Zeolite catalyst, method of preparation thereof, and non-oxidative methane conversion process
FIELD: petrochemical processes and catalysts.
SUBSTANCE: invention provides high-silica zeolite catalyst comprising molybdenum and a second modifying element, namely nickel, content of the former in catalyst being no higher than 4.0 wt % and that of the latter from 0.1 to 0.5 wt %. Preparation of the catalyst involves modifying zeolite with molybdenum and second promoting element, the two being introduced into zeolite in the form of nano-size metal powders in above-indicated amounts.
EFFECT: enhanced efficiency of non-oxidative methane conversion process due to increased activity and stability of catalyst.
3 cl, 1 tbl, 7 ex
The invention relates to the petrochemical and chemical industries, in particular to a method for producing catalysts for the conversion of methane to aromatic hydrocarbons in a non-oxidizing conditions.
It is known that to improve time stable high action of zeolites of type ZSM-5 containing molybdenum, during non-oxidative methane conversion using additives such promoters as Fe, Cr, Ga [Dong Qun, Ichkawa M. Catalytic features of systems of Mo/HZSM-5 promoted additives of the second metal in the aromatization of methane // Fenzi cuihua=J.Mol.Catal. (China) - 2001. - Vol.15. No. 1.-33-36] and Co [Tian Bing-lun Lui Hong-mei, Shu Yu-ying, Wang Lin-sheng, Xu Yi-de Dehydroaromatization methane in the absence of oxygen in the presence of the modified cobalt catalysts of Mo/HZSM-5 // Fenzi cuihua=J.Mol.Catal. (China) - 2000. - vol.14 No. 3-200-204].
Closest to the proposed catalyst is a catalyst containing 4.0 wt.% molybdenum [Jun-Zhong Zhang, Mervyn A. Long, Russell F. Howe Molybdenum ZSM-5 zeolite catalysts for the conversion of methane to benzene // Catalysis Today 44(1998)293-300].
Closest to the proposed method is a method for Mo-Cu/HZSM-5 catalyst by introducing Cu in zeolite H-ZSM-5 by an ion exchange method from an aqueous solution of copper acetate, drying, calcination and subsequent addition of a mechanical mixture of the required number of Moo3. Prepared Mo-Cu/HZSM-5 catalyst thoroughly ismelda the camping and hot air at 500° C for 4 hours [S. Li, S. Zhang, Q. Kan, D. Wang, T. Wu, L. The function of Cu(II) ions in the Mo/Cu-HZSM-5 catalyst for methane conversion under non-oxidative condition // Applied Catalysis A: General 187(1999) 199-206].
The disadvantage of this method is the high time for preparation of the catalyst, due to the multi-stage process, as well as relatively low catalytic activity during non-oxidative conversion of methane at a temperature of 750°and a space velocity of 800 h-1.
Closest to the proposed method is a method of non-oxidative methane conversion in the presence of zeolite catalyst modified Mo [Jun-Zhong Zhang, Mervyn A. Long, Russell F. Howe Molybdenum ZSM-5 zeolite catalysts for the conversion of methane to benzene // Catalysis Today 44(1998) 293-300].
Object of the present invention to provide a catalyst for raising the degree of conversion of methane and yield of aromatic hydrocarbons, and increasing the period of stable action of Mo/ZSM-5 catalyst by adding Ni as a second promoting element.
The technical result is achieved by the fact that Ni-Mo/HZSM-5 catalysts obtained by dry mechanical mixing of zeolite HZSM-5 with a molar ratio of SiO2/Al2O3=40 (M=40) and nanosized powders (APCS) Mo and Ni obtained by electrical explosion of wire metals in an argon atmosphere, followed by annealing the p is vigotovlennya mixtures at a temperature of T=500° C for 4 hours. The result of Ni-Mo/HZSM-5 catalysts containing not more than 4.0 wt.% PPR Mo and not less than 0.1 wt.% APC Ni. Catalytic activity and stability prepared contacts higher than that of catalysts prepared by modification of zeolite HZSM-5 copper by the method of ion exchange from aqueous solution of its salts with subsequent mixing with the Moo3and catalyst obtained by mechanical mixing of zeolite HZSM-5 with nanopowder Mo without the addition of APC Ni, under the same process conditions.
Examples of specific performance.
