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In this study, HZSM-5 was modified by green templates (cellulose, starch and glucose), the mesoporous structure was successfully introduced, and the prepared composite catalyst was used for the catalytic pyrolysis of biomass to prepare aromatics hydrocarbon. It was revealed that the additionally introduced mesopore pore size was closely related to the size of the template molecule. The formation of pore structures with larger pore sizes on the catalyst was facilitated by larger polysaccharide templates (starch and cellulose). The increase in mesopore pore size was promoted by the cellulose and starch templates, while the increase in the number of mesopores was promoted by the glucose template. The pore size of the catalyst has a great influence on selectivity of BTX. Selectivity of BTX with larger carbon numbers (xylene, trimethylbenzene) was improved by the mesoporous structure with larger pore size. Excellent catalytic performance is also shown on template modified catalysts. The maximum yield of BTX was 10.18 wt%, which was about 1.1times higher than HZSM-5. In addition, the decomposition of macromolecular substances in the pyrolysis gas was promoted by the mesoporous structure of the template-modified catalyst, and the formation of coke on the catalyst was prevented. [ABSTRACT FROM AUTHOR]

[Display omitted] • In-situ catalytic reforming of hydrogen from carbon reducing cathode materials. • The cobalt in LiCoO 2 batteries has a catalytic effect on the reforming reaction. • Highest hydrogen yields obtained using catalysts prepared by reduction at 800 °C. • Increasing the specific surface area of carbon will improve the reduction effect. • The highest hydrogen yield of 28.3 mmol/g was achieved at a mass ratio of 10:3. Biomass pyrolysis and in-line steam reforming for hydrogen production is one of the effective ways to promote the sustainable development of global energy. In this study, Co was recovered from the cathode material of LiCoO 2 batteries using the carbon thermal reduction method, and used for biomass pyrolysis and in-line steam reforming for hydrogen production. First, the cathode material was reduced using coconut shell carbon (CC), and it was revealed that cobalt presented in the catalyst prepared at the reduction temperature of 800 °C, giving the hydrogen yield of 24.9 mmol/g. Other carbon source like graphite carbon (GIC) and straw pyrolytic carbon (SC) were then investigated and it was found that a much higher temperature (>800 °C) was required for the reduction of the cathode material with GIC and the catalyst prepared by SC reduction was less effective than that using CC reduction. Considering the great influence of the pore structure of the carbon material on the reduction, activated carbon (AC) was obtained from SC using KOH activation. With a better distribution of cobalt on the carrier prepared by AC reduction, the highest hydrogen yield of 28.3 mmol/g was achieved with the mass ratio of cathode material and AC of 10:3. This study provides a viable avenue for the application of spent lithium-ion battery cathode materials in the production of hydrogen from biomass. [ABSTRACT FROM AUTHOR]

Templating agents were created by utilizing several methods to handle natural cellulose (bagasse), and they were successfully used to treat HZSM-5 to introduce extra mesopores. In addition, the hierarchical HZSM-5 was employed in the catalytic pyrolysis of biomass to produce hydrocarbon fuels. The hydroxyl content in the templating agent could be promoted via hydrothermal and ultrasound-assisted treatment, improving their performance as templates to produce mesopores. The cellulose content in the templating agents was effectively boosted via hydrothermal-assisted treatment, whereas their relative crystallinity was improved by ultrasound assistance. The formation of mesopores was promoted with the increased cellulose content in the templating agents, and the catalytic performance in upgrading pyrolysis gas for aromatic hydrocarbons could be significantly improved. Higher relative crystallinity was advantageous for enhancing the stability of the templating agent in the catalyst synthesis system, and the formation of pore structures of the catalyst was promoted. Among all catalysts synthesized, catalysts synthesized by hydrothermal-assisted treatment (Cat-H(X)) presented the highest specific surface area and average pore size of 397.60 m2/g and 4.53 nm, which were about 1.41 and 1.98 times of commercial HZSM-5 (H-Z). The highest yield of BTX obtained with Cat-H(X) was 8.7 wt%, 1.81 times that obtained with H-Z. • Hierarchical HZSM-5 was synthesized with natural cellulose as templates. • The highest yield of BTX was achieved of 8.7 wt%. • Specific surface area and average pore size were increased by 41% and 98%, compared with H-Z. • Cat-H(X) exhibited the higher catalytic activity for aromatic production. [ABSTRACT FROM AUTHOR]

• MCM-41 catalyst is modified with different concentration of La. • Upgrading of pyrolysis vapor is performed in a vacuum system over above catalyst. • A higher hydrocarbons yield of 34.59% is obtained with La(5)/MCM-41. • Anti-coking performance of La(5)/MCM-41 for the coke is well. • It exhibited good potential for efficient preparation of high-valued bio-oil. By combining the large pore size of MCM-41 and the adjustable acid property of La, La/MCM-41 catalysts with La loading mass fractions of 1%, 5% and 10% were prepared and used in the catalytic upgrading of pyrolysis vapours from vacuum pyrolysis of rape straw to obtain high-value bio-oil. MCM-41 zeolite before and after the La loading was characterized in detail by TEM, Py-IR and TG. The characterization data showed that the amount of Brönsted and Lewis acid sites on the surface of La/MCM-41 increased. The highest hydrocarbon content (35%), and the highest higher heating value (34 MJ kg−1) were obtained at a La loading of 5% (La(5)/MCM-41). This may be closely related to the promotion of the reaction efficiency of the active sites with proper acid concentrations. Simultaneously, the coke content of the catalyst decreased further, and the selectivity for the high-value aromatic hydrocarbons increased. Considering the suitable concentration of La(5)/MCM-41 with strong acidity and stability, it is more appropriate for use in the upgrading of pyrolysis vapour for liquid fuel production. [ABSTRACT FROM AUTHOR]

