and ketones production. In addition, the CO 2 was used as a pyrolysis atmosphere to investigate the synergistic effect between CO 2 and the prepared catalyst. The results showed that the catalyst effectively promoted the depolymerization of cellulose and improved the oxygen transfer behavior between volatile matters during cellulose pyrolysis. As a reaction medium, CO 2 influenced the carbon distribution of products, thereby increasing syngas yield, and the CO 2 atmosphere promoted the formation of furans and ketones. Compared with those obtained by the non-catalytic pyrolysis in N 2 atmosphere, the relative contents of furans and ketones in the liquid products produced by the catalytic pyrolysis of cellulose in CO 2 atmosphere increased by about 13.38% and 9.8%. In the CO 2 environment, the generation ability for furans was Co-Mg catalyst > Co-Ce catalyst > Co-Fe catalyst, and the generation ability for ketones was Co-Ce catalyst > Co-Mg catalyst > Co-Fe catalyst. These works provide an important way for the efficient preparation of furans and ketones from biomass pyrolysis. [ABSTRACT FROM AUTHOR]

In this work, spent mushroom substrate (SMS) was co-pyrolyzed with oil shale semi-coke (OSS) to investigate the effects of the OSS on yield and chemical compositions of bio-oil product. Oil shale semi-coke was mixed with biomass in the OSS/SMS mass ratios of 0:1, 1:4, 1:1, 4:1 and 1:0. The pyrolysis experiment was carried out by using a lab-scale pyrolysis reactor. The experimental results showed that the addition of the OSS led to an increase of bio-oil yield. The maximum of bio-oil yield was obtained at the OSS/SMS mass ratio of 1:1. The characteristics of the obtained oils were studied by elemental analyzer, FTIR and GC–MS. It was found that the bio-oil obtained from the pyrolysis of mixed SMS and OSS had higher carbon and hydrogen content, lower oxygen content than those produced by the pyrolysis of biomass alone. Moreover, there were more aromatics and aliphatic compounds in the obtained bio-oil product. These variations indicated that the existence of the OSS significantly influenced the chemical compositions of bio-oil. [ABSTRACT FROM AUTHOR]

In this work, Huadian oil shale from China was treated by hydrothermal pretreatment at 200 °C with 1.0–2.5 h in order to investigate the effect of hydrothermal pretreatment on pyrolysis product distribution and characteristics of oil. The differences in the elemental composition and thermal behavior between the untreated and treated oil shale were analyzed and compared. The hydrothermal treatment process could decompose oxygen functional groups and remove some water soluble inorganics in oil shale, which decreased the formation of gas and water during the pyrolysis. However, hydrothermal pretreatment was conducive to increasing shale oil yield. The maximum of oil yield was obtained at the pretreatment time of 2.0 h. The enhancement of the free-radical reactions during the pyrolysis and the reduction of the secondary cracking reactions of the generated oil vapors were considered as the main reasons. The oil obtained by the treated oil shale had a higher H/C ratio, indicating it had high energy content. The analysis results of chemical compositions in oils showed that the relative content of aliphatic hydrocarbons significantly increased after hydrothermal pretreatment. The further analysis demonstrated that the increase in the pretreatment time caused the generated long chain hydrocarbons tended to be directly released from oil shale particles, and were condensed into the oil. [ABSTRACT FROM AUTHOR]

Using cellulose to produce high-quality oxygenated fuels or chemicals is becoming an important way to replace chemical synthesis technology. In this work, the Ce–Co–Na ternary composite metal catalyst is synthesized and used for catalytic cracking of cellulose to prepare the ketone-rich bio-oil production. To construct an environment-friendly process, CO 2 is used as a pyrolysis reaction atmosphere to improve the enrichment of ketones. Strong synergistic effects among metal components effectively promote the thermal-cracking of cellulose to produce primary products (anhydrosugars), and further convert to oxygenates due to the excellent oxygen transferability of the catalyst. The introduction of CO 2 enhances the selectivity of ketones in the liquid product, especially 2,3-dimethyl-2-cyclopenten-1-one. The highest content of ketones in the liquid is 22.73%, which is about four times higher than that of the blank sample. In addition, the generation of CO in the syngas is promoted. This study provides an alternative way for the pyrolysis of biomass to prepare ketone platform compounds and syngas production. • A catalyst that can effectively promote cellulose decomposition is synthesized. • The high selectivity of ketones is obtained by CO 2 -assisted catalytic pyrolysis. • The optimal conditions for producing ketones and syngas are given. • A brief reaction pathway of CO 2 -assisted catalytic pyrolysis of cellulose is shown. [ABSTRACT FROM AUTHOR]

