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Ionic liquids (ILs) have attracted increasing attention since last few decades due to their high molecular design abilities and wide applications in different fields. In this study, four novel fluorescent isoquinolino [2,1-a]quinoxalin-5-ium ILs were designed and synthesized via a two-step process including a simple dual Schiff's base formation and a subsequent [RhCp∗Cl2]2-catalyzed oxidative C–H activation/annulation reaction. The as-synthesized ILs were extensively characterized using FT-IR, 1H-NMR, 13C-NMR, 19F-NMR, HSQC-NMR, HMBC-NMR and HR-MS. Their photophysical properties were determined by steady-state fluorescence spectroscopy. The results demonstrate that all these ILs showed dual or triple emissions, large stokes shift (90 nm) and mechanochromic behaviors. Basing on solvatochromism and titration experiments, it is thought that the emission bands of the ILs are raised from their local excited states, charge transfer states or excited state proton transfer of cations, while the substitute effect of these quinoxaline derived ILs on their stokes shifts is negligible.

In order to meet the requirements of sustainable development, the production of aromatic compounds from renewable biomass is of great concern. Herein, a surfactant-free microemulsion (SFME) system ...

The conversion of lignocellulose into a value-added chemical with high selectivity is of great significance but is a big challenge due to the structural diversities of biomass components. Here, we have reported an efficient approach for the one-step conversion of raw lignocellulose into diethyl maleate by the polyoxometalate ionic liquid [BSmim]CuPW12O40 in ethanol under mild conditions. The results reveal that all of the fractions in biomass, i.e., cellulose, lignin and hemicellulose, were simultaneously converted into diethyl maleate (DEM), achieving a 329.6 mg g−1 yield and 70.3% selectivity from corn stalk. Importantly, the performance of the ionic liquid catalyst [BSmim]CuPW12O40 was nearly twice that of CuHPW12O40, which can be attributed to the lower incorporation of the Cu2+ site in [BSmim]CuPW12O40. Hence, this process opens a promising route for producing bio-based bulk chemicals from raw lignocellulose without any pretreatment.

As the most abundant renewable aromatic resource on Earth, lignin is a preferred starting material for producing bulk chemicals via a sustainable route. In this study, we provide a novel and efficient "clip-off" approach for producing methyl

Novel strategies for converting renewable lignin to bulk petrochemicals are highly desirable for achieving sustainable practices in the age of environmental awareness. Herein, we propose an efficie...

Catalytic conversion of lignin to versatile aromatic compounds is attracting increasing attention. However, it is highly desirable but challenging to produce a specific chemical with high yield thr...

Bulk chemicals produced from renewable resources are receiving considerable attention due to the increase in sustainable practices. In this study, a novel, efficient, and sustainable strategy has b...

The isomerization of glucose to fructose is a crucial step in the formation of high-value biochemicals from renewable cellulosic biomass. In this work, we have demonstrated a novel and efficient st...

Bio-fuel production from the renewable resource, such as biomass and its components, becomes increasingly attractive in views of the depletion of fossil fuel and the resulted environmental problems caused by excessive use of these unsustainable energy. In this study, we provide a novel and efficient technology for high quality oxygen-containing fuel production from the lignin bio-oil using cost-effective catalyst of Ni/MgO. guaiacol was chosen as the model compound because it is general one of the most abundant component in lignin bio-oil and has almost all characteristic functional group of lignin depolymerization products. The results demonstrate that guaiacol can be efficient and selective converted over the Ni/MgO. Particularly, calcination temperature has a significant effect on the Ni/MgO catalyst structure and surface properties, leading to distinct difference on the lignin bio-oil upgradation performance. When it is calcined at 850 ˚C, Ni/MgO shows the best catalyst activity. 98% guaiacol conversion is obtained with 97% cyclohexanol selectivity and 3% phenol selectivity at 160 °C for 4 h under 3 MPa of hydrogen pressure, indicating that it would be a promising strategy for the renewable lignocellulosic biomass valorization.

