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18INTENSIFICATION OF THE CATALYTIC PROCESS
I.A.KHALAFOVA, F.Q.SEYIDLI
Azerbaijan State Oil Academy
KATALITIK KREKINQ PROSESÎN9 MAQNiT SAHOSiNiN TOSÎRÎ I.A.XaL9FOVA, F.Q.SEYIDLI
Qaynar qatda mikrosferik katalizator i^tiraki ila aparilan katalitik krekinq prosesindd maqnit sahasinin vakuum qazoylu ifo pentan vd benzin deasfaltizati qariçigma tasiri tadqiq edilmiçdir. Tadqiqatlarin naticasina asasan muayyanla§dirilmi§di ki, qudronun maqnit tasirila içlanmasi zamani alinan deasfaltizatlarin keyfiyyati yax§ila§ir. Hamçinin xammalin va katalizatorun fiziki-kimyavi gostaricilari atrafli verilmiçdir.
ИНТЕНСИФИКАЦИЯ ПРОЦЕССА КАТАЛИТИЧЕСКОГО КРЕКИНГА И.А.ХАЛАФОВА, Ф.Г.СЕЙИДЛИ
Исследовано влияние магнитного поля на смесь вакуумного газойля с пентановым и бензиновым леасфальтизатами гудрона в процессе каталитического крекинга с кипящим слоем микросферического катализатора. Результаты исследований показали, что при предварительной магнитной обработке гудрона улучшается качество получаемых деасфальтизатов, и добавка их к вакуумному газойлю приводит к получению высокооктанового бензина при каталитическом крекинге смеси.
The effect of a magnetic field on a mixture of vacuum gas oil with pentane and gasoline tar deasphalters in the process of catalytic cracking with a fluidized bed of a microspherical catalyst has been studied. The results of the research showed that the quality of the obtained deasphalted oil improves during the preliminary magnetic treatment of the tar, and their addition to vacuum gas oil leads to the production of high-octane gasoline during the catalytic cracking of the mixture.
Due to the growing demand for high-quality components of motor fuels, the deepening of oil processing is one of the most important tasks of the oil refining industry.
The main process that provides the deep refining of oil is catalytic cracking process. The purpose of the process is to increase the yield and improve quality of gasoline fractions and decrease the coke deposits formation on the catalyst surface.
The goal of the work is to obtain high-octane gasoline in the process of catalytic cracking of vacuum gas oil with the addition of tar deasphalting agents subjected to preliminary magnetic treatment.
METHODOLOGY OF THE EXPERIMENT
Vacuum gas oil and tar were used as raw materials for the catalytic cracking process.
Physical and chemical indicators of vacuum gas oil
density, kg/m3......................................................826
solidification temperature, -4
0C.................................
kinematic viscosity at 1000С, mm2/s 6.5
sulfur content, 0.62 %.................................................
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Impact Factor: SJIF 2019 - 5.11
2020 - 5.497
2021 - 5.81
coking, 0.08
wt.%......................................................
fractional composition:
B.P, 0С.......................................................... 270
boils up to 3500C, wt.%................................. 17
F.B.P.,500
0С.........................................................