In our work, a series of experiments on pyrolysis of the large particle oil shale (6–15 mm) were carried out in a self-made retorting pyrolyzer, in order to obtain the optimal final pyrolysis temperature of Huadian oil shale and evaluate the catalytic performance of transition metal salts (CoCl 2 ·6H 2 O, MnSO 4 ·H 2 O) in promoting the shale oil yield and product characteristic. The experiment results showed that the retorting temperature significantly influenced the shale oil yield. The maximum oil yield appeared in 520 °C with the result of 21.59 wt%. Meanwhile, the higher retorting temperature promoted the more production of alkanes/olefins, which led to the increase of alkanes from 20.46% to 32.44%. Moreover, the use of CoCl 2 ·6H 2 O salt further increased the oil yield. The pyrolysis behavior and kinetic analysis indicated the transition metal iron could act as the activation center to accelerate the breakdown of chemical bonds in organic matters. In addition, the addition of the Co salt significantly enhanced the formation of aromatic hydrocarbons in the shale oil, which increased about 18% compared to that of non-catalytic pyrolysis. It had demonstrated the Co iron could increase the selectivity of aromatic hydrocarbons and promote olefin aromatization. The acid compounds were observed in the oil produced from the catalytic pyrolysis of MnSO 4 ·H 2 O, which suggested that it was not suitable to be regarded as the candidate catalysis. [ABSTRACT FROM AUTHOR]

In our work, thermal behavior and kinetic characteristics of spent lark mushroom substrate were evaluated to elaborate the thermal decomposition mechanisms and explore the influence of heating rate by using thermogravimetric analyzer and Coats–Redfern method. The study of pyrolysis temperature of raw material was also operated at the range of 410–530 °C, under the feeding rate 0.36 g/min, and the nitrogen flow 16 L/h. The results showed that the maximum bio-oil yield was obtained at 470 °C with the yield of 14.4 wt.%. The analysis of Fourier transform infrared spectrometer and gas chromatography coupled with mass selective detector indicated that the target liquid production was consisted of phenols, hydrocarbons and other components. Simultaneously, the low oxygen and high hydrogen content in bio-oil was also determined by elemental analysis. Based on the above-mentioned results, we demonstrated that the bio-oil obtained from the substrate had high utilization value as a potential energy resource. [ABSTRACT FROM AUTHOR]

In this work, the effects of formate salts(potassium/nickel/zinc formate) on behavior, yield, and product characteristics were evaluated and compared by using the combination of TGA and the fixed-bed reactor. The results showed that potassium formate had a good catalytic cracking ability , resulting in a forward shift of the decomposition temperature of organic components in biomass and an increase of gas yield. The nickel formate had the strongest catalytic ability for biomass pyrolysis to produce oil. Compared to the non-catalytic pyrolysis, the yield of bio-oil increased about 8 wt%. After adding potassium formate, the generation of phenols in the oil was enhanced, while the presence of nickel/zinc formate obtained the opposite results. The total content of oxygenated compounds(alcohols, ketones, esters and acids) was reduced for all formate salts, and the most signigicant difference among them was that the addition of potassium formate obtained the enrichment of ketones. Moreover, the analysis of gas showed that the yields of CO 2 and CO were increased after adding potassium/nickel formate. The reasons were related to the differences in physicochemical property of catalyst and catalytic ability of metal cation in formate salt. • A comparative study on formate-assisted pyrolysis of CS is performed. • Enhancement of selectivity toward ketones is found by adding potassium formate. • More CO 2 and CO are generated by adding potassium formate and nickel formate. • Effect of potassium formate is most significant among the used formate salts. [ABSTRACT FROM AUTHOR]

