171 results about "M-Xylene" patented technology

The invention provides a strain of Mycobacterium sp.16F for efficiently degrading polycyclic aromatic hydrocarbon and benzene organic matters, which has a preservation number of CGMCC No.6367. The mycobacterium 16F can efficiently, safely and rapidly degrade polycyclic aromatic hydrocarbons and benzene organic matters, can grow and degrade by using fluorene, naphthalene, anthracene, acenaphthene, phenanthrene, pyrene and benzopyrene as the sole carbon source and energy in aerobic condition, and can utilize benzene, m-xylene, toluene, salicylic acid, catechol and other multiple aromatic organic matters. The mycobacterium 16F is sensitive to streptomycin, rifampin, tetracycline, kanamycins and other antibiotics, has good degradation effects to mixed polycyclic aromatic hydrocarbons in aging soils and monocyclic benzene organic matters in water bodies, can be used for restoring and purifying the water-soil environment combinedly polluted by aromatic hydrocarbon organic matters, is important for promoting sustainable development, and has a wide application prospect.

The invention belongs to the technical field of tobacco packing box, and in particular relates to a method for detecting contents of 21 volatile organic compounds (VOC), including benzene, methyl benzene, p-xylene, m-xylene, o-xylene, styrene, methanol, ethanol, acetone, isopropyl alcohol, methyl acetate, normal propyl alcohol, ethyl acetate, butanone, acetic acid isopropyl ester, n-butyl alcohol, propylene glycol monomethyl ether, n-propyl acetate, propylene glycol monoethyl ether, 4-methyl-2-pentanone, butyl acetate, cyclohexanone in a tobacco packing box. The method for detecting 21 volatile organic compounds in the tobacco packing box disclosed by the invention comprises the following steps of: sample pretreatment: preparing a piece of hard box packing paper; cutting and reserving a main packing surface by an area of 22.0cm*5.5cm; rolling the printing surface of the sample inwards to obtain a barrel-shaped part; putting the barrel-shaped part in a headspace bottle; adding 1000mu l of glycerol triacetate; sealing, and implementing a headspace-gas chromatography detection. The method disclosed by the invention is high in sensitivity, high in recovery rate, and excellent in precision of detecting result.

The invention discloses a method for adsorbing and separating paraxylene and ethylbenzene from C8 aromatic components. The method comprises the following steps: performing liquid-phase adsorption and separation on C8 aromatic hydrocarbons, thereby obtaining extracted oil rich in paraxylene and raffinate oil rich in ethylbenzene, m-xylene and o-xylene; introducing the raffinate oil into a gas phase adsorption and separation column, adsorbing ethylbenzene from the raffinate oil under the conditions of 190-270 DEG C, 0.4-0.8MPa and gas phase, allowing the non-adsorbed components to flow out of the gas phase adsorption and separation column to serve as adsorption residues, and purging an adsorbent bed layer by using purge gas under the pressure not less than the adsorption pressure, wherein the purged intermediate components is used as gas phase adsorption feedstock; reducing the pressure to 0.1-0.3 MPa, introducing the purge gas to desorb the adsorbed ethylbenzene so as to obtain the aspirate, performing xylene isomerization on the adsorption residues, wherein the isomerization products are taken as raw materials of the above liquid phase adsorption and separation. According to the method, the high-purity paraxylene and ethylbenzene can be separated from the C8 aromatic components, the adsorption residues hardly contain ethylbenzene, and isomerization can be performed under the non-hydrogen and low-temperature conditions.

A method for production of p-xylene comprises the steps: a raw material containing a C8 aromatic hydrocarbon mixture goes into a rectifying tower, the C8 aromatic hydrocarbon mixture is separated from the lateral line of the rectifying tower, light hydrocarbons having the carbon number of 7 or less are obtained at the tower top, and heavy hydrocarbons having the carbon number of 9 or more are obtained at the tower bottom; the C8 aromatic hydrocarbon mixture goes to an adsorption separation unit, and is subjected to contact separation with an adsorbent to obtain a p-xylene, or m-xylene or ethylbenzene material flow; the remaining C8 aromatic hydrocarbons go to an isomerization unit, and under the action of an isomerization catalyst, isomerized C8 aromatic hydrocarbons are generated and are used as feeding materials to circularly return to the rectifying tower. With adopting of the method for production of p-xylene, equipment investment and occupied land area can be reduced, energy consumption also can be reduced, business operation costs are reduced, and economic benefits and social benefits are improved.

The invention discloses a method for measuring the content of benzene and benzene series in hot melt glue. The method comprises the following steps of: selecting benzene, methylbenzene, ethylbenzene, o-xylene, p-xylene or m-xylene as standard substances of the benzene and the benzene series, and gradually diluting to form a standard working solution by taking glyceryl triacetate as a matrix correction fluid; taking a hot melt glue sample and adding the hot melt glue sample into the matrix correction fluid, and detecting and analyzing the standard working solution and the sample by using a headspace gas chromatography mass spectrometry; and finally, drawing a standard curve and calculating a result. In the invention, a complex pretreatment process of the sample, and influences and interference caused by volatile components in the sample are eliminated. According to the method, the recovery rate ranges from 95% to 101%, the average relative standard deviation ranges from 3.04% to 4.14%, and the repeatability is good.