Lignin selective depolymerization is a crucial step in high-value utilization of this natural aromatic polymer. In this study, we provide a novel and efficient hydrogenolysis process for organosolv lignin selective decomposition and char elimination over non-noble metallic nickel supported on zirconium phosphate (Ni/ZrP). With the optimized catalyst of 15%Ni/ZrP-2.0, 87.3% lignin conversion could be obtained with less than 5.2% char formation under mild condition of 260 °C for 4 h. Product analysis demonstrates that 15.1 wt% phenolic monomer yield is given at the relatively low hydrogen pressure of 2.0 MPa. In particular, 40.4% of these volatile products were identified to be para ethyl phenol (a yield of 6.1 wt%), a versatile compound which is currently originating from the petrochemical industry. Further comparative structure characterization of the original and regenerated lignin shows that the efficient cleavage of carbon bonds between C8 and C9 in the p-coumarate moiety of H-lignin (pCA8 unit) is mainly responsible for this excellent yield of para ethyl phenol. In addition, this process yields 48 wt% nonvolatile products, which mainly consist of phenolic dimers and trimers, indicating its great potential to be a good starting material for high quality aromatic fuel production via simple upgradation techniques.

Direct dehydrogenation of isobutane to isobutene has drawn extensive attention for synthesizing various chemicals. The Mo-based catalysts hold promise as an alternative to the toxic CrOx- and scarce Pt-based catalysts. However, the low activity and rapid deactivation of the Mo-based catalysts greatly hinder their practical applications. Herein, we demonstrate a feasible approach toward the development of efficient and non-noble metal dehydrogenation catalysts based on Mo–CT hybrid nanowires calcined at different temperatures. In particular, the optimal Mo–C700 catalyst exhibits isobutane consumption rate of 3.9 mmol g–1 h–1 and isobutene selectivity of 73% with production rate of 2.8 mmol g–1 h–1. The catalyst maintained 90% of its initial activity after 50 h of reaction. Extensive characterizations reveal that such prominent performance is well correlated with the adsorption abilities of isobutane and isobutene and the formation of η-MoC species. In contrast, the generation of β-Mo2C crystalline phase du...

Selective valorization of lignin to achieve high value and commodity chemicals is attracting increasing attention. In this work, an efficient and reusable metal-based ionic liquid (MBIL) was developed for the selective tailoring of p-coumaric acid ester (pCA), a typical p-hydroxyphenyl (H) unit, into methyl p-hydroxycinnamate (MPC). Under optimized conditions and in the presence of catalyst [Bmim][FeCl4], a volatile aromatic product of 10.5 wt% was obtained, of which, 70.5% separated as pure MPC with an isolated yield of 71.1 mg g−1. FT-IR, 13C NMR, ANO and 2D HSQC demonstrated that the H unit was preferentially tailored from lignin, of which, 86.0 wt% of the H structure unit is cut off from lignin, with 70.6% being selectively converted to MPC. Further investigation demonstrated that MBIL prefers to tailor ester bonds compared to ether bonds using model compounds, and the superior catalytic ester bond cleavage performance exhibited by [Bmim][FeCl4] can be ascribed to the relatively narrow energy gap between the lignin ester bond and [FeCl4]− anion and to the comparatively low absolute binding energy between the cation and anion through DFT calculations.

A series of 1,3-bispropyltriethoxysilane-imidazolium chloride (FILs)-modified SBA-15 adsorbents have been prepared, characterized, and applied in SO2 capture for the first time. At low FILs loadings, significant levels of grafting were observed, while higher loading levels resulted in retention of a greater fraction of FILs precursors, as evidenced by FTIR spectroscopy. Textural properties gradually declined as FILs content increased, in conjunction with an apparent change in the regular nature of the SBA-15 pore structure and bulk particle morphology, as demonstrated by XRD, TEM, and SEM. SO2 adsorption breakthrough curves indicated that all materials possessed rapid and facile adsorption properties, with t0.9 values 1–2 orders of magnitude lower than those obtained over comparable materials under more favorable conditions. The largest total SO2 adsorption was achieved over 10%FILs@SBA-15, which exhibited a maximized FILs adsorption contribution that remained constant at higher loadings. Corrections agai...

