01566nas a2200229 4500008004100000022001400041245011700055210006900172260007100241300001400312490000600326520073200332653001301064653001801077653001901095653000901114653002801123653001201151100002301163700002901186856012101215 2013 eng d a2155-543500aEfficient, stable, and reusable silicoaluminophosphate for the one-pot production of furfural from hemicellulose0 aEfficient stable and reusable silicoaluminophosphate for the one a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcOCT a2299-23030 v33 a

Development of stable, reusable, and water tolerant solid acid catalysts in the conversion of polysaccharides to give value-added chemicals is vital because catalysts are prone to undergo morphological changes during the reactions With the anticipation that silicoaluminophosphate (SAPO) catalysts will have higher hydrothermal stability, those were synthesized, characterized, and employed in a one-pot conversion of hemicellulose. SAPO-44 catalyst at 170 degrees C within 8 h could give 63% furfural yield with 88% mass balance and showed similar activity up to at least 8 catalytic cycles. The morphological studies revealed that SAPO catalysts having hydrophilic characteristics are stable under reaction conditions.

10afurfural10aHemicellulose10ahydrophilicity10aSAPO10awater-tolerant catalyst10azeolite1 aBhaumik, Prasenjit1 aDhepe, Paresh, Laxmikant uhttp://library.ncl.res.in/content/efficient-stable-and-reusable-silicoaluminophosphate-one-pot-production-furfural-001968nas a2200157 4500008004100000022001400041245008500055210006900140260011000209300001600319490000600335520130400341100002301645700002901668856011301697 2014 eng d a2046-206900aExceptionally high yields of furfural from assorted raw biomass over solid acids0 aExceptionally high yields of furfural from assorted raw biomass  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcMAY a26215-262210 v43 a

Development of stable and recyclable solid acid catalysts in the efficient valorisation of hemicellulose to yield C-5 sugars and furfural is vital to boost the prospects of using lignocelluloses for chemicals synthesis. Using an silicoaluminophosphate, namely SAPO-44, as a catalyst, an environmentally benign process of furfural synthesis from diversified real substrates (without any treatment or the need for separation of its components) is shown. In an efficient one-pot methodology, at 443 K and in the presence of a biphasic solvent system, selective conversions of hemicelluloses from raw biomass (bagasse, rice husk and wheat straw) to extraordinarily high yields of furfural of about 93% were attainable. Under similar reaction conditions, an 82% yield of furfural is also achievable directly from isolated hemicellulose within 10 h. Hydrophilic SAPO-44, having higher hydrothermal stability, showed similar activity for all the substrates for a minimum of up to 8 times in recycling runs. Various physicochemical characterizations (X-ray diffraction, thermogravimetric analysis-derivative thermogravimetry, temperature programmed desorption-NH3, N-2 sorption, solid-state nuclear magnetic resonance spectroscopy) of fresh and spent catalysts were used to improve SAPO-44 stability.

1 aBhaumik, Prasenjit1 aDhepe, Paresh, Laxmikant uhttp://library.ncl.res.in/content/exceptionally-high-yields-furfural-assorted-raw-biomass-over-solid-acids-001901nas a2200217 4500008004100000022001400041245009300055210006900148260007300217300001000290490000800300520114400308653001201452653001301464653001801477653001201495653001101507100002301518700002901541856011301570 2015 eng d a0920-586100aEffects of careful designing of SAPO-44 catalysts on the efficient synthesis of furfural0 aEffects of careful designing of SAPO44 catalysts on the efficien aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAUG a66-720 v2513 a

Considering the growing importance of furfural, it is necessary to develop a robust solid acid catalyst for the conversion of xylan (hemicelluloses) into furfural in a one-pot method. In this study, the effects of various components (Si, Al and P) and crystallization time on the preparation of acidic materials and their properties are extensively described. It is seen that with the increase in crystallization time (0, 48, 96, 176 h) during the synthesis of silicoaluminophosphate (SAPO-44), materials morphology changes from amorphous to AFI to CHA and the best activity for furfural synthesis (82%) from xylan was observed with SAPO-44 catalyst aged for 176 h. Since, acidity in the SAPO-44 is guided by the incorporation of Si in the ALPO framework, study on Si molar concentration (0.8, 1.0, 1.2, 1.4 and 1.6) in SAPO-44 was carried out and it was observed that SAPO-44 having 1.0 mole of Si content is the best catalyst for the xylan/xylose conversion to furfural. Catalyst structure-activity correlation is thoroughly defined with the help of several physico-chemical properties. (C) 2014 Elsevier B.V. All rights reserved.

