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This work aims to demonstrate that cresol, an important high added value chemical in petrochemical industry, can be directionally produced using cellulose. This novel controllable transformation process was achieved by selective catalytic pyrolysis of cellulose and catalytic oxidation. The zinc oxide-doped strong acidic zeolite catalyst promoted the formation of toluene intermediate in the catalytic pyrolysis of cellulose. The CuCr2O4@MCM-41 catalyst exhibited high activity and good reusability in the catalytic oxidation process. The highest cresol selectivity of 87.5% with conversion of 83.0% was obtained using the CuCr2O4@MCM-41 catalyst and hydrogen peroxide as a green oxidant under the optimized reaction conditions (60 °C, 4 h). Based on the study of the model compounds and catalyst characterizations, the reaction pathways and possible reaction mechanism for the catalytic transformation of cellulose to bio-based cresol have been proposed.

Benzaldehyde and benzoic acid are high-value aromatic chemicals and important intermediates in chemical industry, and the catalytic conversion of biomass-based sources to these aromatic chemicals is of great significance in both academic and industrial fields. This work demonstrated that bio-oil was directionally converted into benzaldehyde and benzoic acid by three-step process under atmospheric pressure and moderate temperatures. The process included the catalytic cracking of biooil into aromatics over 1% Ga/HZSM-5 catalyst, followed by the dealkylation of heavier alkylaromatics to toluene over Re/HY catalyst and the liquid-phase oxidation of toluene-rich aromatics to the targeted chemicals over CoCl2/NHPI (CoCl2/N-Hydroxyphthalimide) catalyst. The production of benzaldehyde and benzoic acid from the bio-oil-derived aromatics, with the overall selectivity of 86.8%, was achieved using CoCl2/NHPI catalyst at 100 °C. Furthermore, adding a small amount of methanol into the feed would efficiently suppress the coke formation, and thus, enhance the yield of aromatics. Potentially, the novel synthesis route offers a green way for the production of higher value-added aromatic chemicals using renewable and environmentally friendly biomass-based sources.

This work proved that biomass-based polyols (sorbitol, xylitol, erythritol, glycerol and ethanediol) were able to be converted into high-value chemical (p-xylene) by catalytic cracking of polyols, alkylation of aromatics, and the isomerization of xylenes over the SiO2-modified zeolites. Compared to the conventional HZSM-5 zeolite, the SiO2-containing zeolites considerably increased the selectivity and yield of p-xylene due to the reduction of external surface acidity and the narrowing of pore entrance. The influences of the methanol additive, reaction temperature, and types of polyols on the selectivity and yield of p-xylene were investigated in detail. Catalytic cracking of polyols with methanol significantly enhanced the production of p-xylene by the alkylation of toluene with methanol. The highest p-xylene yield of 10.9 C-mol% with a p-xylene/xylenes ratio of 91.1% was obtained over the 15wt%SiO2/HZSM-5 catalyst. The reaction pathway for the formation of p-xylene was addressed according to the study of the key reactions and the characterization of catalysts.

BACKGROUND: Owing to the growing consumption of oil and the negative environmental impacts, the production of p‐xylene (PX) from renewable biomass has gained significant attention recently. However, the major challenge for the production of PX from biomass or furans is how to improve the yield and selectivity of PX, along with reducing coke. RESULTS: The para selectivity in the catalytic conversion of furans was greatly enhanced owing to the deactivation of external surface and the adjustment of pore entrance. Co‐catalytic conversion of furans and methanol significantly enhanced the production of PX by the Diels–Alder reactions between furans and olefins and the alkylation of benzene/toluene with methanol. The highest PX yield of 17.8 C‐mol% with a p‐xylene/xylene ratio of 94.5% was obtained by the co‐conversion of 2‐methylfuran with methanol over the 15%La/10%Ce/HZ catalyst. CONCLUSION: This work proved that furans (2‐methylfuran, 2,5‐dimethylfuran, furfural and furan) were able to be selectively converted into a high‐value chemical (PX) over the 15%La/10%Ce/HZ catalyst. The transformation mainly involved four key reactions: the catalytic cracking of furans, the Diels–Alder reactions, the alkylation of aromatics and the isomerization of xylenes over the surface‐modified zeolite. © 2019 Society of Chemical Industry

This work developed a one-step process for renewable p-xylene production by co-catalytic fast pyrolysis (co-CFP) of cellulose and methanol over the different metal oxides modified ZSM5 catalysts. It has been proven that ${\rm{L}}{{\rm{a}}_{\rm{2}}}{{\rm{O}}_{\rm{3}}}$ -modified ZSM5(80) catalyst was an effective one for the production of bio-based p-xylene. The selectivity and yield of p-xylene strongly depended on the acidity of the catalysts, reaction temperature, and methanol content. The highest p-xylene yield of 14.5 C-mol% with a p-xylene/xylenes ratio of 86.8% was obtained by the co-CFP of cellulose with 33wt% methanol over 20% ${\rm{L}}{{\rm{a}}_{\rm{2}}}{{\rm{O}}_{\rm{3}}}$ -ZSM5(80) catalyst. The deactivation of the catalysts during the catalytic pyrolysis process was investigated in detail. The reaction pathway for the formation of p-xylene from cellulose was proposed based on the analysis of products and the characterization of catalysts.

Lignin only accounts for about 6% of total mass in tobacco stem, but it influences the harmful substances in the side stream smoke of cigarette in a significant way. Traditional researches focus only on the determination of lignin content. In the present work, we investigate four typical imidazolium-based ionic liquids for efficient extraction of lignin under mild conditions and 1-ethyl-3-methylimidazolium diethylphosphate ([Emim][DEP]) shows the best results. The pretreatment of stem using water at 80 °C for 30 min can not only remove most of the sugars but also loose the microfibers. The extractive rate of lignin reaches 85.38% at 150 °C for 4 h and the purity of lignin is 90.21%.

