CS221048B1 - Method of making the olefines from hydrogenated petrol fractions - Google Patents

Abstract

The invention is in the processing field hydrocarbons. It solves the method of olefin production from hydrogenated petroleum fractions which proceeds so that kerosene, atmospheric or vacuum gas oil is hydrogenated in the presence of a catalyst contains actively components WS2 and / or MoS2 and as activators NiS and / or CoS na A12O3, preferably WS2. NiS to 1212O3 at pressure 7 to 30 MPa and a temperature of 280 to 450 ° C; the hydrogenate obtained is pyrolyzed in the case of the \ t water vapor at 750 to 900 ° C and a delay of less than 1 second. The essence of the method according to the invention is that the hydrogenate is treated prior to pyrolysis elemental sulfur, hydrogen sulphide, sulfuric compounds or to the hydrogenate non-hydrogenated petroleum fraction s is added content of sulfur compounds so that the content of sulfur in the feed for pyrosylation was in from 0.001 to 0.3% by weight.

Description

(54) Reduces the production of olefins from hydrogenated petroleum fractions

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The invention falls within the field of hydrocarbon processing. It resolves a process for the production of olefins from hydrogenated petroleum fractions by treating petroleum, atmospheric or vacuum gas oil in the presence of a catalyst which contains actively the components WS ₂ and / or MoS ₂ and as activators NiS and / or CoS to A1 ₂ O ₃ , preferred WS ₂ . NiS to Al ₂ O ₃ at a pressure of 7 to 30 MPa and a temperature of 280 to 450 ° C and the obtained hydrogenate is pyrolyzed in the presence of water vapor at a temperature of 750 to 900 ° C and a residence time of less than 1 second. According to the process of the invention, the hydrogenate is treated with elemental sulfur, hydrogen sulphide, sulfur compounds prior to pyrolysis or a non-hydrogenated petroleum fraction containing sulfur compounds is added to the hydrogenate so that the sulfur content of the pyrosis feed is from 0.001 to 0.3%. weight.

The invention relates to a process for the production of olefins from hydrogenated petroleum fractions by medium-temperature pyrolysis.

Up to now, medium-temperature pyrolysis of hydrocarbon feedstock is one of the basic processes for the production of ethylene, propylene and butadiene. At present, the usual feedstock base of pyrolysis from ethane, propane, C ₄ hydrocarbons, straight-run gasolines is expanding to spilling petroleum fractions such as atmospheric and vacuum gas oil. Pyrolysis of the medium petroleum fractions results in a decrease in the yields of the desired olefins compared to the pyrolysis of gasoline. On the other hand, there is an increasing amount of liquid pyrolysis fractions, mainly pyrolysis oils and coke. This is largely related to the composition of the pyrolysis feedstock, where the transition to gas oils increases the content of aromatic hydrocarbons, which are a potential source of pyrolysis oils and a precursor of coke formation. While the alkane chains are relatively readily accessible to the pyrolysis in the form of a scent, the foaming of the C-C bonds, the degree of decomposition of the aromatic, especially polycondensed structures, is low and generally retains their aromatic character when passing through the pyrolysis apparatus. In medium petroleum distillates, the presence of parallel chain alkanes, less branched alkanes, single ring alkyl naphthenes, polynuclear alkylaromates, heterocyclic compounds and the least desirable polynuclear aromatics are most desirable.

The quality of medium oil fractions! as pyrolysis feedstocks, they can be improved by either extracting the aromatics or hydrogenating them. Typically, the hydrogenation is carried out at a temperature of up to 450 ° C under pressure in the presence of hydrogen and a difunctional catalyst. Under these conditions, in addition to the hydrogenation of aromatics, the hydrogenation of sulfur, nitrogen and oxygen compounds is carried out. It has been found that pyrolysis of hydrotreated feedstocks provides greater yields of ethylene, propylene, butadiene, while decreasing the yield of residual pyrolysis oil. A drawback of the pyrolysis of the hydrogenated feedstocks is that the reaction of the secondary reactions, which is manifested by increased coke production, is favored. Coking in pyrolysis is a limiting factor in many ways as it leads to an increase in temperature and pressure losses. This shortens the operating cycles of pyrolysis furnaces.

The above drawbacks are overcome by a process for the production of olefins from hydrogenated petroleum fractions by the process of hydrogenating gasoline, kerosene, atmospheric or vacuum gas oil in the presence of a catalyst containing actively WS ₂ and / or MoS ₂ components and as NiS activators and / or CoS on Al ₂ O ₃ preferred WS ₂ . NiS to Al ₂ O ₃ at a pressure of 7 to 30 MPa and a temperature of 280 to 450 ° C and the hydrogenate obtained is pyrolyzed in the presence of water vapor at a temperature of 750 to 900 ° C and a residence time of less than 1 second. For example, the hydrogenate is treated with elemental sulfur with hydrogen sulphide, sulfur compounds prior to pyrolysis, or a non-hydrogenated petroleum fraction containing sulfur compounds is added to the hydrogenate such that the sulfur content of the feed is from 0.001 to 0.3% by weight.

The invention is making progress in that the hydrogenated feedstock is pyrolyzed to olefins to a greater extent. In the hydrogenation of gasoline, kerosene, atmospheric or vacuum gas oil in the presence of a catalyst which contains actively the components WS ₂ and / or MoS ₂ and as activators NiS and / or CoS to Al ₂ O ₃ preferred WS ₂ . NiS to Al ₂ O ₃ at a pressure of 7 to 30 MPa and a temperature of 280 to 450 ° C reduces the aromatics content to 5 to 70% by weight of the initial amount, preferably a reduction in the range of 10 to 50% by weight. The action of elemental sulfur and sulfur compounds effectively prevents the conversion of the hydrocarbons to the pyramid, so that it is not deposited in the form of coke on the inner surface of the pyrolysis apparatus. This makes it possible to prolong the operating time of the pyrolysis furnaces continuously and to avoid a complicated operation of the coking of coke from the furnace tubes.

