CA1094491A - Two-stage thermal and catalytic hydrocracking of heavy oils - Google Patents
Two-stage thermal and catalytic hydrocracking of heavy oilsInfo
- Publication number
- CA1094491A CA1094491A CA275,103A CA275103A CA1094491A CA 1094491 A CA1094491 A CA 1094491A CA 275103 A CA275103 A CA 275103A CA 1094491 A CA1094491 A CA 1094491A
- Authority
- CA
- Canada
- Prior art keywords
- hydrocracking zone
- heavy
- hydrogen
- hydrocracking
- hydrocarbon oil
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
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Classifications
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
- C10G65/00—Treatment of hydrocarbon oils by two or more hydrotreatment processes only
- C10G65/02—Treatment of hydrocarbon oils by two or more hydrotreatment processes only plural serial stages only
- C10G65/10—Treatment of hydrocarbon oils by two or more hydrotreatment processes only plural serial stages only including only cracking steps
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
- C10G47/00—Cracking of hydrocarbon oils, in the presence of hydrogen or hydrogen- generating compounds, to obtain lower boiling fractions
- C10G47/22—Non-catalytic cracking in the presence of hydrogen
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- Chemical & Material Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Engineering & Computer Science (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
Abstract
TWO-STAGE THERMAL AND CATALYTIC HYDROCRACKING
OF HEAVY OILS
ABSTRACT OF THE DISCLOSURE
An improved process for the hydrocracking of heavy hydrocarbon oil, such as oils extracted from tar sands, in which the charge oil in the presence of an excess of hydrogen is passed upwardly through a first vertical hydro-cracking zone in the absence of a catalyst, an effluent emerging from the top of the zone is separated into a gaseous stream, containing a wide boiling range material from naphtha to heavy gas oil and a liquid stream containing heavy hydrocarbons, the gaseous stream together with added hydrogen is passed upwardly through a second vertical catalytic hydrogenating zone and the effluent from the catalytic hydrogenating zone is separated into a liquid product and a gaseous component containing predominantly hydrogen which can be reused. This process provides a simple and in-expensive procedure for obtaining from heavy oils lighter hydrocarbon oils having low sulphur and nitrogen contents.
OF HEAVY OILS
ABSTRACT OF THE DISCLOSURE
An improved process for the hydrocracking of heavy hydrocarbon oil, such as oils extracted from tar sands, in which the charge oil in the presence of an excess of hydrogen is passed upwardly through a first vertical hydro-cracking zone in the absence of a catalyst, an effluent emerging from the top of the zone is separated into a gaseous stream, containing a wide boiling range material from naphtha to heavy gas oil and a liquid stream containing heavy hydrocarbons, the gaseous stream together with added hydrogen is passed upwardly through a second vertical catalytic hydrogenating zone and the effluent from the catalytic hydrogenating zone is separated into a liquid product and a gaseous component containing predominantly hydrogen which can be reused. This process provides a simple and in-expensive procedure for obtaining from heavy oils lighter hydrocarbon oils having low sulphur and nitrogen contents.
Description
10~4491 This invention relates to the treatment of hydrocarbon oils and, more particularly, to the hydrogenation and hydro-cracking of relatively heavy hydrocarbon oils to produce improved products of lower boiling range.
Hydrocracking processes for the conversion of heavy hydrocarbon oils to light and intermediate naphthas of good quality for reforming feedstocksJ fuel oil and gas-oil are well known. In such processes, it is normally desirable to be able to control at least to some extent the relative amounts of various products produced. For instance, it may some times be desirable to produce relatively large quantities of gasoline boiling range products, while at other times relatively greater quantities of slightly higher boiling products such as those suitable for fuel oils may be desired.
