SU309533A1 - METHOD OF HYDROGENIZATION OF OIL FRACTION - Google Patents

Description

The invention relates to a method for obtaining from a petroleum fraction a mixture of gaseous hydrocarbons, used, for example, as a fuel gas. The known method of hydrocracking the oil fraction at a temperature of 310-455 ° C and a pressure of 35-210 atm in the presence of a hydrogenation catalyst containing a compound of metal VI or VIII of the periodic system on amorphous oxide of the metal of the PA, IIIA, IVB groups of the periodic system. The proposed method permits the processing of a petroleum fraction into a mixture of liquid hydrocarbons. In order to obtain a mixture of gaseous hydrocarbons, used, for example, as a fuel, a method of hydrogenation is proposed, which means that the oil fraction is purified from sulfur, asphaltenes and ash and sent to hydrogenation at a temperature of 550-700 ° C, pressure 15-100 atm in the presence of hydrogen in excess and a hydrogenation catalyst containing molybdenum, cobalt, nickel or chromium compounds on an alumina or silica carrier. The amount (in%) of hydrogen used in the process (He) is calculated by the formula He-in. 100 - ,,, where H is the stoichiometric amount of hydrogen. Neither is the amount of hydrogen actually consumed in the process. The stoichiometric amount of hydrogen is calculated by the formula Hs, where n and w are the amount of hydrogen and oil fraction, respectively, in mol x The amount of hydrogen does not increase with an increase in the ratio - and decreases. With an increase in the partial pressure of hydrogen. This hydrogen value can be determined (in%) for each hydrocarbon or each mixture of hydrocarbons separately using the formula Hej abn -, mp where p is the partial pressure of hydrogen in the hydrogenating gas, a, b, c are coefficients calculated empirically and process conditions. The sulfur content in the raw material should be no more than 0.05 weight. Vo, asphaltenes not more than 1.5 weight. %, mineral additives not more than 0.0001 weight. 0 / Q. When the content of these components above the specified limits necessary raw materials are cleaned. Hydrogenating gas should not include more than 0.0005% sulfur and 5 vol. % of carbon monoxide and carbon dioxide, the presence of unsaturated hydrocarbons in this gas is undesirable, the presence of paraffins and nitrogen in the gas is harmless. The proposed method can be applied to catalysts that quickly hydrogenate liquid hydrocarbons at a temperature higher than 550 ° C, preferably higher than 600 ° C, and under pressure higher than 15 atm. (pressure depends on the atomic average feed utilization ratio), these catalysts can be easily reduced several times by controlled oxidation with air or air with steam. Such catalysts include catalysts that include a flame-retardant carrier of alumina or magnesium oxide hydrate or mixtures thereof with the possible addition of silica or calcium oxide impregnated with one or more metals, for example molybdenum, cobalt, nickel, iron, tungsten, chromium, thorium and their oxides, sulfides or other salts. These catalysts can be obtained by impregnating flame-retardant carriers or by co-precipitating or displacing the contacts in the form of dust with the addition of binding agents followed by drying and liming, carried out in one or two phases, etc. Hydrogenating gas for the process can be obtained by various methods, for example, by endothermic steam reforming of hydrocarbons from the feedstock. The energy required for compressing the air used to oxygenate asphalt residues under pressure is obtained by expanding the gases emitted from the reduction apparatus of metals or their lower oxides. In practice, the oxidation and reduction operations are carried out cyclically in reactors, inside of which the metals and their oxides are placed as a fixed bed. Metals and their oxides can be circulated under pressure between an oxidizing medium and a reducing medium in a liquid or fixed bed. Below are examples that do not limit the invention. Example 1. Obtaining urban gas calorific value of 4500 kcal / nm. The process diagram is shown in FIG. 1. Gasoline with the following characteristic is used as a raw material: Specific gravity is 1574 ° C, g / slg 0.716 Sulfur, weight. %four