Lignin has been considered as a promising sustainable feedstock for high value-added aromatic chemical production. Here, we propose a novel and efficient process for lignin depolymerization in the presence of cooperative ionic liquid pair, which affords excellent catalytic activity and char inhibition capability. Under the optimized reaction condition, 66.7% lignin conversion is achieved, yielding 14.5 wt.% phenolic monomer, numerous volatile products (identified by GC–MS) and negligible char formation. The structural evolution of the sugarcane lignin was intensively investigated via comparative characterization of raw and regenerated lignin using HSQC, 1H NMR, FT-IR, GPC and elemental analysis. All three structural lignin units are degraded in this process, where, H-lignin is found to be the most susceptible. Satisfactory lignin depolymerization performance was found for the cooperative ionic liquid system, even after the fifth run, demonstrating a reasonable reusability.

A novel and efficient process for levulinic acid/ester production from non-edible cassava is proposed via a one-pot cascade processes of prehydrolysis and delignification. The intensification effect of monosaccharide formation (prehydrolysis) and the solvent effect for delignification were investigated extensively. The influences of reaction conditions, such as, reaction temperature, time and catalyst concentration, were examined. The results show that prehydrolysis and delignification have significant promotional effects on levulinic acid/ester production. 60.36% levulinic acid/ester yield at a process efficiency of 88.90% can be obtained at 160 °C for 3.0 h when cassava is pretreated at 100 °C for 1.0 h. However, only 32.18% yield and 46.98% process efficiency are observed without prehydrolysis. Characterization of the starting feedstock and residues using compositional analysis, Fourier transform infrared spectroscopy, and elemental analysis demonstrate that efficient lignin removal has a positive influence for levulinic acid/ester formation. Moreover, this process is robust and suitable for scale-up, indicating that it has a great potential for industrial levulinic acid/ester production.

The efficient production of γ-valerolactone (GVL) from renewable resources is attracting increasing attention in view of its wide application in fuel and synthetic chemistry. In this study, a series of novel and efficient zirconium phosphate catalysts were developed for the transfer hydrogenation of levulinate esters to GVL using isopropanol as the hydrogen donor. Experimental results show that 98.1% butyl levulinate conversion and 95.7% GVL yield can be achieved with ZrPO-1.00 at 483 K after 2.0 h. Intensive characterization of the synthesized catalysts using N 2 adsorption-desorption, FT-IR, ICP-AES, XPS, NH 3 -TPD, Py-FTIR and XRD demonstrates that the physicochemical properties, particularly hydrophobicity, Lewis to Bronsted acid site ratio and Lewis acid site strength were subtly tuned via adjustment of the molar proportion of phosphorus to zirconium, which is responsible for excellent transfer hydrogenation activity. Furthermore, this optimized catalyst exhibits high stability and recyclability for at least ten reaction cycles. In addition, a plausible reaction pathway and catalytic mechanism are proposed.

The condensation of the dilute platform biochemical from the renewable lignocellulosic cellulose depolymerization for high quality energy production has attracted increasing attention currently. In this study, we propose an efficient process for biogasoline precursor production from the furfural and ethyl levulinate through the Aldol reaction at the ambient temperature. The results show that the furfural and ethyl levulinate can be efficiently condensed with the catalyst of commercial alkalis. Under the optimized condition, 78% of the product isolated yield can be obtained in the presence of KOH. Furthermore, the final product analysis using FT-IR, GPC, 1 H-NMR, 13 C-NMR and elemental analysis demonstrates that it mainly composes of 3-(furan-2-yl(hydroxy)methyl)-4-oxopentanoate acid, an excellent precursor for C9 branched hydrocarbon of gasoline. Moreover, the investigation shows that the product distribution of this Aldol process is high temperature dependent, higher temperature resulting in the recondensation of the product, hence decreasing the C9 gasoline precursor selectivity.

