16 results about "Hydrodealkylation" patented technology

The present application relates to the field of hydrodealkylation catalyst, discloses a kind of hydrodealkylation catalyst and preparation method, the preparation method of xylene, the catalyst includes carrier and first active component and second active component supported on the carrier;Wherein, the first active component is selected from at least one of group IA metal, group IIA metal and phosphorus;The second active component is selected from group VIII metal and / or group IVB metal;The carrier is molecular sieve with multistage pore structure, and the volume ratio of micropore and mesopore in the carrier is 1.5-8.5.The hydrodealkylation catalyst provided by the present application has higher hydrodealkylation activity, low aromatic ring loss rate, and can improve the selectivity of xylene in the hydrodealkylation reaction of ethylbenzene.

The invention relates to the technical field of aromatic hydrocarbon conversion, and discloses a combined method and system for aromatic hydrocarbon conversion, and the method comprises the following steps: respectively feeding C7, C9 and above aromatic hydrocarbons from an upstream device into a catalytic transalkylation unit and a catalytic hydrodealkylation unit for separate treatment; efficient production of benzene, adjustable mixed xylene yield and production of C2-C5 light hydrocarbons with higher value are realized by adjusting the amount of materials entering the two combined systems. The system comprises a catalytic transalkylation unit, a catalytic hydrodealkylation unit and a product separation system. According to the method disclosed by the invention, the high product quality of the benzene product and the xylene product is ensured on the premise of fully producing the benzene product.

A process for producing aromatic compounds from pyrolysis oil, comprising: refining the pyrolysis oil to pyrolysis gasoline in a multi-stage reactor comprising a slurry phase reactor and a fixed-bed reactor, wherein the slurry phase reactor comprises a mixed metal oxide catalyst and the fixed-bed reactor comprises a mesoporous zeolite-supported metal catalyst; aromatizing the pyrolysis gasoline in an aromatization unit; hydrodealkylation and transalkylation of a product from the aromatization unit in a hydrodealkylation-transalkylation unit, thereby generating an aromatic stream; and processing the aromatic stream in an aromatic recovery complex to produce the aromatic compounds comprising benzene, toluene, and xylenes (BTX).

This invention relates to the field of catalyst materials technology, and discloses a hydrodealkylation catalyst, its preparation method, and its application in the hydrodealkylation of toluene to benzene. The hydrodealkylation catalyst comprises an alumina support and a first active component and a second active component supported on the alumina support; wherein the alumina support comprises macroporous alumina and microporous alumina; the first active component is selected from at least one of alkali metals, alkaline earth metals, and phosphorus; the second active component is selected from Group VIB metals and / or Group VIII metals. The hydrodealkylation catalyst provided by this invention exhibits high toluene conversion and high benzene selectivity in the toluene hydrodealkylation reaction, with a benzene mass reaching up to 99.9%, and low aromatic ring loss rate in toluene as a raw material, with an aromatic hydrocarbon yield of over 99.25%, reaching a maximum of 99.89%; furthermore, the catalyst demonstrates good stability.

The invention discloses a method for selective hydrodealkylation of C8 < + > aromatic hydrocarbons. The method comprises the following steps: C8 < + > aromatic hydrocarbon is in contact with a catalyst for a selective hydrodealkylation reaction; wherein the catalyst comprises a catalyst A and a catalyst B, and the catalyst A is arranged at the upstream of the catalyst B; the catalyst A is a composite modified aluminum oxide catalyst; the catalyst B comprises group VIII metal and a molecular sieve with the surface modified by SiO2. According to the method provided by the invention, the C2 + side chain substituent in the C8 + aromatic hydrocarbon is subjected to one-step selective hydrogenation removal, and the method has the characteristics of high C2 + side chain substituent removal rate, low aromatic ring loss rate and low methyl loss rate.

