02014nas a2200241   4500008004100000022001400041245012400055210006900179260009800248300001400346490000700360520106600367653002501433653001301458653002501471653002301496100002501519700002501544700002901569700002001598700002501618856012901643       2010                        eng d  a0268-257500aSynthesis of acrolein by gas-phase dehydration of glycerol over silica supported bronsted acidic ionic liquid catalysts0 aSynthesis of acrolein by gasphase dehydration of glycerol over s  aTHE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, W SUSSEX, ENGLANDbJOHN WILEY & SONS LTDcOCT  a1319-13240 v853 a<p>BACKGROUND: Glycerol has become readily available as a byproduct from the biodiesel industry. High functionality and relatively low price make it a potential building block to produce value-added derivatives such as acrolein. RESULTS: Dehydration of glycerol to acrolein was performed over several silica supported Bronsted acidic ionic liquids as catalysts. All the catalysts prepared were active for the synthesis of acrolein (conversion of glycerol was observed in the range 35-90% with selectivity to acrolein in the range 29-58%). CONCLUSIONS: Catalyst prepared from triphenyl (3-sulfopropyl) phosphonium 4-methylbenzenesulfonate gave good activity and selectivity at 4 h reaction time. The conversion of glycerol decreased with increase in glycerol concentration. Higher temperature (325 degrees C) resulted in significantly lower conversion as well as selectivity to acrolein. With the use of two additional traps cooled to -7 degrees C, the selectivity to acrolein increased significantly for good catalysts. (C) 2010 Society of Chemical Industry</p>10aacidic ionic liquids10aacrolein10aglycerol dehydration10asupported catalyst1 aMunshi, Mudassir, K.1 aLomate, Samadhan, T.1 aDeshpande, Raj, Madhukar1 aRane, Vilas, H.1 aKelkar, Ashutosh, A.  uhttps://library.ncl.res.in/content/synthesis-acrolein-gas-phase-dehydration-glycerol-over-silica-supported-bronsted-acidic-001998nas a2200181   4500008004100000022001400041245009600055210006900151260011000220300001400330490000700344520123700351100002501588700002501613700002301638700002801661856012701689       2013                        eng d  a1463-926200aCatalytic dehydration of lactic acid to acrylic acid using calcium hydroxyapatite catalysts0 aCatalytic dehydration of lactic acid to acrylic acid using calci  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcFEB  a1211-12170 v153 a<p>A series of calcium hydroxyapatite (HAP) catalysts were synthesised with a Ca/P ratio ranging from 1.3 to 1.89 by a co-precipitation method that involved changing the pH of the calcium and phosphorous precursors. The physicochemical characterization by XRD, SEM, BET surface area and CO2 and NH3-TPD techniques confirmed the hydroxyapatite formation. These HAP catalysts were used for the vapour phase dehydration of lactic acid to acrylic acid. The HAP catalyst with a Ca/P ratio of 1.3 was found to be the most efficient catalyst among the synthesised series, which gave 100% conversion of lactic acid and 60% selectivity towards acrylic acid at 375 degrees C when a 50% (w/w) aqueous solution of lactic acid was used. The higher selectivity towards acrylic acid has been correlated to the increased acidity and reduced basicity of the HAP catalyst with a Ca/P ratio of 1.3 compared to the other HAP catalysts. The catalyst was found to be very stable and no deactivation was observed even after 300 h of reaction time. In situ FTIR studies were performed for understanding the mechanistic aspects and showed the formation of calcium lactate as an intermediate species during the dehydration of lactic acid to acrylic acid.</p>1 aGhantani, Vidhya, C.1 aLomate, Samadhan, T.1 aDongare, Mohan, K.1 aUmbarkar, Shubhangi, B.  uhttps://library.ncl.res.in/content/catalytic-dehydration-lactic-acid-acrylic-acid-using-calcium-hydroxyapatite-catalysts-0