This invention discloses an olefin oxidation process, including a step of under olefin oxidation conditions, successively passing a reaction feed from the No.1 catalyst bed through the No.n catalyst bed, wherein if the apparent velocity of each of the reaction materials passing from the No.1 catalyst bed through the No.n catalyst bed is respectively named as v.sub.1 to v.sub.n, and if m represents any integer in the region [2, n], the relationship v.sub.m-1<v.sub.m holds. The process according to this invention is capable of extending the service life of the catalyst, especially the single-pass service life thereof, and at the same time, suppressing any side-reaction over a prolonged period of time. This invention further discloses a fixed-bed reaction apparatus and a system for olefin oxidation.

An apparatus for producing trichlorosilane in which metallurgical grade silicon powder supplied to a reactor is reacted with hydrogen chloride gas while being fluidized by the hydrogen chloride gas, thereby discharging trichlorosilane generated by the reaction from the reactor, includes: a plurality of gas flow controlling members which are installed along a vertical direction in an annular shape R from an inner peripheral wall of the reactor in an internal space of the reactor; and a heat transfer tube which is installed along the vertical direction in the annular space R and through which a heating medium passes.

The invention relates to a catalyst and catalyst layer and process for preparing dimethyl ether from synthesis gas or methanol as well as the use of the catalyst or catalyst layer in this process.

The invention relates to a catalyst system for producing maleic anhydride by means of the catalytic oxidation of n-butane, comprising at least one reactor tube, which has two catalyst layers consisting of different catalyst particles, characterized in that the geometric surface area per catalyst particle is greater in the catalyst layer that is first in the gas flow direction than in the second catalyst layer. The invention further relates to a process for producing maleic anhydride by means of the catalytic oxidation of n-butane, wherein a mixture of oxygen and n-butane is fed through the catalyst system according to the invention and the at least one reactor tube is at elevated temperature.

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.

The present disclosure relates to a shell-and-multi-double concentric-tube reactor and a shell-and-multi-double concentric-tube heat exchanger, and to a shell- and-multi-double concentric-tube reactor and a shell-and-multi-double concentric-tube heat exchanger which provide a new type of reactor and a heat exchanger, thereby maximizing catalyst performance and improving performance of the reactor by optimizing heat exchange efficiency and a heat flow, uniformly distributing a reactant, and increasing a flow rate of the reactant, and accordingly making the reactor and the heat exchanger compact.

The invention relates to a catalyst arrangement for preparing phthalic anhydride by gas-phase oxidation of aromatic hydrocarbons, which comprises a reactor having a gas inlet end for a feed gas and a gas outlet end for a product gas and also a first catalyst zone made up of catalyst bodies and at least one second catalyst zone made up of catalyst bodies, where the first catalyst zone is arranged at the gas inlet end and the second catalyst zone is arranged downstream of the first catalyst zone in the gas flow direction and the length of the first catalyst zone in the gas flow direction is less than the length of the second catalyst zone in the gas flow direction, characterized in that the first catalyst zone has a higher gap content compared to the second catalyst zone.

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.

Processes for the production of olefins are disclosed, which may include: contacting a hydrocarbon mixture comprising linear butenes with an isomerization catalyst to form an isomerization product comprising 2-butenes and 1-butenes; contacting the isomerization product with a first metathesis catalyst to form a first metathesis product comprising 2-pentene and propylene, as well as any unreacted C.sub.4 olefins, and byproducts ethylene and 3-hexene; and fractionating the first metathesis product to form a C3− fraction and a C5 fraction comprising 2-pentene. The 2-pentene may then be advantageously used to produce high purity 1-butene, 3-hexene, 1-hexene, propylene, or other desired products.