01564nas a2200229 4500008004100000022001400041245009000055210006900145260000800214300001600222490000600238520083700244653001301081653001501094653001101109653001301120653002401133653001701157100002201174700002201196856011601218 2019 eng d a2365-654900aAltering the O/C ratio of lignin derived monomers without sacrificing atom efficiency0 aAltering the OC ratio of lignin derived monomers without sacrifi cDEC a14050-140550 v43 a

Synthesis of platform and fuel grade chemicals from lignin without losing atom efficiency and lowering O/C ratio is a challenge in a bio-refinery concept. In this work, we report solid acid catalysed alkylation of lignin derived variety of monomers such as guaiacol, veretrole, phenol, anisole, and catechol using numerous alcohols as alkylating agents. Results elaborate that the type of acidity and structure of catalyst play important role in achieving higher dialkylated products (DAP). With 85% conversion of guaiacol, 30.9% DAP formation was achieved at 250 degrees C within 2 h. A unique substrate adsorption study on the catalyst surface and effect of solubility of substrates on the activity of catalyst is evaluated. Catalyst was observed to be recyclable with marginal loss in the activity due to handling error.

10aAlcohols10aAlkylation10alignin10aMonomers10asolid acid catalyst10aUp-gradation1 aSingh, Dheerendra1 aDhepe, Paresh, L. uhttp://library.ncl.res.in/content/altering-oc-ratio-lignin-derived-monomers-without-sacrificing-atom-efficiency01987nas a2200193 4500008004100000022001400041245011600055210006900171260000800240520124700248653003901495653002101534653003801555653001601593653001101609100002201620700002201642856012901664 2019 eng d a1877-264100aFormic-acid-induced using recyclable-ionic liquids as catalysts for lignin conversion into aromatic co-products0 aFormicacidinduced using recyclableionic liquids as catalysts for cNOV3 a

Lignin has been widely named as a sustainable and renewable bioresource of energy, fuels, chemicals and materials, particularly phenolic chemicals production on Earth. These bio-derived compounds are in great potential need of biorefinery to valorize complete plant biomass. Lignin depolymerization showed a great promise approach to convert into low molecular aromatic products. In this report, high molecular weight (54,000 Da) lignin depolymerization into maximum yields (87%), (>= 95 +/- 6% mass balance) using a formic acid along with dual (-SO3H) functionalized imidazole-based recyclable (4 times) Bronsted acidic ionic liquids (BAILs) as catalysts have been investigated in H2O-CH3OH (1:5, v/v) at 120 degrees C for 1 h. The structural correlations between the lignin and aromatic products were studied by bulk (CHNS, GPC, etc.) and molecular (UV-Vis, FT-IR, NMR (1D/2D) levels experimental techniques. Additionally, the identification of aromatic products was carried out by applying HPLC, GC and GC-MS techniques. Graphic Addition of a formic acid into Bronsted acidic ionic liquids improved the catalytic efficiency significantly for lignin depolymerization into 87% low molecular weight aromatic products. [GRAPHICS] .

10aBulk and molecular levels analysis10adepolymerization10aDual functionalized ionic liquids10aFormic acid10alignin1 aSingh, Sandip, K.1 aDhepe, Paresh, L. uhttp://library.ncl.res.in/content/formic-acid-induced-using-recyclable-ionic-liquids-catalysts-lignin-conversion-aromatic-co02146nas a2200217 4500008004100000022001400041245016000055210006900215260000800284300001600292490000800308520134400316653001701660653002301677653001101700653002101711653002901732100002201761700002201783856012301805 2020 eng d a2468-823100aUnderstanding the influence of alumina supported ruthenium catalysts synthesis and reaction parameters on the hydrodeoxygenation of lignin derived monomers0 aUnderstanding the influence of alumina supported ruthenium catal cJAN aUNSP 1105250 v4803 a

Up-gradation of lignin derived monomers to value-added and fuel grade products is important to make overall bio-refinery process economical. Although, few studies are devoted on this work yet, systematic study on commercially viable (low loading of metal, recyclable catalyst, mild conditions, high selectivities etc.) is scarce and typically done under harsh conditions. Herein, we report, the methodical effect of support (SiO2, Al2O3 (acidic, basic and neutral), SiO2-Al2O3) on the hydrodeoxygenation (HDO) of lignin derived various monomers, guaiacol, veretrol, eugenol, phenol using very low loading (0.5 wt%) Ru catalyst. Very high yield (82%) of cyclohexanol from guaiacol could be achieved in presence of cyclohexane as a solvent and Ru/Al2O3-Acidic catalyst at 225 degrees C and under 1 MPa H-2 pressure. The detailed study on the effect of solvent, stability and adsorption of reactant & products etc. is done and it was observed that products are more prone to adsorb and undergo further reactions. The complete characterization of fresh and spent catalysts revealed that lower catalyst reduction temperature and presence of Ru in partially higher oxidation state proved by XPS, helps in enhancing the cyclohexanol formation. Subsequently, role of Ru particle size and support on the activity was also investigated.