Catalytic upgrading of pyrolysis vapor from rape straw was performed in a vacuum pyrolysis system over La/HZSM-5 with hierarchical structure. When 3M Na 2 CO 3 was used for alkali treatment, the desilication process of HZSM-5 zeolite was highly controllable and the hierarchical porous HZSM-5(Hi-ZSM-5) zeolite was formed. After that, Hi-ZSM-5 was modified by impregnation with lanthanum ion, the acid sites of Lewis increased and the concentrations ratio of Brönsted acid and Lewis acid of the catalyst was improved. The highest hydrocarbons selectivity (49.86%), the lowest carbonyl compounds content (11.06%), and reasonable catalytic stability were obtained by the La/Hi-ZSM-5 catalyst. In addition, La/Hi-ZSM-5 further reduced the coke content of the catalyst to 11.05%, while increasing the selectivity of high value aromatic hydrocarbons. Obviously, La/Hi-ZSM-5 zeolite had high catalytic activity, and exhibited good potential and a beneficial nature for efficient preparation of high-valued bio-oil from rape straw. [ABSTRACT FROM AUTHOR]

Value-added oxygenates, such as acetic acid (HAc), glycolaldehyde and acetol, are present in pyrolysis oil and its cuts in substantial amounts. This work describes the separation of these value-added oxygenates from artificial aqueous fractions of pyrolysis oil via liquid-liquid extraction. Three phosphonium ionic liquids (ILs), two imidazolium ILs and one benchmark organic mixture (40 wt% tri- n -octylamine in 1-octanol: TOA/1-octanol) were applied as solvents. Although suited as solvent for HAc and glycolaldehyde, the benchmark TOA/1-octanol showed a low acetol distribution coefficient (0.05), which makes it less suitable for use in an integrated oxygenates extraction process. Phosphonium ILs showed the highest affinities for HAc and glycolaldehyde, and reasonable affinity for acetol. However, none of these solvents could be applied to remove all oxygenates from the aqueous solution in a single extraction step, because of the difficulty of oxygenates evaporation from phosphonium ILs and the reactivity of glycolaldehyde with P 666,14 [N(CN) 2 ] in the presence of HAc, as was confirmed by NMR. Based on the good affinity of the imidazolium ILs for acetol, a two-step extraction process was proposed where Hmim[B(CN) 4 ] may be used to extract acetol and HAc in the first step and be regenerated by evaporation of the solutes, and P 666,14 [Phos] may be applied to extract glycolaldehyde in the second step and be regenerated by back-extraction with water. [ABSTRACT FROM AUTHOR]

Fermentative bioethanol production from pyrolytic sugars was improved via aromatics removal by liquid–liquid extraction. As solvents, the ionic liquid (IL) trihexyltetradecylphosphonium dicyanamide (P 666,14 [N(CN) 2 ]) and ethyl acetate (EA) were compared. Two pyrolytic sugar solutions were created from acid-leached and untreated pinewood, with levoglucosan contents (most abundant sugar) of 29.0% and 8.3% (w/w), respectively. In a single stage extraction, 70% of the aromatics were effectively removed by P 666,14 [N(CN) 2 ] and 50% by EA, while no levoglucosan was extracted. The IL was regenerated by vacuum evaporation (100 mbar) at 220 °C, followed by extraction of aromatics from fresh pyrolytic sugar solutions. Regenerated IL extracted aromatics with similar extraction efficiency as the fresh IL, and the purified sugar fraction from pretreated pinewood was hydrolyzed to glucose and fermented to ethanol, yielding 0.46 g ethanol/(g glucose), close to the theoretical maximum yield. [ABSTRACT FROM AUTHOR]

Catalytic pyrolysis of rape straw was carried out on a dual-catalyst system to produce benzene, toluene, xylene (BTX), realized by promoted cracking of large-molecule pyrolysis vapor over red mud (RM) and followed by selectively catalytic conversion over HZSM-5. With the pyrolysis temperature of 550 °C and the catalyst/biomass mass ratio of 2:1, the yield of BTX in bio-oil reached the maximum of 10.27 wt%. The coking resistance of HZSM-5 in the cascade catalytic system was obviously better than pure HZSM-5. The pretreatment of RM by calcination and acid washing was also performed. The unstable components of RM like cancrinite were decomposed during the calcination. Besides, the content of active metal oxides in RM after acid washing increased by removing Na 2 O and CaO. Its specific surface area was promoted, due to the new micropores caused by the dispersion of dissolved metal oxides. RM treated with 3 mol/L hydrochloric acid presented the highest specific surface area of 55.24 m2/g while the maximized yield of BTX of 12.91 wt%. Therefore, the dual-catalyst system might be an effective method to dispose and high valued use of rape straw and RM as solid wastes with significant environmental impact to promote carbon neutrality. • Catalytic pyrolysis of rape straw in a cascade dual-catalyst system was subjected. • The coking resistance of HZSM-5 in the cascade dual-catalyst system was enhanced. • The unstable components of red mud were decomposed during the calcination. • Red mud after acid treatment had more active metal oxides. • The highest yield of BTX reached 12.91% over modified red mud and HZSM-5. [ABSTRACT FROM AUTHOR]