The heavy hydrocarbon oils to which this invention is directed can be such materials as petroleum crude oil, atmospheric tar bottoms products, vacuum tar bottoms products, heavy cycle oils, crude oil residuum, top crude oils and the heavy hydro-carbonaceous oils extracted from tar sands. Of particular interest are the oils extracted from tar sands and which contain wide boiling range materials from naphthas through kerosene, gas oil, tar, etc. and which contain a large portion of material boilin~ above 975F.
The heavy hydrocarbon oils of the above type tend to contain nitrogenous and sulfurous compounds in exceedingly large quantities. In addition, such heavy hydrocarbon fractions frequently contain excessive quantities of organo-metallic contaminants which tend to be extremely detrimental to various catalytic processes that may subsequently be carried out, such as hydroforming. Of the metallic contaminants, those containing j: _ ] _ ~
` 10~4491 nickel and vanadium are most common, although other metals are often present. These metallic contaminants, as well as others, are usually present within the hydrocarbonaceous material as organo-metallic compounds of relatively high molecular weight. A considerable quantity of the organo-metallic complexes are linked with asphaltenic material and contain sulfur. Of course, in catalytic hydrocracking procedures, the presence of large quantitites of asphaltenic material and organo-metallic compounds interfers considerably with the activity of the catalyst with respect to the destructive removal of nitrogenous, sulfurous and oxygenated compounds.
Of the non-metallic impurities, nitrogen is probably most undesirable because it effectively poisons most catalysts which may be employed in the conversion of petroleum franctions.
They are particularly damaging to reforming and catalytic cracking catalysts. It is , therefore, particularly necessary that nitrogenous compounds be removed substantially completely from the lighter hydrocarbon oils being obtained from the heavy oils. The nitrogenous and su]furous compounds are further objectionable because combustion of fuels containing these impurities results in release of nitrogen and sulfur oxides which are noxious, corrosive and present a serious problem with respect to pollution of the atmosphere. Furthermore, with respect to motor fuels, sulfur is particularly objectionable because of odour, gum and varnish formation, and significantly decreased lead susceptibility.
.
. .
~0~4~
The necessity for the removal of the above contam-inants is well known in petroleum processing. One of the techniques used in this impurity removal has been catalytic hydrocracking. In this process, the oil is passed with hydrogen, into a fixed bed or an ebullated bed of catalysts.
However, the fixed bed catalytic process has been extremely difficult to operate. This is mainly due to bed plugging and catalyst deactivation by metals, coke and carbonaceous materials deposited on the catalysts and interstitial spaces.
In the ebullated bed process some of the problems are overcome as the catalyst can be added and removed continuously.
However, catalyst cost is high due to rapid deactivation of the catalysts. The catalyst can be reused if it is possible to regenerate the catalyst. This requires high capacity catalyst regeneration equlpment in order to implement the process on a continuous basis.
Following the hydrocracking step, the product is distilled to produce naphtha (IBP-204C), light gas-oil ~; (204-343C) and heavy gas-oil (343-524C) and these are further treated individually to remove sulphur and nitrogen compounds.
Industry has always treated the product in individual fractions through tradition and because of fears that nitrogen compounds would migrate to the naphtha fraction, producing off-specification material. Once-through treatment of the distillates together has advantages in the reduction of capital and operating costs for distillation facilities and hydrotreaters. Further reduction in costs can be obtained if the hot hydrocracked product from the first stage is treated directly without pressure let-down or condensation.
There are various specific examples in the literature of attempts to overcome some of the above problems and one such attempt is described in Ga~sis U.S. Patent 3,453,206, issued - 1094~1 July 1, 1969. That patent describes a multi-stage hydrocracking process for heavy oils in the first stage of which the heavy oil (containing fractions boiling above the gasoline range) is treated with a mixture of hydrogen and water (from about 2 to 30% by weight of water) and in the second stage is treated in the presence of a catalyst at hydrofining conditions. In the first stage, the reactor is packed with stainless steel turnings and the liquid is passed downwardly while the hydrogen-water mixture is passed upwardly countercurrently.