This work demonstrated an integrated catalytic process for the production of high-pure hydrogen by different lignocellulosic biomasses and three major components. The process involved in steam reforming (SR) of biomass, the water gas shift (WGS) and removal of CO2. The results show lignin provided the highest hydrogen yield of 16.6 gH2/(100 gbiomass) with the H2 purity of 99.93 vol%, which was close to theoretical yield of 17.5 gH2/(100 gbiomass). The actual hydrogen yields for three major components of biomasses decreased in the order: lignin > hemicellulose > cellulose. The yield of hydrogen derived from different biomass feedstocks (like rice husk, sawdust and sugarcane bagasse) mainly depended on their oxygen content, the contents of lignin, cellulose and hemicellulose and the reaction conditions. The high hydrogen yield and high purity of hydrogen obtained were attributed to that almost all of carbon-containing species were effectively converted to H2 and CO2 via coupling the SR with the WGS in the integrated process.

BACKGROUND: p‐Xylene is an important bulk chemical in the petrochemical industry, and the production of bio‐based p‐xylene is of great significance in both academic and industrial arenas. However, the biggest challenge for the production of p‐xylene from biomass is how to increase the yield and selectivity of p‐xylene. RESULTS: The highest p‐xylene yield of 20.7 C‐mol% with a p‐xylene/xylenes ratio of 91.6% was obtained by the co‐catalytic pyrolysis of sawdust with 50 wt% methanol over the 20%La₂O₃/HZSM‐5(80) catalyst. Adding a La, Mg, Ce or Zn element into HZSM‐5 promoted the alkylation of benzene and toluene to form xylenes, and the isomerization of m/o‐xylenes to p‐xylene. CONCLUSION: This work developed a one‐pot process in which lignocellulosic biomass (sawdust) was directionally converted into p‐xylene by coupling the catalytic pyrolysis of biomass into aromatic monomers, the alkylation of light aromatics to xylenes and the isomerization of m/o‐xylenes to p‐xylene over the metal oxide‐modified HZSM‐5 catalysts. The selectivity and yield of p‐xylene strongly depended on the acidity of the catalysts, reaction temperature and methanol additive during the catalytic pyrolysis of sawdust. © 2018 Society of Chemical Industry

_Efficient synthesis of bio-based chemicals from renewable lignocellulosic biomass is of great significance to promote the sustainable development of chemical industry. This work aims to demonstrate that terephthalic acid, a bulk high value chemical in petrochemical industry, can be synthesized using biomass. This novel controllable transformation process was started with the selective catalytic pyrolysis of sawdust biomass to form p-xylene intermediate. The high p-xylene yield of 23.4% was obtained using the Ga2O3/SiO2/HZSM-5 catalyst under the optimized reaction condition. Subsequently, the selective oxidation of the biomass-derived aromatic intermediates to terephthalic acid was realized with the metal oxide catalysts. The highest terephthalic acid yield of 72.8% with the terephthalic acid selectivity of 82.3% was achieved using the CoMn2O4@SiO2@Fe3O4 catalyst. Based on the study of the catalytic conversion of the model compounds and the catalyst characterizations, the reaction pathways and possible reaction mechanism have been proposed.

In the present work, we reported a novel route for the conversion of lignocellulosic biomass (sawdust) to a high-value chemical of benzoic acid under atmospheric pressure. The transformation involved the catalytic pyrolysis of sawdust into aromatics, the decomposition of heavier alkylaromatics to toluene, and the liquid-phase oxidation of toluene-rich aromatics to benzoic acid. The production of the desired benzoic acid from the sawdust-derived aromatics, with the benzoic acid selectivity of 85.1 C-mol% and nearly complete conversion of toluene, was achieved using the MnO2/NHPI catalyst at 100 °C for 5 h. The influence of adding methanol on the catalytic conversion of sawdust to the core intermediate of toluene was also investigated in detail.

The directional production of benzene is achieved by the current-enhanced catalytic conversion of lignin. The synergistic effect between catalyst and current promotes the depolymerization of lignin and the selective recombinant of the functional groups in the aromatic monomers. A high benzene yield of 175 gbenzene/kglignin was obtained with an excellent selectivity of 92.9 C-mol%. The process potentially provides a promising route for the production of basic petrochemical materials or high value-added chemicals using renewable biomass.

The hydrodeoxygenation (HDO) of sorbitol in aqueous medium was performed over CNT supported Ru-Mo bimetallic catalyst. Compared with Ru-Mo/AC, Ru-Mo/CNT showed higher yield and selectivity towards C5/C6 alkanes due to the higher relative rate of C O vs. C C bond cleavage of sorbitol. Based on TEM, XPS and H 2 -TPR characterizations, the role of CNT in HDO reaction was studied to clarify the likely reasons for the selective C O vs. C C bond cleavage. It is suggested that an increase concentration of MoO x (x

Cumene is an important intermediate and chemical in chemical industry. In this work, directional preparation of cumene using lignin was achieved by a three-step cascade process. The mixture aromatics were first produced by the catalytic pyrolysis of lignin at 450 °C over 1%Zn/HZSM-5 catalyst, monocyclic aromatics with the selectivity of 85.7 wt% were obtained. Then, the catalytic dealkylation of heavier aromatics resulted in benzene-rich aromatics with 93.6 wt% benzene at 600 °C over Hβ catalyst. Finally, the cumene synthesis was performed by the aromatic alkylation, giving cumene selectivity of 91.6 C-mol% using the [bmim]Cl-2AlCl3 ionic liquid at room temperature for 15 min. Besides, adding a small amount of methanol to the feed can efficiently suppress the coke yield and enhance the aromatics yield. The proposed transformation potentially provides a useful route for production of cumene using renewable lignin.