Base compounds including 1,3-oxazinan-6-one derivatives of N-alkyl or N-alkenyl or N-cycloalkyl or N-aryl propionic acids and paraformaldehyde, and their application as corrosion inhibitors with multifunctional properties serving as inhibitory/dispersant of asphaltene in production processes, transportation, refining and storage of crude oil and derivatives. The corrosion inhibitor with inhibitory/dispersant of asphaltenes properties comprises an active substance base of 1,3-oxaninan-6-ones and hydrocarbon solvents such as benzene, toluene, mixed xylenes, o-xylene, m-xylene and p -xylene, diesel, kerosene, jet fuel, alcohols, aliphatic branched and unbranched alcohols containing from 3 to 10 carbon atoms, such as isopropanol, butanol and pentanol, and mixtures of hydrocarbon solvents with aliphatic branched or unbranched liquid fuels. In addition, a process for obtaining 1,3-oxazinan-6-ones derivatives of N-alkyl or N-alkenyl or N-cycloalkyl or N-aryl propionic acids and paraformaldehyde is described.

The present invention discloses a method and an apparatus for preparing p-xylene from methanol. The method is mainly characterized in that first methanol feedstock produces a methanol aromatization reaction in a methanol aromatization reactor (2), and liquefied gas feedstock, a methanol aromatization gas product and non-aromatic raffinate oil separated from an aromatic hydrocarbon extraction apparatus produce a low-carbon hydrocarbon aromatization reaction in a low-carbon hydrocarbon aromatization reactor (6); second methanol feedstock as well as benzene and methylbenzene separated from an aromatic hydrocarbon rectifying tower (12) produce an alkylation reaction in an alkylation reactor (19), o-xylene, m-xylene and ethylbenzene separated from the aromatic hydrocarbon rectifying tower produce an isomerization reaction in an isomerization reactor (20), and fresh raw material benzene as well as C9 and aromatic hydrocarbons separated from the aromatic hydrocarbon rectifying tower produce a transalkylation reaction in a transalkylation reactor (21). P-xylene (13) separated from the aromatic hydrocarbon rectifying tower serves as a product. The present invention discloses the related apparatus. The method and the apparatus can produce p-xylene as much as possible.

The present invention relates to a process for converting a tertiary OH group of an organic compound into a tertiary Cl group of the organic compound by using a solvent selected from the group comprising toluene, o-xylene, m-xylene, p-xylene and mixtures thereof, and thionyl chloride as the chlorinating agent.

The invention discloses a method for preparing m-xylene diamine by continuous hydrogenation, which adopts m-phthalonitrile as the raw material and carries out multi-phase hydrogenation. The method is characterized in that the mixture of m-phthalonitrile and a solvent and hydrogen contact a granular solid catalyst in a slurry bed reactor to carry out continuous hydrogenation reaction; the reactive solution and the solid catalyst are continuously fed into a separator for liquid-solid separation; the separated reactive solution is separated to obtain the final product; and the separated catalyst can be recycled after regeneration and returned to the slurry bed reactor. The method can achieve continuous hydrogenation of m-phthalonitrile, and has the advantages of good conversion rate and selectivity, convenient operation, and high equipment utilization rate and hydrogenation efficiency, and the catalyst is not easy to abrade and crush and can be continuously regenerated and recycled.

The invention discloses a preparation method of tetraglycidyl m-xylene diamine epoxy resin, which comprises the following steps: (1) adding epichlorohydrin and deionized water into a reaction device, dropwisely adding m-xylene diamine for a ring-opening reaction; (2) adding an aqueous alkali into the material obtained in step (1) for a ring-closure reaction, wherein the molar ratio of the alkali in the aqueous alkali to the m-xylene diamine is 4:1; (3) after the reaction, recovering epichlorohydrin, adding an inert solvent and deionized water, performing extraction layering, removing the water layer; (4) refining the organic layer with the aqueous alkali, wherein the molar ratio of the alkali in the aqueous alkali to the m-xylene diamine is 1:1-2.5:1; (5) washing the refined material with water, removing the solvent to obtain the tetraglycidyl m-xylene diamine epoxy resin. The method of the invention is simple in process, easy to implement, and low in cost, and the prepared tetraglycidyl m-xylene diamine epoxy resin has low viscosity, low organic chloride content, and a high epoxy value.

Polyester films which comprise not only thermoplastic polyester, e.g. polyethylene terephthalate, but also from 5 to 45% by weight of poly(m-xyleneadipamide) and optionally from 0.02 to 1% by weight of fillers, and which have, on at least one surface, an adhesion-promoting layer comprised of a hydrolyzed amino-functional silane. The films of the invention are produced by a sequential stretching process, and feature improved mechanical properties, such as a modulus of elasticity greater than 3500 N/mm² in both orientation directions, high gloss, low haze, and very good barrier properties with respect to oxygen transmission. Films of the invention are therefore a suitable packaging material for foods and other consumable items, and as starting material for production of laminates via extrusion coating.