Example 1. To 4.0 g decationizing zeolite H-ZSM-5 (M=40) added 0.16 g PPR Mo (4.0 wt%) and 0.004 g APCS Ni (0.1 wt.%), obtained by the method of electrical explosion of wires of metal in argon. The resulting mixture was stirred in a vibratory mill for 0.5 h and calcined at 500°C for 4 hours and Then the catalyst was pressed into tablets, cut up and taken away for research fraction of 0.5-1.0 mm
Catalytic testing of the samples is carried out in flow-through installation at the reaction temperature of 750°C, the volumetric flow rates of methane 800-1000 h-1and atmospheric pressure. The catalyst in the amount of 1 ml was placed in a quartz tubular reactor with a diameter of 12 mm Before the beginning of the reaction the catalyst is heated in a current of 750°C and maintained at this temperature for 20 min, then in eactor serves methane, the degree of purity is 99.9%. The reaction products and not converted methane come in castigados tap for sampling for analysis.
To prevent condensation or solid adsorption forming higher hydrocarbons tube at the exit of the reactor and castigados crane are at temperatures above 200°C. Analysis of the products of the methane conversion is performed after 60 min of operation of the catalyst by gas chromatography. Conversion of methane flow rate 800 h-1after 60 min of operation the catalyst is 14.2%. Study of the effect of reaction time on the activity of the catalyst shows that conversion remains almost constant (13-14%) for 300 min of operation catalyst, then there is a gradual reduction, and reaction time 480 min, it decreased to 10.9%.
Example 2. In the same way as in example 1, but the content APC Ni is 0.25% by weight of the zeolite. The conversion of methane at 800 h-113.8% after 60 min of operation of the catalyst and reduced to 10.0% for a reaction time of 480 minutes
Example 3. In the same way as in example 1, but the content APC Ni is 0.5% by weight of the zeolite. The conversion of methane at 800 h-112.5% after 60 min of operation of the catalyst and decreases to 7.8% for a reaction time of 480 minutes
Example 4. In the same way as in example 1, but the content APC Ni is 1.0% by weight of the zeolite. The conversion of methane is at 800 h -1is 11.1% after 60 min of operation of the catalyst and reduced to 3.5% for a reaction time of 480 minutes
Example 5. In the same way as in example 1, but Mo/HZSM-5 catalyst does not contain Ni. The conversion of methane 13.8% after 60 min of operation of the catalyst and reduced to 8.4% for a reaction time of 480 minutes
Example 6. In the same way as in example 1, but the volumetric flow rate of methane is equal to 1000 h-1while methane conversion after 60 min of operation the catalyst is 13.6% and decreased to 8.4% for a reaction time of 480 minutes
Example 7. In the same way as in example 6, but Mo/HZSM-5 catalyst does not contain Ni. The conversion of methane is 12.1% after 60 min of operation of the catalyst and decreases to 5.4% for a reaction time of 480 minutes
The table shows the comparative characteristics of catalytic activity and stability samples of Ni-Mo/HZSM-5 and Mo/ZSM-5 obtained by modification of zeolite PPR Mo and Ni, and Mo-Cu/ZSM-5 catalyst obtained by modifying the zeolite with copper by an ion exchange method from an aqueous solution of copper acetate and subsequent mechanical mixing of sample Cu/ZSM-5 with molybdenum oxide (prototype).
As can be seen from the table, the proposed method allows to obtain a catalyst that is different from the prototype of the higher activity and stability in the process of conversion of methane into aromatic hydrocarbons.
|Comparative characteristic activity of modified zeolite catalysts|
|Indicators||The proposed method||Prototype|
|Space velocity, h-1||800||800||800||800||800||1000||1000||800|
|Conversion for a reaction time of 60 min, %||14,2||13,8||12,5||11,1||13,8||13,6||12,1||10,0|
|Selectivity for arenas, %||81,7||81,2||79,2||79,3||79,0||78,7||78,5||85,0|
|Output arenes %||the 11.6||11,2||9,9||8,8||10,9||10,7||9,5||8,5|
|Conversion for reaction time 480 min, %||10,9||10,0||7,8||3,5||8,4||8,4||of 5.4||7,2 (300 min)|
|The ratio of the Ni(Cu)/Mo in the catalyst||0,04||0,1||0,2||0,4||-||0,04||-||0,13|
1. High-silica zeolite catalyst process for non-oxidative methane conversion, incorporating molybdenum and the second modifying element, characterized in that the content of molybdenum in the catalyst is not more than 4.0 wt.%, second modifying element - Nickel from 0.1 to 0.5 wt.%.
2. The method of preparation of the zeolite catalyst process for non-oxidative methane conversion, including the modification of the zeolite with molybdenum and the second modifying element with subsequent annealing, characterized in that the molybdenum and the second the promoting element Nickel is introduced into the zeolite in the form of nanosized powders of metals, while the molybdenum content in the resulting catalyst is not more than 4.0 wt.%, and Nickel, from 0.1 to 0.5 wt.%.