It is the object of the present invention to provide a hydrocracking process which is effective in removing various , contaminating influences from heavy hydrocarbon oils and , particularly those extracted from tar sands.
SUMMARY OF THE INVENTION
~, Thus, in accordance with the present invention there is described a process for hydrocracking a heavy hydrocarbon oil, at least about 50% by volume of which boils above 975F
^i which comprises:
, a) passing the heavy hydrocarbon oil in the presence 20 of 500 to 50,000 Scf of hydrogen per barrel of oil upwardly through a first vertical hydrocracking zone in the absence of a catalyst, the hydrocracking zone being maintained at a temperature between about 400 and 470C, a pressure between about 500 and 2500 psig. and a space velocity of between about 0.5 and 1.5 volume of hydrocarbon oil per hour per volume of hydrocracking zone capacity, b) removing from the top of the hydrocracking zone a mixed effluent containing a gaseous phase comprising hydrogen ~ and vapourous hydrocarbons and a liquid phase comprising un-;~ 30 vapourized hydrocarbons, . ;
- 4 ~
~0~449~.
c) separating the effluent into a gaseous stream containing wide boiling range material from naphtha to heavy gas oil and a liquid stream containing heavy oils, d) recycling at least a portion of the above liquid stream as part of the heavy hydroca~bon oil feed to ; the first hydrcracking zone, e) passing the above gaseous stream together with added hydrogen upwardly through a second vertical hydrocracking zone containing a hydrogenating catalyst, this second hydrocracking ; 10 zone being maintained at a temperature between about 400 and 470C, a pressure the same as the first hydrocracking zone and a space velocity between about 0.5 and 1.5 volume of hydrocarbon oil ; per hour per volume of hydrocracking zone capacity, f) removing from the top of this second hydrocracking zone a second mixed effluent containing a gaseous phase comprising hydrogen and vapourous hydrocarbons and a liquid phase, and g) separating this second effluent in a low tempera-ture - high pressure separator into a liquid product stream and a gaseous stream comprising hydrogen with minor amounts of gaseous hydrocarbons and impurities.
The process of this invention is particularly well suited for the treatment of heavy oils having a large portion, preferably at least 50% by volume, which boils above about 975F
and which contains a wide boiling range of materials from ~aphtha through kerosene, gas oil and tar.
-` By mixing the charge stock and hydrogen together and passing these upwardly through a vertical empty column in the absence of catalyst under the conditions as set out above, it has been found that the high molecular weight compounds hydro-genate and/or hydrocrack into lower boiling ranges. For example, in the case of Athabaska bitumen, about 80% of the material boiling above 975F is converted to lower boiling materials.
109~491 About 50~ of the sulfur and 15~ of the nitrogen are also removed in this first stage.
The mixture of gas and liquid removed from the top of the first stage is preferably separated in a hot separator which is kept at the same temperature as the reactor. A
portion of heavy oil stream separated from the hot separator is recycled into the first stage as part of the charge stock with a portion of this recycled stream being drawn off to prevent the build-up of metals and mineral matter within the first 10 stage reactor. The pitch (material boiling above 975F) can be separated from the heavy oil purge. The pitch can either be gasified or sold as a by-product.
The gaseous s~ream from the hot separator, contain-ing wide boiling range materials, is sent directly to a catalytic hydrocracking zone which again is a vertical zone, ! preferably in the form of a fixed bed catalytic reactor.
The pressure in the catalytic reactor is the same as the first stage and this pressure is maintained through the separator between the reactors. The gaseous stream from the hot separator is preferably passed through the catalytic zone in an upward flow with the size of the catalyst bed being adjusted to give the space velocity between 0.5 and 1.5 hr 1 The temperature within this zone is selected so as to meet desired product specifications with fresh make up hydrogen being added to maintain hydrogen purity.
Suitable hydrogenation catalysts include the oxides and/or sulfides of cobalt, nickel, and molybdenum. These metals may be supported on a base such as silica, alumina, magnesia or mixtures of these.