10aBiomass10afurfural10aHemicellulose10aSAPO-4410aXylose1 aBhaumik, Prasenjit1 aDhepe, Paresh, Laxmikant uhttp://library.ncl.res.in/content/effects-careful-designing-sapo-44-catalysts-efficient-synthesis-furfural-001943nas a2200217 4500008004100000022001400041245011800055210006900173260009900242300001000341490000800351520108300359653002301442653002401465653001801489653002001507653002001527100002101547700002901568856012801597 2015 eng d a0960-852400aEfficient method for the conversion of agricultural waste into sugar alcohols over supported bimetallic catalysts0 aEfficient method for the conversion of agricultural waste into s aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLANDbELSEVIER SCI LTDcFEB a36-440 v1783 a

Promoter effect of Sn in the PtSn/gamma-Al2O3 (AL) and PtSn/C bimetallic catalysts is studied for the conversion of variety of substrates such as, C5 sugars (xylose, arabinose), C6 sugars (glucose, fructose, galactose), hemicelluloses (xylan, arabinogalactan), inulin and agricultural wastes (bagasse, rice husk, wheat straw) into sugar alcohols (sorbitol, mannitol, xylitol, arabitol, galactitol). In all the reactions, PtSn/AL showed enhanced yields of sugar alcohols by 1.5-3 times than Pt/AL. Compared to C, AL supported bimetallic catalysts showed prominent enhancement in the yields of sugar alcohols. Bimetallic catalysts characterized by X-ray diffraction study revealed the stability of catalyst and absence of alloy formation thereby indicating that Pt and Sn are present as individual particles in PtSn/AL. The TEM analysis also confirmed stability of the catalysts and XPS study disclosed formation of electron deficient Sn species which helps in polarizing carbonyl bond to achieve enhanced hydrogenation activity. (C) 2014 Elsevier Ltd. All rights reserved.

10aAgricultural waste10aBimetallic catalyst10aHydrogenation10aMonosaccharides10aPolysaccharides1 aTathod, Anup, P.1 aDhepe, Paresh, Laxmikant uhttp://library.ncl.res.in/content/efficient-method-conversion-agricultural-waste-sugar-alcohols-over-supported-bimetallic-001755nas a2200145 4500008004100000245016000041210006900201260000800270300001400278490000700292520113600299100002001435700002901455856012501484 2017 eng d00aEfficient hydrogenation of concentrated aqueous furfural solutions in to furfuryl alcohol under ambient conditions in presence of PtCo bimetallic catalysts0 aEfficient hydrogenation of concentrated aqueous furfural solutio cJAN a1144-11540 v193 a

Furfural (FAL), a major biomass-derived chemical, can be hydrogenated to yield the industrially importantplatform chemical, furfuryl alcohol (FOL). Although heterogeneous catalyst-based methods are known toyield FOL from dilute solutions of FAL, they mainly operate at high temperatures and/or high pressures ofhydrogen and in the presence of organic solvents. In this work, we employ bimetallic PtCo/C catalysts withvarying metal concentrations to achieve the maximum possible FOL yield (100%) at 35 °C under 0.1 MPa H2in water. With concentrated FAL (40 wt%) at 50 °C and under 1 MPa H2pressure, 86% yield of FOL wasobserved. Moreover, efficient catalyst recycling was observed over at least four runs with marginal loss inactivity due to handling error and isolation of FOL in pure form confirmed by NMR and HPLC.Characterization of catalysts with several physico-chemical techniques (XRD, TEM, XPS, ICP, TPR) revealsthe presence of electron-rich Pt and ionic Co species in proximity with each other and these worksynergistically to facilitate maximum possible yield of FOL under ambient conditions and in water medium

1 aDohade, Manisha1 aDhepe, Paresh, Laxmikant uhttp://library.ncl.res.in/content/efficient-hydrogenation-concentrated-aqueous-furfural-solutions-furfuryl-alcohol-under02070nas a2200205 4500008004100000022001400041245015900055210006900214260000800283300001200291490000800303520129000311100002401601700001801625700002501643700001901668700001801687700002901705856013001734 2024 eng d a0970-414000aExploring thermocatalytic pyrolysis to derive sustainable chemical intermediates from plastic waste; role of temperature, catalyst, and reactor conditions0 aExploring thermocatalytic pyrolysis to derive sustainable chemic cAPR a383-3940 v1043 a

Plastic waste is a growing concern globally on account of the increasing use of plastic worldwide, compounded by single-use applications, poor waste collection and management practices, and its consequent leakage into the environment. In addition, plastics are derived from non-renewable fossil resources, and their growing demand is also partly responsible for greenhouse gas emissions and climate change. The aim of this paper is to explore the potential of plastic waste as a material resource, and thermocatalytic pyrolysis as a recycling process, to produce aliphatic and aromatic hydrocarbons, which are important chemical intermediates for various industries. We show that plastic pyrolysis can achieve a high yield of liquid hydrocarbons (similar to 80%) with a suitable distribution of aliphatic and aromatic compounds, by using different pyrolysis conditions and a catalyst. Specifically, this paper demonstrates the possibility of deriving two key classes of hydrocarbons, i.e., aliphatic (C10-C20 hydrocarbons) and aromatic hydrocarbons (xylene, toluene and benzene derivatives) with a yield of similar to 80% liquid hydrocarbons via catalytic pyrolysis. We also briefly discuss the challenges and opportunities, and the environmental and economic implications.

1 aVenkataraghavan, R.1 aBhure, Arvind1 aKhan, Tufeil, Sartaj1 aShikare, Dipak1 aDevi, Nandini1 aDhepe, Paresh, Laxmikant uhttp://library.ncl.res.in/content/exploring-thermocatalytic-pyrolysis-derive-sustainable-chemical-intermediates-plastic-waste