This paper investigated the effect of cellulose, xylan and lignin content on biomass pyrolysis characteristics and analyzed the interaction rules of the 3 biomass components. The proportions of the 3 components i.e. cellulose, xylan and lignin were reasonably designed, and there were 7 experimental samples according to different quality proportions. The Thermo TGA/DSC 1 was used to analyze the thermo-gravimetric processes of the samples composed of the 3 components. And the pyrolysis characteristics of the cellulose, xylan and lignin were studied. Supposing that the 3 components' thermo-gravimetric processes were isolated with each other, the overall weightlessness process of the mixed samples was attributed to the superposition of every single component's weightlessness. By comparing the experimental and calculated values, the three components' interaction rules when they were mixed and pyrolyzed were analyzed. The Coats integration method was adopted to calculate and analyze the three components' pyrolysis dynamic parameters. At the same time, on the basis of the biomass vacuum pyrolysis liquefaction system, the vacuum pyrolysis experiments of each component and the mixed samples were carried out. Taking biomass as a benchmark, oil and solid production rate and production rate of gas were calculated at the end of the pyrolysis. The production rate of mixed samples' pyrolysis products could be acquired by the superposition of the production rate of single component pyrolysis products according to the mixed proportion. The (GC-MS) Agilent 7890A were adopted to analyze the composition of bio-oil which was obtained through vacuum pyrolysis and liquefaction of 7 samples. By comparing the experimental and calculated value, the influence of those 3 components content on the distribution of pyrolysis product and bio-oil composition was also evaluated. The results indicated that cellulose had good thermal stability, the pyrolysis range was narrow, and its pyrolysis was relatively intense which generated less solid residues, and bio-oil production rate was higher which generated more aromatics, sugars, aldehydes and alcohols. Xylan with a poor thermal stability could generate more aromatics, ketone and acid in bio-oil, and the initial pyrolysis temperature was lower which could generate more gases. Lignin with a poor thermal stability could generate aromatic compounds, the pyrolysis range was narrow and the pyrolysis was relatively mild which generated more solid residues. By analyzing the three components' pyrolysis dynamic parameters, it could be concluded that cellulose had considerable effect on the activation energy and pre-exponential factors while xylan and lignin had greater effects on reaction order. By comparing the experimental and calculated value, it could be concluded that cellulose pyrolysis was beneficial to the reduction of the solid residue while lignin pyrolysis products could promote the decomposing of sugars. Xylan had a negative effect on the cellulose pyrolysis and could benefit the low-temperature pyrolysis of lignin. The co-pyrolysis of xylan and lignin had little influence on the bio-oil composition. Therefore, biomass with high cellulose content could foster the bio-oil yield and a certain amount of lignin could promote the decomposing of cellulose. The results provide a theoretical basis for further improving the yield and quality of the bio-oil. [ABSTRACT FROM AUTHOR]

Catalytic upgrading of the vapors from rape straw vacuum pyrolysis was conducted over HZSM-5 zeolite in a fixed bed reactor. Univariate analysis was employed in this study to investigate the effects of the operating parameters, including catalyst quality, Si/Al ratio of catalyst, and catalyzing temperature, on the product yields and the composition of upgraded bio-oil. Based on the univariate analysis, the preliminary operating parameters of catalytic reactor were optimized. The results showed that, when the catalyzing temperature was 500°C and HZSM-5 (Si/Al=50) quality was 60 g, a lower oxygen content (27.97 percent), higher heating value (30.14kJ/kg-1), and a lower hydrogen-to-carbon ratio (0.12) were obtained. Moreover, the components of the obtained bio-oil contained a small amount of high oxygen contents, such as aldehydes, acids, and ketones. Meanwhile, phenols and aromatic hydrocarbons obviously increased. Product distribution and yield between upgraded bio-oil and crude bio-oil was also compared to study the catalytic refining effects and catalytic deoxygenation performance of HZSM-5 zeolite. This capacity of HZSM-5 zeolite was the key to make up for the two shortcomings of crude bio-oil, which were corrosivity and instability. The catalyst quality had significant effects on the properties of the upgraded bio-oil. Catalytic upgrading of pyrolysis vapors was incomplete when the catalyst quality was not high enough. However, when the catalyst quality was excessive, a decreased yield of upgraded oil resulted due to excessive secondary cracking reactions. In this study, the quality ratio of the catalyst to biomass was about 0.4. Catalyzing temperature also had an important effect on the properties of upgraded oil. When the catalyzing temperature was lower, the activation energy could not meet the needs of cracking reactions, and the catalytic effect was poor. When the catalyzing temperature was higher than optimal value, deactivation of the catalyst resulted because the structure of the catalyst was destroyed. Accordingly, the upgraded bio-oil with a higher gross heating value and lower oxygen content was obtained when the catalyzing temperature was about 500°C. The Si/Al ratio of the catalyst, which determined its density of acid sites and acid strength, had a great impact on catalytic product distribution. Four different Si/Al ratios of HZSM-5 were investigated. Upgraded bio-oil with a higher gross heating value and lower oxygen content was obtained when the Si/Al ratio of HZSM-5 was 50. Also, there were significant differences between upgraded bio-oil and crude bio-oil in product distribution and yield. The yield of crude bio-oil was 43.98 percent while the yield of upgraded bio-oil was 36.12 percent. Oxygenated components in the upgraded bio-oil, such as aldehydes, carboxylic acids, and ketones, which were 13.71 percent, 11.75 percent, and 13.59 percent, dropped significantly to 3.38 percent, 1.68 percent, and 4.48 percent, respectively. However, phenols containing lower oxygen and non-oxygenated hydrocarbons increased observably. These results showed that the HZSM-5 catalyst had a strong catalytic refining and catalytic deoxygenation capacity. Based on the results of this study, a catalytic reaction mechanism of HZSM-5 was proposed by comparing non-catalytic and catalytic bio-oil compositions. HZSM-5 was highly active in catalytic deoxidation. However, the online catalytic upgrading mechanism of bio-oil vapors was complex and it needs to be further studied in the future. [ABSTRACT FROM AUTHOR]

