3 research outputs found

    Isolation of Starch from Oil Palm Trunks

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    Oil palm trunks were harvested and divided in three sections to represent top, middle and bottom part of the trunk. The trunks were processed in a plywood factory within 24 hours of felling. The inner cores, which remained after removal of the outer layer for veneer production, were chipped and immediately frozen. Fresh samples showed starch granules with sizes between 5 and 15 μm, which is in agreement with earlier reports on palm starch from different palm tree species. The presence of native starch in the samples prepared by cryogenic milling was confirmed by the Maltese crosses after examination with polarized light. The concentration of starch showed a gradient over the oil palm trunk with 42-59% at the top decreasing to less than 10% at the bottom. The concentration of (hemi)cellulose was the reverse. As free sugars were virtually absent, starch hydrolysis seemed to be successfully prevented by this method

    Surface texturing of Mo-V-Te-Nb-O-x selective oxidation catalysts

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    The paper concentrates on the study of Mo-V-Te-Nb oxide mixtures by electron microscopy combined with catalytic investigation of these materials in the partial oxidation of propane. Surface texturing of catalyst particles composed of two phases referred to in the literature as M1 and M2 is revealed by high-resolution transmission electron microscopy of high performing catalysts. The chemical composition of the catalyst surface is modified by treatment in water to obtain a significant increment in yield of acrylic acid. A chemical realization of the site isolation concept recurring on a supramolecular arrangement of catalyst and reactant rather than on atomic site isolation is suggested. A complex Mo-V-Te-Nb-O (x) precursor phase carries nanoparticles made from a network of oxoclusters active as catalyst for the conversion of propane to acrylic acid. The designed synthesis of the multi-element oxide bulk and of the surface structure with a different composition than the precursor phase improved the performance by a factor of 4