This work indicated that p-xylene, an important bulk chemical in petrochemical industry, was able to be produced using the renewable biomass pyrolysis-derived bio-oil. The multifunctional catalysts (especially 3%Zn/20%SiO2/HZSM-5) simultaneously promoted the selectivity and yield of p-xylene in the catalytic upgrading of the bio-oil or bio-oil/methanol mixture. The SiO2 layer loaded on the catalysts significantly increased the selectivity of p-xylene by decreasing the external acidity of the catalyst surface. The addition of the active elements such as Zn and Ga into the HZSM-5 zeolite further improved the p-xylene yield by promoting the decarbonylation, decarboxylation and aromatization reactions. The optimized catalyst of 3%Zn/20%SiO2/HZSM-5 showed the maximum p-xylene yield of 18.7% with high p-xylene to xylenes ratio of 93.8%. The reaction pathways were proposed according to the detailed investigation for the catalytic cracking of different bio-oils and the functional groups in the products. Potentially, the resulting p-xylene product from the bio-oil can be used for high added value chemical or high octane gasoline additive.

This work demonstrated that triglycerides based vegetable oils were directly converted into cycloparaffinic and aromatic components in jet fuel by a three-step process. This process involved the catalytic cracking of vegetable oils into light aromatics over the zeolite catalyst (HZSM-5(80)), followed by the aromatic alkylation of light aromatics using the ionic liquid of [bmim] Cl-2AlCl(3) and the hydrogenation of aromatics over the Pd/AC catalyst. The production of C-8-C-15 aromatics with an 86.2 wt% in the aromatic biofuel was achieved by the room temperature alkylation at 25 degrees C for 30 min. The carbon number distribution in the resulting biofuels was readily adjustable to the desired range by varying the reaction time. The aromatic and cycloparaffinic biofuels obtained basically meet the requirements of jet fuels based on the combustion heat, the H/C mol ratio and the average molecular formulation. (C) 2016 Elsevier Ltd. All rights reserved.

In recent years, production of engine fuels and energy from biomass has drawn much interest. In this work, we conducted a novel integrated process for the preparation of bio-hydrogen and bio-fuels using lignocellulosic biomass pyrolysis-oil (bio-oil). The process includes (i) the production of bio-hydrogen or bio-syngas by the catalytic cracking of bio-oil, (ii) the adjustment of bio-syngas, and (iii) the production of bio-fuels by olefinic polymerization (OP) together with Fischer-Tropsch synthesis (FTS). Under the optimal conditions, the yield of bio-hydrogen was 120.9 g H2/(kg bio-oil). The yield of hydrocarbon bio-fuels reached 526.1 g/(kg bio-syngas) by the coupling of OP and FTS. The main reaction pathways (or chemical processes) were discussed based on the products observed and the catalyst property.

The continual growth in transportation fuels and more strict environmental legislations have led to immense interest in developing green biomass energy. In this work, a proposed catalytic transformation of oxygenated organic compounds (related to bio-oil) into pure hydrogen was desighed, involving the catalytic reforming of oxygenated organic compounds to hydrogen-rich mixture gas followed by the conversion of CO to CO2 via the water gas reaction and the removal of CO2. The optimization of the different reforming catalyst, the reaction conditions as well as various sources of oxygenated organic compounds were investigated in detail. The production of pure hydrogen, with the H2 content up to 99.96% and the conversion of 97.1%, was achieved by the integrated catalytic transformation. The reaction pathways were addressed based on the investigation of decomposition, catalytic reforming, and the water gas reaction.

This work demonstrated a novel catalytic transformation of gaseous olefins into jet fuel range iso-paraffins by the low-temperature olefin polymerizations under atmospheric conditions. The production of the desired C8–C15 iso-paraffins with the selectivity of 80.6 C mol% was achieved by the room-temperature polymerizations of gaseous light olefins using the [BMIM] Al2Cl7 ionic liquid. The influences of the reaction conditions on the olefinic polymerizations were investigated in detail. The properties of hydrocarbons in the synthetic fuels were determined by the GC–MS analyses combined with 1H NMR, and 13C NMR analyses. The formation of C8–C15 hydrocarbons from gaseous light olefins was illustrated by the identified products and the functional groups. This transformation potentially provides a useful avenue for the production of the most important components of iso-paraffins required in jet fuels.

Identifying a relation between current and channel luminosity is beneficial for producing an approximation to channel current via channel optical signal. In this paper, damped sinusoidal oscillation currents with more or less symmetrical waveshapes are injected into a tungsten copper hemispherical air gap and into a graphite rod air gap. Repeatability and reliability in channel luminosity measurement are compared between two air gap channels. Parametric correlation analyses, involving 12 sequences of lightning currents with a current peak from 13.0 kA to 34.4 kA, a current 10–90% risetime from 9.7 μs to 20.2 μs, and a current half-peak width from 21.6 μs to 46.4 μs, show the luminosity signatures also exhibit more or less symmetrical pulses, although they lag behind the corresponding current pulses. In initial primary pulses of these damped sinusoidal oscillations, the current peak is approximately direct proportional to the luminosity peak. Direct proportional relations are also observed between current 10–90% risetime and luminosity 10–90% risetime, between current half-peak width and luminosity half-peak width, as well as between current charge transfer and luminosity-time integration. These features are similar to those found in classical M-component current pulses associating with the M-component mode of charge transfer. Applicability of the results is further discussed to estimate the channel current from the channel luminosity.