A method of template removal by direct non-thermal plasma (DNTP) system for the synthesis of HZSM-5/MCM-41 meso-micropore composite catalyst was proposed for the production of aromatic hydrocarbons by catalytic pyrolysis of rape straw. It was revealed most of the template on the catalyst was removed by oxidizing substances such as ozone produced by DNTP. During DNTP treatment, the removal effect of the template was greatly affected by the oxygen flow rate. Also, the catalyst structure was bombarded by high-energy electrons obtained by DNTP treatment, and the physicochemical property of the synthetic composite catalysts was treated quite different from that obtained by calcination method. Under the treatment condition of 22 kV-2 L/min, the BET surface area was boosted significantly by 29.91% and the amount of acid sites was boosted by 37.71%, the yield of MAHs reached 10.57 wt%. Generally, not only the template can be effectively removed by DNTP treatment, but also the physicochemical property of meso-micropore composite catalyst can be improved, and thus promoted the catalytic performance for monocyclic aromatic hydrocarbons. Therefore, DNTP is an effective technology for removing template and the catalytic performance can be efficiently improved. • Template removal by DNTP system for synthesis of HZSM-5/MCM-41 catalyst. • Template was removed layer by layer from outside to inside. • Catalytic performance of catalyst was increased by DNTP treatment. • Removal effect of the template was greatly affected by oxygen flow rate. • Pore structure and BET surface area of catalyst were greatly affected by voltage. [ABSTRACT FROM AUTHOR]

• The concentration of active material of the DNTP reactor was controllable. • Carbon deposits will be removed and the catalyst perform better by DNTP reactor. • The pore size of regenerated catalysts increased due to electronic bombardment. • The regenerated catalyst at 22 kV performed best during catalytic pyrolysis. • High catalytic activity could be maintained after 15 cycles at 20 kV. A direct non-thermal plasma (DNTP) method was proposed to remove coke after catalytic pyrolysis of rape straw at atmospheric pressure and room temperature. Through the optical emission spectroscopy (OES) analysis, it was found that the active substances O 3 and O were generated inside the deactivated catalyst and reacted violently with the coke. After DNTP regeneration under different voltages of 20 kV, 22 kV, 24 kV, and 26 kV, the residual coke of each regenerated catalyst was almost completely removed, which were 2.65 %, 1.99 %, 1.29 %, and 0.30 %. Compared with fresh catalyst, the specific surface area of Cat-22 increased the most (34.09 %), and the total acid content increased by 24.11 %. The bio-oil obtained by Cat-22 had the highest monocyclic aromatic hydrocarbons content (46.93 %), which was 29.65 % higher than that of fresh catalyst. After fifteen cycles of catalysis-regeneration at 20 kV, it was found that the content of hydrocarbons of the bio-oil sample could be retained at 94.5 % of that in the original catalytic test. Through the DNTP technology based on the theoretical basis to realize the recycling of the catalyst, it will promote the development of biomass field in a more sustainable and cleaner way. [ABSTRACT FROM AUTHOR]

[Display omitted] • Catalytic fast pyrolysis of rape straw over composite catalysts was investigated. • HZSM-5@MCM-41 (H@M) was synthesized by external recrystallization method. • H@M with THR of 1 exhibited a highest yield of hydrocarbons of 11.43 wt.%. • H@M presented less formation of hydrogen-deficient or graphite-like coke. • Compared with HZSM-5, a lower pyrolysis temperature (500 °C) was demanded for H@M. In order to promote the production of hydrocarbons in the catalytic pyrolysis of rape straw, a core-shell catalyst fabricated by external recrystallization method was employed. The composite catalyst HZSM-5@MCM-41 was prepared by varying the mass ratio of template and HZSM-5 (THR), and the effect of zeolite acidity and mesoporosity on the production of hydrocarbons was analyzed. A final pyrolysis temperature of 500 °C was suitable to obtain high yield of hydrocarbons over composite catalysts. Compared with ZSM-5 with a favorable pyrolysis temperature of 550 °C, a lower pyrolysis temperature meant a more efficient process, which may be related closely to the good diffusion of large-sized pyrolysis vapors over HZSM-5@MCM-41 catalysts. In addition, the highest yield of monocyclic aromatic hydrocarbons obtained over HZSM-5@MCM-41 with THR of 1 was 11.43 wt.%, which was boosted by 2.5 times compared with HZSM-5. A proper THR was suitable to fabricate a core-shell catalyst with excellent crystallinity, acidity and mesoporosity, and resulting in a high yield of hydrocarbons. Furthermore, the core-shell catalyst presents less formation of graphite-like coke, which indicated the easier removal of coke. Therefore, the composite HZSM-5@MCM-41 catalysts were more appropriate for upgrading of pyrolysis vapors for hydrocarbons. [ABSTRACT FROM AUTHOR]