Physical and chemical indicators of tar
density, kg/m3............................................................................................................979.2
sulfur content, wt.%..............................................................................2.01
coking, wt.%..........................................................................................13.8
group hydrocarbon composition, wt. %:
paraffin-naphthenic..........................................................................35.9
aromatic................................................................................................38.8
including:
lights............................................................................................................7.3
heavy........................................................................................................24.4
resin......................................................................................................................17.5
asphaltenes......................................................................................................7.8
An industrial microspherical catalyst with the following physicochemical properties used:
specific surface, m2/g............................................................................180-220
bulk density, g/sm3..................................... 0.61-0.65
average particle size, |im................................... 70
chemical composition, wt.%:
Al2O3...........................................................44
Na2O............................................................0.25
Re2O3............................................................1.9
Pt......................................................................2 ppm
The process Catalytic cracking of mixtures of vacuum gas oil with deasphalting agents was carried out on a laboratory flow-type unit with a fluidized catalyst bed (Pic. 1) at a pressure close to atmospheric
Pic. 1. Fluidized bed catalytic cracking unit with micro spheroidal catalyst
The raw material enters the reactor where the regenerated catalyst descends by gravity. The reaction products rise to the top of the reactor, pass through cyclones, in which the entrained catalyst is separated and fed to distillation. Then the coked catalyst enters the regenerator, where coke is burned off from the catalyst surface. The characteristics of the technical mode of catalytic cracking with a microspherical catalyst are as follows:
cracking temperature, 0C................................................................500-540
mass feed rate of raw materials, h-1..................................................1
pressure in the reactor, atm...............................................................1
regeneration temperature, 0C...........................................................620-630
catalyst loading, g..............................................................................100
the content of residual coke on the catalyst, wt................................0.02
Magnetic treatment of the deasphalted oil is provided.
The magnetic field for processing the tar was created by a conventional solenoid. The induction flux of the magnetic field created by the electromagnet was calculated using the following formula:
B tJ^K^nJ , (<J>/m)2A,
where Do - magnetic constant =8.85 10-12 F/m; □ - magnetic permeability of the medium, F/m; n is the number of turns of the solenoid winding; J - current strength, A.
The hydrocarbon composition of the cracking gas was determined by gas chromatography on a Perkin Elimer Auto System XL chromatograph. The length of the column is 100 m, the diameter of the column is 250 mm.
Polydimethylsiloxane was used as a sorbent, and helium served as a carrier gas. The octane number of gasoline was determined with an octanometer brand "OKTAN-IM". The octane meter is made in the form of a portable device which is shown in Fig. 2. It consists of a sensor and a measuring unit connected by a connector.
Pic. 2. Octanometer "OKTAN-IM"
The results of our experiments correspond to the data of GOST: the content of asphalt-resinous substances was determined according to GOST 1158-85; the content of low-sulfur petroleum coke is determined according to GOST 22898-78 and 19932-74;
- content of aromatic hydrocarbons - according to GOST-6994-74;
- content of aromatic hydrocarbons - according to GOST-6994-74;
- group chemical composition - according to GOST 13379-67;
- fractional composition - according to GOST 2177-66;
- kinetic viscosity - according to GOST 33-606.
Catalytic cracking of mixtures of vacuum gas oil with pentane and gasoline deasphalted oils, obtained without magnetic treatment of tar was carried out at a temperature of 4600C.
The results of catalytic cracking of a mixture of pentane deasphalted oil with vacuum gas oil are shown in Table.1. As can be seen from the table that with an increase in the deasphalted oil content in the range from 0 to 5 vol.% the yield of gasoline drops from 46.0 wt.% up to 45.5 wt.% and then rises and passes through a maximum at a 13% deasphalted oil content in a vacuum gas oil. In this case, the gasoline yield is 46.5 wt.%, i.e. 0.5 wt.% more than in the case of pure gas oil. The yield of heavy gas oil of catalytic cracking also increases from 11.2 wt.% up to 14.4 wt.%. The yields of gas and light gas oil are reduced. Thus during the cracking of pure gas oil the gas yield is 18.8 wt.%, and light gas oil 20.4 wt.%; at the extremum, the gas and gas oil yields are 16.8 and 19.9 wt.%, respectively.
Data of Table 1 show that coking also decreases from 3.6 wt. % to 3.3 wt.%. In other words,
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coking is reduced by 7% by weight.