This work aimed to develop an integrated process for production of gasoline fraction bio-fuels from bio-oil under atmospheric conditions. This novel transformation process included the catalytic cracking of bio-oil to light olefins and the subsequent synthesis of liquid hydrocarbon bio-fuels from light olefins with two reactors in series. The yield of bio-fuel was up to 193.8 g/(kg bio-oil) along with a very low oxygen content, high RONs (research octane numbers), high LHVs (lower heating values) and low benzene content under the optimizing reaction conditions. Coke deposition seems to be the main cause of catalyst deactivation in view of the fact that the deactivated catalysts was almost recovered by on-line treating the used catalyst with oxygen. The integrated transformation potentially provides a useful way for the development of gasoline range hydrocarbon fuels using renewable lignocellulose biomass.

The growing demand of commercial jet fuels, in combination with the strict environmental legislations, has led to immense interest in developing aviation biofuels. This work demonstrated that the bio-oil derived from fast pyrolysis of straw stalk was able to be converted into the jet and diesel fuel range hydrocarbons by a designed transformation route. This transformation included three reaction steps: (i) the catalytic cracking of bio-oil into low-carbon aromatics and light olefins, (ii) the synthesis of C8-C15 aromatic hydrocarbons by the alkylation of low-carbon aromatics with light olefins, and (iii) the production of C8-C15 cyclic alkanes by the hydrogenation of C8-C15 aromatics. It was also demonstrated that the production of the desired C8-C15 aromatics with a high selectivity of 88.4% was achieved by the low temperature alkylation reactions of the bio-oil-derived aromatics using the ionic liquid of [bmim]Cl-2AlCl(3) (1-butyl-3-methylimidazolium chloroaluminate). The synthetic biofuels basically met the main technical specifications of jet fuels based on the combustion heat, viscosity, freeze point and other characteristics of fuels. (C) 2015 Elsevier Ltd. All rights reserved.

The continual growth in commercial aviation fuels and more strict environmental legislations have led to immense interest in developing green aviation fuels from biomass. This paper demonstrated a controllable transformation of lignin into jet and diesel fuel range hydrocarbons, involving directional production of C8-C15 aromatics by the catalytic depolymerization of lignin into C6-C8 low carbon aromatic monomers coupled with the alkylation of aromatics, and the directional production of C8-C15 cycloparaffins by the hydrogenation of aromatics. The key step, the production of the desired C8-C15 aromatics with the selectivity up to 94.3%, was achieved by the low temperature alkylation reactions of the lignin-derived monomers using ionic liquid. The synthetic biofuels basically met the main technical requirements of conventional jet fuels. The transformation potentially provides a useful way for the development of cycloparaffinic and aromatic components in jet fuels using renewable lignocellulose biomass.

A series of bifunctional catalysts composed of a component for higher alcohol synthesis (CuCoMn oxides, CCM) and an acidic zeolite (SAPO-34, ZSM-5, Y, MCM-41) were prepared for production of liquid hydrocarbon directly from a bio-syngas through a one-stage process. The effects of zeolite type, zeolite content, Si/Al ratio and preparation method on catalyst texture and its reaction performance were investigated. Higher selectivities and yields of liquid products were obtained by using bifunctional catalysts. The yields of liquid hydrocarbons decreased in the order CCM-ZSM-5>CCM-SAPO-34>CCM-Y>CCM-MCM-41. CCM-ZSM-5 (20wt%, Si/Al=100) prepared by coprecipitation method displayed the optimal catalytic performance with the highest CO conversion (76%) and yield of liquid products (30%). The catalysts were characterized by N2 adsorption/desorption, NH3-TPD, XRD, and H2-TPR analysis. The results showed that higher specific surface areas and pore volumes of bifunctional catalysts were achieved by adding zeolites into CuCoMn precursors. Medium pore dimension and moderate acidity in CCM-ZSM-5 were observed, which probably resulted in its excellent reaction performance. Additionally, a higher number of weaker acid sites (weak and/or medium acid sites) were formed by increasing ZSM-5 content in CCM-ZSM-5 or decreasing Si/Al ratio in ZSM-5. It was also seen that metal dispersion was higher and reducibility of metal ions was easier on the CCM-ZSM-5 catalyst prepared by coprecipitation. The higher alcohols-to-hydrocarbon process provides a promising route to hydrocarbon fuels via higher alcohols from syngas or biobased feedstocks.

A series of surfactant-modified CuCoMn-based catalysts were prepared for higher alcohol synthesis from biomass-based syngas. Three typical surfactants, cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS) and pluronic P123 triblock copolymer (EO20PO70EO20), were employed. Compared to surfactant-free CuCoMn catalyst, CO conversion increased from 17.4% to 29.7% over SDS-modified CuCoMn catalyst, and the selectivity of higher alcohols increased from 22.0% to 41.2% over CTAB-modified catalyst. Besides, the proportions of higher alcohols in total alcohols increased over all surfactant-modified catalysts. The catalysts were characterized by N2 adsorption/desorption, XRD, XPS and IR analysis. The results showed that several more favorable features rendered the CTAB-modified CuCoMn catalyst to be suitable for higher alcohol production, such as the larger pore size, better crystallinity of CuCoMnO4 spinel, moderate surface atomic distribution and lower valence of metallic ions. In addition, it was verified that CTAB addition at the metal precipitation stage was beneficial to higher alcohol synthesis. Surfactant-induced modification provides a promising alternative method for catalyst improvement in synthesis of higher alcohols.