Summary Green production of bulk chemicals traditionally obtained from fossil resources is of great importance. One potential route toward realizing this goal is through the utilization of renewable lignin; however, current techniques generally lead to low product specificity because of the structural diversity of this recalcitrant biopolymer. Herein, we devised a new catalytic system to promote selectively oxidative lignin in air, and diethyl maleate was formed at impressively high yield of 404.8 mg g−1 and selectivity of 72.7% over the polyoxometalate ionic liquid of [BSmim]CuPW12O40. This high catalytic activity is ascribed to a five-coordinated Cu+ species, which, through the formation of end-on dioxygen species in vacant orbitals, facilitates the selective oxidation of basic lignin aromatic units (phenylpropane C9 units). Therefore, these results represent significant progress toward the realization of an industrially applicable and highly selective lignin oxidation process for the generation of value-added and bulk chemicals.

In this study, we propose a novel and efficient process for bagasse liquefaction in subcritical water over the solid alkali catalyst of MgMOx (M = Mn, Ni, Fe, Cr, Zn and Al). The intensification effect of the catalyst was investigated via hydrothermal liquefaction, where the product distribution and composition of volatiles and residue were compared using GC–MS, GPC, FT-IR and elemental analysis. The results show that the materials substantially promote bagasse liquefaction. Under optimized conditions (250 °C for 15 min), MgMnO 2 liquefied 93.7% of the bagasse yielding a water-soluble fraction of 59.5%. Of particular note, lignin, the most recalcitrant fragment in biomass hydrothermal liquefaction, is efficiently depolymerized to volatile phenolic monomers with these catalysts. Furthermore, the MgMnO 2 catalyst shows good recyclability, where no significant activity loss is demonstrated even after the fifth run.

An efficient one-pot approach for the production of levulinate ester from renewable carbohydrates is demonstrated over heteropolyanion-based ionic liquid (IL-POM) catalysts with alcohols as the promoters and solvents. The relationships between the structure, acidic strength, and solubility of the IL-POM in methanol and the catalytic performance were studied intensively. A cellulose conversion of 100 % could be achieved with a 71.4 % yield of methyl levulinate over the catalyst [PyPS]3PW12O40 [PyPS=1-(3-sulfopropyl)pyridinium] at 150 °C for 5 h. This high efficiency is ascribed to the reasonably high activity of the ionic liquid (IL) catalyst and reaction coupling with rapid in situ esterification of the generated levulinic acid with the alcohol promoter, which allows the insolubility of cellulose encountered in biomass conversion to be overcome. Furthermore, the present process exhibits high feedstock adaptability for typical carbohydrates and handy catalyst recovery by a simple self-separation procedure through temperature control.

Efficient conversion of lignin to fine chemicals and biofuel become more and more attractive in biorefinery. In this work, we used a series of silica-alumina catalysts (i.e., SiO2-Al2O3, HY, Hβ, and HZSM-5) to degrade lignin into arenes and phenols. The relationship between the catalyst structure and lignin depolymerization performance was investigated. The results showed that both acidity and pore size of the catalyst could influence the conversion of lignin. In the volatilizable product, phenols were identified as the main phenolic monomers via gas chromatography-mass spectrometer. SiO2-Al2O3 was the most efficient catalyst, giving 90.96% degree of conversion, 12.91% yield of phenols, and 2.41% yield of arenes in ethanol at 280 °C for 4 h. The Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance spectroscopy analysis demonstrated that deoxygenation and alkylation occurred in this process. The effect of solvents was also investigated and the results showed that ethanol was the most efficient solvent.