The upward flow through the catalytic hydrocracker is particularly preferred because in this manner the naphtha leaves the reactor fastest, followed by kerosene-range material and ; finally the gas-oil range material. This provides longer contact time for heavier boiling materials.
The gases from the catalytic hydrocracker are separated in a low temperature - high pressure separator and by using this type of separator the gaseous stream obtained contains mostly hydrogen with some impurities such as hydrogen sulfide and 10 light hydrocarbon gases. This gaseous stream is passed through .
a scrubber and recycled as part of the hydrogen feed to the first hydrocracking stage. The recycled hydrogen gas purity is maintained by adding make up hydrogen.
The liquid stream from the low temperature -;high pressure separator represents the product of the present process and it can be sent to a fractionator. There it can be conveniently broken down into different fractions including a naphtha fraction, a light gas oil fraction and a heavy gas oil fraction. As has been pointed above, nitrogen is highly 2d poisonous to reforming catalysts and is also a pollutant. This has made it necessary for naphtha feeds to be pretreated to reduce nitrogen content below about 1 ppm before sending it to ` a catalytic reformer. With the procedure of the present inven-tion, the naphtha fraction from the fractionator already has a nitrogen level below 1 ppm and can be used without further treatment as reformed feedstock. The light gas-oil and heavy gas-oil fractions meet the fuel oils and catalytic cracking gas-oil specifications respectively. Thus, the present inventions ~; eliminates the need for secondary refining of distillates in separate stages.
- 1094~91 According to an alternative feature of the present invention, the above process sequence can be modified whereby the gas - liquid mixture effluent from the first stage hydro-craclcigg zone is fed directly to a catalytic hydrocracking unit without separating the heavy bottoms. Although the high boiling materials such as asphaltenes and metal complexes are well known to poison the hydrocracking catalyst, the first stage hydrocracking of the present invention has been found to be capable of converting sufficient of the pitch into lower boiling fractions, that the life 10 of the catalyst is considerable extended. Again with this procedure~ the gases from the catalytic hydrocracking unit are separated in a low-temperature, high-pressure separator and the liquid component is sent to a fractionator.
For a better understanding of the invention, reference is made to the accompanying drawing which illustrates diagra-1 matically a preferred embodiment of the present invention.
Hydrocarbon oil feed 10 together with recycled hydrogen , and make up hydrogen from line 11 is introduced through oil-heater 12 into the bottom of an empty tower 13. A gas-liquid mixture is withdrawn from the top of the tower through line 14 and introduced into a hot separator 15 in which the temperature is maintained at that of the outlet of tower 13. In the hot separator 15 the effluent from tower 13 is separated into a gaseous stream lô and a liquid stream 16. The liquid stream 16 is in the form of heavy pitch bottoms and this is recycled into the oil in feed line 10 with a portion of the recycle being drawn off through line 17.
The gaseous stream from hot separator 15 is carried by ; way of line 18 into the bottom of a catalyst tower 19 which contains a hydrogenation catalyst. This gaseous stream travels upwardly through tower 19 together with hydrogen being added through line 20.
''' The effluent from the catalyst tower 19 is drawn off at the top through line 21 and is fed into a high pressure - low temperature separator 22. Within this separator the product is separated into a gaseous stream rich in hydrogen which is drawn off through line 24. This hydrogen rich stream is passed through scrubber 25 and is combined with fresh make up hydrogen added through line 28 and recycled through gas compressor 27 and line 11 back to tower 13.
The liquid stream from separator 22 represents the final product of the invention and is drawn off through line 23 aad can be fed to a fractionator, etc.
