摘要:
There is provided a process for efficient production of a solid catalyst usable for synthesis of methacrylic acid from methacrolein which comprises adding a lower alcohol or acetone to a dried product obtained from a mixed solution or aqueous slurry containing at least Mo, P and V as catalyst components and shaping the mixture by extrusion molding.
摘要:
A method of preparing a catalyst used for producing methacrylic acids through gas phase catalytic oxidation of methacrolein with molecular oxygen. The catalyst is represented by the formula:P.sub.a Mo.sub.b V.sub.c Ge.sub.d X.sub.e Y.sub.f Z.sub.g O.sub.hwherein P, Mo, V, Ge and O represent phosphorous, molybdenum, vanadium, germanium and oxygen, respectively; X represents at least one element selected from the group consisting of arsenic, antimony, bismuth, zirconium, tellurium, silver and boron; Y represents at lest one element selected from the group consisting of iron, copper, zinc, chromium, magnesium, tantalum, manganese, barium, gallium, cerium and lanthanum; Z represents at least one element selected from the group consisting of potassium, rubidium, cesium and thallium, and a, b, c, d, e, f, g and h represent the atomic ratios of the respective elements, and when b=12, then a=0.5-3, c=0.01-3, d=0.01-3, e=0-3, f=0-3, g=0.01-3, and h is the number of oxygen atoms necessary for satisfying the above atomic ratios of the respective components. The method includes providing an aqueous mixture containing at least P, Mo, V, Ge, X, Y and Z and removing water from the aqueous mixture, where the improvement comprises providing at least part of the Ge for the aqueous mixture by dissolving germanium dioxide in an aqueous solution of a hydroxide of an element represented by Z in the above formula. The catalyst prepared according to the method is remarkably elevated in activity in the methacrolein oxidation reaction and allows enhancement of the yield of methacrylic acid.
摘要:
In a process for producing a catalyst having a composition represented by the following formula usable to produce methacrylic acid by the gas-phase catalytic oxidation of methacrolein with molecular oxygen,P.sub.a Mo.sub.b Cu.sub.c V.sub.d X.sub.e Y.sub.f Z.sub.g O.sub.hwherein P, Mo, Cu, V and O are phosphorus, molybdenum, copper, vanadium and oxygen, respectively, X is at least one element selected from the group consisting of arsenic, antimony, bismuth, germanium, zirconium, tellurium and silver, Y is at least one element selected from the group consisting of iron, zinc, chromium, magnesium, tantalum, manganese, barium, boron, gallium, cerium and lanthanum, Z is at least one element selected from the group consisting of potassium, rubidium, cesium and thallium, a, b, c, d, e, f, g and h are an atomic ratio of each element, and when b is 12, a is 0.5 to 3, c is 0.01 to 2, d is 0.01 to 3, e is 0.01 to 3, f is 0 to 3, g is 0.01 to 2 nd h is the number of oxygen atoms necessary to satisfy the valence of each component, an improvement comprising adding 0.05 to 1.0 mole of nitric acid based on 12 moles of a molybdenum atom to a slurry containing materials for the catalyst components. According to the present invention, a catalyst for gas-phase catalytic oxidation excellent in the conversion of methacrolein and selectivity for methacrylic acid is obtained.
摘要:
A method for packing of catalyst, which comprises mixing, into a shaped catalyst containing at least molybdenum and iron, used in the gas-phase catalytic oxidation of propylene, isobutylene, tert-butyl alcohol or methyl tert-butyl ether with molecular oxygen to synthesize an unsaturated aldehyde and an unsaturated carboxylic acid both corresponding to the raw material used, metal-made Raschig rings as auxiliary packing material having a bulk volume of 0.3-3.5 times that of the shaped catalyst and a packing density of 0.5-1.5 kg/l, and packing the resulting mixture into a fixed bed type reactor; and a process for producing an unsaturated aldehyde and an unsaturated carboxylic acid, which comprises subjecting propylene, isobutylene, tert-butyl alcohol or methyl tert-butyl ether to gas-phase catalytic oxidation using molecular oxygen, in a fixed bed type reactor wherein a catalyst is packed by the above method.
摘要翻译:一种包装催化剂的方法,其包括将至少含有钼和铁的成形催化剂混合,用于丙烯,异丁烯,叔丁醇或甲基叔丁基醚与分子氧的气相催化氧化以合成 对应于所使用的原料的不饱和醛和不饱和羧酸,金属制的拉西奇环作为本体体积为成形催化剂的0.3-3.5倍的辅助包装材料,填充密度为0.5-1.5kg / l 并将所得混合物包装到固定床型反应器中; 以及制造不饱和醛和不饱和羧酸的方法,其包括在固定床型反应器中使丙烯,异丁烯,叔丁醇或甲基叔丁基醚用分子氧进行气相催化氧化,其中催化剂 由上述方法包装。
摘要:
A process for preparing a catalyst used for production of methacrolein and methacrylic acid by vapor phase oxidation of isobutylene or tertiary butanol includes adding an organic high-molecular weight compound having an average particle size of 0.01 .mu.m to 10 .mu.m, especially polymethyl methacrylate and/or polystyrene, to a MoBiFeCoNi-based catalyst, then molding the mixture and heat treating the molded product.