An efficient and eco-friendly process is proposed for sugarcane bagasse liquefaction under mild condition using IL catalyst and environmental friendly solvent of ethanol/H2O. The relationship between IL acidic strength and its catalytic performance is investigated. The effects of reaction condition parameters such as catalyst dosage, temperature, time and solvent are also intensively studied. The results show that ethanol/H2O has a significant promotion effect on the simultaneous liquefaction of sugarcane bagasse carbohydrate and lignin. 97.5% of the bagasse can be liquefied with 66.46% of volatile product yield at 200°C for 30min. Furthermore, the IL catalyst shows good recyclability where no significant loss of the catalytic activity is exhibited even after five runs.

Catalytic conversion of sustainable cellulose to the value-added chemicals and high quality biofuel has been recognized as a perfect approach for the alleviation of the dependence on the non-renewable fossil resources. Previously, we successfully designed and explored novel and efficient cooperative ionic liquid pairs for this renewable material, which has advantages of high reactor efficiency than current technologies because of the dissolution and in situ catalytic decomposition mechanism. Here, the determinant of this process is further studied by the intensive investigation on the relationship between the cellulose conversion and the properties of ionic liquid catalyst and solvent. Scanning electron microscope (SEM), thermogravimetric analysis (TG) and elemental analysis were used for the comparative characterization of raw cellulose and the residues. The results demonstrate that this consecutive dissolution and in situ catalysis process is much more dependent on the dissolution capability of ionic liquid solvent, while comparatively, the effect of in situ acid catalysis is relatively insignificant.

Studies on kinetic analysis and process modeling are important and necessary for the development of novel and efficient technology for cellulose utilization. In this study, a kinetic model for the batch reactor was described for catalytic cellulose degradation in cooperative ionic liquid pairs based on an intensive analysis of the experimental parameters. Our fitting results show that the proposed model agrees well with the experimental data. The kinetic parameters obtained from the above model were subsequently applied to the continuous stirred tank reactor (CSTR) by constructing a mathematical process model for the continuous operation of cellulose degradation combined with product separation. The effects of reaction temperature, retention time, extract flow rate and distribution coefficients were intensively investigated. The numerical results demonstrate that relatively high temperature and larger retention time are favorable in cellulose conversion, whereas the product distribution coefficient and extract flow rate mainly affect the concentration of the hexane-soluble fraction (volatile chemicals). The findings presented in this work will serve as a beneficial reference for further biomass transformation of industrial purpose.

Large-scale production of isobutene from isobutane requires high-performance and cost-effective catalysts. Carbon-based nanomaterials such as carbon nanotubes have attracted great attention as substrates for decorating with functional groups or doping with heteroatoms. In this paper, oxidized multi-walled carbon nanotubes were modified with nitrogen at 900 °C and applied in direct dehydrogenation of isobutane. Upon surface oxidization and high temperature annealing, the 1.93 atom% nitrogen-doped oxidized multi-walled carbon nanotubes are found to be an effective dehydrogenation catalyst, which exhibits an isobutane conversion of 51.8% (17.4 mmol g−1 h−1), isobutene selectivity and yield of 45.9% and 23.8% (8.0 mmol g−1 h−1) respectively. The increased catalytic performance is well-correlated with enhanced adsorption strength of isobutane and reduced adsorption strength of isobutene, which relates to the presence of nitrogen species, as revealed by XPS and TPD measurements. Minimal deactivation of the catalyst, as indicated by time on stream studies, may be caused by the loss of nitrogen heteroatoms and the change in ID/IG.