EXAMPLE
The charge stock employed was an Athabaska bitumen having the following characteristics:
I. Specific gravity, 60/60F 1.009
Hydrocracking processes for the conversion of heavy hydrocarbon oils to light and intermediate naphthas of good quality for reforming feedstocksJ fuel oil and gas-oil are well known. In such processes, it is normally desirable to be able to control at least to some extent the relative amounts of various products produced. For instance, it may some times be desirable to produce relatively large quantities of gasoline boiling range products, while at other times relatively greater quantities of slightly higher boiling products such as those suitable for fuel oils may be desired.
The heavy hydrocarbon oils to which this invention is directed can be such materials as petroleum crude oil, atmospheric tar bottoms products, vacuum tar bottoms products, heavy cycle oils, crude oil residuum, top crude oils and the heavy hydro-carbonaceous oils extracted from tar sands. Of particular interest are the oils extracted from tar sands and which contain wide boiling range materials from naphthas through kerosene, gas oil, tar, etc. and which contain a large portion of material boilin~ above 975F.
The heavy hydrocarbon oils of the above type tend to contain nitrogenous and sulfurous compounds in exceedingly large quantities. In addition, such heavy hydrocarbon fractions frequently contain excessive quantities of organo-metallic contaminants which tend to be extremely detrimental to various catalytic processes that may subsequently be carried out, such as hydroforming. Of the metallic contaminants, those containing j: _ ] _ ~
` 10~4491 nickel and vanadium are most common, although other metals are often present. These metallic contaminants, as well as others, are usually present within the hydrocarbonaceous material as organo-metallic compounds of relatively high molecular weight. A considerable quantity of the organo-metallic complexes are linked with asphaltenic material and contain sulfur. Of course, in catalytic hydrocracking procedures, the presence of large quantitites of asphaltenic material and organo-metallic compounds interfers considerably with the activity of the catalyst with respect to the destructive removal of nitrogenous, sulfurous and oxygenated compounds.
Of the non-metallic impurities, nitrogen is probably most undesirable because it effectively poisons most catalysts which may be employed in the conversion of petroleum franctions.
They are particularly damaging to reforming and catalytic cracking catalysts. It is , therefore, particularly necessary that nitrogenous compounds be removed substantially completely from the lighter hydrocarbon oils being obtained from the heavy oils. The nitrogenous and su]furous compounds are further objectionable because combustion of fuels containing these impurities results in release of nitrogen and sulfur oxides which are noxious, corrosive and present a serious problem with respect to pollution of the atmosphere. Furthermore, with respect to motor fuels, sulfur is particularly objectionable because of odour, gum and varnish formation, and significantly decreased lead susceptibility.
.
. .
~0~4~
The necessity for the removal of the above contam-inants is well known in petroleum processing. One of the techniques used in this impurity removal has been catalytic hydrocracking. In this process, the oil is passed with hydrogen, into a fixed bed or an ebullated bed of catalysts.
However, the fixed bed catalytic process has been extremely difficult to operate. This is mainly due to bed plugging and catalyst deactivation by metals, coke and carbonaceous materials deposited on the catalysts and interstitial spaces.
In the ebullated bed process some of the problems are overcome as the catalyst can be added and removed continuously.
However, catalyst cost is high due to rapid deactivation of the catalysts. The catalyst can be reused if it is possible to regenerate the catalyst. This requires high capacity catalyst regeneration equlpment in order to implement the process on a continuous basis.
Following the hydrocracking step, the product is distilled to produce naphtha (IBP-204C), light gas-oil ~; (204-343C) and heavy gas-oil (343-524C) and these are further treated individually to remove sulphur and nitrogen compounds.
Industry has always treated the product in individual fractions through tradition and because of fears that nitrogen compounds would migrate to the naphtha fraction, producing off-specification material. Once-through treatment of the distillates together has advantages in the reduction of capital and operating costs for distillation facilities and hydrotreaters. Further reduction in costs can be obtained if the hot hydrocracked product from the first stage is treated directly without pressure let-down or condensation.