3. The way non-oxidative methane conversion in the presence of high zeolite catalyst, characterized in that the use of the catalyst according to claim 1.
FIELD: petrochemical process catalysts.
SUBSTANCE: group of inventions relates to conversion of hydrocarbons using micro-mesoporous-structure catalysts. A hydrocarbon conversion process is provided involving bringing hydrocarbon raw material, under hydrocarbon conversion conditions, into contact with micro-mesoporous-structure catalyst containing microporous crystalline zeolite-structure silicates composed of T2O3(10-1000)SiO2, wherein T represents elements selected from group III p-elements and group IV-VIII d-elements, and mixture thereof, micro-mesoporous structure being characterized by micropore fraction between 0.03 and 0.40 and mesopore fraction between 0.60 and 0.97. Catalyst is prepared by suspending microporous zeolite-structure crystalline silicates having above composition in alkali solution with hydroxide ion concentration 0.2-1.5 mole/L until residual content of zeolite phase in suspension 3 to 40% is achieved. Thereafter, cationic surfactant in the form of quaternary alkylammonium of general formula CnH2n+1(CH3)3NAn (where n=12-18, An is Cl, Br, HSO4 -) is added to resulting silicate solution suspension and then acid is added formation of gel with pH 7.5-9.0. Gel is then subjected to hydrothermal treatment at 100-150°C at atmospheric pressure or in autoclave during 10 to 72 h to produce finished product.
EFFECT: enlarged assortment of hydrocarbons and increased selectivity of formation thereof.
16 cl, 2 dwg, 2 tbl
FIELD: petroleum chemistry and petroleum processing.
SUBSTANCE: method involves contacting the raw containing 6-60 vol.% of propane and/or butane, and methane and/or ethane as a diluting agent also with catalyst comprising zeolite of the pentasil group. Contacting is carried out at temperature 480-600°C, the volume rate raw feeding 300-1000 h-1, under pressure 0.1-3 MPa and partial pressure of propane and/or butane 0.8 MPa, not above. Invention provides enhancing stability of the catalyst performance and retaining the high degree of raw conversion.
EFFECT: improved method for stability enhancement.
2 cl, 1 tbl, 7 ex
FIELD: petrochemical processes.
SUBSTANCE: feedstock olefins are submitted to oligomerization in contact with zeolite oligomerization catalyst and C4-hydrocarbons isolated from resulting products are then aromatized on zeolite aromatization catalyst. Hydrogen-containing dry gas recovered from aromatization products is used for oligomerization-preceding selective hydrogenation of butadiene in feedstock to give butylene-enriched starting material.
EFFECT: prolonged catalyst lifetime.
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In addition, the invention relates to a new method of producing ethylene by means of direct conversion of methane or purified natural gas in the presence of the above catalyst and nitrogen at a temperature of from about 670 to 810oC, preferably in the range from 710 to 810oC, which is significantly below the reaction temperature normal synthesis of hydrocarbon(s) by dehydrogenation
FIELD: production of monomers used for production of high-molecular compounds, alkylation of benzene by lower olefins in alkylator.
SUBSTANCE: proposed method is carried out in three stages: at the first stage, liquid hydrocabons, viz.: dehydrated benzene, polyalkylbenzenes and return benzene are mixed; at the second stage, ethylene and other olefins are introduced in liquid hydrocarbon mixture and at the third stage, aluminum chloride-based catalytic complex is introduced; at all three stages, flow moves in alkylator in turbulent mode; alkylator is provided with turbulization aids. Alkylator includes vertical cylindrical hollow housing with component inlet branch pipes fitted from below; components are delivered also through comb; branch pipes for discharge of reaction mass and gaseous products are mounted in the upper position. Housing is made from contraction tube, diffuser and cylindrical members interconnected coaxially. Initial component inlet branch pipes are located along housing axis; olefin and catalytic complex inlet branch pipes are located at distance from liquid hydrocarbon inlet branch pipes no less than two turbulization sections.
EFFECT: increased yield of alkyl benzene due to continuous process in small-sized equipment.
3 cl, 1 dwg, 3 ex
FIELD: petroleum chemistry.