The harsh reaction conditions for the valorization of lignin-derived phenolic compounds considerably limit the efficient utilization of the lignin derivatives. Here, we put forward a high efficient and selective hydrogenation process for phenolic compounds at a mild condition over step by step precipitated Ni/SiO2 catalyst. The properties of the Ni/SiO2 catalysts by different preparation methods were detailedly compared using various characterization measurements. Catalytic activity of the catalysts was tested by the hydrogenation of guaiacol, and the results showed that guaiacol could be completely converted into cyclohexanol with 99.9% selectivity at 120 °C, 2 MPa H2 atmosphere for 2 h. Other typical lignin-derived phenolic compounds also had excellent hydrogenation performance and great energy efficiency. Catalyst characterization results demonstrated that the high catalytic activity of the step by step precipitated Ni/SiO2 was mainly ascribed to its polyporous spherical structure, which led to the large specific surface area and high nickel dispersion. The appropriate acidity of the catalyst also promoted the catalytic performance significantly. Furthermore, the catalyst exhibited an excellent recyclability, where no significant loss of the catalytic activity was showed out after 3 runs.

Lignocellulose is generally resistant to dissolving in water and conventional organic solvents, which significantly hinders its efficient utilization. In this work, we provide a novel and efficient technology on lignocellulose dissolution under mild conditions for down-stream conversion with heterogeneous catalysts. In a mixture of hydrogen peroxide, sulfuric acid, ethanol and water, corn straw was completely dissolved in the mixture at 170 °C for 120 min without significant volatile chemical production (less than 16%). Cellulose and hemicellulose existed as water-soluble oligosaccharides in the solvent, which were more easily converted than the original polymeric carbohydrate. During the dissolved process, peroxide hydrogen exhibited a significant intensification effect on dissolving the hemicellulose, decrystallization of cellulose and delignification with sulfuric acid. Furthermore, lignin was destroyed into fragments in the course of dissolution, which had a looser structure and lower molecular weight.

The catalytic depolymerization process for lignin to produce value added chemicals is often challenged by the limited mass transfer over heterogeneous catalysts, the complex aromatic biopolymer structures, and the high recalcitrance of C C bonds. Herein, a series of hierarchical MFI nanosheets (MFI-ns) supported metal oxide catalysts have been designed and used for the selectively oxidative cleavage of organosolv lignin. As expected, 81.6 % conversion of lignin can be achieved over 15Ce-5Cu/MFI-ns with 294.0 mg g−1 yield of volatile products, including 180.9 mg g−1 of diethyl maleate. Quantum chemistry calculation coupled with static adsorption measurements shows that the superior catalytic activities of these catalysts are ascribed to the favorable mass transport of lignin to the active sites by the unique layer structure, and the hierarchical pore sizes distribution, as well as the electronic effect between Cu and Ce components. In addition, the catalytic mechanism for the cleavage of C C bonds in β-O-4 model probes has been studied via the controlled oxidative degree of model compounds and the isotope-labeling experiments. Therefore, this work provides a new insight into the efficient utilization of lignin via the rational design of catalysts.

In this study, an efficient strategy is proposed for selective methyl levulinate production from duckweed, a typical fast-growing aquatic microalgae in warm and humid regions, in the presence of acidic ionic liquids (ILs). The results show that IL structure has a significant effect on its acidic strength, which finally determines the process efficiency for levulinate methyl generation. With the optimized catalyst of [C3H6SO3HPy]HSO4, 88.0% duckweed is consumed, resulting in a comparable methyl levulinate yield of 73.7% and a process efficiency of 81.8% at 170 °C for 5 h. Furthermore, this process is substantially influenced by the reaction condition, particularly, it is significantly temperature-dependent. In addition, solvent has a remarkable intensified effect on the process efficiency, which dramatically decreases from 81.8 to 53.7% when methanol is replaced by water.