There are various specific examples in the literature of attempts to overcome some of the above problems and one such attempt is described in Ga~sis U.S. Patent 3,453,206, issued - 1094~1 July 1, 1969. That patent describes a multi-stage hydrocracking process for heavy oils in the first stage of which the heavy oil (containing fractions boiling above the gasoline range) is treated with a mixture of hydrogen and water (from about 2 to 30% by weight of water) and in the second stage is treated in the presence of a catalyst at hydrofining conditions. In the first stage, the reactor is packed with stainless steel turnings and the liquid is passed downwardly while the hydrogen-water mixture is passed upwardly countercurrently.
It is the object of the present invention to provide a hydrocracking process which is effective in removing various , contaminating influences from heavy hydrocarbon oils and , particularly those extracted from tar sands.
SUMMARY OF THE INVENTION
~, Thus, in accordance with the present invention there is described a process for hydrocracking a heavy hydrocarbon oil, at least about 50% by volume of which boils above 975F
^i which comprises:
, a) passing the heavy hydrocarbon oil in the presence 20 of 500 to 50,000 Scf of hydrogen per barrel of oil upwardly through a first vertical hydrocracking zone in the absence of a catalyst, the hydrocracking zone being maintained at a temperature between about 400 and 470C, a pressure between about 500 and 2500 psig. and a space velocity of between about 0.5 and 1.5 volume of hydrocarbon oil per hour per volume of hydrocracking zone capacity, b) removing from the top of the hydrocracking zone a mixed effluent containing a gaseous phase comprising hydrogen ~ and vapourous hydrocarbons and a liquid phase comprising un-;~ 30 vapourized hydrocarbons, . ;
- 4 ~
~0~449~.
c) separating the effluent into a gaseous stream containing wide boiling range material from naphtha to heavy gas oil and a liquid stream containing heavy oils, d) recycling at least a portion of the above liquid stream as part of the heavy hydroca~bon oil feed to ; the first hydrcracking zone, e) passing the above gaseous stream together with added hydrogen upwardly through a second vertical hydrocracking zone containing a hydrogenating catalyst, this second hydrocracking ; 10 zone being maintained at a temperature between about 400 and 470C, a pressure the same as the first hydrocracking zone and a space velocity between about 0.5 and 1.5 volume of hydrocarbon oil ; per hour per volume of hydrocracking zone capacity, f) removing from the top of this second hydrocracking zone a second mixed effluent containing a gaseous phase comprising hydrogen and vapourous hydrocarbons and a liquid phase, and g) separating this second effluent in a low tempera-ture - high pressure separator into a liquid product stream and a gaseous stream comprising hydrogen with minor amounts of gaseous hydrocarbons and impurities.
The process of this invention is particularly well suited for the treatment of heavy oils having a large portion, preferably at least 50% by volume, which boils above about 975F
and which contains a wide boiling range of materials from ~aphtha through kerosene, gas oil and tar.
-` By mixing the charge stock and hydrogen together and passing these upwardly through a vertical empty column in the absence of catalyst under the conditions as set out above, it has been found that the high molecular weight compounds hydro-genate and/or hydrocrack into lower boiling ranges. For example, in the case of Athabaska bitumen, about 80% of the material boiling above 975F is converted to lower boiling materials.
109~491 About 50~ of the sulfur and 15~ of the nitrogen are also removed in this first stage.
The mixture of gas and liquid removed from the top of the first stage is preferably separated in a hot separator which is kept at the same temperature as the reactor. A
portion of heavy oil stream separated from the hot separator is recycled into the first stage as part of the charge stock with a portion of this recycled stream being drawn off to prevent the build-up of metals and mineral matter within the first 10 stage reactor. The pitch (material boiling above 975F) can be separated from the heavy oil purge. The pitch can either be gasified or sold as a by-product.
The gaseous s~ream from the hot separator, contain-ing wide boiling range materials, is sent directly to a catalytic hydrocracking zone which again is a vertical zone, ! preferably in the form of a fixed bed catalytic reactor.
