摘要:
The present invention relates to a method for preparing a heteropolyacid catalyst and method for preparing methacrylic acid using thereof. More particularly, the present invention relates to a method for preparing heteropolyacid catalyst, which is produced by the recrystallization of a heteropolyacid and/or its salt dissolved in a basic organic solvent and heat-treatment, and further to a method for preparing metachrylic acid using thereof, wherein the use of the heteropolyacid catalyst increases the activity of oxidation reaction induced by the modified electronic properties of heteropolyanions and provides high efficiency production of methacrylic acid from methacrolein, since the basic property of solvent inhibits peculiar acidic property of heteropolyacid.
摘要:
A fixed bed hydroprocessing system, and also a method for upgrading a pre-existing fixed bed hydroprocessing system, involves preliminarily upgrading a heavy oil feedstock in one or more slurry phase reactors using a colloidal or molecular catalyst and then further hydroprocessing the upgraded feedstock within one or more fixed bed reactors using a porous supported catalyst. The colloidal or molecular catalyst is formed by intimately mixing a catalyst precursor composition into a heavy oil feedstock and raising the temperature of the feedstock to above the decomposition temperature of the precursor composition to form the colloidal or molecular catalyst in situ. Asphaltene or other hydrocarbon molecules otherwise too large to diffuse into the pores of the fixed bed catalyst can be upgraded by the colloidal or molecular catalyst. One or more slurry phase reactors may be built and positioned upstream from one or more fixed bed reactors of a pre-existing fixed bed system and/or converted from one or more pre-existing fixed bed reactors.
摘要:
Solvent extraction is used to remove wax and contaminants from an iron-based Fischer-Tropsch catalyst in a natural circulation continuous-flow system. The wax-free catalyst is then subjected to controlled oxidation to convert the iron to its initial oxidized state, Fe2O3. Reactivation of the oxide catalyst precursor is carried out by addition of synthesis gas.
摘要翻译:溶剂萃取用于在自然循环连续流动系统中从铁基费 - 托催化剂中除去蜡和污染物。 然后对无蜡催化剂进行受控氧化以将铁转化为其初始氧化态Fe 2 O 3。 氧化物催化剂前体的再活化通过加入合成气进行。
摘要:
A process for recovering cobalt and manganese components from a product stream or a residue stream that resulted from a process which employs a catalyst system containing the cobalt and manganese components for oxidizing pseudocumene to trimellitic acid includes the steps of adding a precipitating agent to the product stream or the residue stream in an effective amount to react with the cobalt and manganese components in the product stream or the residue stream.
摘要:
This invention relates to a method of improving the catalytic performance of palladium or ruthenium, rhenium-on-carbon hydrogenation catalysts operating in aqueous media where loss of soluble rhenium may result in rapid catalytic failure. A rhenium-containing hydrogenation catalyst comprised of rhenium on a support material is regenerated by first treating the catalyst with aqueous perrhenic acid or potassium perrhenate followed by treating the catalyst under reducing conditions at elevated temperature and pressure. Treatment of the catalyst as described replenishes dispersed fresh finely divided rhenium which enhances the activity of the catalyst while at the same time allowing the operations to be carried out in situ in the hydrogenation reactor or in a side stream reactor with significant savings in reducing reactor down time and precious metal expenses.
摘要:
Provided are high activity catalysts based upon gamma alumina containing substrates impregnated with one or more catalytically active metals, which catalysts in addition contain a nanocrystalline phase of alumina of a crystalline size at the surface of less than 25 Å. Also provided are processes for preparing such high activity catalysts and various uses thereof.
摘要:
A method for producing a catalytic converter including a honeycomb body having flow channels with catalytically active surfaces, includes at least partially cleaning foreign materials from a honeycomb body of a catalytic converter that has been in service. Catalytically active surfaces of the catalytic converter are restored through application of a catalytically active surface coating.
摘要:
A process for the preparation of iron-, potassium- and cerium-containing catalysts for the dehydrogenation of hydrocarbons from the same spent catalysts (regeneration) by grinding and, if necessary, purifying the spent material, restoring the original activity by adjusting the composition and restoring the external shape comprises adding to the ground material an effective amount of potassium and such an amount of cerium that the total amount of cerium is greater than the amount originally present.
摘要:
The invention presented involves a method for regenerating, replacing or treating the catalyst in a hydroprocessing reactor, the method comprising admixing with the feedstock, recycle stream or hydrogen stream of the reactor an additive which comprises a nonionic, organometallic platinum group metal coordination composition which is a) resistant to breakdown under ambient temperatures; b) capable of breakdown at temperatures existing in the vicinity of the catalyst; and c) does not contain a disadvantageous amount of phosphorus, arsenic, sulfur, antimony or halides.
摘要:
Noble metal catalyst, in particular platinum catalysts, which are applied on carriers and have become poisoned by metals as a result of being used for many years in the preparation of hydroxyl-ammonium salts by catalytic reduction of nitric oxide with hydrogen in an aqueous mineral acid are regenerated by a process in which the metallic impurities are dissolved using nitric acid or aqua regia, the solution is neutralized, the troublesome metals are precipitated from the neutralized solution by means of a selective precipitating reagent, and the purified platinum solution is reused for the preparation of the catalyst. Organic complexing agents which form insoluble or sparingly soluble complexes with the metallic impurities are preferably used as precipitating reagents.