CS230144B1 - Manufacturing process of power and reactive fuel and aromatic hydrocarbon concentrate - Google Patents

Description

The invention relates to a process for the production of alkenes, motor and reactive fuels, and aromatic hydrocarbon concentrates from the TLC and medium, narrow or broad hydrocarbon fractions by combining processes for isolating n-alkanes, reforming or dehydrogenation, hydrogenation, pyrolysis and distillation.

Current technology schemes for the production of alkenes by pyrolysis use a primary hydrocarbon, usually petroleum, gas, gasoline or medium fraction, such as kerosene or gas oil, as the feedstock ·

The following characteristic product yields are achieved in percent by weight per transition:

naphtha gas oil - .1 35-180. * C

H ₂ .................. 1.1 1- 1 CH ₄ ................ 16.5 11.0 ethylene .................. 26.1 18.5 ethane ....... o ............ 5.4 5.2 propene ................ on. 13.5 15.0 propane .................. 0.8 0.8 C ^ -carbohydrates ........... 8.5 10.0 hydrocarbons ........... 2.0 1.5 pyrobenzine + aromatic hydrocarbons .............. 23.1 12.9 pyrolysis oil ......... · 3.0 24.0

It is clear from the table that pyrolysis of gas oil results in substantially lower ethylene yields than in the case of gasoline pyrolysis.

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In addition, the pyrolysis of the gas oil rapidly cokes the pyrolysis plant due to the large coke formation, which results in a considerable reduction in the production capacity of the plant.

Motor naphtha fractions are also used to prepare motor gasolines by desulfurization and catalytic reforming. Their low-octane components, the n-alkane hydrocarbons, are both split into hydrocarbon gases on the reforming catalyst and passed through the catalyst unchanged. They are an unwelcome component of the raw materials used for gasoline reforming, as shown in the table below.

Composition of the hydrocarbon fraction in percent by weight before the reforming reform

n-butene ...................... n-pentane ..................... n — hexane ... .. ···· ··· .. ······. 0.04 C, 12 1.72 5.69 6.03 5.73 2.63 1.16 1.95 2.55 3.08 1.78 0.56 0.17 n-heptane ..................... n-decane ...................... nC ₄ nC ₁₀ ............... 21.16 11.25 i-alkenes ♦ cycloalkanes ... 67,02 30.69 2.— both ir— aromatic hydrocarbons ^C 6 - ^C 10 ................. 11.02 58,06

Equally disadvantageous components are n-alkanes in reactive fuels.

Aircraft kerosene with a crystallization point of -55 * 0 can be produced from the primary paraffinic oil fraction only at the cost of lowering the end of the distillation curve, for example to 240 ° C. primary

230 144 A petroleum fraction boiling in the range of 140 ° C to 300 ° C, prepared from paraffinic oil, has a pour point of -30 ° C.

Gas oil prepared from a paraffinic fraction boiling up to 360 ° C excludes n-alkane hydrocarbons at 3 ° C · Not applicable as diesel fuel in winter ·

Previous analysis of the simultaneous processing of oil into low molecular weight alkenes and fuels suggests that primary oil fractions with a boiling point of 30 to 320 ° C are not a preferred raw material for the production of low molecular weight alkenes and also for the production of fuels - petrol and reactive cotors.

It has been found that these deficiencies are overcome and that a synergistic effect is achieved resulting in a substantially higher efficiency in the production of low molecular weight alkenes, motor and reactive fuels and aromatic hydrocarbon concentrate by combining n-alkane isolation processes, adsorption or adduct formation with urea, pyrolysis, catalytic reforming or dehydrogenation, hydrogenation and distillation are isolated from hydrocarbon fractions boiling in the range of 30 to 360 ° C, or from the narrower fractions boiling in this range, initially partially or fully n-alkane hydrocarbons, which lead to low-molecular-weight pyrolysis processes alkenes and partially or fully dealcanised fractions with a boiling point of 60 ° to 210 ° C.or narrower fractions boiling in this range are partly used for the production of motor fuels and partially or fully led to the reforming or dehydrogenation process for the production of high-octane The fossil fuels and the production of aromatic hydrocarbon concentrates and dealcanised hydrocarbon fractions in the range of 140 to 274 ° C or 140 to 320 ° C are led to hydrogenated dearomatization to produce diesel and / or reactive fuels.

In accordance with the present invention, C 6 alkene yields are increased to 60% by weight when the hydrocarbons pass through the pyrolysis furnace when pyrolyzing high concentration n-alkanes.