Limits vykipani, ° C

starting point

500/0

90%

end point Bottom calorific value

kcal / kg One part gasoline (19.80 / 0) is supplied as fuel for reduction, and the rest of the gasoline comes along with the hydrogenating gas coming from the CO2 separator to the unit / hydrodesulfurization, which includes a reactor filled with cobalt and molybdenum catalyst, and two tanks filled with iron oxide and zinc oxide. Gasoline together with the hydrogenating gas at a temperature of 380-400 ° C and under pressure of 25 atm passes through a hydrodesulfurization catalyst, where the decomposition of sulfonated compounds occurs with the formation of H2S. On subsequent catalyst beds consisting of iron and zinc oxides, absorption of P28 and decomposition of more stable sulfonated compounds occurs. Then, vapors of hydrodesulfurized gasoline and excess hydrogenating gas are supplied under a pressure of 25 at and at a temperature of 650 ° C to hydrogasification unit 2, containing a catalyst with an average hydrogenating activity, easily reduced, consisting of 16% molybdenum, 2% nickel, and 1% chromium alumina carrier. Here, gasoline is completely converted to gas G, having the following composition, vol. V / A: 0.25. Calming power cal. 6430 kcal / nm. This gas is divided into three streams. One stream (approximately half of the total) is returned to the reactor of the hydrogasification unit 2 via cooler 3 for temperature control. Another stream (approximately a quarter of the total) is fed to distribution line 4, and a third stream (approximately a quarter) is fed to the reduction reactor 5, from which the resulting gas T. is sent to reactor 6. In this reactor, fire-resistant steel pipes filled with alumina catalyst are located with a content of 35% nickel, heated outside and maintained under a pressure of 24-25 at a temperature of 75 ° C. In reactor 6, oxygenolysis takes place, as a result of which Gz gas is obtained, consisting of CO, COa, hydrogen and an insignificant part of the residual meta. TZ gas together with excess water vapor passes through oxygenolysis reactor 6 and then through node 7 where dioxide is removed. Part of the gas leaving the oxygenolysis reactor (Gz - 940 nm) is fed to line 4 together with gas Gj (1760 n) coming from the hydrogasification unit 2. Out of 1000 kg of gasoline (raw material), 2,700 NW of city gas of the following composition (vol. o / o) is obtained: 48–50 25 –27 1–2 0.10–0.20 2–3, 5 18 -20 The net calorific value of gas is 4500 kcal / nm. FIG. 1, the recovery apparatus is not shown, it includes a heating blower through which the mixed air with steam passes at a temperature of 630 ° C, restoring the hydrogasification catalyst. In accordance with the above conditions, recovery is carried out every 10-15 days. Recovery takes 6 hours. Example 2. This example relates to the hydrogasification of a crude oil for the production of hydrogen-rich gas replacing natural gas. The process diagram is shown in FIG. 2. Raw materials have the following characteristics: Specific weight of npKl5 ° / 4 ° C, g / slz 0.845 Sulfur,% 1.9 C,%: 85 N,% 12.7 Na + Oa, O / o0.3 Asphaltenes,% 0 , 8 Residue, o / o3.7 Viscosity according to Engler at 38 ° C 1.383.1 thousand kg of this raw material is supplied to the site / atmospheric distillation, where the raw material is divided into residue (42%) and distillate (50.4 T 1.6%). The residue is mixed with oxygen (95% purity, flow rate 334 nm3) and steam (1800 nm). Gas Gj obtained from gasification of the raw material, is desulfurized in apparatus 2, then sent to the conversion unit 3, 4 WITH and purification of CO2 from water with soda in apparatus 5. Gas G4 has the following composition (in o / o) Na95.2 CO1.0 CO2 = CH40.3 Na1.4 This gas is displaced with the distillate in the vapor state, transferred to hydrodesulfurization in the apparatus (5 and to hydrogasification to apparatus 7, which is carried out as in Example 1. The operating pressure in the system is 75 at. Get 1000 nm gas T, having the following composition (% by volume): H211.0 CB., 86.5 CO0.9 Na1.6 Highest calorific value of gas 8600 kcal / nm. Example 3. This at The epr is concerned with heat catalytic deasphalting (briefly called combination operation) combined with hydrogasification.The process cycle is shown in Fig. 3. Raw materials are fed to the column / for fractional reheating.Pairs coming from the top of the column / are cooled in aprate 2 and collected in receiver 3 The residue leaving column 1 is collected in receiver 4 and from there pump 5 is fed through heater 6 to deasphalting reactor 7 and then, together with hydrogen or hydrogenating gas, pump 8 is sent to the reactor. Products in the vapor state from the upper part of the reactor 7 are fed to the column 9, into the lower part of which an additional hydrogenation gas stream is injected. Products leaving the top of column 9 can be sent to hydrogasification via line 10 or to hydrodesulfurization through apparatus P. In the latter case, products leaving the desulfurization unit cooled in apparatus 12 are cooled in heat exchanger 13 with gas-liquid. The gases leaving the top of the heat exchanger 13 are cleaned, i.e. they are desulfurized, in apparatus 14 and returned to the cycle via line 15. Liquid products are washed in an apparatus 16 with a solution of caustic soda. Further, these products and first-stage gasoline are shifted in the column with hydrogen or hydrogenating gas and, passing them through the preheater, are fed to the hydro gasifier 17. Some of the gases leaving the hydro gasifier 17 are cooled in the device 18 and separated from the unconverted liquid in the device 19, and then served in the consumption line. Another part of the gas is preheated in apparatus 20 and, after catalytic reforming, in reactor 21 is sent to reactor 22, where oxidation of carbon monoxide occurs with water vapor in order to produce hydrogen-rich gas. This gas is cooled in apparatus 23, washed with water or other absorption liquid in apparatus 24 for separating carbon monoxide, and after recompression (if necessary) is recycled to supply with hydrogenating gas used for deasphalting, hydrodesulfurization and hydrogasification. Between phases, the gas can be compressed to compensate for the pressure loss at the intermediate stage. If carbon monoxide needs to be replaced, a certain amount of gas is reduced by adding air. In this way, a gas having a lower calorific value is obtained. This gas is mixed with the gas coming from the hydrogasification.