Efficient production of clean biofuels using CO2-rich bio-oil-based syngas obtained from bio-oil steam reforming was performed over a Fe1.5Cu1Zn1Al1K0.117 catalyst. The effects of synthesis parameters (temperature, pressure, gas hourly space velocity) on the performance of the biofuel synthesis were investigated. The maximum biofuel yield reaches about 0.63 kg biofuels/(kgcata·h) with a contribution of 0.40 kg alcohols/(kgcata·h) and 0.23 kg liquid hydrocarbons/(kgcata·h). The content of C2+ alcohols (mainly C2–C6 alcohols) in the alcohols products is 87.04–91.15 wt%. Some important elementary steps involved in the biofuel synthesis, including the reverse water-gas shift reaction and methanation, were also investigated in detail.

Lignin is the only nature renewable resource which can provide large quantities of aromatic compounds. In the work, transformation of lignin into benzene, toluene, and xylenes (BTX) was investigated over the HZSM-5, HY, and MCM-22 catalysts, and the HZSM-5 catalyst showed the highest carbon yield of BTX. The reaction condition, including temperature, the gas flow rate, and the catalyst/lignin ratio, was also investigated. The carbon yield of BTX reached about 25.3 C-mol% over HZSM-5 catalyst under T=550 °C, f(N2)=300 cm3/min, and catalyst/lignin ratio of 2.

Transformation of lignin to ethylbenzene can provide an important bulk raw material for the petrochemical industry. This work explored the production of ethylbenzene from lignin through the directional catalytic depolymerization of lignin into the aromatic monomers followed by the selective alkylation of the aromatic monomers. For the first step, the aromatics selectivity of benzene derived from the catalytic depolymerization of lignin reached about 90.2 C-mol% over the composite catalyst of Re-Y/HZSM-5 (25). For the alkylation of the aromatic monomers in the second step, the highest selectivity of ethylbenzene was about 72.3 C-mol% over the HZSM-5 (25) catalyst. The reaction pathway for the transformation of lignin to ethylbenzene was also addressed. Present transformation potentially provides a useful approach for the production of the basic petrochemical material and development of high-end chemicals utilizing lignin as the abundant natural aromatic resource.

BACKGROUND Catalytic transformation of bio-oil into higher olefins can provide valuable bio-fuels and chemicals used in the manufacture of high-octane gasoline, detergents, plasticizers and other petrochemicals. This work explores the production of higher olefins from bio-oil through catalytic cracking of bio-oil along with light olefins oligomerization. RESULTS For bio-oil catalytic cracking, the olefins yield reached 43.8 C-mol% with near-complete bio-oil conversion. The oxygenated organic compounds in bio-oil go through deoxygenation, cracking and hydrogen transfer reactions and form light olefins over the zeolite acid sites. For the oligomerization of light olefins, the highest selectivity and yield of C5+ olefins over the LTGO catalyst reached 85.4 C-mol% and 326.7 g kg−1cata h−1, respectively. Main products below 300°C were C6=—C12= olefins, originating from light olefin oligomerization. The influences of the reaction conditions were investigated in detail, and the reaction mechanism was addressed. CONCLUSION Bio-oil can be catalytically converted to C2=–C4= light olefins over HZSM-5, and further selectively transformed to C5+ high olefins via the oligomerization of light olefins over LTGO. The transformation of bio-oil to higher olefins may be useful for the production of bio-fuels and high value chemicals using renewable biomass. © 2013 Society of Chemical Industry

Biomass conversion into benzene, toluene and xylenes (BTX) can provide basic feedstocks for the petrochemical industry, which also serve as the most important aromatic platform molecules for development of high-end chemicals. Present work explored a new route for transformation of bio-oil tar into BTX through current-enhanced catalytic conversion (CECC), involving the synergistic effect between the zeolite catalyst and current to promote the deoxygenation and cracking reactions. The proposed transformation shows an excellent BTX aromatics selectivity of 92.9 C-mol% with 25.1 wt.% yield at 400 °C over usual HZSM-5 catalyst. The study of the model compounds revealed that the groups such as methoxy, hydroxyl and methyl in aromatics can be effectively removed in the CECC process. Present transformation potentially provides an important approach for production of the key petrochemicals of BTX and the overall use of bio-oil tar derived from bio-oil or biomass.

Low‐carbon light olefins are the basic feedstocks for the petrochemical industry. Catalytic cracking of crude bio‐oil and its model compounds (including methanol, ethanol, acetic acid, acetone, and phenol) to light olefins were performed by using the La/HZSM‐5 catalyst. The highest olefins yield from crude bio‐oil reached 0.19 kg/(kg crude bio‐oil). The reaction conditions including temperature, weight hourly space velocity, and addition of La into the HZSM‐5 zeolite can be used to control both olefins yield and selectivity. Moderate adjusting the acidity with a suitable ratio between the strong acid and weak acid sites through adding La to the zeolite effectively enhanced the olefins selectivity and improved the catalyst stability. The production of light olefins from crude bio‐oil is closely associated with the chemical composition and hydrogen to carbon effective ratios of feedstock. The comparison between the catalytic cracking and pyrolysis of bio‐oil was studied. The mechanism of the bio‐oil convers...

A new kind of multiple metal (Cu, Mg, Ce) doped Ni based mixed oxide catalyst, synthesized by the co‐precipitation method, was used for efficient production of hydrogen from bio‐oil reforming at 250–500 °C. Two reforming processes, the conventional steam reforming (CSR) and the electrochemical catalytic reforming (ECR), were performed for the bio‐oil reforming. The catalyst with an atomic mole ratio of Ni : Cu : Mg : Ce : Al =5.6:1.1:1.9:1.0:9.9 exhibited very high reforming activity both in CSR and ECR processes, reaching 82.8% hydrogen yield at 500 °C in the CSR, yield of 91.1% at 400 °C and 3.1 A in the ECR, respectively. The influences of reforming temperature and the current through the catalyst in the ECR were investigated. It was observed that the reforming and decomposition of the bio‐oil were significantly enhanced by the current. The promoting effects of current on the decomposition and reforming processes of bio‐oil were further studied by using the model compounds of bio‐oil (acetic acid and ethanol) under 101 kPa or low pressure (0.1 Pa) through the time of flight analysis. The catalyst also shows high water gas shift activity in the range of 300–600 °C. The catalyst features and alterations in the bio‐oil reforming were characterized by the ICP, XRD, XPS and BET measurements. The mechanism of bio‐oil reforming was discussed based on the study of the elemental reactions and catalyst characterizations. The research catalyst, potentially, may be a practical catalyst for high efficient production of hydrogen from reforming of bio‐oil at mild‐temperature.