Table 1. Catalytic cracking of a mixture of vacuum gas oil with pentane deasphalted oil (deasphalted oil obtained without magnetic treatment of tar)
Products, wt.% The content of c easphalted oil in raw materials, vol. %
0 5 10 13 15 20 25
hydrogen 0.30 0.30 0.30 0.25 0.25 0.30 0.35
dry gas 2.4 2.3 2.20 1.95 2.05 2.30 2.45
isobutane 1.8 1.7 1.3 1.1 1.2 1.5 2.6
butylenes 13.8 14.0 13.9 13.9 14.7 13.6 13.2
total gas 18.8 18.3 17.6 16.8 17.2 17.7 18.4
petrol B.P.- 1950C 46.0 45.5 46.0 46.5 45.9 44.5 43.0
fraction 195-3500C 20.4 20.0 19.4 19.9 19.5 20.5 21.1
fraction above 3500C 11.2 12.5 13.4 14.4 13.9 13.5 13.0
coke 3.6 3.7 3.6 3.3 3.3 3.8 4.5
Impact Factor: SJIF 2019 - 5.11 TE^HHK^ ^YKH
2020 - 5.497
2021 - 5.81
The cataly The analysis of the composition of gaseous products shows that the decrease in gas yield occurs mainly due to a decrease in its composition of dry gases and isobutane. Table 2. Catalytic cracking of a mixture of vacuum gas oil with gasoline deasphalted oil (deasphalted oil obtained without magnetic treatment of tar)
Products, wt.% The content of deasphalted oil in raw materials, vo
0 5 10 13 15 20 25
hydrogen 0.30 0.30 0.30 0.25 0.30 0.30 0.35
dry gas 2.4 2.4 2.3 2.15 2.2 2.4 2.45
isobutane 1.8 1.7 1.5 1.4 1.6 1.9 2.7
butylenes 13.8 13.8 13.8 13.8 13.7 13.7 14.3
total gas 18.8 18.8 17.9 17.6 17.8 18.3 19.8
petrol n.k.-1950C 46.0 44.9 45.3 45.7 45.2 43.3 42.2
fraction 195-3500C 20.4 20.2 20.0 19.9 20.1 21.4 21.6
fraction above 3500C 11.2 12.9 13.1 13.3 13.1 13.0 11.6
coke 3.6 3.8 3.7 3.5 3.8 4.0 4.8
tic cracking of a mixture of vacuum gas oil with gasoline deasphalted oil has the same character. The output of petrol in this case, as can be seen from the table. 2 drops to 44.9 wt.% at 5% deasphalted oil content in the feedstock and passes through a maximum at 13% content of the latter in the mixture. If the results of cracking pure gas oil and its mixture with petrol deasphalted oil as compared then they are almost the same with the optimal content of the latter in the feedstock. Thus, the yield of petrol decreases by only 0.3 wt.%, the yield of light catalytic cracking gas oil by 0.5 wt.%. The yield of coke also decreases by 0.1 wt.% and gas by 1.2 wt.%. The yield of heavy gas oil increases from 11.2 up to 13.3 wt.%.
Table 2 also shows that, the use of pentane deasphalted oil as an additive lead the decrease the gas yield which occurs due to the decrease in the proportion of dry gases and isobutane in its composition.
With preliminary magnetic treatment of tar, the quality of the resulting deasphalted products improves. From this point of view, it is of interest to study the cracking of mixtures of these deasphalted oils with vacuum gas oil.
Table 3 shows the results of cracking a mixture of vacuum gas oil with pentane deasphalting oil obtained after magnetic treatment of tar. As can be seen from this table, when this mixture is cracked, the gasoline yield increases, passes through a maximum at 13% d asphalted oil content in the mixture, and then decreases. Compared to the cracking of a mixture of vacuum gas oil with pentane deasphalting oil obtained without preliminary magnetic treatment of tar (Table 2), where the gasoline yield increases by 0.5 wt.%, in the case of preliminary magnetic treatment of tar (Table 3), it increased by 1.4 wt%. The yield of heavy gas oil also increases from 11.2 up to 15.1 wt%, by reducing the gas from 18.8 to 15.4 wt.% and light gas oil from 20.4 to 19.2 wt.%.
