02687nas a2200217   4500008004100000022001400041245013900055210006900194260007700263300001200340490000600352520183700358653002302195653001202218653001802230653002802248653001302276100002002289700002902309856013102338       2012                        eng d  a1864-563100aOne-Pot method for the selective conversion of hemicellulose from crop waste into C5 sugars and furfural by using solid acid catalysts0 aOnePot method for the selective conversion of hemicellulose from  aPO BOX 10 11 61, D-69451 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcAPR  a751-7610 v53 a<p>We present a solid-acid catalyzed one-pot method for the selective conversion of solid hemicellulose without its separation from other lignocellulosic components, such as cellulose and lignin. The reactions were carried out in aqueous and biphasic media to yield xylose, arabinose, and furfural. To overcome the drawbacks posed by mineral acid methods in converting hemicelllulose, we used heterogeneous catalysts that work at neutral pH. In a batch reactor, these heterogeneous catalysts, such as solid acids (zeolites, clays, metal oxides etc.), resulted in &gt;90% conversion of hemicellulose. It has been shown that the selectivity for the products can be tuned by changing the reaction conditions, for example, a reaction carried out in water at 170 degrees C for 1 h with HBeta (Si/Al=19) and HUSY (Si/Al=15) catalysts gave yields of 62 and 56% for xylose and arabinose, respectively. With increased reaction time (6 h) and in presence of only water, HUSY resulted in yields of 30% xylose+arabinose and 18% furfural. However, in a biphasic reaction system (water+p-xylene, 170 degrees C, 6 h) yields of 56% furfural with 17% xylose+arabinose could be achieved. It was shown that with the addition of organic solvent the furfural yield could be increased from 18 to 56%. Under optimized reaction conditions, &gt;90% carbon balance was observed. The study revealed that catalysts were recyclable with a 20% drop in activity for each subsequent run. It was observed that temperature, pressure, reaction time, substrate to catalyst ratio, solvent, and so forth had an effect on product formation. The catalysts were characterized by means of X-ray diffraction, temperature-programmed desorption of NH3, inductively coupled plasma spectroscopy, elemental analysis, and solid-state NMR (Si-29, Al-27) spectroscopy techniques.</p>10aanalytical methods10aBiomass10acarbohydrates10aheterogeneous catalysis10azeolites1 aSahu, Ramakanta1 aDhepe, Paresh, Laxmikant  uhttps://library.ncl.res.in/content/one-pot-method-selective-conversion-hemicellulose-crop-waste-c5-sugars-and-furfural-using-001746nas a2200253   4500008004100000022001400041245006400055210006400119260008600183300001100269490000700280520093000287653002301217653001801240653001401258653001101272653001301283653001901296653000801315653002401323100002301347700002901370856009301399       2016                        eng d  a0161-494000aSolid acid catalyzed synthesis of furans from carbohydrates0 aSolid acid catalyzed synthesis of furans from carbohydrates  a530 WALNUT STREET, STE 850, PHILADELPHIA, PA 19106 USAbTAYLOR & FRANCIS INCcJAN  a36-1120 v583 a<p>The alternative feedstock, biomass (particularly lignocelluloses), having the profuse availability, is promising for the synthesis of several value-added chemicals which are currently obtained from fossil feedstock. In this article, the synthesis of two extremely significant furan chemicals viz. furfural and 5-hydroxymethylfurfural (HMF) are discussed. In the synthesis of furans from biomass, numerous challenges, i.e., use of edible sugars as substrates, selectivity to furans, their isolation in pure form, reuse of catalyst, environmental issues, etc., are perceived and in the recent past researchers tried to resolve those by developing advance methodologies. This article comprehensively summarizes the latest progress made in the above-mentioned areas and also provides commentary on the analyses of results, rationale for observed activity and mechanisms, etc. It also discusses future aspects of this work.</p>10aBiomass conversion10acarbohydrates10acellulose10afurans10afurfural10ahemicelluloses10aHMF10asolid acid catalyst1 aBhaumik, Prasenjit1 aDhepe, Paresh, Laxmikant  uhttps://library.ncl.res.in/content/solid-acid-catalyzed-synthesis-furans-carbohydrates-0