Catalytic conversion of rice husk, sawdust, sugarcane bagasse, cellulose, hemicellulose and lignin into olefins was performed with HZSM-5 containing 6 wt.% lanthanum. The olefins yields for different feedstocks decreased in the order: cellulose > hemicellulose > sugarcane bagasse > rice husk > sawdust > lignin. Biomass containing higher content of cellulose or hemicellulose produced more olefins than feedstocks with higher content of lignin. Among the biomass types, sugarcane bagasse provided the highest olefin yield of 0.12 kg olefins/(kg dry biomass) and carbon yield of 21.2 C-mol%. Temperature, residence time and the catalyst/feed ratio influenced olefin yield and selectivity. While the HZSM-5 zeolite was catalytically active, the incorporation of lanthanum at 2.9, and 6.0 wt.% increased the production of olefins from rice husk by 15.6% and 26.5%, respectively. The conversion of biomass to light olefins potentially provides an alternative and sustainable route for production of the key petrochemicals.

Catalytic conversion of bio-oil into light olefins was performed by a series of molecular sieve catalysts, including HZSM-5, MCM-41, SAPO-34 and Y-zeolite. Based on the light olefins yield and its carbon selectivity, the production of light olefins decreased in the following order: HZSM-5>SAPO-34>MCM-41> Y-zeolite. The highest olefins yield from bio-oil using HZSM-5 catalyst reached 0.22 kg/kgbio-oil with carbon selectivity of 50.7% and a nearly complete bio-oil conversion. The reaction conditions and catalyst characterization were investigated in detail to reveal the relationship between the catalyst structure and the production of olefins. The comparison between the pyrolysis and catalytic pyrolysis of bio-oil was also performed.

Autothermal steam reforming (ATR) of bio-oil, which couples the endothermic steam reforming reaction with the exothermic partial oxidation, offers many advantages from a technical and economic point of view. Effective production of hydrogen through ATR of bio-oil was performed at lower temperature with NiCuZnAl catalyst. The highest hydrogen yield from bio-oil reached 64.3% with a nearly complete bio-oil conversion at 600 °C, the ratio of steam to carbon fed (S/C) of 3 and the oxygen to carbon ratio (O/C) of 0.34. The reaction conditions in ATR including temperature, O/C, S/C and weight hourly space velocity can be used to control both hydrogen yield and products distribution. The comparison between the ATR and common steam reforming of bio-oil was studied. The mechanism of the ATR of bio-oil was also discussed.

Highly efficient synthesis of clean biofuels using the bio-syngas obtained from biomass gasification was performed over Fe1.5Cu1Zn1Al1K0.117 catalyst. The maximum biofuel yield from the bio-syngas reaches about 1.59 kg biofuels/(kgcatal·h) with a contribution of 0.57 kg alcohols/(kgcatal·h) and 1.02 kg liquid hydrocarbons/(kgcatal·h). The alcohol products in the resulting biofuels were dominated by the C2+ alcohols (mainly C2—C6 alcohols) with a content of 73.55%–89.98%. The selectivity of the liquid hydrocarbons (C5+) in the hydrocarbon products ranges from 60.37% to 70.94%. The synthesis biofuels also possess a higher heat value of 40.53–41.49 MJ/kg. The effects of the synthesis conditions, including temperature, pressure, and gas hourly space velocity, on the biofuel synthesis were investigated in detail. The catalyst features were characterized by inductively coupled plasma and atomic emission spectroscopy, X-ray diffraction, temperature programmed reduction, and the N2 adsorption-desorption isotherms measurements. The present biofuel synthesis with a higher biofuel yield and a higher selectivity of liquid hydrocarbons and C2+ alcohols may be a potentially useful route to produce clean biofuels and chemicals from biomass.

A dual-reactor, assembled with the on-line syngas conditioning and methanol synthesis, was successfully applied for high efficient conversion of rich CO2 bio-oil derived syngas to bio-methanol. In the forepart catalyst bed reactor, the catalytic conversion can effectively adjust the rich-CO2 crude bio-syngas into the CO-containing bio-syngas using the CuZnAlZr catalyst. After the on-line syngas conditioning at 450 °C, the CO2/CO ratio in the bio-syngas significantly decreased from 6.3 to 1.2. In the rearward catalyst bed reactor, the conversion of the conditioned bio-syngas to bio-methanol shows the maximum yield about 1.21 kg/(kgcatal·h) MeOH with a methanol selectivity of 97.9% at 260 °C and 5.05 MPa using conventional CuZnAl catalyst, which is close to the level typically obtained in the conventional methanol synthesis process using natural gas. The influences of temperature, pressure and space velocity on the bio-methanol synthesis were also investigated in detail.