When the n-alkane-depleted gasoline fraction is reformed, a reformate having a metal aromatic hydrocarbon content of up to 68% by weight is obtained. 230 144

Dehydrogenation of the naphtha-depleted naphtha yields a product containing up to 71% aromatic hydrocarbons

The distillation range of aviation reactive fuels may be extended to 300 to 320 ° C if the relevant hydrocarbon fraction is freed from n-alkanes to a value below 3% by weight ·

Winter diesel fuel can be prepared from gas oil derived from paraffinic akδρ by removing n-alkane hydrocarbons.

Experimental work has shown that the yield of Cg and alkenes is almost independent of the carbon chain length of the n-alkanes in the homologous range of C-C ^ n-alkanes, regardless of whether the individual hydrocarbon or mixture of n-alkanes is pyrolyzed. decreases from 835 ° C when pyrolyzing n-hexane to 820 ° C, when pyrolyzing n-decane to tridecane, if, under otherwise identical conditions, the same yield of ethylene and propene sum of about 60% by weight calculated on the feedstock is achieved

In accordance with the present invention, either a wide hydrocarbon fraction boiling in the range of 30 to 360 ° C may be used as the starting material, but preferably a fraction suitable for cannon fuel production or aromatic hydrocarbons such as a gasoline fraction boiling in the range of 60 to 210 ° C C, the kerosene fraction boiling in the range of 140-275 ° C and the gas oil fraction boiling in the range of 140-360 or quite narrow fractions suitable for the isolation of chemical individuals.

Isolation of n-alkanes from hydrocarbon ffaccils can be accomplished by adsorption processes using CaA, MgA or CaMgA type zeolite molecular sieves having a microcrystalline cavity inlet diameter of 0.48 nm to 0.52 nm. -alkanes also using urea adducts ·

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Conventional catalysts containing platinum, rhenium, optionally in combination with rare earth elements deposited on alumina or on a mixture of alurines with an amorphous and / or crystalline aluminosilicate may be used for reforming dealcanized gasoline fractions. The technological parameters of the reforming are the same as for the work with primary hydrocarbon raw materials.

The dehydrogenation of the dealcanised fraction of bepzine can be carried out at a total pressure of 0.1 MPa to 1.0 MPa, at temperatures from 400 to 620 ° C, at a volume rate of 0.5 h ¹ to 5.0 h ^-1 , without a diluent or at a molar the ratio of diluent to dealt-lowered hydrocarbon fraction 1: 0.05 to 20, under adiabatic, preferably isothermal conditions in the catalyst bed. As the catalyst, the catalyst used for the dehydrogenation of alkanes and cycloalkanes to alkenes and dienes can be used.

The dehydrogenation of the dealcanized hydrocarbon fraction can be carried out in the presence of a diluent such as hydrogen, carbon dioxide or carbon monoxide or mixtures of the individual diluents in any desired ratio.

By dealcanizing the hydrocarbon fraction falling within the boiling range into kerosene applied to reactive aircraft engines, the aromatic hydrocarbon content generally increases to 28-30% by weight. Excess aromatic hydrocarbons can be removed by catalytic hydrogenation dearomatization.

Platinum or platinum group metals or mixtures thereof may be used as the dearomatizing catalyst. It is expedient to limit the migration of the active metal over the surface of the catalyst support by depositing a rare earth element or mixture on the support. An amorphous or crystalline aluminosilicate or a mixture thereof, a mixture of an amorphous or crystalline aluminosilicate with alumina may be used to prepare the dearomatization catalyst.

An advantage of the process for producing alkenes, motor and reactive fuels and aromatic hydrocarbon concentrates by combining the technological processes of isolating n-alkanes, pyrolysis, reforming or dehydrogenation, hydrogenation and distillation according to the invention is:

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- a reduction in the consumption of feedstocks from 2.53 parts by weight to 1.66 parts by weight for the production of one part by weight of the total C 8 and alkenes, a reduction in the energy consumption for their production and a reduction in production costs. Compared to the pyrolysis of a primary petroleum fraction, pyrolysis of n-alkane hydrocarbons results in a reduction in the specific consumption of hydrocarbons for the production of ethylene and propene at the expense of destroyed pyrolysis yield and other pyrolysis liquid fractions;

- an increase in the yield of reformate, an increase in the aromatic hydrocarbon content of the reformate and thus an overall increase in the yield of aromatic hydrocarbons, and a reduction in the cost of their isolation;

increasing the butadiene concentration in the pyrolysis C? -fraction to 55 to 65% by weight and increasing the butadiene yield calculated on the starting n-alkanes;

- high yield of aromatic hydrocarbons from petrol dehydrogenate;

- allowing for the extension of the distillation range of reactive aviation kerosene prepared from paraffinic petroleum, thereby increasing its oil extract;

from paraffinic oil

- allowing the production of diesel fuel) suitable for winter use.