Heavy bio-oil based carbon material (HBC) was prepared via carbonization and activation, and the basic Mg-Al-O/HBC using HBC as the carrier was synthesized for the first time for the aldol condensation of cyclopentanone to produce aviation fuel precursor. It revealed that a higher carbonization temperature and heating rate led to the decreasing production of biochar. HBC presented the highest specific surface area (2046.92 m2/g) and total pore volume (1.2964 cm3/g) at the carbonization temperature of 700 °C, the heating rate of 15 °C/min, A/C ratio of 3:1, and the activation temperature of 800 °C, in which the largest proportion of micropores was 87.19%. Compared with Mg-Al-O, a higher strength of weak and moderate basic sites was found in Mg-Al-O/HBC, which was beneficial for the aldol condensation. A higher yield of targeted condensates in the range of C9∼C16 was achieved at 87.28% in the aldol condensation of cyclopentanone over Mg-Al-O/HBC catalyst. However, the condensation performance of the composite catalysts decreased seriously in the 5th run, which was related closely to the appearance of boehmite AlO(OH) and the pore blockage of HBC. To match the basic catalyst and HBC carrier well from the viewpoint of pore property, Al ions were substituted with Zr ions, and the yield of the target condensates over Mg-Zr-O/HBC was kept stably at 72.07% at the fifth use. This study provides a unique, viable and effective method to produce porous carbon from heavy fraction of bio-oil as the carbon source, and also its good application in the production of high-valued fuels. [Display omitted] • HBC was efficiently prepared from heavy bio-oil (HB) as carbon source. • HBC was firstly composited with Mg-Al-O to obtain Mg-Al-O/HBC for aldol condensation. • Abundant weak basic sites in Mg-Al-O/HBC were beneficial for aldol condensation. • The yield of targeted precursor of aviation fuel was boosted to 87.28%. • Mg-Al-O/HBC had excellent reusability in the aldol condensation of cyclopentanone. [ABSTRACT FROM AUTHOR]

In order to clarify the relationships between biomass pyrolysis mechanism and its main constituents. The effects of main constituents on biomass pyrolysis characteristics were firstly determined by thermo-gravimetric analysis based on the Simplex Lattice Mixture Design to investigate that whether the prediction of the pyrolysis behavior of a certain lignocellulosic biomass is possible when its main constituent contents are known. The results showed that there are constituent interactions in the pyrolysis process, which can be intuitively reflected through the change laws of kinetics parameters. The mathematical models for calculating kinetics values were established, and the models were proved to be valid for predicting lignocellulosic biomass pyrolysis behavior. In addition, the effects of biomass constituents on bio-oil compositions were explored by subsequent vacuum pyrolysis experiments. The xylan pyrolysis had a certain inhibitory effect on the pyrolysis of cellulose, and the pyrolysis products of lignin might promote the further decomposition of sugars from cellulose pyrolysis, while the interaction between xylan and lignin had a little effect on the bio-oil composition. [ABSTRACT FROM AUTHOR]

This work aimed to develop an in-situ upgrading process for production of refined bio-oil from primary biomass pyrolysis vapors. The phosphorus, zinc and titanium modified HZSM-5 were developed and first employed in the process. The yield of refined bio-oil was in the range of 17.85–19.97% along with low oxygen content (18.06–20.04%), high pH value (4.96–5.02), low dynamic viscosity (5.85–6.02 mm 2 /s), high HHV (higher heating value) (32.70–33.98 MJ/kg) and high hydrocarbon content. However, the composition of hydrocarbon varied with modified elements, so the catalytic mechanism of modified HZSM-5 was discussed. Simultaneously, anti-coking performance of modified catalyst was investigated to evaluate sustainability of the process. This work demonstrated that the refined bio-oil produced in this study basically met the technical requirements of combustion in power machinery, which provided a useful way to utilize renewable lignocellulose biomass. Though anti-coking capability of modified HZSM-5 was enhanced, coke deposition still hindered the continuous production of refined bio-oil to a certain extent. [ABSTRACT FROM AUTHOR]

Ketonization of bagasse pyrolysis gas was performed over red mud-based oxides. The maximum yield of ketones in the catalytic conversion of bagasse pyrolysis gas over original red mud was 18.66% at 420 °C. To promote the oxidability of red mud and obtain a higher yield of ketones, the effect of metal oxides (CeO 2 , MnO 2 , TiO 2 , CaO, ZrO 2) loading and loading amount of CeO 2 on red mud on ketonization of bagasse pyrolysis gas were studied. The highest yield of ketones of 27.86% was obtained over red mud-based oxides with 40 wt% CeO 2 loading. The oxidability of the catalyst was enhanced greatly by the high loading of CeO 2 , leading to the peroxidation of acetone as the side reaction. To control the oxidability and cut costs, bimetallic oxides were loaded on red mud. The yield of ketones reached 30.12% over the composite red mud catalyst with the loading of 20 wt% CeO 2 and 20 wt% MnO 2. The rough coating of MnO 2 on the surface of red mud was beneficial to the loading of CeO 2 , resulting in smaller and more uniform grains. This study provides the efficient utilization of red mud and biomass as solid wastes for high-valued chemicals and fuels. [ABSTRACT FROM AUTHOR]

