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(11) | EP 0 636 678 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
| published in accordance with Art. 158(3) EPC |
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| (54) | METHOD OF REFINING HEAVY OIL MATERIALS. |
(57) A method for processing heavy petroleum crude provides for preliminary modification
of a part of the initial raw material and/or heavy petroleum crude which is different
by its content from the initial raw material to be processed. For that purpose it
is subjected to processing by air at a temperature of 200-300 °C at a mass ratio between
the air and the raw material equalling 0.1-0.6:1, respectively, giving a gaseous phase
which is removed and a liquid product which is then subjected to vacuum distillation
with extraction of a distillate evaporating before the temperature of 540 °C. The
distillate is mixed with the initial petroleum crude to be processed at the distillate
content of 2.0-25.0 % by weight of the total of the obtained modified mixture. The
modified mixture is subjected to cracking.
Field of the Invention
[0001] The present invention relates to the sphere of oil refining, specifically to the method of refining heavy oil materials.
[0002] Heavy oil materials is a complex mixture of hydrocarbons of various chemical compositions and offer valuable oil material for production of a variety of oil refining products. One of the most valuable products is represented by a fraction that boils out at temperatures below 350°C (light distillated products), which are widely used as motor fuels.
Desription of the Prior Art
[0003] One of the most widely employed method for heavy oil material refining is a catalystic cracking. Under the conditions of cracking, the catalyst is quickly deactivated, which reduces the yeild of light distillated products.
[0004] There are known different methods of increasing the output of light distillated products. One of the most common ways of achieving said target is the elaboration and construction of special catalystic systems. The elaboration of such systems, however, requires considerable expenditures.
[0005] Another way is an improvement of the provision for cracking equipment, which is also expensive and limited in effectiveness.
[0006] There is still another method, directed at the increase of light distillated product output, the essence of which is an introduction of various additional agents into the feed. For instance, oxygen-containing surfactants can be used as such additional agents.
[0007] Known is, for example, a method of vacuum gas-oil refining by means of the catalystic cracking at a temperature of from 500 to 530°C in the presence of a zeolite-containing aluminosilicate catalyst. When said method is employed, an oxyalkalized alkylphenol or block copolymers of ethylene and propylene oxides are introduced in advance (SU, A, 1474168). The use of additional agents with said method makes it possible to increase the yeild of gasoline from 27.78 mass % to 28.92 mass %; however, said additional agents are very expensive products.
[0008] There is a number of methods in which the catalytic cracking is carried out in the presence of oxygene, taken from air. Accroding to one of such methods a heavy oil raw material is heated up to 450-550°C and mixed with air. The mixture is fed to the reactor having a fixed bed of an aluminosilicate catalyst. The temperature of cracking is additionally raised by burning a part of the charged feed in the upper section of the reactor.
[0009] When said method is employed, air is used with a solo aim of increasing temperature in the reactor. Thanks to it conversion can be enhanced, however, a part of the valuable oil feed is wasted as a result of burning. The described method is applicable only in case low-active catalysts are used (US, A, 2476729).
[0010] In another method of heavy oil material refining, namely, in refining a vacuum gas-oil, the oil feed ia also heated up to a temperature of from 200 to 300°C. The heated oil feed is charged to the cracking reactor simultaneously with the delivery of air in the quantity of 1.3 to 4.0 mass % (if converted to oxygene) on feed. The cracking process is carried out in the presence of a zeolite-containing catalyst at a temperature of from 500 to 530°C. The air consumption varies depending on the desired target product (gasoline, light gas-oil). To ensure an increase in the output of the target product from 52 mass % (when air is not used) to 64 mass %, the method calls for a relatively great consumption of air, resulting in an increased energy load on the compression equipment (SU,A, 1555344).
[0011] There exists still another method of heavy oil material refining. Said method involves preheating of the feed-vacuum gas-oil, up to a temperature of from 200 to 300°C and the treatment of said feed by air with an air/vacuum gas-oil mass ratio being 0.013-0.2 : 1. Then treated vacuum gas-oil is delivered for cracking. The cracking is carried out under the standard conditions: at a temperature of baout 500°C with a catalyst being ziolete-containing aluminosilicate one (SU, A, 1754764).
[0012] The realization of said method results in an increase of the light distillated product output from 47.0 mass % (with no air used) up to 61.0 mass %.
[0013] To ensure such an output of the target products, the method envisages a rather great air consumption. Besides, this method is applicable only to gas-oil refining.