The following are non-limiting examples.

Example 1

The hydrocarbon fraction containing 4 to 10 carbon atoms per molecule is fed at a temperature of 30 ° C to an adsorber filled with a zeolite molecular sieve CaA in which the sodium has been replaced by calcium at 62% by weight. The zeolite is formed into beads having a diameter of 0.8 to 1.2 nm. The hydrocarbons are metered onto the zeolite at a forward rate of 3 cm per minute from the bottom up. The adsorber height is 9 m. The dealcanized fraction was removed

230 144 takes the upper outlet of the adsorber until the alkane content of the withdrawn gasoline reaches 2.1 Ίο by weight. The content of cycloalkanes and isoalkanes in the dealcanised hydrocarbon fraction increases to 83.9% by weight and the aromatic hydrocarbon content to 14% by weight.

The dealcanised hydrocarbon fraction obtained is divided into two parts, one of which is processed by a processor, by a dehydrogenation process and the other by a reforming process.

In the dehydrogenation process, the dealcanised hydrocarbon fraction is fed to a catalyst containing 90% by weight of alumina, 8% by weight of chromium trioxide and 2% by weight of potassium oxide at a temperature of 565 ° C and at a volume rate of 2 t ^-1 . Thereby, a product is obtained which contains 71.6% by weight of aromatic hydrocarbons, in particular in percentage by weight of 5.21 benzene, 14.9 toluene, 5.71 ethylbenzene, 3.71 1,4-dimethylbenzene, 10.2 1,3- dimethylbenzene, 5.83 1,2-dimethylbenzene, 0.75 2-propylbenzene, 5.69 1-methyl-4-ethylbenzene and 1-methyl3-ethylbenzene, 1,26-tert-butylbenzene, 1.7 1.3, 5-trimethylbenzene, 1.96 l-methyl-2-ethylbenzene, 4.78 1,2,4-trimethylbenzene,

9.9 C ^-C Q-aromatic hydrocarbons.

In the reforming process, the parent hydrocarbon fraction is contacted with a catalyst containing 99.3% by weight of alumina, 0.35% by weight of platinum and 0.35% by weight of rhenium at a rate of 2.0 h ^-1 at 490 ° C, at a pressure of 3 ° C. MPa and at a molar ratio of hydrogen to hydrocarbons of 7: 1. A reformate is obtained containing in percent by weight 11.25 n-alxanic hydrocarbons, 30.69 isoalkanes and cycloalkanes and 58.06 aromatic hydrocarbons.

The dealcanized hydrocarbon fraction provides a reformate containing 68.1% by weight of aromatic hydrocarbons, in particular 5.2% by weight of benzene, in the reforming process at a bulk velocity of 1.5 t ^-1 , at 480 ° C and a total pressure of 3.0 MPa, 15,6 toluene, 4,2 2,4-dimethylbenzene,

8,7 2,3-dimethylbenzene, 3,1 ethylbenzene, 5,0 1,2-dimethylbenzene, 4,9 l-methyl-4-ethylbenzene and 1-methyl-3-ethylbenzene, 2,6 1,3,5 trimethylbenzene, 2.0 l-methyl-2-ethylbenzene, 7.0 1,2,4-trimethylbenzene, 9.8 C-4-aromatic hydrocarbons.

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After purging the bed of zeolite molecular sieve with CaA with nitrogen-free nitrogen, n-butanes of n-alkanes were desorbed at 220 ° C and 0.5 MPa from which n-hexane and n-heptane were obtained by rectification as a percentage weight:

n-hexene n-heptonate n-hexane ............ 87.4 n-heptane ........... 99.1 i-hexanes ........... 4.7 -hole 0 in 0 thanks ...... 0.5 methylcyclopentane ... 7.5 Ογ-uhTovoóíky ...... 0.4 aromatic hydrocarbons 0.4

Example 2

A paraffinic petroleum fraction boiling in the range of 160 to 320 ° C having a freezing point of -30 ° C is contacted at a temperature of 360 ° C, a pressure of 0.6 MPa and a 150: 1 hydrogen to kerosene volume ratio by contacting a Ca-type zeolite molecular sieve *, in which the sodium cation is exchanged to 62 $ by weight calcium. The adsorbent is deposited in the adsorber in a 9 m high layer. After the n-alkanes have passed through the adsorbent bed, the kerosene fraction is cut off to the adsorbent, and the zeolite bed is purged with a stream of hydrogen at the same rate as during feed. The straight chain alkanes are desorbed from the adsorbent cavities by a stream of ammonia at 360 ° C for 15 minutes at 0.2 kg NH 4 / kg zeolite. From desorbed

