The present invention is directed to improved methods and systems for increasing the efficiency of a dehydrogenation section of an alkenyl aromatic hydrocarbon production facility, wherein an alkyl aromatic hydrocarbon, such as ethylbenzene, is dehydrogenated to produce an alkenyl aromatic hydrocarbon, such as styrene. The disclosed methods are more energy-efficient and cost effective than currently known methods for manufacturing styrene. The methods and systems advantageously utilize multiple reheat exchangers arranged in a series and/or parallel configuration that result in an energy consumption reduction and, consequently, a utility cost savings, as well as a reduction in styrene manufacturing plant investment costs.

An object of the present invention is to suppress performance deterioration of a molybdenum composite oxide-based catalyst at the time of performing gas-phase catalytic partial oxidation with molecular oxygen by using a tubular reactor. The present invention relates to a catalytic oxidation method using a tubular reactor in which a Mo compound layer containing a Mo compound and a composite oxide catalyst layer containing a Mo composite oxide catalyst are arranged in this order from a reaction raw material supply port side and under a flow of a mixed gas containing 75 vol % of air and 25 vol % of water vapor at 440° C., a Mo sublimation amount of the Mo compound is larger than a Mo sublimation amount of the Mo composite oxide catalyst under the same conditions.

There is provided a method for producing an optionally substituted olefin, comprising the steps of: dehydrogenating an optionally substituted alcohol in a first reaction zone comprising a first catalyst supported on a porous silica-based particle to form an optionally substituted carbonyl at a first set of reaction conditions; converting the optionally substituted alcohol and the optionally substituted carbonyl from the first reaction zone in a second reaction zone at a second set of reaction conditions that is different to the first set of reaction conditions and is selected to form the optionally substituted olefin, wherein the second reaction zone comprises a second catalyst supported on a porous silica-based particle. There is also provided a system for producing the optionally substituted olefin.

There is provided a method for producing an optionally substituted olefin, comprising the steps of: dehydrogenating an optionally substituted alcohol in a first reaction zone comprising a first catalyst supported on a porous silica-based particle to form an optionally substituted carbonyl at a first set of reaction conditions; converting the optionally substituted alcohol and the optionally substituted carbonyl from the first reaction zone in a second reaction zone at a second set of reaction conditions that is different to the first set of reaction conditions and is selected to form the optionally substituted olefin, wherein the second reaction zone comprises a second catalyst supported on a porous silica-based particle. There is also provided a system for producing the optionally substituted olefin.

The present disclosure relates to a reactor and a method of operation for an exothermal process being catalyzed by a catalytically active material receiving a reactant gas and providing a product gas, in which said exothermal process has a heat development having a potential for thermally degrading said catalytically active material, and which exothermal process operates at a temperature at which the reactants and at least 80% or all of the products are present as gases, said method comprising the steps of a) directing the reactant gas to a first zone of a material catalytically active in the exothermal process producing an first product gas, and b) directing the first product gas to a second zone of a material catalytically active in the exothermal process producing a product gas, with the option of fully or partially by-passing either said first zone or said second zone, while directing a non-condensing gas stream having a temperature at least 50° C. lower than the product gas to said by-passed zone, wherein the choice of by-passing said zone is made based on the time of operation or a process parameter reflecting the catalytic activity of the zone of catalytically active material which is not by-passed with the associated benefit of reducing the extent of thermal deactivation of the catalytically active material, and thus increasing the overall lifetime of the catalytically active material.

The present disclosure provides a premixer for at least two gases, comprising: a tubular body having a closed end and an opposite, open end; a first flow passage for receiving a first gas, the first flow passage axially extending through the closed end into the tubular body in a sealable manner; a conical tube arranged in the tubular body, wherein a small end of the conical tube communicates with the first flow passage, and a large end of the conical tube extends toward the open end with an edge thereof being fixed to an inner wall of the tubular body, thereby defining a sealed distribution chamber between the tubular body and the conical tube; and a second flow passage arranged on a side portion of the tubular body for receiving a second gas, wherein the second flow passage communicates with the distribution chamber, so that the second gas can be introduced into said conical tube via the distribution chamber in a substantially radial manner. The present disclosure further relates to a radially fixed bed reactor comprising the premixer, a reaction system of oxidative dehydrogenation of butene comprising the racially fixed bed reactor, and a corresponding process.

The present disclosure provides a premixer for at least two gases, comprising: a tubular body having a closed end and an opposite, open end; a first flow passage for receiving a first gas, the first flow passage axially extending through the closed end into the tubular body in a sealable manner; a conical tube arranged in the tubular body, wherein a small end of the conical tube communicates with the first flow passage, and a large end of the conical tube extends toward the open end with an edge thereof being fixed to an inner wall of the tubular body, thereby defining a sealed distribution chamber between the tubular body and the conical tube; and a second flow passage arranged on a side portion of the tubular body for receiving a second gas, wherein the second flow passage communicates with the distribution chamber, so that the second gas can be introduced into said conical tube via the distribution chamber in a substantially radial manner. The present disclosure further relates to a radially fixed bed reactor comprising the premixer, a reaction system of oxidative dehydrogenation of butene comprising the racially fixed bed reactor, and a corresponding process.

The present invention provides a method for producing α-hydroxyisobutyric acid amide by hydration of acetone cyanohydrin under the presence of a catalyst composed mainly of manganese oxide using a reactor in which at least two reaction regions are connected in series, the method being characterized by comprising: a step (B) of cyclically supplying at least a portion of a reaction liquid withdrawn from at least one reaction region to a first reaction region (I) in the reactor; and a step (b1) of further cyclically supplying at least a portion of the reaction liquid withdrawn from at least one reaction region to at least one reaction region other than the first reaction region. The method is also characterized in that an oxidizing agent is supplied to at least one reaction region in the reactor.

A method of forming a hydrocarbon product, the method comprising a first step of enriching a carrier liquid with carbon monoxide and hydrogen and a subsequent step of bringing the enriched carrier liquid into contact with a catalyst in a first reaction zone of a reactor, wherein the catalyst catalyzes reaction of the carbon monoxide and hydrogen to form the hydrocarbon product.

A process for producing 2,3,3,3-tetrafluoropropene comprises the steps: i) in a first adiabatic reactor comprising a fixed bed composed of an inlet and an outlet, bringing 2-chloro-3,3,3-trifluoropropene into contact with hydrofluoric acid in the gas phase in the presence of a catalyst to produce a stream A comprising 2,3,3,3-tetrafluoropropene, HF and unreacted 2-chloro-3,3,3-trifluoropropene; and ii) in a second adiabatic reactor comprising a fixed bed composed of an inlet and an outlet, bringing hydrofluoric acid into contact in the gas phase, optionally in the presence of a catalyst, with at least one chlorinated compound to produce a stream B comprising 2-chloro-3,3,3-trifluoropropene. The stream A obtained in step i) feeds said second reactor. The inlet temperature of the fixed bed of one of said first or second reactors is between 300° C. and 400° C. The longitudinal temperature difference between the inlet and the outlet of the fixed bed in question is less than 20° C.