The pressure in the catalytic reactor is the same as the first stage and this pressure is maintained through the separator between the reactors. The gaseous stream from the hot separator is preferably passed through the catalytic zone in an upward flow with the size of the catalyst bed being adjusted to give the space velocity between 0.5 and 1.5 hr 1 The temperature within this zone is selected so as to meet desired product specifications with fresh make up hydrogen being added to maintain hydrogen purity.
Suitable hydrogenation catalysts include the oxides and/or sulfides of cobalt, nickel, and molybdenum. These metals may be supported on a base such as silica, alumina, magnesia or mixtures of these.
The upward flow through the catalytic hydrocracker is particularly preferred because in this manner the naphtha leaves the reactor fastest, followed by kerosene-range material and ; finally the gas-oil range material. This provides longer contact time for heavier boiling materials.
The gases from the catalytic hydrocracker are separated in a low temperature - high pressure separator and by using this type of separator the gaseous stream obtained contains mostly hydrogen with some impurities such as hydrogen sulfide and 10 light hydrocarbon gases. This gaseous stream is passed through .
a scrubber and recycled as part of the hydrogen feed to the first hydrocracking stage. The recycled hydrogen gas purity is maintained by adding make up hydrogen.
The liquid stream from the low temperature -;high pressure separator represents the product of the present process and it can be sent to a fractionator. There it can be conveniently broken down into different fractions including a naphtha fraction, a light gas oil fraction and a heavy gas oil fraction. As has been pointed above, nitrogen is highly 2d poisonous to reforming catalysts and is also a pollutant. This has made it necessary for naphtha feeds to be pretreated to reduce nitrogen content below about 1 ppm before sending it to ` a catalytic reformer. With the procedure of the present inven-tion, the naphtha fraction from the fractionator already has a nitrogen level below 1 ppm and can be used without further treatment as reformed feedstock. The light gas-oil and heavy gas-oil fractions meet the fuel oils and catalytic cracking gas-oil specifications respectively. Thus, the present inventions ~; eliminates the need for secondary refining of distillates in separate stages.
- 1094~91 According to an alternative feature of the present invention, the above process sequence can be modified whereby the gas - liquid mixture effluent from the first stage hydro-craclcigg zone is fed directly to a catalytic hydrocracking unit without separating the heavy bottoms. Although the high boiling materials such as asphaltenes and metal complexes are well known to poison the hydrocracking catalyst, the first stage hydrocracking of the present invention has been found to be capable of converting sufficient of the pitch into lower boiling fractions, that the life 10 of the catalyst is considerable extended. Again with this procedure~ the gases from the catalytic hydrocracking unit are separated in a low-temperature, high-pressure separator and the liquid component is sent to a fractionator.
For a better understanding of the invention, reference is made to the accompanying drawing which illustrates diagra-1 matically a preferred embodiment of the present invention.
Hydrocarbon oil feed 10 together with recycled hydrogen , and make up hydrogen from line 11 is introduced through oil-heater 12 into the bottom of an empty tower 13. A gas-liquid mixture is withdrawn from the top of the tower through line 14 and introduced into a hot separator 15 in which the temperature is maintained at that of the outlet of tower 13. In the hot separator 15 the effluent from tower 13 is separated into a gaseous stream lô and a liquid stream 16. The liquid stream 16 is in the form of heavy pitch bottoms and this is recycled into the oil in feed line 10 with a portion of the recycle being drawn off through line 17.
The gaseous stream from hot separator 15 is carried by ; way of line 18 into the bottom of a catalyst tower 19 which contains a hydrogenation catalyst. This gaseous stream travels upwardly through tower 19 together with hydrogen being added through line 20.