Table 3. Catalytic cracking of a mixture of vacuum gas oil with pentane tar deasphalting oil obtained by magnetic treatment_
Products, wt.% The content of deasphalted oi in raw materials, vol.%
0 5 10 13 15 20 25
hydrogen 0.30 0.30 0.25 0.20 0.23 0.25 0.30
dry gas 2.4 2.3 1.95 1.7 1.87 2.25 2.2
isobutane 1.8 1.7 1.1 0.8 1.0 1.1 2.5
butylenes 13.8 13.6 12.3 12.9 11.2 12.0 12.1
total gas 18.8 18.0 15.% 15.4 15.3 15.6 16.1
petrol B.P-1950C 46.0 46.4 46.9 47.4 47.0 45.5 44.3
fraction 195-3500C 20.4 20.0 19.5 19.2 19.6 21.0 22.0
fraction above 3500C 11.2 12.2 13.9 15.1 15.0 14.2 13.3
coke 3.6 3.5 3.2 2.9 3.1 3.5 4.3
able 3 shows that the co^
ce yield also drops from 3.6 wt.% with pure gas oil to 2.9 wt.% at 13 vol.%
deasphalted oil content in the mixture, i.e. almost 20 wt.%. An analysis of the gas composition shows that in this case, as it was in the case of the use of petrol and pentane deasphalted oil obtained without preliminary magnetic treatment of tar, the decrease in gas yield occurs mainly due to a decrease in hydrogen, dry gases and isobutane in its composition.
While comparing the results of mixture cracking using gasoline deasphalted oil obtained by magnetic treatment of tar (Table 3), and a mixture in which deasphalted oil obtained from tar that are not subjected to magnetic treatment (Table 4) The results are seen more clearly and better unlike to first case. Thus the yield of petrol at 13 vol.% content of deasphalted oil in the mixture reaches 46.3 wt.%, while the yield of coke decreases by 0.6 wt.% and amount to 3.0 wt.% (Table 4). The yield and change in the composition of the gas is of the same nature. The yield of light gas oil practically does not change with a change in the composition of the mixture, while the yield of heavy gas oil, as in previous experiments, increases from 11.2 to 15.2 wt %.
Table 4. Catalytic cracking of a mixture of vacuum gas oil with petrol tar deasphalting oil obtained by magnetic treatment_
Products, wt.% The content of deasphalted oi in raw materials, vol.%
0 5 10 13 15 20 25
hydrogen 0.30 0.30 0.30 0.25 0.30 0.35 0.35
dry gas 2.4 2.3 1.9 1.75 1.9 2.35 2.65
isobutane 1.8 1.7 1.3 1.1 1.3 1.8 2.1
butylenes 13.8 13.2 13.1 12.9 13.0 13.3 13.6
total gas 18.8 18.4 16.6 16.0 16.5 17.8 18.7
petrol B.P-1950C 46.0 45.7 45.9 46.3 45.8 44.8 43.0
fraction 195-3500C 20.4 20.0 20.2 19.5 19.5 19.8 20.4
fraction above 3500C 11.2 12.4 14.1 15.2 15.1 14.0 12.2
coke 3.6 3.5 3.2 3.0 3.1 3.6 4.7
In conclusion, the catalytic cracking of mixtures of deasphalted oil with vacuum gas oil with the ratio of 13:87 vol.% is optimal and it is desirable to obtain deasphalted oil from tar previously subjected to magnetic treatment.
BIBLIOGRAPHY
1. Kolesnikov S.I. Scientific basis for the production of high-octane petrol with additives in catalytic processes. Moscow: Petrol and gas. 2007. 175 p.
2. Vladimirov A.I. Catalytic cracking with a fluidized (fluidized) catalyst bed. Reactor-regenerative block. Moscow: Petrol and gas. 1992. 538 p.
3. Kapustin V.M., Gureev A.A. Petrol refining technology. Part 2. Destructive processes. M.: Kolos. 2007. 334 p.
4. Cracking of petroleum fractions on zeolite-containing catalysts / Ed. S.A.Khadzhieva. Moscow: Chemistry, 1982. 280 p.