We reports an efficient approach for production of hydrogen from crude bio-oil and biomass char in the dual fixed-bed system by using the electrochemical catalytic reforming method. The maximal absolute hydrogen yield reached 110.9 g H2/kg dry biomass. The product gas was a mixed gas containing 72%H2, 26%CO2, 1.9%CO, and a trace amount of CH4. It was observed that adding biomass char (a by-product of pyrolysis of biomass) could remarkably increase the absolute H2 yield (about 20%-50%). The higher reforming temperature could enhance the steam reforming reaction of organic compounds in crude bio-oil and the reaction of CO and H2O. In addition, the CuZn-Al2O3 catalyst in the water-gas shift bed could also increase the absolute H2 yield via shifting CO to CO2.

The NOx storage features and mechanism of a K-doped [Ca24Al28O64]4+·4O– catalyst (designated as C12A7-O–/K) were systematically investigated. The NOx storage capability (NSC) of the C12A7-O–/K catalyst was found to depend primarily on the temperature, the K-doping level, and the oxygen concentration in the gas mixture. The C12A7-O–/10%K catalyst exhibited the highest storage capacity among the C12A7-O–/M (M = K, Na, Mg) catalysts investigated, attaining a maximum NSC value of 183.9 μmol/g at about 550 °C. The optimum temperature window for NOx storage with C12A7-O–/10%K catalyst ranged from 400 to 650 °C. Thermogravimetric analysis (TGA), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) spectroscopy were utilized to identify the catalyst characteristics and the active species, both in the body of the catalyst and on its surface. Additionally, anionic time-of-flight mass spectrometry (TOF-MS) measurements were employed to investigate the anionic intermediates desorbed from the catalyst surfa...

We provides a novel approach to generate low-temperature atomic oxygen anions (O?) emission using the cesium oxide-doped 12CaO?7Al2O3 (Cs2O-doped C12A7). The maximal emission intensity of O? from the Cs2O-doped C12A7 at 700 ?C and 800 V/cm reached about 0.54 ?A/cm2, which was about two times as strong as that from the un-doped C12A7 (0.23 ?A/cm2) under the same condition. The initiative temperature of the O? emission from the Cs2O-doped C12A7 was about 500 ?C, which was also much lower than the initiative temperature from the un-doped C12A7 (570 ?C) in the given field of 800 V/cm. High pure O? emission close to 100% could be obtained from the Cs2O-doped C12A7 under the lower temperature (

A novel approach for high efficient conversion of the CO(2)-rich bio-syngas into the CO-rich bio-syngas was carried out by using biomass char and Ni/Al(2)O(3) catalyst, which was successfully applied for production of bio-methanol from bio-oil. After the bio-syngas conditioning, the CO(2)/CO ratio prominently dropped from 6.33 to 0.01-0.28. The maximum CO yield in the bio-syngas conditioning process reached about 1.96 mol/(mol CO(2)) with a nearly complete conversion of CO(2) (99.5%). The performance of bio-methanol synthesis was significantly improved via the conditioned bio-syngas, giving a maximum methanol yield of 1.32 kg/(kg(catalyst)h) with a methanol selectivity of 99%. Main reaction paths involved in the bio-syngas conditioning process have been investigated in detail by using different model mixture gases and different carbon sources.

Ab initio and Rice–Ramsperger–Kassel–Marcus theories are carried out to study the potential energy surface and the energy-dependent rate constants and branching ratios of the products for O(1D) + CH3CHF2 reaction. Optimized geometries and vibrational frequencies have been obtained by MP2/6-311G(d,p) method. The main products of the title reaction are CH3CFO + HF, CH2CFOH + HF, and CH3 + CF2OH at lower collision energy; and CH3 + CF2OH, CH3CF2 + OH are the main products at higher collision energy. CHF2 + CH2OH are the main products in the whole range of collision energy. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012

We investigated high catalytic activity of Ni/HZSM-5 catalysts synthesized by the impregnation method, which was successfully applied for low-temperature steam reforming of bio-oil. The influences of the catalyst composition, reforming temperature and the molar ratio of steam to carbon fed on the stream reforming process of bio-oil over the Ni/HZSM-5 catalysts were investigated in the reforming reactor. The promoting effects of current passing through the catalyst on the bio-oil reforming were also studied using the electrochemical catalytic reforming approach. By comparing Ni/HZSM-5 with commonly used Ni/Al2O3 catalysts, the Ni20/ZSM catalyst with Ni-loading content of about 20% on the HZSM-5 support showed the highest catalytic activity. Even at 450 °C, the hydrogen yield of about 90% with a near complete conversion of bio-oil was obtained using the Ni20/ZSM catalyst. It was found that the performance of the bio-oil reforming was remarkably enhanced by the HZSM-5 supporter and the current through the catalyst. The features of the Ni/HZSM-5 catalysts were also investigated via X-ray diffraction, inductively coupled plasma and atomic emission spectroscopy, hydrogen temperature-programmed reduction, and Brunauer-Emmett-Teller methods.

A series of Mo-based catalysts prepared by sol-gel method using citric acid as complexant were successfully applied in the high efficient production of mixed alcohols from bio-syngas, derived from the biomass gasification. The Cu1Co1Fe1Mo1Zn0.5−6%K catalyst exhibited a higher activity on the space-time yield of mixed alcohols, compared with the other Mo-based catalysts. The carbon conversion significantly increases with rising temperature below 340 °C, but the alcohol selectivity has an opposite trend. The maximum mixed alcohols yield derived from biomass gasification is 494.8 g/(kgcatal·h) with the C2+ (C2—C6 higher alcohols) alcohols of 80.4% under the tested conditions. The alcohol distributions are consistent with the Schulz-Flory plots, except methanol. In the alcohols products, the C2+ alcohols (higher alcohols) dominate with a weight ratio of 70%–85%. The Mo-based catalysts have been characterized by X-ray diffraction and N2 adsorption/desorption. The clean bio-fules of mixed alcohols derived from ...