This invention relates to the field of mesitylene production technology, specifically a method for producing mesitylene from C9 aromatics. The method involves reacting C9 aromatics with hydrogen via a hydrodealkylation reaction. The dealkylation products are then separated; the gaseous product is returned to a reverse dealkylation reactor, while the liquid product is separated. The bottom product from the BTX tower is then fed into a mesitylene tower for further separation. The bottom product from the mesitylene tower is then fed into a mixing tower for further separation. The top product from the mixing tower undergoes an isomerization reaction, and the isomerization products are then separated to obtain mesitylene. This invention features a simple process flow, using C9 aromatics as raw material. The combined production process of dealkylation and tricresyl isomerization minimizes side reactions, reduces hydrogen consumption, and allows for further utilization of byproducts. The resulting product contains less than 0.5% methyl ethyl phenyl (MEP), eliminating MEP interference with tricresyl separation, improving the yield and purity of mesitylene, reducing production costs, and enhancing the utilization value of C9 aromatics resources.

The present application relates to the field of hydrodealkylation, discloses a kind of hydrodealkylation catalyst and preparation method and hydrodealkylation method.The hydrodealkylation catalyst includes silicon-containing carrier and first active component and second active component supported on the silicon-containing carrier;Wherein, the first active component is chromium element;The second active component is selected from at least one of group VIB metal, group VIIB metal and group VIII metal;The first active component and second active component metal are different;Wherein, the ratio of the weak acid amount and the strong acid amount of the hydrodealkylation catalyst is 1:0.1-0.5.The hydrodealkylation catalyst proposed in the present application is applied to hydrodealkylation method, using alkylbenzene as raw material, converts alkylbenzene into benzene, the conversion rate of alkylbenzene is high, the benzene selectivity is high, and the aromatic ring loss rate of alkylbenzene as raw material is low, and the aromatic hydrocarbon yield can reach more than 99.92%, and the stability of catalyst is good.

The application provides application of a supported alkali metal hydride as an aromatic hydrodealkylation reaction catalyst. The catalyst is low in cost, reusable, capable of catalyzing the cleavage of a carbon-carbon bond under mild conditions, realizing the hydrodealkylation reaction of an aromatic hydrocarbon, for example, is capable of realizing a conversion rate higher than 45% of the hydrodealkylation reaction of C8-C10 aromatic hydrocarbons at 200 DEG C-250 DEG C, greatly reducing the energy consumption of the reaction, and having high activity and high selectivity.

The invention discloses a production method of p-xylene, which comprises the following steps: (I) C8 < + > aromatic hydrocarbon enters a hydrodealkylation unit, and a dealkylation liquid phase product enters a BTX fractionation unit; (II) feeding methylbenzene and trimethylbenzene / tetramethylbenzene separated by the BTX fractionation unit into a liquid-phase transalkylation unit, and feeding a liquid-phase transalkylation product into the BTX fractionation unit; (III) the C8 aromatic hydrocarbon separated by the BTX fractionation unit enters a PX separation unit, and a p-xylene product and PX-poor C8 aromatic hydrocarbon are obtained through separation; and (IV) the PX-poor C8 aromatic hydrocarbon enters a liquid phase isomerization unit, and a liquid phase isomerization product enters a BTX fractionation unit. The method provided by the invention adopts a process combining a C8 < + > aromatic hydrocarbon gas-phase high-selectivity hydrodealkylation technology, a liquid-phase transalkylation reaction and a liquid-phase isomerization reaction, and has the characteristics of low loss and energy consumption and less investment.

The application relates to a method for preparing benzene by toluene hydrodealkylation with a chromium oxide-aluminum oxide catalyst, and relates to the field of chemical production technology, which comprises the following steps: S1, preheating p-toluene and hydrogen; S2, mixing the preheated toluene and hydrogen in step S1 through a mixer; S3, conveying the mixed gas in step S2 to a heating furnace; S4, adding an additive to the mixed gas output by the heating furnace, and conveying the mixed gas with the additive to a reactor; S5, heat-exchanging the reactant through the toluene and hydrogen in step S1; S6, conveying the heat-exchanged reactant in step S5 to a high-pressure separator; S7, removing heavy components generated by a side reaction in the reactor in step S6 through a heavy component removal tower, and conveying the remaining benzene and toluene to a benzene tower; and S8, conveying methane separated by the high-pressure separator to a hydrogen production system.