摘要:
A process for producing methacrylic acid which includes subjecting methacrolein to gaseous phase catalytic oxidation using molecular oxygen and a catalyst represented by the general formula:P.sub.a Mo.sub.b V.sub.c Fe.sub.d Ce.sub.e (NH.sub.4).sub.f X.sub.g Y.sub.h Z.sub.i O.sub.jwherein P, Mo, V, Fe, Ce, NH.sub.4 and O represent phosphorus, molybdenum, vanadium, iron, cerium, ammonium group and oxygen, respectively; X represents at least one element selected from the group consisting of copper, zinc, bismuth, chromium, magnesium, silver, tantalum and lanthanum; Y represents at least one element selected from the group consisting of arsenic, antimony, zirconium, barium, manganese, germanium and tellurium; Z represents at least one element selected from the group consisting of potassium, rubidum, cesium and thallium; a, b, c, d, e, g, h, i and j each represents an atomic ratio of each element, and b is 12, a is in a range of 0.5-3, c is in a range of 0.01-3, d is in a range of 0.01-2, e is in a range of 0.01-2, g is in a range of 0.01-3, h is in a range of 0.01-3, i is in a range of 0.01-2 and j is the number of oxygen atoms taken to satisfy the valence requirements stoichiometrically; f represents a number of ammonium groups and is in a range of 0.1-3.6.
摘要:
A method for preparing a multicomponent catalyst including molybdenum, bismuth, iron and cesium or thallium for producing methacrolein and methacrylic acid by the gas-phase catalytic oxidation of isobutylene or tert-butanol with molecular oxygen, wherein an aqueous nitric acid solution containing 0.01 to 0.36 mole of nitric acid per mole of ammonium molybdate, which is a material for the molybdenum component of the catalyst, and at least one material for the bismuth, iron, cesium and thallium components of the catalyst is added to an aqueous solution containing ammonium molybdate and materials for the remaining catalyst components, if any, to obtain a slurry which is then dried and calcined, provided that the nitric acid excludes nitric acid radicals contained in the materials containing the catalyst components. The amount of nitric acid used is controlled in a particular range, so that a highly active catalyst for gas-phase catalytic oxidation is obtained.
摘要:
The present invention provides a process for the preparation of a catalyst used in the production of unsaturated carboxylic acids such as methacrylic acid by the gas phase catalytic oxidation of the corresponding unsaturated aldehydes such as methacrolein. Said catalyst is composed of a multi-component composition containing at least phosphorus, molybdenum and antimony. The present invention has attained an improved in its catalytic performance such as conversion rate, selectivity, single-pass yield etc. by using antimony trioxide with average particle size of no more than 0.2 micron as a starting material upon preparing said catalyst.
摘要:
This invention provides a process for manufacturing a methyl methacrylate polymer comprising the steps of feeding a monomer containing at least 80 wt % of methyl methacrylate and a radical polymerization initiator represented formula (III) to a reactor; polymerizing the material at a polymerization temperature of 110 to 160° C. under the conditions satisfying particular equations between an initiator concentration and a polymerization temperature; feeding a reaction mixture taken out from the reactor to a devolatilization step (feeding step); and separating and removing volatiles from the reaction mixture (devolatilization step). A methyl methacrylate polymer having adequately good optical properties and a plastic optical fiber having improved transmission performance can be prepared according to this invention.
摘要:
A carrier-supported catalyst for the synthesis of unsaturated aldehydes and unsaturated carboxylic acids, comprising a catalyst active substance comprising at least molybdenum and bismuth as its components, glass fiber having an average diameter in a range of more than 5 .mu.m and not more than 200 .mu.m and an average length in a range of from 50 .mu.m to 1 mm, which is used as a carrier assistant in an amount of 0.5-50% by weight based on the catalyst active substance, and a carrier. The carrier-supported catalyst of this invention suffers no release or fall-off of the catalyst active substance from the carrier even if the catalyst supporting rate is increased. It also has high mechanical strength and is helpful for providing the objective product in a high yield. Further, the carrier-supported catalyst preparation process of this invention is capable of producing a carrier-supported catalyst having excellent mechanical strength and enabling high-yield production of an objective product, with ease and good reproducibility.