The n-alkanes are fractionated to give a narrow fraction 0 of this composition in percent by weight: n-nonane .............. ----- 0.3 n-decene .............. ..... 7.2 n-undecane ............ ..... 44.1 n-dodecane ............ ..... 40.2 n-tridecane ........... ----- 7,3 n-tetradecane ......... ----- 0.1 i-alkanes ............. .... 0,8

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The freezing point of the -30 ° C effluent petroleum fraction drops to -60 ° C by removing n-alkanes from it and the aromatic hydrocarbon content increases from 20 volume to 31 volume%.

Pyrolysis of the resulting n-hexane, n-heptane, and n-alkanes _of C ^ to C ^, in the presence of water vapor obtained in a model performance of the pyrolyzer 2 kg of raw material per hour, the temperature control of the radiation section was set by testing a wide gas pyrolý- zou fractions boiling in the range of 30 ° C to 180 ° C, the following products:

raw material n-hexane n-heptane n-alkanes ^C 10 ' ^C 13 1 2 3 4 Operating conditions at pyrolysis * temperature, ° C 835 830 820 The weight ratio of water vapor to hydrocarbons 0.46 0.53 0.68 Sulfur content - in hydrocarbons, % by weight 0.01 0.01 0.02 Hydrocarbon residence time in the pyrolysis snake, seconds 0.24 0.3 0.25 Extracts of pyrolysis products,% by weight of ^H 2 1.78 2.18 1.87 methane 16.71 14.22 12.53 Ethane 4.23 4.2 3.38 , Ethylene 43.71 49,79 44.96 propane 0.57 0.37 0.57 propene 14.41 12.74 15.3 propadiene 0.23 0.16 0.27 C ^ alkanes 0.4 0.06 0.12 C ^ -alkenes 2.71 1.36 2.9 C ^ -diene 5.19 5.18 6.98 C ^ -uhTovodíky 0.40 0.36 0.51 benzene 2.76 2.87 2.84 toluene 1.77 1.87 1.92

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1 -5 4 styrene 1.41 1.6 1.47 Indeed, Οθ-aromatics 0.69 0.43 0.56 Cg-aromatics 0.37 0.32 0.54 Non-aromatic hydrocarbons 2.03 0.86 2.32 Pyroolej 0.83 1.43 C, 96

Analysis of pyrolysis products of n-alkane hydrocarbons shows that 88-90% by weight of pyroplyn is obtained, the yield of basic alkenes such as ethylene, propene and 1,4-butadiene being 63.31 to 67.71% by weight, which is by one third, it yields the yield compared to the current industrial result. Pyro-oil is obtained in an amount of only 0.83 to 1.43% by weight, calculated on the starting alkanes, and pyrobenzine contains 72.15 to 85.00% by weight of aromatic hydrocarbons.

Claims (1)

OBJECT OF THE INVENTION 230 144 Process for the production of alkenes, motor and reactive fuels and aromatic hydrocarbon concentrates from light and medium hydrocarbon fractions, characterized in that in the combination of technological processes the isolation of n-alkanes, pyrolysis, catalytic reforming or dehydrogenation, hydrogenation and distillation is isolated from hydrocarbon fractions n-alkane hydrocarbons by contacting the hydrocarbon fractions boiling in the range of 30 ° C to 360 ° with a zeolite molecular sieve having a hole diameter in the crystal cavities of 0.48 to 0.52 nm, then dealcanized boiling fractions in the range of 60 ° C to 60 ° C 210 ° C or narrower fractions boiling in this range are contacted either with the reforming catalyst in the presence of hydrogen to obtain a fraction containing at least 65% by weight of aromatic hydrocarbons or with a dehydrogenation catalyst yielding a product containing above 70% by weight of aromatics atopic hydrocarbons, the dealcanised hydrocarbon fraction boiling in the range of 140 ° C to 275 ° 0 or in the range of 140 ° C to 320 ° 0 is contacted with a dearomatizing catalyst in the presence of hydrogen and the aromatic hydrocarbon content of the kerosene fractions is reduced below 25% by weight, their crystallization temperature drops below -55 * 0, the freezing point of the gas oil drops below -30 * 0, and finally the n-alkane hydrocarbons desorbed from the molecular sieve cavities are pyrolyzed in the presence of water vapor to ethylene and propene in at least 55% yield, N-alkenes and dienes, to N-alkenes and dienes, and to aromatic hydrocarbons.