Direct dehydrogenation of isobutane to isobutene has drawn extensive attention for synthesizing various chemicals. The Mo-based catalysts hold promise as an alternative to the toxic CrO

An efficient emulsion microreactor was constructed for selective conversion of lignosulfonate via hydrogen transfer reaction based on the self-surfactivity of this natural aromatic polymer. Industrial Raney Ni and isopropanol were used as catalyst and hydrogen donor, respectively. The results showed that the emulsion microreactor has a remarkable process intensification effect on the lignosulfonate depolymerization. Under mild condition of 473 K for 2.0 h, 116.1 mg g−1 of volatile phenolic monomer can be obtained, which is twice of that from other investigated processes without emulsion of this work. In particular, 39.3 mg g−1 of which is composed of 4-ethyl guaiacol, an important and versatile chemical currently from petrochemical industry. Furthermore, the solvent separates to two phases automatically after reaction due to the consumption of lignosulfonate, which makes handy products enrichment and separation. Additionally, the emulsion microreactor is significantly affected by hydrogen donor and is efficient for other lignin sources as well.

The high-quality bio-jet fuel derived from biomass resources can directly replace commercial fossil fuels for aviation due to the similar composition and properties. However, conventional technologies on hydrodeoxygenation of plant oil can’t produce renewable aromatics, which is the key component in the jet fuel. In this paper, the bio-jet fuels were produced by aqueous-phase processing of plant sugar/polyol. Liquid fuel yield of 31.8% with sorbitol conversion of 98% was obtained under the conditions of 280 °C, WHSV of 1.25 h −1 , GHSV of 2500 h −1 and 4.0 MPa hydrogen pressure. The content of aromatics and napthenes was above 72 wt.% in the produced liquid fuels. This process uses a wide variety of both cellulosic and conventional plant sugars, providing an economic route to sustainable bio-based jet fuel production, which includes normal and iso-paraffins, naphthenes, and aromatics required for aviation.

A novel and efficient water/oil emulsion reactor for organosolv lignin depolymerization is presented using an ionic liquid catalyst based on the self-surfactivity of lignin. The physical–chemical properties of the emulsion reactor and lignin were intensively studied using optical photo, dynamic light scattering, surface tension measurement, and hydrophile–lipophile balance value determination. The results show that the emulsion reactor demonstrates a more significant process intensification effect on lignin depolymerization, with more than 29.60 mg g–1 desired phenolic compounds obtained, which is about 3.3 times higher than that from a reactor without emulsification. Another advantage of this water/oil emulsion reactor is that both the organic solvent (n-butanol) and the ionic liquid catalyst can be recycled easily, as the depletion of lignin surfactant at the end of depolymerization can result in the phase partition and the enrichment of final products in the oil phase automatically.

Selective production of cyclohexanol from renewable lignin derived phenolic has been presented using the cost-efficient catalyst Ni/MgO which shows excellent catalytic activity in the hydrogenation reaction and dehydroxylation inhibition. Guaiacol, one of the most abundant lignin depolymerization products, was selected as the model compound. The hydrogenation performance of guaiacol was investigated over various catalysts. The effect of the reaction parameters was also studied. The results showed that guaiacol could be efficiently converted to cyclohexanol, which is a highly value-added precursor and additive for bio-fuel that is generally obtained from unsustainable fossil resources. Under the mild condition (160 °C, 3 h and 3 MPa H2), more than 97.74% of guaiacol conversion with 100% cyclohexanol selectivity can be achieved in the presence of 20% Ni/MgO. Intensive catalyst characterization demonstrated that the efficient promotion effect of the base carrier for the Ni active center was responsible for efficient guaiacol conversion and selective cyclohexanol production. Furthermore, the Ni/MgO catalyst showed excellent recyclability, where no significant activity loss was observed even after four runs. Moreover, the reaction pathway and the catalytic mechanism are proposed.

Efficient conversion of lignin depolymerization products to more stable chemicals has attracted increasing attention during last few years. Here, we reported a novel and efficient method for lignin depolymerization products valorization on the simple and economic catalyst NixMg1−xO. In which, the unsaturated ingredients were converted to thermal and chemical stable products, resulting in the obvious decreasing of the unsaturated degree of the products and the repolymerization of the phenolic oligomer. The results showed that more than 98% of phenol, a model chemical of lignin depolymerization products, could be converted to cyclohexanol with 100% selectivity. Further investigation demonstrated that it was also efficient for the real lignin depolymerization products, where a significant decrease on the oxygen content and the average molecular weight were shown. Moreover, the NixMg1−xO catalyst was recyclable, and no significant loss of the catalytic activity was exhibited even after 5 runs.