The potential energy surface of O(1D) + CH3CH2Br reaction has been studied using QCISD(T)/6-311++G(d,p)//MP2/6-311G(d,p) method. The calculations reveal an insertion-elimination reaction mechanism of the title reaction. The insertion process has two possibilities: one is the O(1D) inserting into CBr bond of CH3CH2Br producing one energy-rich intermediate CH3CH2OBr and another is the O(1D) inserting into one of the CH bonds of CH3CH2Br producing two energy-rich intermediates, IM1 and IM2. The three intermediates subsequently decompose to various products. The calculations of the branching ratios of various products formed though the three intermediates have been carried out using RRKM theory at the collision energies of 0, 5, 10, 15, 20, 25, and 30 kcal/mol. CH3CH2O + Br are the main decomposition products of CH3CH2OBr. CH3COH + HBr and CH2CHOH + HBr are the main decomposition products for IM1; CH2CHOH + HBr are the main decomposition products for IM2. As IM1 is more stable and more likely to form than CH3CH2OBr and IM2, CH3COH + HBr and CH2CHOH + HBr are probably the main products of the O(1D) + CH3CH2Br reaction. Our computational results can give insight into reaction mechanism and provide probable explanations for future experiments. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2011

The reforming of anisole (as model compound of bio-oil) was performed over the NiCuZn-Al2O3 catalyst, using a recently-developed electrochemical catalytic reforming (ECR). The influence of the current on the anisole reforming in the ECR process has been investigated. It was observed that anisole reforming was significantly enhanced by the current approached over the catalyst in the electrochemical catalytic process, which was due to the non-uniform temperature distribution in the catalytic bed and the role of the thermal electrons originating from the electrified wire. The maximum hydrogen yield of 88.7% with a carbon conversion of 98.3% was obtained through the ECR reforming of anisole at 700°C and 4 A. X-ray diffraction was employed to characterize catalyst features and their alterations in the anisole reforming. The apparent activation energy for the anisole reforming is calculated as 99.54 kJ/mol, which is higher than ethanol, acetic acid, and light fraction of bio-oil. It should owe to different physical and chemical properties and reforming mechanism for different hydrocarbons.

High-efficient production of hydrogen from bio-oil was performed by electrochemical catalytic reforming method over the CoZnAl catalyst. The influence of current on the hydrogen yield, carbon conversion, and products distribution were investigated. Both the hydrogen yield and carbon conversion were remarkably enhanced by the current through the catalyst, reaching hydrogen yield of 70% and carbon conversion of 85% at a lower reforming temperature of 500°C. The influence of current on the properties of the CoZnAl catalyst was also characterized by X-ray diffraction, X-ray photoelectron spectroscopy, thermal gravimetric analysis, and Brunauer-Emmett-Teller measurements. The thermal electrons would play an important role in promoting the reforming reactions of the oxygenated-organic compounds in the bio-oil.

High efficient production of hydrogen from the crude bio-oil was performed in the gasification-reforming dual beds. A recently developed electrochemical catalytic reforming method was applied in the downstream reforming bed using NiCuZnAl catalyst. Production of hydrogen from the crude bio-oil through both the single gasification and integrative gasification-reforming processes was investigated. The maximum hydrogen yield of 81.4% with carbon conversion of 87.6% was obtained through the integrative process. Hydrogen is a major product (∼73 vol%) together with by-products of CO2 (∼26 vol%) as well as very low content of CO (

Present study reports on high catalytic activity of CNTs-supported Ni catalyst (x% Ni-CNTs) synthesized by the homogeneous deposition–precipitation method, which was successfully applied for low-temperature reforming of organic compounds in bio-oil. The optimal Ni-loading content was about 15 wt%. The H2 yield over the 15 wt% Ni-CNTs catalyst reached about 92.5% at 550 °C. The influences of the reforming temperature (T), the molar ratio of steam to carbon fed (S/C) and the current (I) passing through the catalyst, on the reforming process of the bio-oil over the Ni-CNTs' catalysts were investigated using the stream as the carrier gas in the reforming reactor. The features of the Ni-CNTs' catalysts with different loading contents of Ni were investigated via XRD, XPS, TEM, ICP/AES, H2-TPD and the N2 adsorption–desorption isotherms. From these analyses, it was found that the uniform and narrow distribution with smaller Ni particle size as well as higher Ni dispersion was realized for the CNTs-supported Ni catalyst, leading to excellent low-temperature reforming of oxygenated organic compounds in bio-oil.

The potential energy surface of O( 1 D) + CH 3 CH 2 F reaction has been studied using QCISD(T)/6-311++G(d,p)//MP2/6-311G(d,p) method. The calculations reveal an insertion–elimination reaction mechanism of the title reaction. The insertion process has two possibilities: one is the O( 1 D) atom inserting into C–F bond of CH 3 CH 2 F produces one energy-rich intermediate CH 3 CH 2 OF and another is the O( 1 D) atom inserting into one of the C–H bonds of CH 3 CH 2 F produces two energy-rich intermediates, IM1 and IM2. The three intermediates subsequently decompose to various products. The calculations of the branching ratios of various products formed though the three intermediates have been carried out using RRKM theory at the collision energies of 0, 5, 10, 15, 20, 25 and 30 kcal/mol. CH 3 CH 2 O is the main decomposition product of CH 3 CH 2 OF. HF and CH 3 are the main decomposition products for IM1; CH 2 OH is the main decomposition product for IM2. Since IM1 is more stable and more likely to form than CH 3 CH 2 OF and IM2, HF and CH 3 are probably the main products of the O( 1 D) + CH 3 CH 2 F reaction. Our computational results can give insight to reaction mechanism and provide probable explanations for future experiments.