SUBSTANCE: claimed method includes thermal hydrodealkylation of alkylaromatic compounds (e.g. toluene, benzene-toluene-xylene fraction of pyrocondensate, etc.) at increased temperature and pressure followed by recycling of un-reacted compounds. As additional raw materials phenol or other oxygen-containing aromatic fractions from various manufactures (e.g. phenol fraction from cookery production, phenol resin, acetophenon fraction or p-cumylphenol fraction from phenol production, etc.) are added to starting material in amount of 1-40 mass % based on mass of main raw materials. Process is carried out at 620-740°C, pressure of 2-5 MPa, 100 % hydrogen consumption of 700-1200 nm3/m3 of raw materials.
EFFECT: increased benzene yield, utilization of waste from various manufactures.
6 cl, 1 tbl, 1 dwg, 2 ex
FIELD: petroleum processing and petrochemistry.
SUBSTANCE: catalysate of reforming of long gasoline fractions containing more than 2% benzene is separated by rectification into three fractions: light-boiling fraction containing mainly nonaromatic C4-C6-hydrocarbons and no more than 1%, preferably no more than 0.5%, benzene; high-boiling fraction containing mainly aromatic and nonaromatic hydrocarbons C7 or higher and no more than 1%, preferably no more than 0.5%, benzene; and benzene fraction boiling within a range of 70-95°C and containing no more than 0.1%, preferably no more than 0.02%, toluene and no more than 0.02% nonaromatic hydrocarbons with boiling temperature above 110°C. Benzene fraction is routed into benzene isolation process involving extractive rectification with polar aprotic solvent having ratio of dipole moment to square root of molar volume above 0.3 db/(cm3/g-mole)1/2, preferably above 0.4 db/(cm3/g-mole)1/2, and boiling temperature 150 to 250°C.
EFFECT: improved quality of benzene.
4 dwg, 2 tbl, 5 ex
FIELD: petrochemical processes.
SUBSTANCE: liquid pyrolysis products are processed to recover C6-C11-fraction, which is then separated into C6-C8 and C9-C11-fractions. C6-C8-Fraction is subjected to catalytic hydrostabilization and hydrofining. C9-C11-Fraction is hydrostabilized in presence of catalyst and then processed to isolate C10-C11-fraction. C6-C8 and C10-C11-fractions are combined at specified proportion and resulting mixture is subjected to thermal hydrodealkylation. Desired benzene and naphthalene products are recovered from hydrodealkylation product via rectification. High-purity benzene is obtained after fine catalytic posttreatment.
EFFECT: increased yield of desired products and service time of hydrostabilization catalyst.
2 cl, 1 dwg, 4 tbl, 10 ex
FIELD: chemical technology.
SUBSTANCE: invention is designated for detoxification of chloroaromatic hydrocarbons or their mixtures by dechlorination method resulting to preparing benzene. Dechlorination process of chloroaromatic hydrocarbons is carried out by hydropyrolysis at temperature 700-850°C and in the mole ratio hydrogen : chloroaromatic hydrocarbons = (7-10):1 under pressure 0.1-5 MPa. Benzene is separated by rectification and the following recirculation unreacted chloroaromatic hydrocarbons. Formed hydrogen chlorine is adsorbed with alkali solution. Invention provides simplified technology, excluding toxic reagents and solvents in using and absence of toxic waste.
EFFECT: improved processing method.
FIELD: chemistry of aromatic compounds, organic chemistry, chemical technology.
SUBSTANCE: method involves purification of benzene from thiophene in the presence of diene compounds, water and urotropin by its treatment with sulfuric acid solution at 20-40°C in cascade of mixing units and with fractional (distributed) feeding sulfuric acid solution in mixing units. Method provides simplifying the process and enhanced yield of benzene.
EFFECT: improved method for treatment.
3 cl, 3 tbl, 6 dwg, 7 ex
FIELD: alternate fuel production.
SUBSTANCE: invention relates to synthesis of hydrocarbons from CO and H2, in particular to catalysts and methods for preparation thereof in order to carrying out synthesis of hydrocarbons C5 and higher according to Fischer-Tropsch reaction. Method resides in that non-calcined zeolite ZSM-12 in tetraethylammonium-sodium form is subjected to decationation at pH 5-9, after which decationized zeolite (30-70 wt %) is mixed with alumina binder while simultaneously adding cobalt (7.5-11.5 wt %) as active component and modifier, in particular boron oxide (3-5 wt %). Proposed method allows catalyst preparation time to be significantly reduced owing to combining support preparation and deposition of active component and modifier in one stage with required catalytic characteristics preserved. In addition, method is environmentally safe because of lack of waste waters, which are commonly present when active components are deposited using impregnation, coprecipitation, and ion exchange techniques.
EFFECT: reduced catalyst preparation time and improved environmental condition.
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