Enhancement of the cellulose accessibility is significant for biomass enzymatic hydrolysis. Here, we reported an efficient combined pretreatment for corn straw enzymolysis using ball milling and dilute acid hydrothermal method (a mixture solvent of H2O/ethanol/sulfuric acid/hydrogen peroxide liquid). The process intensification effect of ball milling on the pretreatment of the corn straw was studied through the comparative characterization of the physical–chemical properties of the raw and pretreated corn straw using FT-IR, BET, XRD, SEM, and HPLC analysis. The effect of the pretreatment temperature was also investigated. Furthermore, various pretreatment methods were compared as well. Moreover, the pretreatment performance was measured by enzymolysis. The results showed that ball milling had a significant process intensification effect on the corn straw enzymolysis. The glucose concentration was dramatically increased from 0.41 to 13.86 mg mL−1 after the combined treatment of ball milling and hydrothermal. The efficient removal of lignin and hemicellulose and the enlargement of the surface area were considered to be responsible for this significant increase based on the intensive analysis on the main components and the physical–chemical properties of the raw and pretreated corn straw.

Gasoline production by one-pot catalytic conversion of biomass derived sugar/polyol was investigated over bifunctional heterogeneous catalyst. Ni@HZSM-5/SG catalyst showed excellent performance of converting sugar/polyol to gasoline. The gasoline yield of 46.94% was obtained. Its composition and properties are similar to petroleum based gasoline. It provides a novel approach for the production of gasoline by one-pot aqueous phase catalytic conversion of sugar/polyol derived from biomass.

The biorefinery process for sugarcane bagasse saccharification generally requires significant accessibility of cellulose. We reported a novel method of cascade cellulase enzymatic hydrolysis coupling with ultrafine grinding pretreatment for sugarcane bagasse saccharification. Three enzymatic hydrolysis modes including single cellulase enzymatic hydrolysis, mixed cellulase enzymatic hydrolysis, and cascade cellulase enzymatic hydrolysis were compared. The changes on the functional group and surface morphology of bagasse during cascade cellulase enzymatic hydrolysis were also examined by FT-IR and SEM respectively. The results showed that cascade enzymatic hydrolysis was the most efficient way to enhance the sugarcane bagasse saccharification. More than 65% of reducing sugar yield with 90.1% of glucose selectivity was achieved at 50 °C, pH=4.8 for 72 h (1200 r/min) with cellulase I of 7.5 FPU/g substrate and cellulase II of 5 FPU/g substrate.

Bio-oil can't be directly used as fuel due to its deteriorate properties. Here, an efficient catalytic upgrading process for the bio-oil, including esterification, hydrogenation, hydrodeoxygenation and depolymerization, is proposed with multifunctional catalyst Ni/SiO 2 –ZrO 2 and biomass-derived solvent ethanol. Results showed that esters, alcohols, phenolics, and cyclo-ketones were the main components in the upgraded bio-oil while aldehydes were removed completely via catalytic hydrogenation and acids were removed by catalytic esterification with supercritical ethanol. The pH value of upgraded bio-oil rose drastically from 2.38 to 5.24, and the high heating value increased to 24.4 MJ kg −1 . Comparison characterization on the upgraded and crude bio-oil using FT-IR, GPC (Gel permeation chromatography) and 13 C NMR (Nuclear Magnetic Resonance) demonstrated that lignin-derived oligomers contained in crude bio-oil were further depolymerized over Ni/SiO 2 –ZrO 2 catalyst. The improved properties suggest that the upgraded bio-oil is more suitable to be used as boiler fuel. Furthermore, the loss of carbon is negligible because formation of coke is suppressed during the upgrading process.