10aCyclohexanol10aHydrodeoxygenation10alignin10areaction pathway10asupported metal catalyst1 aSingh, Dheerendra1 aDhepe, Paresh, L. uhttp://library.ncl.res.in/content/understanding-influence-alumina-supported-ruthenium-catalysts-synthesis-and-reaction01529nas a2200217 4500008004100000022001400041245014900055210006900204260000900273300001100282490000800293520071800301653004301019653001701062653002301079653001101102653003001113100002201143700002201165856012401187 2021 eng d a1566-736700aEfficient catalytic transfer hydrogenation-hydrodeoxygenation of lignin derived monomers: investigating catalyst properties-activity correlation0 aEfficient catalytic transfer hydrogenationhydrodeoxygenation of  cJAN  a1062200 v1493 a

Reduction of O/C ratio of lignin derived monomers via hydrodeoxygenation (HDO) pathway is conventionally furnished using molecular hydrogen under severe conditions. Nonetheless, due to a prerequisite to accomplish HDO through commercially attractive methodology we report, HDO reactions of various phenolic compounds via catalytic transfer hydrogenation (CTH) pathway using very low loading of Ru (0.5 wt%) on neutral and acidic Al2O3 under nitrogen atmosphere. With guaiacol as a substrate, 74% cyclohexanol yield at 225 degrees C in the presence of IPA is realized. Bi-functionality of metal state, acidity of support and nature of alcohol are perceived to be responsible for the variation in activity.

10aCatalytic transfer hydrogenation (CTH)10aCyclohexanol10aHydrodeoxygenation10alignin10aSupported metal catalysts1 aSingh, Dheerendra1 aDhepe, Paresh, L. uhttp://library.ncl.res.in/content/efficient-catalytic-transfer-hydrogenation-hydrodeoxygenation-lignin-derived-monomers01844nas a2200229 4500008004100000022001400041245007500055210006900130260000800199300001100207490000800218520112400226653002201350653001801372653001101390653001601401653002901417653001601446100002101462700002201483856010901505 2021 eng d a0016-236100aUpgrading lignin derived monomers over basic supported metal catalysts0 aUpgrading lignin derived monomers over basic supported metal cat cDEC a1215880 v3063 aCatalytic upgradation of aromatic monomers derived from lignin depolymerization is of high interest for the production of sustainable fuels and chemicals. Basic support has potential to provide advantages of better substrate-support interaction and reduced coke formation. Hence, we report the effect of various basic supports for metal catalysts (Pt, Pd, Ru) on the upgradation of phenol, guaiacol and eugenol. The complete hydrogenation product is achieved due to the strong interaction of the substrate with catalyst. Phenol is converted (55%) into cyclohexanol (49% yield) with low loading of Pt catalyst (1 wt%), supported by the higher TON of 1 wt% Pt/NaX (TON = 14844) than 3 wt% Pt/NaX (TON = 5128). Effect of basic support with moderate (NaX) and strong (CHT) basic strengths are corelated for the higher cyclohexanone formation. Presence of strong basic sites and higher TON of 3 wt% C-HT (TON = 6806) directs the significant substrate-support interaction. Catalytic activity and recyclability are supported by the comparable performance of recycle runs and characterizations of the fresh and spent catalysts.10aaromatic monomers10aHydrogenation10alignin10aSolid bases10asupported metal catalyst10aUpgradation1 aChaudhary, Richa1 aDhepe, Paresh, L. uhttp://library.ncl.res.in/content/upgrading-lignin-derived-monomers-over-basic-supported-metal-catalysts01966nas a2200205 4500008004100000022001400041245017600055210006900231260000800300300001400308490000700322520116900329653001801498653004401516653001101560653001501571100002201586700002201608856013001630 2022 eng d a1877-264100aAlpha-, beta- and gamma-cellulose quantification and two-stage concentrated-dilute acid lignin recovery from three rice husks: lignin characterization and depolymerization0 aAlpha beta and gammacellulose quantification and twostage concen cJUN a2963-29770 v133 a

Investigations on the compositional analysis of lignocellulosic materials and their properties upon recovery are essential to be studied in order to examine the effects of recovery method, their dependency on the substrate, etc. In this work, three rice husks (RHs) samples were subjected for alpha-, beta- and gamma-cellulose, pentosan, and silica quantifications. Correlations between the source of biomass, lignin recovery by two-stage concentrated and dilute sulphuric acid treatment, their properties and their depolymerization into low molecular mass aromatic fractions using homogeneous and heterogeneous Bronsted acidic ionic liquids as catalysts, is carried out. Correlation between the properties of RHs and recovered lignin were performed using destructive (CHNS, TGA, ICP-OES, etc.) and non-destructive (XRD, UV-Visible, FT-IR, and C-13 CP-MAS NMR) analytical techniques. It was observed that the recovered lignin was polysaccharides free and associated with dibenzodioxocin, spirodienone, and tricin type moieties with variable intensities. The effects of lignin structures showed a change of depolymerisation product pattern. [GRAPHICS] .

10aHolocellulose10aHomogeneous and heterogeneous catalysts10alignin10aRice husks1 aSingh, Sandip, K.1 aDhepe, Paresh, L. uhttp://library.ncl.res.in/content/alpha-beta-and-gamma-cellulose-quantification-and-two-stage-concentrated-dilute-acid-lignin