02356nas a2200253   4500008004100000022001400041245011800055210006900173260010100242300001200343490000800355520142000363653002201783653001201805653001101817653001801828653001101846653002401857100002301881700002401904700002001928700002901948856012501977       2014                        eng d  a0974-362600aValue addition to lignocellulosics and biomass-derived sugars: an insight into solid acid-based catalytic methods0 aValue addition to lignocellulosics and biomassderived sugars an   aC V RAMAN AVENUE, SADASHIVANAGAR, P B \#8005, BANGALORE 560 080, INDIAbCatalysis Soc IndiacMAR  a373-3850 v1263 a<p>For the synthesis of important platform chemicals such as sugars (xylose and arabinose) and furans (furfural and 5-hydroxymethylfurfural (HMF)) from carbohydrates (hemicellulose and fructose) solid acid catalysts are employed. Similarly, over solid acid catalysts, conversion of lignin into aromatic monomers is performed. It is observed that in the dehydration of fructose, because of higher hydrothermal stability, silicoaluminophosphate (SAPO) catalysts give better activity (78% HMF yield) compared with other solid acid catalysts (&lt;63% HMF yield) at 175 degrees C. Particularly, SAPO-44 catalyst can be reused at least 5 times with marginal decrease in the activity. Zeolite, BUSY (Si/Al = 15) is active in the conversion of isolated (pure) hemicellulose to produce 41% C-5 sugars in water. The catalyst is also active in the selective conversion of hemicellulose from bagasse to yield 59% C-5 sugars. It is possible to obtain high yields of furfural (54%) directly from bagasse if instead of water, Water+toluene solvent system is used. Depolymerization of lignin using HUSY catalyst produced aromatic monomers with 60% yield at 250 degrees C. A detailed catalyst characterization study is performed to understand the correlation between catalyst activity and morphology. To understand the effect of impurities present in the substrate over solid acid catalysts, metal-exchange study is carried out.</p>10aaromatic monomers10aBiomass10afurans10aHemicellulose10alignin10asolid acid catalyst1 aBhaumik, Prasenjit1 aDeepa, Ayillath, K.1 aKane, Tanushree1 aDhepe, Paresh, Laxmikant  uhttps://library.ncl.res.in/content/value-addition-lignocellulosics-and-biomass-derived-sugars-insight-solid-acid-based-002642nas a2200229   4500008004100000022001400041245007700055210006900132260007100201300001200272490000600284520184300290653002202133653001202155653002602167653002102193653001102214653002502225100002402250700002902274856010902303       2015                        eng d  a2155-543500aLignin depolymerization into aromatic monomers over solid acid catalysts0 aLignin depolymerization into aromatic monomers over solid acid c  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcJAN  a365-3790 v53 a<p>It is imperative to develop an efficient and environmentally benign pathway to valorize profusely available lignin, a component of nonedible lignocellulosic materials, into value-added aromatic monomers, which can be used as fuel additives and platform chemicals. To convert lignin, earlier studies used mineral bases (NaOH, CsOH) or supported metal catalysts (Pt, Ru, Pd, Ni on C, SiO2, Al2O3, etc.) under a hydrogen atmosphere, but these methods face several drawbacks such as corrosion, difficulty in catalyst recovery, sintering of metals, loss of activity, etc. Here we show that under an inert atmosphere various solid acid catalysts can efficiently convert six different types of lignins into value-added aromatic monomers. In particular, the SiO2Al2O3 catalyst gave exceptionally high yields of ca. 60% for organic solvent soluble extracted products with 95 +/- 10% mass balance in the depolymerization of dealkaline lignin, bagasse lignin, and ORG and EORG lignins at 250 degrees C within 30 min. GC, GC-MS, HPLC, LC-MS, and GPC analysis of organic solvent soluble extracted products confirmed the formation of aromatic monomers with ca. 90% selectivity. In the products, confirmation of retention of aromatic nature as present in lignin and the appearance of several functional groups has been carried out by FT-IR and H-1 and C-13 NMR studies. Further, isolation of major products by column chromatography was carried out to obtain aromatic monomers in pure form and their characterization by NMR is presented. A detailed characterization of six different types of lignins obtained from various sources helped in substantiating the catalytic results obtained in these reactions. A meticulous study on fresh and spent catalysts revealed that the amorphous catalysts are preferred to obtain reproducible catalytic results.</p>10aaromatic monomers10aBiomass10acolumn chromatography10adepolymerization10alignin10asolid acid catalysts1 aDeepa, Ayillath, K.1 aDhepe, Paresh, Laxmikant  uhttps://library.ncl.res.in/content/lignin-depolymerization-aromatic-monomers-over-solid-acid-catalysts-0