Disclosure of the Invention
[0014] The basis for the invention is a purpose to create a method of refining heavy oil materials, which permits the refining of oil materials of various compositions, ensures a high output of light distillated products, and has economic advantages.
[0015] In the applied method this purpose is achieved by refining heavy oil materials, including a catalytic cracking at a temperature of from 500 to 530°C in the presence of a zeolite-containing aluminosilicate catalyst, in which, according to the invention, a part of the original heavy oil raw material and/or a heavy oil material that is different in composition from the original oil material, is first subjected to modification by treatment with air at a temperature of from 200 to 300°C with the air/oil material mass ratio equal to 0.1-0.6:1, respectively, accompanied by a gas phase, obtained and removed out of the system, and a liquid product that is subjected to vacuum distillation with the extraction of a distillate which boils out at a temperature below 540°C, followed by it, subsequent mixing with the original oil material, the percentage of the distillate in the modified mixture, subjected to cracking, being 2.0-25.0 mass %.
[0016] As a heavy oil raw material use can be made of, e.g., vacuum gas-oil various origins, residual heavy oil material, or their mixtures. Traditional catalysts of cracking process serve as catalysts of said processes, Microspherical ball-type zeolite-containing catalyst can be employed as such a catalyst.
[0017] To realize the applied method, first a part of the original oil material and/or a heavy oil raw material of another composition relative to the original material, subjected to refining, is preliminarily modified. To this end, said oil material first is exposed to air treatment under the indicated above conditions. The selected conditions are optimal ones. A drop of the temperature below the indicated level results in a decrease of the light distillated product output. The same result is achieved when the selected air consumption is decreased. A rise in the temperature over 300°C brings about the formation of undesirable tar products, which have a determinal effect on the cracking process, whereas an increase in the air consumption leads to an escape of the oil material along with the developing gas phase.
[0018] As a result of such a treatment a gas phase and a liquid product are developed. The gas phase is vented out of the system, otherwise the process of vacuum distillation becomes hampered.
[0019] The quantity of oil material, taken for air treatment, depends on the composition of the original oil material and on the processing equipment.
[0020] A further modification of the oil material takes place at the stage of the liquid phase vacuum distillation and when the distillate obtained is mixed with oil products, subjected to refining. As a consequence, a modified mixture is obtained, which is subjected to cracking.
[0021] The selcted quantity of distillate in the modified mixture is also optimal. The employment of the distillate in a smaller quantity does not bring a considerable increase in the light distillated product output, whereas an increase in the quantity of the distillate results in additional energy wastes that are not compensated by an increase of the target products.
[0022] To provide for vacuum distillation when a residual heavy oil material is being refined, it is advised prior to vacuum distillation to mix the liquid product with the oil material subjected to refining, in the quantity up to 90 mass % of the total quantity of the mixture obtained.
[0023] On the basis of the known technical solutions, it is possible to make a conclusion, that an increase in the output of the light distillated products depends on the air consumption: the more air is consumed, the more target product output rises.
[0024] In the applied method a considerable increase of the target product output is achieved with a less consumption of air relative to the known art, which is not evident.
[0026] The applied method of refining heavy oil materials makes it possible to refine oil materials of various qualities, for instance, a gas-oil of various origines, residual oil material - mazout, their mixtures.
[0027] The method ensures the production of light distillated products with a high output. Thus, for example, in the course of the vacuum gas-oil refining on the output of light distillated products is equal to about 67mass %, whereas the output of refining a mixture of gas-oil and mazout is about 62 mass %.
[0029] The applied method of refining heavy oil raw materials is technologically simple and can be realized as follows.
[0030] A part of the original oil material or another heavy oil raw material or their mixture is delivered to the furnace of preliminary heating where said material is heated to a temperature of from 200 to 300°C. After it, the heated oil material is fed to a reaction apparatus where it is treated by air at the desired mass ratio. Such a treatment can be carried out, for instance, by means of air bubbling through movable oil material bed or a flow of turbulent air through a flow of the moving oil material. The gas phase obtained is vented out of the system, whereas the liquid product is fed to the vacuum tower for distillation. As a result of distillation, a distillate is separated that boils out at a temperature below 540°C. The fraction that boils out at a temperature above 540°C is removed out of the system. The separated distillate is mixed with the original heavy oil material being refined, for instance, by means of the distillate delivery into the pipeline of original oil material, and the modified mixture obtained is fed to the reactor of the catalytic cracking. The cracking is carried out under the traditional conditions, namely, at a temperature of from 500 to 530°C in the presence of a circulating zeliote-containing microspherical or ball-type catalyst. A flow, discharged from the reactor in the form of vapours, is delivered into the fractionating tower for separation.
