摘要:
A method of reactivating a catalyst, such as a solid catalyst or a liquid catalyst is provided. The method comprises providing a catalyst that is at least partially deactivated by fouling agents. The catalyst is contacted with a fluid reactivating agent that is at or above a critical point of the fluid reactivating agent and is of sufficient density to dissolve impurities. The fluid reactivating agent reacts with at least one fouling agent, releasing the at least one fouling agent from the catalyst. The at least one fouling agent becomes dissolved in the fluid reactivating agent and is subsequently separated or removed from the fluid reactivating agent so that the fluid reactivating agent may be reused. A system for reactivating a catalyst is also disclosed.
摘要:
Improved methods for conducting solid acid-catalyzed, near- or supercritical heterogeneous chemical reactions (e.g., alkylation reactions) are provided which give enhanced product yields and permit longer processing runs. The preferred reactions of the invention are carried out in the presence of a solid macroporous catalyst having a surface area of from about 50-400 m2/g and a pore size of from about 70-150 null. Product selectivity is enhanced by pressure-tuning of the reaction to promote production and separation of desired reaction products. In continuous processing, the chemical reaction may be interrupted before significant catalyst deactivation, followed by increasing reactor pressure and/or reducing reactor temperature to remove the accumulating coke; when the catalyst is regenerated, the original reaction conditions and reactant introduction may be resumed.
摘要:
This invention, in one embodiment, is drawn to a process for forming olefin product by contacting an oxygenate with an olefin-forming catalyst under supercritical conditions to form an olefin product. This invention also relates to methods for activating molecular sieve catalyst, regenerating molecular sieve catalyst, and forming and/or disposing a co-catalyst within a molecular sieve catalyst, each under supercritical conditions.
摘要:
Improved methods for conducting solid acid-catalyzed, near- or supercritical heterogeneous chemical reactions (e.g., alkylation reactions) are provided which give enhanced product yields and permit longer processing runs. The preferred reactions of the invention are carried out in the presence of a solid macroporous catalyst having a surface area of from about 50-400 m2/g and a pore size of from about 70-150 Å. Product selectivity is enhanced by pressure-tuning of the reaction to promote production and separation of desired reaction products. In continuous processing, the chemical reaction may be interrupted before significant catalyst deactivation, followed by increasing reactor pressure and/or reducing reactor temperature to remove the accumulating coke; when the catalyst is regenerated, the original reaction conditions and reactant introduction may be resumed.
摘要:
There is provided a process for renewing the activity of used, supported metal catalysts for the hydrogenation of carbon monoxide to form a mixture of hydrocarbons comprising decreasing the hydrocarbon content of the catalyst, impregnating said catalyst under an non-oxidative atmosphere with a solution at least one weak organic acid, preferably a mono- or di-carboxylic acid, to the point where it has absorbed a volume of said solution equal to at least about 10% of its calculated pore volume, oxidizing the catalyst with a gaseous oxidant in the presence of the impregnating solution and activating the catalyst by reduction with hydrogen at elevated temperatures. Optionally, the catalyst is calcined after the oxidation step, and passivated after the activation step. A preferred means of decreasing the hydrocarbon content of the catalyst is contacting it with a hydrogen-containing gas at elevated temperatures.
摘要:
There is provided a process for regenerating the activity of used metal catalysts for the hydrogenation of carbon monoxide comprising decreasing the hydrocarbon content thereof, calcining under an oxidant-containing atmosphere, impregnating with a solution of at least one of a metal compound, calcining under an oxidant-containing atmosphere and activating by contacting with a hydrogen-contacting gas at elevated temperatures to form an active catalyst. The process regenerates and enhances both supported and dispersed active metal (DAM) catalysts. Used catalysts enhanced by the process are initially treated to decrease their hydrocarbon content. The treatment may be carried out in a single reactor, or by carrying out up to all steps after catalyst may be withdrawn from a reactor and returned to at least one reactor, both preferably during operation thereof. Up to all steps may be effected in a subsequent reactor, or in specialized apparatus.
摘要:
The invention is concerned with the oligomerization of supercritical ethene. An essential aspect of the invention is that of mixing ethene with an inert medium and setting the conditions in the reaction such that both ethene and inert medium are supercritical. This is because the solubility for ethene in the inert medium is greater in the supercritical state, such that more ethene is dissolved in the supercritical inert medium than in a liquid solvent. The process regime in the supercritical state therefore enables the use of a much higher proportion of ethene in a homogeneous mixture of ethene and inert medium than is possible on the basis of the thermodynamic solubility restriction in a purely liquid hydrocarbon stream. In this way, the space-time yield is distinctly enhanced. Since a greater amount of ethene can be passed into the reactor, it is possible as a result to better exploit the apparatus volume compared to a liquid phase process. The inert medium used may, for example, be isobutane.
摘要:
The invention provides a process for the off site regeneration of a solid catalyst, comprising two consecutive steps: a first step of washing the catalyst using one or more fluid(s) in the supercritical state, so as to extract from the catalyst at least a portion of the hydrocarbons present at the surface of the latter, followed by a second step of combustion of at least a portion of the coke present at the surface of the said catalyst by a heat treatment of the latter in the presence of oxygen and at a temperature ranging from 300° C. to 600° C.
摘要:
A method for reactivating a solid alkylation catalyst is provided which can be performed within a reactor that contains the alkylation catalyst or outside the reactor. Effective catalyst reactivation is achieved whether the catalyst is completely deactivated or partially deactivated. A fluid reactivating agent is employed to dissolve catalyst fouling agents and also to react with such agents and carry away the reaction products. The deactivated catalyst is contacted with the fluid reactivating agent under pressure and temperature conditions such that the fluid reactivating agent is dense enough to effectively dissolve the fouling agents and any reaction products of the fouling agents and the reactivating agent. Useful pressures and temperatures for reactivation include near-critical, critical, and supercritical pressures and temperatures for the reactivating agent. The fluid reactivating agent can include, for example, a branched paraffin containing at least one tertiary carbon atom, or a compound that can be isomerized to a molecule containing at least one tertiary carbon atom.
摘要:
A method of reactivating a catalyst, such as a solid catalyst or a liquid catalyst. The method comprises providing a catalyst that is at least partially deactivated by fouling agents. The catalyst is contacted with a fluid reactivating agent that is at or above a critical point of the fluid reactivating agent and is of sufficient density to dissolve impurities. The fluid reactivating agent reacts with at least one fouling agent, releasing the at least one fouling agent from the catalyst. The at least one fouling agent becomes dissolved in the fluid reactivating agent and is subsequently separated or removed from the fluid reactivating agent so that the fluid reactivating agent may be reused. A system for reactivating a catalyst is also disclosed.