Highlights: [•] A 2-in-1 process is proposed to directly catalyze the vacuum pyrolysis vapors. [•] Temperature, catalyst mass and Si/Al ratio affect the product yields significantly. [•] Oil phase yield is optimized by employing RSM and obtained at a higher value of 9.81%. [•] Oil phase has higher qualities with the HHV of 33.80MJ/kg and pH value of 5.15. [•] A large amount of aromatic hydrocarbons and light phenols are detected in oil phase. [ABSTRACT FROM AUTHOR]

Highlights: [•] Rape straw is a potential pyrolysis material for bio-oil preparation. [•] Effects on yield: heating rate>pyrolysis temperature>reactor pressure>holding time. [•] Heating rate and pyrolysis temperature have the interactive effects on bio-oil yield. [•] Polymerization contributes to the higher average molecular weight distribution. [•] Light aromatics are the dominant component contributing to the lower polydispersity. [Copyright &y& Elsevier]

In this study, metal-loaded HZSM-5 was prepared with metal ion extracted from the cathode materials of spent lithium batteries (lithium iron phosphate, LFP; lithium nickel-cobalt manganate, NCM) with citric acid for the improved production of light aromatic hydrocarbons by catalytic pyrolysis of rape straw. Because of the dealuminization effect of citric acid on HZSM-5, mesopores were introduced, and the diffusion and conversion of pyrolysis gas over acid sites were improved. After metal loading with acid-leaching solution, the amount of weak and total acids in metal-loaded HZSM-5 increased a lot, which was conducive to the dehydration, deoxygenation, decarbonylation and aromatization of pyrolysis, and the production of monocyclic aromatic hydrocarbons (MAHs). With 0.1 mol/L citric acid for LFP and NCM treatment, the metal-loaded catalyst showed a higher yield of benzene, toluene and xylene (BTX) of 11.10 wt% during catalytic pyrolysis of rape straw. Compared with 0.1-NCM-H5, a higher yield of MAHs was obtained over 0.1-LFP-H5 with a more favorable pore structure and higher amounts of weak and total acid sites. In general, the high-valued utilization of agricultural wastes and spent lithium batteries was realized in this study to produce clean energy. [Display omitted] • Effective utilization of rape straw and spent lithium batteries was studied. • The pore structure and acidity of HZSM-5 were improved by acid-leaching solution. • Kinetic model of catalytic pyrolysis over metal-loaded catalysts was established. • The yield of benzene, toluene and xylene reached 11.10 wt% over 0.1-LFP-H5. • 0.1-LFP-H5 with better pore structure and acidity presented a better performance. [ABSTRACT FROM AUTHOR]

Catalytic conversion of pyrolysis vapor from biomass was performed over CeO 2 catalysts to produce ketones. Thermogravimetric-gas chromatography/mass spectrometry (TG-GC/MS) and TG-MS were applied to understand the distribution of pyrolysis vapors from various biomass including rape straw, poplar, cypress and bagasse. The favorable biomass feedstock with high yield of ketones and other useful components were screened out for directional ketonization. The results showed that the temperature range of biomass pyrolysis was generally below 400 °C, and bagasse was a reasonable raw material for ketonization with the highest yield of ketones of 33.68% at 380 °C, since it contained the most cellulose and hemicellulose in biomass of the same quality. The activity of acetone increased at higher temperature, and secondary reaction occurred, resulting in a reduction in the overall yield of ketones. The total yield of ketones from bagasse treated for 9 h was boosted by 16.18% higher than that from nonseawater-treated biomass. By the introduction of metal ions effectively, the component of the pyrolysis vapor changed, making it easier for large molecular substances to be converted to small ones during pyrolysis. Through this research, the effective utilization of biomass could be realized. [ABSTRACT FROM AUTHOR]

[Display omitted] • Production of aldehydes and ketones from holocellulose pyrolysis vapor was studied.Yield of carbonyls reached 57.6% with cellulose/hemicellulose mass ratio of 3:2. • Bayer-RM with more Fe 2 O 3 presented better catalytic performance for carbonylation. • The yield of aldehydes and ketones reached 50.2% over 30ZrO 2 -RM. • Correlation between catalyst oxidizability and product distribution was established. This work proposes an effective method for the utilization of agricultural residues and red mud (RM) to produce the carbonyl platform compounds for the synthesis of high-value biofuels. The carbonyl platform compounds were synthesized by catalytic upgrading of pyrolysis vapor from holocellulose over RM composite catalyst. The maximized yield of aldehydes and ketones was obtained with the cellulose-to-hemicellulose mass ratio of 3:2, which was consistent with that of bagasse. Two types of RM were selected for the carbonylation of pyrolysis vapors, in which the type prepared by Bayer process containing more Fe 2 O 3 exhibited better carbonylation performance. The ZrO 2 -loaded RM composite catalyst was prepared, and it was found that the yield of aldehydes and ketones was greatly boosted. Finally, RM composite catalysts supported by five individual metal oxide were prepared, the correlation between the oxidizability of catalyst and the aldehyde/ketone mole ratio was established, and it was revealed that the stronger oxidizability of the composite catalysts was usually accompanied with the decreased aldehydes/ketones mole ratio. Biomass and RM wastes were used as resources in this study, this waste-to-energy idea contributes to optimizing the utilization of waste and promoting the production of biofuels. [ABSTRACT FROM AUTHOR]

