摘要:
Acid-resistant copper oxide-chromium oxide catalysts for hydrogenation of fatty acids or fatty acid mixtures and/or the esters thereof are obtained through heat treatment of copper oxide and chromium oxide or of precursor compounds that are convertible into copper oxide or chromium oxide and which contain aluminum zirconium, cerium and/or lanthanum oxide as an additional metal component. The acid resistance is defined by the fact that the amount of copper which is dissolved by stirring 10 g of the catalyst for 2 minutes in 100 ml of 10 weight percent acetic acid at 20.degree. C., is a maximum of 200 mg.
摘要:
A catalyst for decreasing the content of nitrogen oxides in flue gases. The catalyst contains at least one of the metals titanium, zirconium, vanadium, tungsten, molybdenum, or cerium in the form of one or more of their oxides combined with a silicate with a three-layer structure (three-layer silicate) selected from the group consisting of illite and mica. The atomic ratio of the silicon in the three-layer silicate to the metal in the oxide is from 0.2 and 50 and preferably from 0.4 to 25.
摘要:
An improvement in a process for the production of xylose or xylitol wherein a vegetable material is contacted with a basic substance and the solid residue is thereafter treated with an acid, the improvement resides in the use of stone nut shells, in employing a two-stage digestion initially with a 1.5-6 molar alkali metal hydroxide solution at 10.degree.-50.degree. C. and thereafter diluting the digestion mass to 0.75 molar or less and digesting at a temperature of at least 60.degree. C.
摘要:
A catalyst for the selective hydrogenation of polyunsaturated hydrocarbons which contain entirely or predominantly more than five carbon atoms, containing palladium with a promotor on a metal oxide support. The promotor is a metal from the subgroup IB of the periodic system (preferably silver) and the metal oxide support (TiO.sub.2 optionally mixed with CeO.sub.2 and/or ZrO.sub.2) is macroporous, the pore volume being about 0.2 to 0.4, preferably about 0.25 to 0.30 ml per g of carrier and the proportion of the macropores having a diameter of more than 14 nm being at least 65%.
摘要:
A catalyst for decreasing the content of nitrogen oxides in flue gases. The catalyst contains at least one of the metals titanium, zirconium, vanadium, tungsten, molybdenum, or cerium in the form of one or more of their oxides combined with a silicate with a three-layer structure (three-layer silicate) comprising acid-activated pyrophyllite. The crystalline layer structure of the acid-activated pyrophyllite is essentially retained, while being not yet X-ray amorphous. The acid activation increases the BET surface area at least 15% and preferably at least 50% in terms of the BET surface area of the pyrophyllite before acid activation. The atomic ratio of the silicon in the acid-activated pyrophyllite to the metal in the oxide is from 0.2 and 50 and preferably from 0.4 to 25.
摘要:
Catalyst for the selective hydrogenation of multi-unsaturated organic compounds, in particular of diolefins and dienes in mixtures with other hydrocarbons; the catalyst is characterized by(A) a metal component from one or more elements of Group VIII of the Periodic Table on(B) a support material on the basis(b.sub.1) of one or more n-semiconducting oxides of one or more elements from the Subgroups IVb, Vb and VIb of the Periodic Table or of thorium or cerium, or respectively on the basis(b.sub.2) of one or more n-semiconducting mixed oxide systems of the formula Me.sub.2 Me.sub.1 (0).sub.x, where Me.sub.1 is an element of the group defined in (b.sub.1), Me.sub.2 an alkaline earth metal or an element different from Me.sub.1 or the group defined in (b.sub.1), and x signifies the number of oxygen atoms required for the saturation of Me.sub.1 and Me.sub.2 to the range of an n-semiconducting state;the hydrogen chemisorption capacity, expressed as the atomic ratio between chemisorbed hydrogen atoms and metal atoms of the metal component (A) present on the surface of the metal particles, (H/Me.sub.A), being at least 0.6:1.
摘要:
Process for the removal of nitrogen oxides from exhaust gases, in particular from exhaust gases containing sulfur oxides, by catalytic reduction. As a reduction agent a gas mixture obtained by catalytic conversion of methanol either by catalytic dissociation or by steam reforming is mixed with the exhaust gases and passed over a catalyst, wherein the nitrogen oxides are reduced to nitrogen. According to the first variant, one operates with conventional catalysts above 300.degree. C., according to the second variant, with new catalysts below 300.degree. C.
摘要:
A fluidized-bed catalyst for the production of synthetic natural gas by the methanization of carbon monoxide which catalyst in the unreduced state contains nickel oxide on a carrier material resistant to temperature changes, and a hydraulic cement, said catalyst obtainable by compressing a composition comprising a carrier material and nickel oxide in admixture with hydraulic cement as binder in the wetted condition at a pressure above 1600 kp/cm.sup.2 into a formed body, calcining the so-compressed formed body, curing the so-calcined formed body by treatment with water or steam, recalcining the so-cured formed body and comminuting the same and recovering a comminuted material having a particle size fraction ranging from 40 to 350.mu.. Also disclosed is a process for production of synthetic natural gas by fluidized-bed methanization of carbon monoxide with hydrogen employing such a catalyst.
摘要:
An SiO.sub.2 -containing copper oxide-chromium oxide catalyst is obtained through heat treatment of copper oxide and chromium oxide, or of a precursor compound convertible into copper oxide or chromium oxide in the presence of an SiO.sub.2 component; it is characterized by the fact that, after the heat treatment,(a) the intensity ratio between the X-ray diffraction lines (XRD reflexes) of the copper oxide with d=0.232 nm and of the CuCr.sub.2 O.sub.4 spinel with d=0.240 nm formed through heat treatment, determined as the ratio of the reflex amplitudes, is 0.7 to 4.0:1, and(b) the copper mass, which is dissolved by stirring 10 g of the catalyst in 100 ml of 10 weight percent acetic acid at 20.degree. C. for 2 minutes, amounts to a maximum of 200 mg.
摘要:
A catalyst for decreasing the content of nitrogen oxides in flue gases. The catalyst contains at least one of the metals titanium, zirconium, vanadium, tungsten, molybdenum, or cerium in the form of one or more of their oxides combined with a silicate with a three-layer structure (three-layer silicate). The three-layer silicate is acid-activated while essentially retaining its crystalline layer structure. The three-layer silicate has a cation-exchange capacity of 30 mvals/100 g or more before acid activation. The acid activation lowers the concentration of interlayer cations and increases the BET surface at least 15% and preferably at least 50% in terms of the BET surface of the three-layer silicate before acid activation. The atomic ratio of the silicon in the acid-activated three-layer silicate to the metal in the oxide is from 0.2 and 50 and preferably from 0.4 to 25.