[0031] In case a residual heavy oil material is subjected to refining, prior to the vacuum distillation the liquid product is mixed with the original residual heavy oil material in the desired quantities.
Example 1.
[0033] Subject to refining is a sulfurous vacuum gas-oil, containing 1.24 mass % of sulphur with a Conradson carbon of 0.123 mass %, a density of 0.9058, fractions, boiling out at a temperature below 350°C-9.0 mass %, below 360°C-11.0 mass %, below 500°C-97.5 mass %, and a group composition (in mass %):
| paraffin-naphthenic hydrocarbons | 50.7; |
| aromatic hydrocarbons | 48.4; |
| tars | 0.9. |
[0034] 500 g of gas-oil is heated in the reaction apparatus up to a temperature of 250°C, then treated with air by means of bubbling procedure via a oil material layer for 45 min at a rate of 4 l/kg.min. Air/vacuum gas-oil mass ratio is equal to 0.468:1. The resultant gas phase is vented out of the upper part.
[0035] The liquid product obtained (with a Conradson carbon of 6.51 mass % and sulfur content of 0.66 mass %) is subjected to the vacuum distillation thanks to which a distillate is separated, which boils out at a temperature of from 90 to 540°C. The distillate obtained (5 mass % of the total mass of the mixture) is mixed with the original sulfurous vacuum gas-oil. 10 ml (9.07 g) of the mixture, modified as indicated above (with a Conradson carbon of 0.180 mass % and a group chemical composition being: paraffinnaphthenic hydrocarbons - 41.9 mass %, aromatic hydrocarbons - 58.1 mass %), is delivered to the flow-through reactor of the catalyst cracking. Said cracking is effected in the presence of a microspherical zeolite-containing aluminosilicate catalyst
[0039] Should the cracking procedure deal directly with the sulfurous vacuum gas-oil, the output of the light distillated products is equal to 47.2%.
Example 2.
[0040] Subject to refining is a sulfurous vacuum gas-oil of the composition, indicated in Example 1.
[0041] 500 g of a mazout with a density of 0.9566, containing 1.83mass % of sulfur with a Conradson carbon of 8.72 mass %, comprising fractions that boil out at temperatures: below 350°C - 10.0 mass %, below 360°C - 14.0 mass % and below 500°C - 53.0 mass % and a group chemical composition in mass %:
| paraffin-naphthenic hydrocarbons | 45.3; |
| aromatic hydrocarbons | 32.6; |
| tars | 17.8; |
| asphaltens | 4.3; |
are heated in the furnace up to a temperature of 300°C, then delivered to the reaction apparatus, where they are exposed to a turbulent air flow for 38 min at a rate of 4 l/kg.min. The air/mazout mass ratio is equal to 0.378:1. The resultant gas phase is vented out. 100 g of the liquid product obtained is subjected to the vacuum distillation and a distillate separated which boils out at a temperature below 540°C. The resultant distillate (3 mass % of the total mixture mass) is mixed with the sulfurous vacuum gas-oil, the composition of which is indicated in Example 1.
[0042] 10 ml of the mixture, modified as indicated above (with a Conradson carbon of 0.145 mass % a group chemical composition being:
| paraffin-naphthenic hydrocarbons | 40.3 mass %, |
| aromatic hydrocarbons | 59.7 mass %) |
is subjected to cracking under the conditions of Example 1.
[0044] Should the cracking procedure deal directly with the sulfurous vacuum gas-oil, the output of the light distillated is equal to 47.2%.
Example 3.
[0045] Subject to refining is a sulfurous vacuum gas-oil of the compositionm indicated in Example 1.
[0046] 500 g of a mazout with a composition, indicated in Example 2, is heated in the reaction apparatus up to a temperature of 200°C, then it is bubbled through with air for 45 min at a rate of 4 l/kg.min. The air/mazout mass ratio is equal to 0.47:1, respectively.
[0047] The liquid product obtained is mixed with a sulfurous vacuum gas-oil with a mass ratio of 47:53, respectively, and delivered for the vacuum distillation.