The present disclosure relates to a process for hydrodealkylation of a hydrocarbon stream rich in aromatic compounds to produce benzene, toluene, and mixed xylenes (BTX) with high selectivity to high value xylenes. The process uses a catalyst containing a framework-substituted zirconium and / or titanium and / or hafnium modified ultra-stable Y (USY) type zeolite.

The invention discloses a method and system for prolonging the service life of a fixed bed reactor and application, the method is carried out in one or more fixed bed reactors, the fixed bed reactors are connected in series and / or in parallel, the feeding and discharging position of at least one fixed bed reactor is switched in the reaction process, and the fixed bed reactors are connected in series and / or in parallel. And feeding from the original discharging position and discharging from the original feeding position. The method and the system can prolong the operation period of toluene disproportionation and alkylation transfer, heavy aromatics lightening or hydrodealkylation and other reactions, the reaction temperature is more stable under the condition of controlling the same total conversion rate, and the actual service life of the catalyst is prolonged.

The present application relates to the field of paraxylene production, and discloses a method for producing paraxylene and co-producing dimethylnaphthalene. The method comprises: separating C5 + raw materials to obtain C6, C7 and C8 + components; selectively performing hydrodealkylation reaction on the C8 + component to obtain C8 + product; performing aromatic hydrocarbon separation on the C8 + product to obtain C8 component, C9-C 10 component and C 10 + component; performing disproportionation and transalkylation reaction on at least part of the C9-C 10 component and the C7 component to obtain a product rich in dimethylbenzene; performing demethylation reaction on the C 10 + component to obtain C 10 -C 11 component and C 12 + component; performing transalkylation reaction on the C 10 -C 11 component and the remaining part of the C9-C 10 component to obtain a product rich in 2,6-dimethylnaphthalene. The method can realize high-value utilization of by-product naphthalene series and co-production of 2,6-dimethylnaphthalene.

The invention discloses a hydrodealkylation catalyst and a preparation method and application thereof, and the hydrodealkylation catalyst comprises the following components based on the total weight of the hydrodealkylation catalyst: 30.0-70.0 wt% of a metal modified molecular sieve, 30.0-70.0 wt% of alumina, 0.05-10.0 wt% of a first active component based on metal elements, and 1.0-10.0 wt% of a second active component based on metal elements, the first active component is selected from two of VIII group metals, and the second active component is selected from one of VIB group metals. The hydrodealkylation catalyst provided by the invention is applied to the process of producing high-purity benzene by hydrodealkylation of aromatic hydrocarbon in a fixed bed, and has the characteristics of high conversion rate of heavy aromatic hydrocarbon raw materials, high yield of product benzene, high purity and low loss rate of aromatic hydrocarbon.

The invention relates to the technical field of mesitylene production, in particular to a method for producing mesitylene from C9 heavy aromatics, which comprises the following steps of: carrying out hydrodealkylation reaction on C9 heavy aromatics and hydrogen, separating an obtained dealkylation reaction product, returning a gas-phase product to a reverse dealkylation reactor, separating a liquid-phase product, feeding a BTX tower bottom product into a mesitylene tower for separation, and separating the mesitylene from the BTX tower bottom product. A mesitylene tower bottom product enters a mixing tower to be separated, and after a mixing tower top product is subjected to an isomerization reaction, an isomerization reaction product is separated to obtain mesitylene. The process flow is simple, the C9 heavy aromatics are adopted as the raw material, and the combined production process of dealkylation reaction and trimethylbenzene isomerization reaction is adopted, so that side reactions are few, hydrogen consumption is low, by-products can be further utilized, the content of methyl-ethylbenzene in the obtained product is lower than 0.5%, interference of methyl-ethylbenzene on trimethylbenzene separation is eliminated, and the yield of trimethylbenzene is increased. The yield and the purity of mesitylene are improved, the production cost is reduced, and the utilization value of C9 heavy aromatic hydrocarbon resources is improved.