The invention is directed to a combined naphtha hydrotreating (NHT) and isomerization process scheme, which includes dividing wall columns (DWC) that replace multiple distillation columns and allow optimized heat integration within the system. The disclosed design provides reductions in both capital and energy costs compared to conventional schemes.

The present invention relates to a continuous process for preparing phosgene as well as a production unit for carrying out said process.

Thermoneutral systems and methods for producing carbon monoxide (CO) and sulfur dioxide (SO.sub.2) are disclosed. The systems can include a first reaction zone and a second reaction zone, where heat generated in the first reaction zone is sufficient to drive a carbon dioxide gas (CO.sub.2(g)) and elemental sulfur gas (S(g)) reaction to produce a product stream that includes CO(g) and SO.sub.2(g).

To allow hydrogen to be supplied to a dehydrogenation reaction unit for dehydrogenating an organic hydride by using a highly simple structure so that the activity of the dehydrogenation catalyst of the dehydrogenation reaction unit is prevented from being rapidly reduced. The hydrogen production system (1) comprises a first dehydrogenation reaction unit (3) for producing hydrogen by a dehydrogenation reaction of an organic hydride in presence of a first catalyst, and a second dehydrogenation reaction unit (4) for receiving a product of the first dehydrogenation reaction unit, and producing hydrogen by a dehydrogenation reaction of the organic hydride remaining in the product in presence of a second catalyst, wherein an amount of the first catalyst used in the first dehydrogenation reaction unit is equal to or less than an amount of the second catalyst used in the second dehydrogenation reaction unit, and an amount of hydrogen produced in the first dehydrogenation reaction unit is less than an amount of hydrogen produced in the second dehydrogenation reaction unit.

The present disclosure relates generally to methods and systems for achieving enhanced catalytic performance via the strategic arrangement of multiple catalyst beds in series, where each catalyst bed comprises a compositionally-distinct catalyst, and each catalyst facilitates the conversion of the same structural moieties on the reactant to form the same product. Arranging multiple catalyst beds according to the methods and systems disclosed herein allows a predictable enhancement of conversion of the reactant to product without the need for time-consuming experimentation to test all possible catalysts configurations.

Disclosed herein is an integrated small and medium-sized natural gas steam reforming reactor comprising a furnace body, a combustion module located outside the furnace body, and a conversion reaction module, a steam generation and superheating module, a medium temperature shift module and a desulfurization module arranged inside the furnace body, wherein the combustion module supplies combustion flue gas into an interior of the furnace body, the interior of the furnace body is partitioned into a plurality of flue cavities by a plurality of high-temperature partition plates, and adjacent flue cavities are communicated via gaps between the high-temperature partition plates and an inner wall of the furnace body, thus forming a flue gas channel that zigzags several times; and the flue cavities and the modules arranged therein sequentially form a conversion unit, a steam generation unit, a medium temperature shift unit and a desulfurization unit.

The invention relates to a process for preparing ,-ethylenically unsaturated carboxylic acids by two-stage catalytic gas phase oxidation of alkenes, in which a gas stream (1) containing at least one alkene, in a first reactor (A) in the presence of oxygen, is subjected to a first catalytic oxidation reaction over a first catalyst (K1) in the form of a multimetal oxide of molybdenum to obtain a gas stream (2) containing at least one ,-ethylenically unsaturated aldehyde, the gas stream (2) containing the at least one ,-ethylenically unsaturated aldehyde is guided through a connecting conduit (V) into a second reactor (B) and the gas stream (2) containing the at least one ,-ethylenically unsaturated aldehyde, in the second reactor (B) in the presence of oxygen, is subjected to a second catalytic oxidation reaction over a second catalyst (K2) to obtain a gas stream (3) containing at least one ,-ethylenically unsaturated carboxylic acid. In the process according to the invention, the gas stream (2) containing the at least one ,-ethylenically unsaturated aldehyde is guided through an exchangeable structure (S) having high specific surface area which is disposed within the connecting conduit (V). The invention further relates to a corresponding plant.

In accordance with one or more embodiments, a tubular catalyst-containing reactor system is provided. The system includes a housing and a vaporizer unit in the housing comprising a helically wound tubular assembly for receiving and at least partially vaporizing a liquid chemical reactant stream. A reformer unit in the housing receives a vaporized chemical reactant stream from the vaporizer unit. The reformer unit comprises a helically wound tubular assembly connected to and positioned coaxially relative to the helically wound tubular assembly of the vaporizer unit. The helically wound tubular assembly of the reformer unit contains a catalyst for catalyzing formation of gas product stream from the vaporized chemical reactant stream. A burner unit heats the vaporizer unit and the reformer unit. The burner unit receives a fuel stream and an air stream and produces a flame generally inside the helically wound tubular assemblies of the vaporizer unit and the reformer unit.

To allow hydrogen to be supplied to a dehydrogenation reaction unit for dehydrogenating an organic hydride by using a highly simple structure so that the activity of the dehydrogenation catalyst of the dehydrogenation reaction unit is prevented from being rapidly reduced. The hydrogen production system (1) comprises a first dehydrogenation reaction unit (3) for producing hydrogen by a dehydrogenation reaction of an organic hydride in presence of a first catalyst, and a second dehydrogenation reaction unit (4) for receiving a product of the first dehydrogenation reaction unit, and producing hydrogen by a dehydrogenation reaction of the organic hydride remaining in the product in presence of a second catalyst, wherein an amount of the first catalyst used in the first dehydrogenation reaction unit is equal to or less than an amount of the second catalyst used in the second dehydrogenation reaction unit, and an amount of hydrogen produced in the first dehydrogenation reaction unit is less than an amount of hydrogen produced in the second dehydrogenation reaction unit.