Bio-aromatics preparation via in-situ catalytic pyrolysis of cellulose with lithium-ion battery ternary cathodes and ex-situ upgrading over Ru/HZSM-5 was studied. Three ternary cathodes with different ratios of Ni, Co, and Mn (NCM111, NCM532 and NCM811) were selected, and the effects of ternary cathodes and bifunctional Ru/HZSM-5 on the cellulose conversion were investigated from the perspectives of thermogravimetric kinetics and fixed-bed upgrading. The results indicated that cellulose pyrolyzed with cathodes reduced the solid residue content from 13.07% to 7.78%, 7.11%, and 6.63%, and decreased the weightlessness peak temperature from 358 ℃ to 348 ℃, 347 ℃, and 341 ℃; herein, the reaction order gradually elevated from 1.34 to 1.67 with the increased cathode Ni ratio, but the activation energy and pre-exponential factor obviously reduced. In-situ catalytic pyrolysis of ternary cathodes combined with ex-situ upgrading of Ru/HZSM-5 resulted in more cellulose-derived products being converted, increasing bio-oil yield from 22.47% to 25.08%, 24.75%, and 25.42%. Furfural was largely deoxygenated and dehydrated to become the precursor of aromatics, so NCM111, NCM532 and NCM811 usage increased the MAHs selectivity from 28.42% to 78.69%, 85.98%, and 87.27%, and high Ni ratio had higher deoxygenation capability and aromatic selectivity, simultaneously, it prone to creating material basis and spatiotemporal conditions for alkylation side reaction to increase C9 and above hydrocarbons. However, 1H NMR analysis confirmed that the main reaction of aromatization was still stronger than the side reaction even under high Ni ratio condition. Aromatics and coke production from acidic zeolite catalyzed reforming of oxygenates were competing reactions. In-situ catalysis of ternary cathodes produced more small molecule products to enter the inner pores of Ru/HZSM-5, forming more difficult to remove microporous coke, and the effect of increased Ni ratio was more obvious, but coke content reduced from 4.51% to 4.11%, 4.13%, and 3.05%, respectively. • Cellulose to aromatics was studied by in-situ catalytic pyrolysis and ex-situ upgrade. • Ternary cathode with high Ni ratio was beneficial for regulating kinetic parameters. • MAHs production was elevated, and high Ni cathode had higher aromatic selectivity. • Alkylation reaction under high Ni ratio increased C9 and above aromatic hydrocarbons. • Ternary cathodes contributed to more microporous coke, and high Ni ratio reduced coke. [ABSTRACT FROM AUTHOR]

Coke deposition in the catalytic fast pyrolysis of biomass includes active coke and inert coke, which promote or inhibit the formation of hydrocarbons. This study aims at the evolution of coke formation on various catalysts in the catalytic conversion of furan as an important intermediate from biomass fast pyrolysis. The functional groups on the surface of each catalyst at every moment were recorded by in situ diffuse reflectance Fourier transform infrared spectroscopy. The results indicated that the coke formation was closely related to the structure and acid property of the catalysts combined with catalytic tests in a fixed-bed reactor. Though dealumination only changed the acid distribution, it increased the hydrocarbon yield and introduced different chemical component of active coke. Because MCM-22 had a large internal space and small windows, its coke content should be quite large. However, the coke on MCM-22 did not show large molecules in this study because of the wide acid distribution, and similar active coke species with ZSM-5 were detected of polymethyl benzaldehyde. The coke content of HY was small because of large quantities of weak acid, although HY showed a significantly large internal space. The main components of active coke on HY and Hβ were diolefinic alcohols and polymethyl benzenes. The understanding of coke formation on various catalysts will provide guidelines for catalyst design, i.e., it is suggested that 3-dimensional structures such as MCM-22 with large supercages and small windows can be introduced into the original ZSM-5 system to form a core-shell catalyst to increase the hydrocarbon yields. [ABSTRACT FROM AUTHOR]

[Display omitted] • The carbonyls from CFP of holocellulose as platform compounds were prepared. • The carbonylation of pyrolysis gas from bagasse-derived holocellulose was more favorable. • 400 °C was optimized for the production of hydrocarbons from bagasse-derived bio-oil. • Mass yield of aviation fuel of 14.23% can be obtained from the original biomass. • Theoretical and economic analysis was provided for the production of aviation fuel. The carbonyl platform compound from the catalytic pyrolysis of holocellulose was employed for the integrated aldol condensation and hydrogenation to produce hydrocarbons in the range of jet fuel. By the carbonylation of the pyrolysis vapor from holocellulose prepared from rape straw, bagasse and poplar (RS-Holo, BG-Holo and PL-Holo), it was revealed that BG-Holo rich in cellulose as the raw material presented the most production of carbonyl compounds including aldehydes and ketones. The optimal temperature for carbonylation of pyrolysis vapor from holocellulose was determined to be 400 °C, with the maximized carbon yield of carbonyls reaching 46.11%, which was boosted to the summit of 53.59% with more addition of ZrO 2 catalyst. The integrated aldol condensation and hydrogenation were carried out using the catalytic pyrolysis bio-oil as the reactant over Ni/Mg-Al-O/AC bifunctional catalyst, with the highest carbon yield of hydrocarbons reaching 78.11%. The production mechanism of the final targeted alkanes was speculated, and it was discovered that ketones and aldehydes with short carbon chains are more prone to secondary condensation than those with long carbon chains, resulting in high-energy–density aviation fuel. Furthermore, the heating value of final oil was calculated based on an empirical formula, which was comparable to that of Jet A, meeting the standard of ASTM7566. The final oil's distillation range distribution was simulated, and most of it fell in the range of aviation fuel. In this study, catalytic fast pyrolysis of holocellulose followed by integrated aldol condensation and hydrogenation was proved to be a promising way for producing aviation fuel. [ABSTRACT FROM AUTHOR]

