An ebullated bed hydroprocessing system is upgraded and operated at modified conditions using a dual catalyst system to produce less fouling sediment. The less fouling sediment produced by the upgraded ebullated bed reactor reduces the rate of equipment fouling at any given sediment production rate and/or concentration compared to the sediment produced by the ebullated bed reactor prior to upgrading. In some cases, sediment production rate and/or concentration are maintained or increased, after upgrading the ebullated bed reactor, while equipment fouling is reduced. In other cases, sediment production rate and/or concentration are increased, after upgrading the ebullated bed reactor, without increasing equipment fouling. In some cases, sediment production rate and/or concentration are decreased by a given percentage, after upgrading the ebullated bed reactor, and the rate of equipment fouling is decreased by a substantially greater percentage.

An ebullated bed hydroprocessing system is upgraded and operated at modified conditions using a dual catalyst system to produce less fouling sediment. The less fouling sediment produced by the upgraded ebullated bed reactor reduces the rate of equipment fouling at any given sediment production rate and/or concentration compared to the sediment produced by the ebullated bed reactor prior to upgrading. In some cases, sediment production rate and/or concentration are maintained or increased, after upgrading the ebullated bed reactor, while equipment fouling is reduced. In other cases, sediment production rate and/or concentration are increased, after upgrading the ebullated bed reactor, without increasing equipment fouling. In some cases, sediment production rate and/or concentration are decreased by a given percentage, after upgrading the ebullated bed reactor, and the rate of equipment fouling is decreased by a substantially greater percentage.

A catalyst may include a support and from 5 to 20 wt.-% of a promoter, based on the total weight of the catalyst, wherein the support may include titanium dioxide, zirconium dioxide, and/or a mixture thereof, and the promoter may be an alkali metal oxide. Processes for preparing such catalysts may include impregnating a support of titanium dioxide and/or zirconium dioxide with an aqueous solution including a preferably soluble alkali compound and calcining. Alkyl mercaptans may be prepared in the presence of such catalysts or catalysts obtained by such processes.

Methods of synthesizing Bi.sub.2S.sub.3-CdS particles in the form of spheres as well as properties of these Bi.sub.2S.sub.3-CdS particles are described. Methods of photocatalytic degradation of organic pollutants employing these Bi.sub.2S.sub.3-CdS particles and methods of preventing or reducing microbial growth on a surface by applying these Bi.sub.2S.sub.3-CdS particles in the form of a solution or an antimicrobial product onto the surface are also specified.

Methods of synthesizing Bi.sub.2S.sub.3-CdS particles in the form of spheres as well as properties of these Bi.sub.2S.sub.3-CdS particles are described. Methods of photocatalytic degradation of organic pollutants employing these Bi.sub.2S.sub.3-CdS particles and methods of preventing or reducing microbial growth on a surface by applying these Bi.sub.2S.sub.3-CdS particles in the form of a solution or an antimicrobial product onto the surface are also specified.

An ebullated bed hydroprocessing system is upgraded and operated at modified conditions using a dual catalyst system to produce less fouling sediment. The less fouling sediment produced by the upgraded ebullated bed reactor reduces the rate of equipment fouling at any given sediment production rate and/or concentration compared to the sediment produced by the ebullated bed reactor prior to upgrading. In some cases, sediment production rate and/or concentration are maintained or increased, after upgrading the ebullated bed reactor, while equipment fouling is reduced. In other cases, sediment production rate and/or concentration are increased, after upgrading the ebullated bed reactor, without increasing equipment fouling. In some cases, sediment production rate and/or concentration are decreased by a given percentage, after upgrading the ebullated bed reactor, and the rate of equipment fouling is decreased by a substantially greater percentage.

An ebullated bed hydroprocessing system is upgraded and operated at modified conditions using a dual catalyst system to produce less fouling sediment. The less fouling sediment produced by the upgraded ebullated bed reactor reduces the rate of equipment fouling at any given sediment production rate and/or concentration compared to the sediment produced by the ebullated bed reactor prior to upgrading. In some cases, sediment production rate and/or concentration are maintained or increased, after upgrading the ebullated bed reactor, while equipment fouling is reduced. In other cases, sediment production rate and/or concentration are increased, after upgrading the ebullated bed reactor, without increasing equipment fouling. In some cases, sediment production rate and/or concentration are decreased by a given percentage, after upgrading the ebullated bed reactor, and the rate of equipment fouling is decreased by a substantially greater percentage.

It has been discovered that mixed-alcohol production can utilize the waste tail gas stream from the pressure-swing adsorption section of an industrial hydrogen plant. Some variations provide a process for producing mixed alcohols, comprising: obtaining a tail-gas stream from a methane-to-syngas unit (e.g., a steam methane reforming reactor); compressing the tail-gas stream; separating the tail-gas stream into at least a syngas stream, a CO.sub.2-rich stream, and a CH.sub.4-rich stream; introducing the syngas stream into a mixed-alcohol reactor operated at effective alcohol synthesis conditions in the presence of an alcohol-synthesis catalyst, thereby generated mixed alcohols; and purifying the mixed alcohols to generate a mixed-alcohol product. Other variations provide a process for producing clean syngas, comprising: obtaining a tail-gas stream from a methane-to-syngas unit; compressing the tail-gas stream; separating the tail-gas stream into at least a syngas stream, a CO.sub.2-rich stream, and a CH.sub.4-rich stream; and recovering a clean syngas product.

It has been discovered that mixed-alcohol production can utilize the waste tail gas stream from the pressure-swing adsorption section of an industrial hydrogen plant. Some variations provide a process for producing mixed alcohols, comprising: obtaining a tail-gas stream from a methane-to-syngas unit (e.g., a steam methane reforming reactor); compressing the tail-gas stream; separating the tail-gas stream into at least a syngas stream, a CO.sub.2-rich stream, and a CH.sub.4-rich stream; introducing the syngas stream into a mixed-alcohol reactor operated at effective alcohol synthesis conditions in the presence of an alcohol-synthesis catalyst, thereby generated mixed alcohols; and purifying the mixed alcohols to generate a mixed-alcohol product. Other variations provide a process for producing clean syngas, comprising: obtaining a tail-gas stream from a methane-to-syngas unit; compressing the tail-gas stream; separating the tail-gas stream into at least a syngas stream, a CO.sub.2-rich stream, and a CH.sub.4-rich stream; and recovering a clean syngas product.

Disclosed are a Z-type heterojunction composite material of a tungsten oxide nanorod/a titanium carbide quantum dot/an indium sulfide nanosheet, a preparation method therefor and an application thereof. The method includes: preparing a titanium carbide quantum dot by using freeze-thaw and ultrasound methods for multiple times, and then placing a tungsten trioxide nanorod prepared by a hydrothermal method into a titanium carbide quantum dot aqueous solution, stirring same, and then standing same to obtain a tungsten oxide nanorod loading a quantum dot; stirring and uniformly mixing an indium compound and a sulfur compound in an ethylene glycol solvent, and then adding the tungsten oxide nanorod loading the quantum dot, and performing a reflux reaction at constant temperature to obtain the composite material. The titanium carbide quantum dot of the present invention can provide good electron transport channels at different semiconductor interfaces.