[0048] The distillate is obtained as indicated in Example 1. Said distillate is mixed with a sulfurous vacuum gas-oil and the modified oil material is subjected to cracking. The quantity of the distillate makes up 25 mass % of the total quantity of the modified mixture.
[0050] Should the cracking procedure deal directly with the vacuum gas-oil, the output of the light distillated products is equal to 47.2%.
Example 4.
[0051] Subject to refining is a hydrotreated vacuum gas-oil, containing 0.31mass % of sulfur with a Conradson carbon of 0.118 mass %, a density of 0.8950, comprising fractions boiling out below a temperature of 350°C - 14 mass %, below 360°C - 15 mass % and below 500°C - 98 mass %.
[0052] The gas-oil is treated by air as indicated in Example 1, but with the air/gas mass ratio being 0.28:1, respectively.
[0053] The liquid product obtained is subjected to the vacuum distillation, as indicated in Example 1.
[0054] The distillate is mixed with the original gas-oil. The quantity of the distillate amounts to 8 mass % of the total mixture quantity. The resultant mixture is subjected to the vacuum distillation, as indicated in Example 1.
[0055] The distillate is mixed with the original gas-oil. The quantity of the distillate makes up 8 mass % of the total quantity of the mixture. The resultant modified mixture is subjected to cracking.
[0057] Should the cracking procedure deal directly with the hydrotreated vacuum gas-oil, the output of light distillated products is equal to 53.1%.
Example 5.
[0058] Subject to refining is a mixture of the vacuum gas-oil and mazout (the mass ratio in 4:1, respectively). The characteristics of the mixture: a density of 0.9159, sulfur content in 1.55 mass %, a Conradson carbon is 1.7 mass %, fractions, boiling out at a temperature below 350°C - 12 mass %, below 360°C - 15 mass %, below 500°C - 87 mass %. The mixture refining is carried out as in Example 1, but with a temperature of the oil material air treatment being 200°C and the air/raw material mass ratio being 0.1:1, whereas the quantity of the distillate obtained, after it is mixed with the original oil material mixture, is 2.0 mass % of the total quantity of the modified mixture.
[0060] Should the cracking procedure deal with the original oil material directly, the output of light distillated products is equal to 46.5%.
Example 6.
[0061] Subject to refining is a sulfurous vacuum gas-oil of the composition, indicated in Example 1.
[0062] A mixture of a vacuum gas-oil and mazout in the composition indicated in Example 5, is exposed to air treatment. The temperature of air treatment amounts to 250°C, whereas the air oil material ratio is 0.6:1.
[0063] The quantity of the distillate obtained after it is mixed with the original sulfurous vacuum gas-oil makes up 15.0 mass % of the total quantity of the modified mixture, subjected to cracking.
[0065] Should the cracking procedure deal with the sulfurous vacuum gas-oil directly, the output of light distillated products is equal to 47.2%.
Example 7.
[0066] Subject to refining is a mixture of a gas-oil and a mazout of the composition, indicated in Example 5. The mixture is air treated as specified in Example 2. The resultant liquid product is mixed with the original mixture in a quantity of 90 mass % of the total quantity of the mixture, and then subjected to distillation. The distillate is mixed with the original oil material. The quantity of said distillate amounts to 20 mass % of the total quantity of the modified mixture.
[0068] Should the cracking procedure deal with original oil material mixture directly, the output of light distillated products is equal to 46.5 mass %.
Induatrial Applicability
1. A method of refining a heavy oil materials, comprising a cracking at a temperature
of from 500 to 530°C in the presence of a zeolite-containing aluminosilicate catalyst,
characterized in that a part of the original heavy oil materials and/or a heavy oil material, different
in composition from the original oil material, is subjected to modification by means
of an air treatment at a temperature of from 200 to 300°C, an air oil material ratio
of 0.1-0.6:1, respectively, with obtaining a gas phase and its removal from the system
and a liquid product which is subjected to a vacuum distillation with a separation
of a distillate, boiling out at a temperature below 540°C, and its subsequent mixing
with the original heavy oil materials, with the quantity of said distillate being
2.0 to 25.0 mass % from the total quantity of the modified mixture obtained, which
is subjected to cracking.
2. The method according to Claim 1, characterized in that in case a residual heavy oil material is refined, prior to the vacuum distillation
said liquid product is mixed with this oil material, taken in the quantity up to 90
mass % of the total quantity of the mixture obtained.