Catalytic upgrading of pyrolysis gas components from cellulose and xylan was investigated over ZrO 2 catalyst to produce aldehydes and ketones. The oxygen content in the bio-oil was reduced by aldol condensation and hydrogenation of aldehydes and ketones. The optimal pyrolysis temperature of cellulose and xylan were determined to be 400 °C and 350 °C and the carbon yields of aldehydes and ketones reached 54.49% and 52.05% respectively. In order to explore the formation mechanism of aldehydes and ketones, the evolution of typical products by controlling the reaction time was studied. The catalytic pyrolysis was complete and the product content was maximum at 20 min H 2 O played a role in providing oxygen atoms and increasing ZrO 2 reaction activity in the carbonylation process. The binding energy of the catalyst was calculated as −15.69 kcal/mol by density functional theory (DFT). It was found that the presence of water can remove the coke on the catalyst surface and increase the activity of ZrO 2. The yield of aldehydes and ketones reached 58.17% and 55.85% of cellulose and xylan with the presence of 15 wt% H 2 O in the carbonylation process. According to the evolution of the above experimental products, the generation pathways of four main carbonylation products (acetone, methyl ethyl ketone, butyraldehyde and furfural) were proposed. Through this research, the effective utilization of biomass could be realized. • The biomass was converted into aldehydes and ketones over ZrO 2. • The optimal pyrolysis temperature for cellulose and xylan were 400 °C and 350 °C. • Optimal yield of carbonylation from cellulose and xylan were 54.49% and 52.05%. • The presence of H 2 O was conducive to the formation of aldehydes and ketones. [ABSTRACT FROM AUTHOR]

Abstract: Both carbon nanospheres and CNTs with different morphologies were synthesized without any catalyst by microwave pyrolysis chemical vapor deposition using methane as carbon source and nitrogen as diluted gas. The morphology and structure of the products were characterized by field-emission scanning electron microscopy, high resolution transmission electron microscopy and Raman spectroscopy. The experimental results demonstrated that reaction temperature, gas ratio of methane to nitrogen and total gas flow rate strongly influenced the nature of various nanocarbon materials. Raman spectra indicated that the carbon nanospheres and CNTs possess relatively low degree of graphitization. [Copyright &y& Elsevier]

Abstract: Both Y-junction carbon nanotubes and individual carbon nanotubes were synthesized without any additive catalyst by microwave decomposition of methane. Detailed microstructures of as-synthesized products have been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. The results show that these Y-junction CNTs possess an internal bamboo-shaped structure, and some three dimensional multi-terminal junctions are also observed on CNTs. As gas flow rate decreased to 15sccm, only individual nanotubes could be obtained. A possible mechanism is proposed for the synthesis of the Y-junction carbon nanotubes on these observations. This technique may also have great potential in making other nano-structured carbon materials on a large scale and at low cost. [Copyright &y& Elsevier]

Abstract: A simple method was used to synthesize SiC nanowires directly on quartz plate by microwave pyrolysis of methane. The samples have been characterized by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction and Raman spectroscopy techniques. The results showed that the nanowires are of cubic β-SiC structure with stacking faults. The diameters of SiC nanowires are in the range of 50–200nm and their lengths up to several tens of microns. The effect of the reaction gas concentration and the reaction temperature on the morphologies of SiC nanowires was also investigated. Two broad photoluminescence peaks at the center wavelength of about 309 and 417nm were observed at room temperature. [Copyright &y& Elsevier]

Aldol condensation of biomass-derives coupled with hydrogenation is a promising route for the production of renewable aviation fuel. In this study, a bifunctional catalyst was prepared to integrate the aldol condensation of cyclopentanone and hydroprocessing for aviation fuel in one pot. Due to its strong mild-basic sites, Mg–Al–O performed the best with the total yield of dimer and trimer of 80.4%. Nickel was screened out to be favorable for hydrogenation. Considering the unsatisfactory porous structure of Ni/Mg–Al–O, the bifunctional catalyst was prepared with activated carbon (AC) as carrier. With Ni loading of 20 wt%, the maximum yield of targeted alkanes reached 81.1% over Ni/Mg–Al–O/AC. The calcination and reduction temperature in the preparation process were both optimized at 550 °C. In the reusability test, the yield of targeted alkanes reduced to 31.6% in the 5th run. To attenuate the hydration effect, n-pentane was introduced as solvent, and the bifunctional Ni/Mg–Al–O/AC performed stably in 5 runs. By the design of bifunctional catalyst based on the theoretical basis to realize the integration of C–C coupling and hydrogenation in one pot, it will promote the development of aviation fuel from biomass in a more sustainable and green way. Image 1 • A bifunctional catalyst was explored to integrate condensation & hydroprocessing. • Mg–Al–O and Ni/γ-Al 2 O 3 were screened out for aldol condensation and hydroprocessing. • To obtain better porosity of Ni/Mg–Al–O, activated carbon was chosen as the support. • The maximal yield of targeted alkanes in the range of aviation fuel reached 81.1%. • The bifunctional Ni/Mg–Al–O/AC performed stably in 5 runs with n-pentane as solvent. [ABSTRACT FROM AUTHOR]