• Coupling effect advanced the thermal decomposition of organic matters in oil shale. • A significant coupling effect was achieved at the MMT/CoCl 2 ·6H 2 O mass ratio of 5:1. • MMT and CoCl 2 ·6H 2 O promoted decarboxylation and free-radical reaction of pyrolysis. • Coupling effect significantly promoted the formation of saturated hydrocarbons. In this work, the effects of the coupling between montmorillonite and CoCl 2 ·6H 2 O on pyrolysis behavior, products distribution and characteristics of liquid fuel were investigated by the combination of pyrolysis experiment and kinetic analysis. The mass fraction of the MMT in oil shale was 3–9%, and the mass fraction of CoCl 2 ·6H 2 O was 10–25%. The results showed that the coupling effect promoted the formation of shale oil. The maximum yield of shale oil (17.75 wt%) was obtained at 20CoCl 2 ·6H 2 O5MMT. Catalytic pyrolysis behavior and kinetic analysis indicated that the presence of CoCl 2 ·6H 2 O and montmorillonite led to the prominent advance of kerogen decomposition temperature and the decrease of apparent activation energy. Significantly, the addition of the 20CoCl 2 ·6H 2 O5MMT led that the average apparent activation energy was decreased by about 122.42 kJ/mol compared to the catalyst-free pyrolysis. The strong cracking ability produced by their coupling effect was considered to be the main reason. Montmorillonite and CoCl 2 ·6H 2 O enhanced the decarboxylation and free-radical reaction, resulting in a decrease of acids yield and an increase of aliphatic hydrocarbons yield. The relative content of aliphatic hydrocarbons increased from 41.55% to 51.27%. These results demonstrated that the combined use of montmorillonite and CoCl 2 ·6H 2 O was beneficial to the generation of saturated hydrocarbon production. [ABSTRACT FROM AUTHOR]

Pyrolysis of Trichosporon fermentans biomass, a type of oleaginous yeast from the fermentation of refined soybean oil wastewater, was studied in the present work. Based on the TG/DTG curves, the activation energy values for the thermal decomposition of Trichosporon fermentans biomass were evaluated by the KAS method (111.69 kJ/mol) and FWO method (116.93 kJ/mol), respectively. The pyrolysis behavior was represented by considering the parallel degradation of four components, namely carbohydrates, proteins, lipids, and others, and the fitting degree of the simulated curve was over 0.99. According to the FTIR spectra of the end-products, the increasing hydrocarbons at a temperature around 400 °C indicated the lipid degradation. Biocrude oil was collected from a fixed bed reactor and the chemical composition was characterized by GC-TOF/MS. The yield of hydrocarbons in the bio-oil was identified as being over 28% when the pyrolysis temperature was higher than 500 °C, whilst the content of nitrogen compounds was less than 18%. The fractional yield distributions of the end-products at different pyrolysis temperatures were compared and the maximum yield of bio-oil was achieved (around 42%) at 500 °C. This study proposed a cost-effective and environmentally friendly method for the preparation of biofuel from oleaginous yeast pyrolysis. Image 1 • Oleaginous yeast from wastewater treatment was a potential feedstock of pyrolysis. • Activation energy of oleaginous yeast pyrolysis was estimated by KAS and FWO methods. • The simulated DTG was obtained by Gaussian fitting method and R2 > 0.99 at 20 °C/min. • The hydrocarbon content in the bio-oil of oleaginous yeast was greater than 28%. [ABSTRACT FROM AUTHOR]

• The pyrolysis characteristics of thermal bitumen in semi-coke and extracted bitumen were analyzed and compared. • The extracting solvents (a mixture of ionic liquid [Bmim]Cl and NMP) were rarely used in the oil shale extraction. • Gaussian fitting method was used to evaluate the proportions of bond cleavages and their kinetic parameters. Fushun oil shale semi-coke and its extracted bitumen were prepared for analyzing their pyrolysis characteristics by TG–DTG, TG–FTIR, and Py–GC/MS. Semi-coke was the residue of oil shale pyrolyzed to 450 °C, and extracted bitumen was the organic matter extracted from semi-coke with [Bmim]Cl/NMP mixed solvents. Gaussian fitting method was used to analyze the proportions of bond cleavage reactions occured during the pyrolysis to 700 °C at a heating rate of 20 °C/min. Results showed that 3–4 kinds of bond cleavages were mainly involved. The outstanding pyrolysis behaviors were contributed by the cleavages of C al C al and weak bonds (including volatilization). The kinetic parameters based on Coats–Redfern method were calculated from the points for each pyrolysis stage and bond cleavage reaction. The evolution processes of typical gaseous products and distributions of flash pyrolysis products were displayed in detail, exhibiting the prominent roles of aliphatic compounds, CH 4 , and CO 2. Moreover, the releases of the typical gaseous products for semi-coke tended to occur at higher temperatures. [ABSTRACT FROM AUTHOR]