02176nas a2200169   4500008004100000245017900041210006900220260000800289300001600297490000700313520147900320100001901799700002401818700001901842700001801861856012701879       2018                        eng d00aAcid modified H-USY zeolite for efficient catalytic transformation of fructose to 5-hydroxymethyl furfural (biofuel precursor) in methyl isobutyl ketone-water biphasic system0 aAcid modified HUSY zeolite for efficient catalytic transformatio  cFEB  a3783–37910 v323 aSustainable process and efficient heterogeneous acid catalyst for the preparation of platform chemicals like 5-hydroxymethyl furfural (5-HMF) from renewable source is much in demand in the context of heterogeneous catalysis. Commercially available solid acid catalyst, H-USY zeolite was modified by treating with aqueous solution of H3PO4 and H2SO4 (10–30 wt %). Modified H-USY was completely characterized by XRD, NH3-TPD, energy dispersive analysis X-ray (EDAX), FT-IR, pyridine-IR, and NMR. Its catalytic performance was evaluated for the fructose conversion to 5-HMF in methyl isobutyl ketone (MIBK)–water system. Modified H-USY zeolite was identified to have potential in enhancement of 5-HMF yield up to 65% from 32% (parent H-USY) with minimum formation of furfural (8%). H-USY modified with 10 wt % H3PO4 (10P–Y) was found to be the best compared to other studied catalysts, namely, H-USY modified with 20 and 30 wt % H3PO4 (20 and 30P–Y) or 10–30 wt % H2SO4 (10- to 30S–Y). Best performance of 10P–Y is associated with the optimum combination of moderate acidity (both weak as well as strong), moderate dealumination of Al from extra-framework sites as well as from framework sites of H-USY, formation of new Al–O–P bonds between framework Al and elemental monomeric phosphorus, presence of Brønsted as well as Lewis acidity, and creation of mesopores. This gives new insight on a potential heterogeneous acid catalyst for the synthesis of 5-HMF.1 aPande, Ashwini1 aNiphadkar, Prashant1 aPandare, Kiran1 aBokade, Vijay  uhttps://library.ncl.res.in/content/acid-modified-h-usy-zeolite-efficient-catalytic-transformation-fructose-5-hydroxymethyl02026nas a2200253   4500008004100000022001400041245019800055210006900253260000800322490000700330520102100337653003401358653003401392653001801426653002201444653003301466100002701499700003501526700001801561700001901579700001801598700003001616856012601646       2023                        eng d  a2190-681500aComparative studies of the influence of particle size on various pretreatments of rice husk by assessment of chemical and structural components and wastewater characteristics of liquid fraction0 aComparative studies of the influence of particle size on various  cAPR0 v133 a<p>The dilute acid (DA), steam explosion (SE), and a 2-step: steam explosion followed by alkali (SEA) were evaluated for pretreatment of rice husk. The maximum hemicellulose and lignin removal via degradation and dissolution was observed for SEA pretreatment, enabling higher cellulose enrichment (up to 44% w/w) and recovery (up to 78%). The hemicellulose solubilization was &gt;90% for all the pretreatments, while maximum lignin removal (up to 62%) was observed for SEA pretreatment. The particle size in the range of 0.3-0.6 mm enabled higher pretreatment efficiencies in terms of cellulose enrichment. The liquid fraction obtained after DA pretreatment indicated higher COD values (20800-24440 mg/L) as compared to SEA (7800-11400 mg/L) due to lower cellulose recoveries in DAP (54-68%). SEM analysis of the biomass indicated disrupted regions with multiple pores. FTIR analysis revealed cleavage of lignin side chains, and XRD analysis confirmed the increase in cellulose crystallinity post-pretreatment.</p>
10aLignocellulosic crop residues10aLiquid-waste characterization10aParticle size10aRice husk biomass10aSteam explosion pretreatment1 aShahabazuddin, Mohmmad1 aBanuvalli, Bhavana, Karibasapp1 aMulik, Nagesh1 aPande, Ashwini1 aBokade, Vijay1 aMudliar, Sandeep, Narayan  uhttps://library.ncl.res.in/content/comparative-studies-influence-particle-size-various-pretreatments-rice-husk-assessment