The present invention is an improved process and apparatus for producing para-xylene, particularly with respect to a process that involves the methylation of toluene and/or benzene to selectively produce para-xylene, wherein streams having differing amounts of ethylbenzene are separately treated in the recovery of para-xylene. A first hydrocarbon feed comprising xylenes and ethylbenzene is provided to a first para-xylene adsorption section, and a second hydrocarbon feed comprising xylenes and less EB than the first hydrocarbon feed is provided to a second para-xylene adsorption section. Segregating the feeds with differing ethylbenzene contents increases the overall efficiency of the adsorption of para-xylene by the adsorption units. Efficiency and energy savings may be further improved by subjecting the lower-content ethylbenzene stream to liquid phase isomerization.

The present invention discloses a method for producing aromatic carboxylic acid by m-xylene and ethylbenzene multi-step co-oxidation. The method includes the following steps of: (1) rectifying p-xylene raffinate containing p-xylene, m-xylene, o-xylene and ethylbenzene to remove o-xylene and obtain mixture A containing o-xylene and ethylbenzene; (2) subjecting the mixture A to multi-step oxidation to produce a mixture B containing isophthalic acid and benzoic acid, and separating the mixture B by crystallization to obtain a crude product of isophthalic acid and crystallizing mother solution to obtain benzoic acid by evaporation and concentration; (3) washing the crude product of isophthalic acid using acetic acid and distilled water respectively and drying to obtain refined isophthalic acid. The steps of the production process and each unit operation are simple and feasible. In the meantime, the method has no organic wastewater discharged, and is a new economic and environmental protection process.

The invention discloses a preparation method of an m-xylene adsorbent. The method comprises the following steps: (1) uniformly mixing Y zeolite and kaolin to obtain initial molding powder, wherein thekaolin content is 1-10% by mass; putting the initial molding powder into rolling forming equipment; spraying water while rolling until all the powder is gathered into pellets so as to obtain initially-formed pellets; and (2) spraying water on the initially-formed pellets prepared in the step (1) while adding later-stage molding powder for later-stage ball rolling molding, wherein the later-stagemolding powder consists of 11-100 mass percent of kaolin and 0-89 mass percent of Y zeolite; drying the molded pellets, roasting at the temperature of 500-700 DEG C, treating with an alkaline solutionfor in-situ crystallization, and drying. The adsorbent prepared by the method has high compressive strength and burning bulk density, good adsorption selectivity and good mass transfer performance.

The invention provides a preparation method of 3,5-dimethylphenol. The method comprises the following steps: xylene (one or a mixture of o-xylene, m-xylene and p-xylene) and alkyl halide or anhydride are subjected to a reaction under the effect of a catalyst, and an intermediate 3,5-dimethylcarbonyl compound is produced under a certain condition; the intermediate is oxidized under the effect of a peroxide, such that 3,5-dimethylphenol ester is produced; and 3,5-dimethylphenol ester is hydrolyzed, such that 3,5-dimethylphenol is obtained. According to the method, xylene is adopted as an initial raw material, and is processed through the tree steps of carbonylation, oxidation and hydrolysis, such that a target product can be prepared with high yield. Therefore, an assumption of synthesizing 3,5-dimethylphenol with high yield under a mild condition is made possible. Compared to prior arts, the method provided by the invention has the advantages of low raw material cost, less three-waste, and mild reaction condition. The method is especially suitable for large-scale productions.

Polyester films which comprise not only thermoplastic polyester, e.g. polyethylene terephthalate, but also from 5 to 45% by weight of poly(m-xyleneadipamide) and optionally from 0.02 to 1% by weight of fillers. The polyester films have been ceramic-coated or metallized on at least one surface, and are produced by a sequential stretching process. The films of the invention feature improved mechanical properties, such as a modulus of elasticity greater than 3500 N/mm² in both orientation directions, high gloss, low haze, and very good barrier properties with respect to oxygen transmission. The inventive films are therefore a suitable packaging material for foods and other consumable items.

The present invention provides a process for producing an RSH-depleted gas stream from a feed gas stream comprising natural gas, RSH and an aromatic compound selected from the group consisting of benzene, toluene, ortho-xylene, meta-xylene and para-xylene, said process comprising the steps of : (a) contacting said feed gas stream with an absorption liquid comprising a physical solvent in an aromatics removal zone to obtain aromatics comprising benzene, toluene, ortho-xylene, meta-xylene and para-xylene a loaded absorption liquid of compounds and a gas stream depleted of these aromatic compounds; (b) contacting the gas stream obtained in step (a) with a solid adsorbent in a mercaptan removal zone to obtain an RSH-loaded solid adsorbent agent and RSH-depleted gas stream.

The invention relates to a molecular sieve with shape-selective performance and a direct synthesis method thereof. The content of aluminum on the outer surface of the molecular sieve is lower than that of bulk phase aluminum; in the room-temperature static absorption test of the molecular sieve, pX/mX is larger than 8, wherein pX is p-xylene, and mX is m-xylene. The molecular sieve can be applied to the shape-selective catalytic reaction of toluene and/or benzene and alkylating reagents.