The subject matter of the invention is apparent from the examples without departing from the examples.

Example 1

Atmospheric gas oil was hydrogenated on a test rig under the following conditions:

temperature, ° C 330, 350, 370 pressure, MPa 20 space velocity, m ³ / m ³ . h 1 catalyst WS ₂ . NiS / Al ₂ O ₃ commercially available under the designation CHEROX 3402.

The properties of the starting material and the hydrogenates obtained are given in Table 1. The hydrogenation should be carried out in such a way that the aromatics content is reduced to 5 to 70% of the original amount, preferably 10 to 50%. It is desirable that the catalyst used has a reduced isomerization activity.

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Table 1

Properties of atmospheric gas oil and its hydrogenates

Hydrogenation temperature, ° C 330 350 370

QSample designation / 12 3 4 raw material products

density, kg / m ³ 838 distillation range, ° C hydrocarbon composition,% wt. 197-354 £ aromatics 215 Cyclanes 14.5 alkanes 60.5 sulfur content,% / wt. 0.83

Sulfur compounds in an amount of 0.001 to 0.3% by weight (based on the total sulfur in the hydrogenate) are added to the hydrotreated middle petroleum distillates prior to pyrolysis. Among the inorganic compounds, it is elemental sulfur, hydrogen sulfide, carbon disulfide, sulfur dioxide, sulfides, sulfates, metal thiosulfates of the first and second groups of the periodic table of ammonium or organic bases. Among the organic compounds, these were mercaptans, sulfides, sulfoxides, disulfides, xanthals, thiophenes, thiophenols and their aromatic and aliphatic derivatives, the derivatives having 1 to 32 carbon atoms. They may furthermore be phosphorus and sulfur compounds of the alkenylthiophosphonic or O, O-dialkyldithiophosphoric acid type or their inorganic salts or esters, in particular the salts of the metals of the first and second groups of the periodic table, the alkyls having 1 to 16 carbon atoms. Example 2

Pyrolysis of Hydrogenates Obtained Hydrotables Table 2

822 818 815 192-338 191-338 188-337 12.7 6.1 3.3 20.3 26.6 26.1 67.0 67.3 70.6 0.0006 0.0003 0.0002 genáciou gas oil took place

after treatment with sulfur compounds in stainless steel flow-through tubular reactors at a temperature range of 600 to 1000 ° C. The pressure ranged from 0.05 to 0.5 MPa, preferably from 0.1 to 0.2 MPa, and the residence time was less than 1 s. The reaction was carried out in the presence or absence of an inert diluent. Water inert in an amount of 20 to 150% by weight per hydrocarbon feed was used as the inert diluent. The method of dosing the sulfur additives into the pyrolysis system was determined by their nature. Sulfur compounds, which are normally gaseous, were fed directly into the reactor. The water-soluble compounds were dosed in the form of aqueous solutions, and the hydrocarbon-soluble additives were added to the starting material.

The effect of hydrogenation of gas oil on pyrolysis yields is shown in Table 2.

Pyrolysis of the primary gas oil and its hydrogenates at 800 ° C; hm. H ₂ O / crude ratio. = 0.8

LABELING OF THE RAW MATERIAL (a) residence time, with pyrop gas yield,% wt.

raw material 1 2 0.19 0.19

49,77 66,10 hydrogenates 3 4

0.19 0.19

67.33 64.46

methane 9.04 10.43 11.98 11.65 to ethan 2.41 2.97 3.08 2.16 • j ethylene 19.98 26.86 24.83 26.80 propylene 8.77 12.54 12.56 11.89 1,3-butadiene 3.71 4.69 5.69 4.04 remainder (gaseous + liquid) 56.09 42.51 41.86 43.46

The legend:

(a) the labeling of the raw material is the same as in Table 1.

Coke formation in pyrolysis of the primary gas oil, gas oil hydrogenates hydrogenates and after the addition of sulfur compounds was monitored at 810 ^Q C in the absence of water vapor at a holding time of 0.5 s. The feedstock feed was 25 g / h. The results are shown in Table 3.

Table 3

Formation of coke by pyrolysis of primary gas oil, its hydrogenates, without or in the presence of sulfur compounds. Experiment time 30 minutes.

Identification of raw material a 1 2 3 4 amount of coke, g coke after addition 0.05 o / o wt. Elment. S 0.26 2.9 2.08 1.62 0.17 0.12 0.08 0.01% hydrogen sulfide - 0.20 0.18 0.10 0.10% methyl mercaptan - 0.37 0.25 0.22

and the raw material labeling is the same as in Table 1.

Claims (1)

SUBJECT Process for producing olefins from gasoline, kerosene, atmospheric or vacuum gas oil, which are hydrogenated in the presence of a catalyst containing actively the components WS ₂ and / or MoS ₂ and as activators NiS and / or CoS to Al ₂ O ₃ , preferably WS ₂ . NIS to Al ₂ O ₃ at a pressure of 7 to 30 MPa and a temperature of 280 to 450 ° C, whereby the aromatic content is reduced to 5 to 70% by weight of the initial amount, preferably 10 to 50% by weight, and the resulting hydrogenate is rolled in the presence of water vapor at a temperature of 750 to 900 ° C and a residence time of less than 1 second, characterized in that the hydrogenate is treated prior to pyrolysis with elemental sulfur, hydrogen sulfide, sulfur compounds, or a hydrogenated non-hydrogenated petroleum fraction containing sulfur compounds is added to the hydrogenate the feed for pyrolysis was in an amount of from 0.001 to 0.3% by weight.