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在批次和固定床反应器中用于菜子油酯化K/Al_2O_3催化剂的稳定性(英文)

催化学报 2014年第7期35卷 1084-1090页

作者： Petr Kutálek Libor apek Lucie Smoláková David Kubikb Martin Hájek Department of Physical Chemistry Faculty of Chemical TechnologyUniversity of PardubiceStudentská 573532 10 PardubiceCzech Republic Research Institute of Inorganic Chemistry RENTECH-UniCREChempark Litvínov Záluí-Litvínov436 70Czech Republic

Catalytically active, stable, and mechanically durable solid K/Al 2 O 3 catalysts for the transesterification of rapeseed oil with methanol was studied. In a batch reactor, high catalytic activity was accompanied by leaching of K species, caused by glycerol, and mechanical destruction of the solid catalyst as a result of contact with the stirrer. In a fixed-bed reactor, some leaching of K species into the liquid phases was also observed, but approached 0 during 30 h of time-on-stream; the activity of the K/Al 2 O 3 catalyst (∼83% ester yield) was stable for 100 h of time-on-stream and no mechanical destruction of the catalyst was observed. The populations of K 2 O and K-O-Al species for fresh and used K/Al 2 O 3 catalysts were compared using Fourier transform infrared spectroscopy. It was found that some K 2 O species leached into the liquid phases at the beginning of the reaction.

关键词：固定床反应器固体催化剂 Al2O3 稳定性菜籽油转移反应傅立叶变换红外光谱法酯基

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Phenolic Acid Content and Free Radical-Scavenging Activity of Two Differently Processed Carob Tree(Ceratonia siliqua L.)Pod

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Food and Nutrition sciences 2013年第5期4卷 547-553页

作者： Hülya Torun Faik Ahmet Ayaz Nesrin Colak JiríGrúz Miroslav Strnad Department of Biology Karadeniz Technical UniversityTrabzonTurkey Laboratory of Growth Regulators Institute of Experi-mental BotanyPalacky UniversityOlomoucCzech Republic Centre of the Region Haná for Biotechnological and Agricultural Research Palacky UniversityOlomoucCzech Republic

The phenolic acids in free phenolic acid (FPHA), methanol-soluble phenolic ester (MSPE), and methanol-soluble phenolic glycoside (MSPG) fractions of two carob products, natural carob-pod flour (CPF) and commercial carob-pod flour (CCPF), were identified and quantified using high-performance liquid chromatography-mass spectrometry (HPLC-MS). Six phenolic acids were identified in the carob flours (gallic acid, protocatechuic acid, gentisic acid, syringic acid, p- coumaric acid, and sinapic acid). Gallic acid was the major phenolic acid;and its concentrations in CCPF were substantially higher than in CPF (135 - 166 and 85.2 - 91.3 mg/g dw, respectively). The concentrations of p-coumaric acid and sinapic acid were also higher in CCPF than in CPF. In contrast, the concentrations of protocatechuic acid and gentisic acid were generally lower in CCPF than in CPF, with the only exception being gentisic acid glycosides. Both carob-pod flours contained almost the same amount of sinapic acid and syringic acid. The total phenolic contents of the FPHA, MSPE, and MSPG fractions of CPF were found to be 44%, 38%, and 69% that of the respective fractions of CCPF. Correspondingly, the FPHA, MSPE, and MSPG fractions of CCPF had higher free radical-scavenging activity (28.4%, 33.1%, and 26.2%, respectively) than the corresponding fractions of CPF (9.2%, 28.0%, and 9.2%, respectively). Notably, the FPHA and MSPG fractions of each sample had very similar scavenging activity while the MSPE fraction always had higher activity. The FPHA and MSPG fractions of CPF had the lowest activities.

关键词： Ceratonia siliqua Phenolic Acids Ester Glycoside Carob-Pod Flour

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