摘要:
The invention concerns a method for converting a feedstock selected from sugars or sugar alcohols, alone or in a mixture, into mono- or polyoxygenated compounds, wherein the feedstock is contacted with at least one heterogeneous catalyst comprising a support selected from perovskites of formula ABO3, in which A is selected from the elements Mg, Ca, Sr and Ba and B is selected from the elements Fe, Mn, Ti and Zr, and the oxides of elements selected from lanthanum, neodymium, yttrium and cerium, alone or in a mixture, which oxides can be doped with at least one element selected from alkali metals, alkaline earths and rare earths, in a reducing atmosphere, at a temperature of 100° C. to 300° C. and at a pressure of 0.1 MPa to 50 MPa.
摘要:
A catalyst comprising gold and a porous support containing at least one refractory oxide, in which the gold content is in the range 0.01% to 5% by weight with respect to the total weight of catalyst, and in which the particles of gold are distributed homogeneously through said porous support and have a dimension, measured by transmission electron microscopy, in the range 0.5 to 5 nm.
摘要:
The invention relates to a method for hydroprocessing a hydrocarbon feed, operated at a temperature of between 180° C. and 450° C., in the presence of a catalyst comprising i) a composite material comprising a compound based on at least one crystalline aluminium solid and carbon, the deposited carbon content being between 1 and 25 wt. % of the total mass of the composite material, and ii) at least one element of group VIB and at least one element of group VIII, in the sulfide form thereof, said catalyst being produced by a method comprising at least: a) a step of bringing a carbon precursor into contact with a compound based on at least one crystalline aluminium solid, b) a step of thermally treating the solid produced by step a), c) repeating steps a) and b) until the desired deposited carbon content is reached, d) depositing at least one element of group VIB and at least one element of group VIII on the surface of the solid produced by step c), and e) a step of sulfidisation of the solid produced in step d).
摘要:
The invention concerns a process for the transformation of lignocellulosic biomass or cellulose into mono- or poly-oxygenated compounds, in which the lignocellulosic biomass or the cellulose is brought into simultaneous contact with a catalytic system comprising a combination of one or more homogeneous catalysts and one or more heterogeneous catalysts, in the same reaction chamber, in the presence of at least one solvent, said solvent being water alone or as a mixture with at least one other solvent, in a reducing atmosphere, and at a temperature in the range 80° C. to 250° C. and at a pressure in the range 0.5 MPa to 20 MPa.
摘要:
Disclosed are a catalyst, its preparation and use in selective hydrogenation, which catalyst has a porous support grain on which are deposited palladium and silver, and at least one alkali and/or alkaline earth metal; the porous support contains a refractory silica, alumina and/or silica-alumina oxide, where at least 80 wt. % of the palladium is distributed in a crust at the periphery of the support, and at least 80 wt. % of the silver is distributed in a crust at the periphery of the support, the local content of palladium at each point along the diameter of the grain follows the same course as the local content of silver.
摘要:
A catalyst comprising gold, palladium, and a porous support, in the form of at least one grain, in which: the gold content in the catalyst is in the range 0.5% to 3% by weight with respect to the total weight of catalyst; the mean particle size of the gold, estimated by transmission electron microscopy (TEM), is in the range 0.5 nm to 5 nm; the gold is distributed homogeneously in said porous support; at least 80% by weight of the palladium is distributed in an eggshell at the periphery of said porous support; the gold/palladium molar ratio is more than 2.
摘要:
Disclosed are a catalyst, its preparation and use in selective hydrogenation, which catalyst has a porous support grain on which are deposited palladium and silver, and at least one alkali and/or alkaline earth metal; the porous support contains a refractory silica, alumina and/or silica-alumina oxide, where at least 80 wt. % of the palladium is distributed in a crust at the periphery of the support, and at least 80 wt. % of the silver is distributed in a crust at the periphery of the support, the local content of palladium at each point along the diameter of the grain follows the same course as the local content of silver.
摘要:
The invention relates to a process for transformation of lignocellulosic biomass or cellulose using in a simultaneous manner an original combination of at least two homogeneous catalysts and one or more heterogeneous catalyst(s). The use of these catalysts makes it possible to obtain mono-oxidized or poly-oxidized upgradable products directly and to limit the formation of non-upgradable products. Non-upgradable products are defined as soluble and non-soluble humins, i.e., products of high molecular weight obtained from undesirable condensation reactions of sugars and their derivatives.
摘要:
Process for transformation of a feedstock of lignocellulosic biomass and/or the carbohydrates, into mono-oxidized or poly-oxidized compounds, wherein the feedstock is contacted, simultaneously, with a catalytic system that comprises one or more homogeneous catalysts selected from Brønsted acids and heterogeneous catalysts comprising at least one metal selected from groups 6 to 11 and 14 of the periodic table, and a substrate selected from perovskites of formula ABO3, in which A is Mg, Ca, Sr, Ba, and La, and B is selected from Fe, Mn, Ti and Zr, oxides of lanthanum, neodymium, yttrium, cerium, and niobium, or mixtures thereof, and mixed oxides of aluminates of zinc, copper, and cobalt, or mixtures thereof, in the same reaction chamber, with at least one solvent, being water or water with at least one other solvent, under reducing atmosphere, and temperature of 50° C. to 300° C., and pressure of 0.5 MPa to 20 MPa.