A method for producing light aromatics, includes the steps of: i) contacting a feedstock comprising heavy aromatic(s) with a catalyst in a fluidized reactor for aromatics lightening reaction in the presence of hydrogen to obtain a product rich in C6-C8 light aromatic(s) and a spent catalyst, wherein the heavy aromatic is one or more selected from C9+ aromatics; ii) separating the resulted product rich in C6-C8 light aromatic(s) to obtain hydrogen, a non-aromatic component, C6-C8 light aromatic(s) and a C9+ aromatic component; and iii) recycling at least a part of the C9+ aromatic component to the fluidized reactor. The method has strong adaptability to feedstocks and high flexibility in operation and allows a long-period stable operation. The method can produce high-value light aromatics from heavy aromatics that are difficult to be treated and utilized.

A catalyst that includes heterogeneous metal carbide nanomaterials and a novel preparation method to synthesize the metal carbide nanomaterials under relatively mild conditions to form an encapsulated transition metal and/or transition metal carbide nanoclusters in a support and/or binder. The catalyst may include confined platinum carbide nanoclusters. The preparation may include the treatment of encapsulated platinum nanoclusters with ethane at elevated temperatures. The catalysts may be used for catalytic hydrocarbon conversions, which include but are not limited to, ethane aromatization, and for selective hydrogenation, with negligible green oil production.

A catalyst that includes heterogeneous metal carbide nanomaterials and a novel preparation method to synthesize the metal carbide nanomaterials under relatively mild conditions to form an encapsulated transition metal and/or transition metal carbide nanoclusters in a support and/or binder. The catalyst may include confined platinum carbide nanoclusters. The preparation may include the treatment of encapsulated platinum nanoclusters with ethane at elevated temperatures. The catalysts may be used for catalytic hydrocarbon conversions, which include but are not limited to, ethane aromatization, and for selective hydrogenation, with negligible green oil production.

The modified graphene includes a structure represented by the following formula (I), wherein the modified graphene has a ratio (g/d) of an intensity “g” of a G band to an intensity “d” of a D band of 1.0 or more in a Raman spectroscopy spectrum thereof:
Gr1-Ar1-X1-(Y1).sub.n1  (I)
in the formula (I), Gr1 represents a single-layer graphene or a multilayer graphene, Ar1 represents an arylene group having 6 to 18 carbon atoms, X1 represents a single bond, a linear, branched, or cyclic alkylene group having 1 to 20 carbon atoms, or a group obtained by substituting at least one carbon atom in a linear, branched, or cyclic alkylene group having 1 to 20 carbon atoms with at least one structure selected from the group consisting of —O—, —NH—, ##STR00001##
—CO—, —COO—, —CONH—, and an arylene group.

The modified graphene includes a structure represented by the following formula (I), wherein the modified graphene has a ratio (g/d) of an intensity “g” of a G band to an intensity “d” of a D band of 1.0 or more in a Raman spectroscopy spectrum thereof:
Gr1-Ar1-X1-(Y1).sub.n1  (I)
in the formula (I), Gr1 represents a single-layer graphene or a multilayer graphene, Ar1 represents an arylene group having 6 to 18 carbon atoms, X1 represents a single bond, a linear, branched, or cyclic alkylene group having 1 to 20 carbon atoms, or a group obtained by substituting at least one carbon atom in a linear, branched, or cyclic alkylene group having 1 to 20 carbon atoms with at least one structure selected from the group consisting of —O—, —NH—, ##STR00001##
—CO—, —COO—, —CONH—, and an arylene group.

Methods and phosphorus-containing solid catalysts for catalyzing dehydration of cyclic ethers (e.g., furans, such as 2,5-dimethylfuran) and alcohols (e.g., ethanol and isopropanol). The alcohols and cyclic ethers may be derived from biomass. One example includes a tandem Diels-Alder cycloaddition and dehydration of biomass-derived 2,5-dimethyl-furan and ethylene to renewable p-xylene. The phosphorus-containing solid catalysts are also active and selective for dehydration of alcohols to alkenes.

Methods and phosphorus-containing solid catalysts for catalyzing dehydration of cyclic ethers (e.g., furans, such as 2,5-dimethylfuran) and alcohols (e.g., ethanol and isopropanol). The alcohols and cyclic ethers may be derived from biomass. One example includes a tandem Diels-Alder cycloaddition and dehydration of biomass-derived 2,5-dimethyl-furan and ethylene to renewable p-xylene. The phosphorus-containing solid catalysts are also active and selective for dehydration of alcohols to alkenes.

Disclosed herein are embodiments of a method and system for converting ethanol to para-xylene. The method also provides a pathway to produce terephthalic acid from biomass-based feedstocks. In some embodiments, the disclosed method produces p-xylene with high selectivity over other aromatics typically produced in the conversion of ethanol to xylenes, such as m-xylene, ethyl benzene, benzene, toluene, and the like. And, in some embodiments, the method facilitates the ability to use ortho/para mixtures of methylbenzyaldehyde for preparing ortho/para xylene product mixtures that are amendable to fractionation to separate the para- and ortho-xylene products thereby providing a pure feedstock of para-xylene that can be used to form terephthalic anhydride and a pure feedstock of ortho-xylene that can be used for other purposes, such as phthalic anhydride.

Disclosed herein are embodiments of a method and system for converting ethanol to para-xylene. The method also provides a pathway to produce terephthalic acid from biomass-based feedstocks. In some embodiments, the disclosed method produces p-xylene with high selectivity over other aromatics typically produced in the conversion of ethanol to xylenes, such as m-xylene, ethyl benzene, benzene, toluene, and the like. And, in some embodiments, the method facilitates the ability to use ortho/para mixtures of methylbenzyaldehyde for preparing ortho/para xylene product mixtures that are amendable to fractionation to separate the para- and ortho-xylene products thereby providing a pure feedstock of para-xylene that can be used to form terephthalic anhydride and a pure feedstock of ortho-xylene that can be used for other purposes, such as phthalic anhydride.

A method for recovering paraxylene from a mixture of aromatic hydrocarbons. The process uses a pressure swing adsorption zone followed by a paraxylene recovery zone. The invention provides for lower throughput through the paraxylene recovery zone, resulting in lower capital costs and operating costs.