Tables a

Below are the results of the processing of asphalt raw materials from the Ragusa (Sicili) oil field.

Characteristics of raw materials:

Specific weight at 15 ° / 4 ° С, 0.938

Engler viscosity at 50 ° C18

Residue, o / o7.1

Asphaltenes,% 9.1

Carbon% 84.1

Hydrogen,% 11.6

Atomic ratio H / S1,66

Capacity obtained by subtracting the gas consumption for preheating the recovery furnace and for producing steam and gas for hydrogasification (the latter is recycled to hydrogen production), as follows (from 1 kg of raw material): combustible oil 60 g, asphalt residue 272.5 g, gas 0.590 nlgz .

Gas Composition (V / V)

N-2 + CO + CO21.66 Na19.00 CH479.26 CaHb0.08 Lower calorific value, kcal / kg8136

The same treatment was carried out on lighter raw materials, having the following characteristics:

Specific weight 15 ° / 4 °,, 773

Carbon% 85,64

Hydrogen, o / o14.30

Atomic ratio H / C1,99

Sulfur% 0.08

Higher calorific value, kcal1kg11140

Limits vykipani, ° C:

initial boiling point

50 vol. %

90 about %

final boiling point

From 1 kg of raw material, bitumen is obtained, of which oil 70.0 g, gas 1.083 nm.

Gas composition (in v / v);

NS + CO -f CO 2 Na

CH4

Sgnb

Heat output gas

kcal / nm 8631

Example 4. This example shows the effect of excess hydrogen (and its partial pressure) on the formation of carbon. A series of experiments on the catalytic hydrogasification of gasoline in a straight race has been carried out. Pure hydrogen is used as a hydrogenation gas.

As the raw material, gasoline is taken, and it can have the following characteristic:

Specific weight 15 ° / 4 ° С,, 719 Sulfur,% 0.06 Atomic ratio H / C2.14 Higher calorific value, kcal1kg11360 Limits of vipheni, ° С:

initial boiling point 41

50 vol. o / o115

90 about % 164

final boiling point 186

The table shows the process conditions and the results of five tests carried out with an increasing ratio Hu / Hs (in the last trial, the process pressure was also increased). The catalyst was a carrier of aluminum with a content of 7% molybdenum, 1% cobalt, and 2o / o nickel.

From the table it can be seen that the percentage of carbon deposition and weight loss decreases with increasing excess of hydrogen (and hence the percentage of free hydrogen in the resulting gas).

In the last test, the ratio is

reaches 214%, (i.e., 114 o / o of excess hydrogen) and pressure — 60 atm, losses are reduced to 0.10% and the amount of carbon on the catalyst is to 0.05%.

10 Subject of the invention

The method of hydrogenating the oil fraction at elevated temperature and pressure in the presence of a hydrogenation catalyst containing metal compounds of the VI and VIII groups of the periodic system on the amorphous oxide of the metal of the PA, IIIA and IVB groups of the periodic system, characterized in that, to obtain a mixture of gaseous hydrocarbons, as a fuel, the oil fraction is preliminarily purified from sulfur, asphaltenes and ash by known methods, and the process is carried out at a temperature of 550-700 ° C, a pressure of 15-100 atm in the presence of hydrogen in excess.

Raw material

Oxygen

steam

one

€ 02

2

body rich