''' The effluent from the catalyst tower 19 is drawn off at the top through line 21 and is fed into a high pressure - low temperature separator 22. Within this separator the product is separated into a gaseous stream rich in hydrogen which is drawn off through line 24. This hydrogen rich stream is passed through scrubber 25 and is combined with fresh make up hydrogen added through line 28 and recycled through gas compressor 27 and line 11 back to tower 13.
The liquid stream from separator 22 represents the final product of the invention and is drawn off through line 23 aad can be fed to a fractionator, etc.
EXAMPLE
The charge stock employed was an Athabaska bitumen having the following characteristics:
I. Specific gravity, 60/60F 1.009
2. Sulphur, % by wt 4.48
3. Ash, % by wt 0.59
4. Conradson Carbon Residue, % by wt 13.3
5. Pentane Insolubles, % by wt 15.5 : 20
6. Benzene Insolubles, % by wt 0.72
7. Vanadium content, PPM by wt 213 ~ 8. Nickel content, PPM by wt 67 : 9. Total Acid number 2.77 10. Total Base number 1.89 11. Carbon, %-by wt 83.36 12. Hydrogen, % by wt10.52 `~ 13. Nitrogen, % (Dohrmann micro-coulometer) 0.43 ~ 14. Oxygen, % - ----:` 30 15. Chlorine, % 0.00 16. Viscosity at 210F
kinematic centispokes 133.3 _9_ . ~
10!~491 The above feed stock was passed through a reaction sequence as shown in the attached drawing, with the operating conditions in the first hydrocracking tower being as follows:
Pressure = 2000 psig Temperature = 450C
Space velocity = 1.0 hr (4500 gms/hr) Hot separator temperature = 450C
Hydrogen = 5000 c.ft/bbl Recycle oil = 9060 gms/hr The second stage catalytic hydrocracking was ; simulated using a bench scale reactor unit. The reactor contained as catalyst a product available from Harshaw Chemical Co. under - the designation Ho. HT 400 E. It contains 3 wt. % CoO and 15 wt % MoO3 supported on an alumina base. The operating conditions in the reactor were as follows:
~- Pressure = 2000 psig Temperature = 400 to 450C
Space velocity = 1 hr 20, Hydrogen = 5000 c.ft/bbl The gas stream collected from separator 15 and fed to the catalytic hydrocracking reactor had the following properties:
Boiling range = IBP to 950F
Specific gravi-ty 60/60F = 0.872 Sulphur, wt % = 1.97 Nitrogen, ppm = lg50 .
., , 1094~1 \
Distilled Fractions:
Naphtha (IBP to 400F) Content, vol % = 32.7 Specific gravity, 60/60F = 0.768 Sulphur, wt % = 0.88 Nitrogen, ppm = 575 Light Gas Oil (400 to 650F) Content, vol % = 46.0 Specific gravity, 60!60F = 0.897 Sulphur, wt ~ = 2.18 Nitrogen, ppm = 1404 Heavy Gas Oil (650 to 950F) Content, vol % = 21.3 ; Specific gravity, 60/60F = 0-991 Sulphur, wt % = 2.82 Nitrogen, ppm = 4542 The liquid product from the bench scale reactor (from separator 22 and collected by line 23 in the actual process) had the following properties:
Specific gravity, 60/60F = 0-825 Sulphur, wt % = 0-15 Nitrogen, ppm = 15 Distilled Fractions: -Naphtha (IBP - 400F) Content, vol % = 40-6 Specific gravity, 60/60F = 0-764 Sulphur, wt % = 0.04 ; Nitrogen, ppm = 0-5 109~
Light Gas Oil (400 - 650F) Content, vol % = 52.8 Specific gravity, ; 60/60F = 0.867 Sulphur, wt % = 0.06 Nitrogen, ppm = 10 Heavy Gas Oil (650 - 950F) Content, vol % = 6.6 Specific gravity, 60160F = O. 901 Sulphur, wt % = --~~~
rogen, pp~ = 99 ,~ .
1 :
~, :
: ` .
~ ~:
:
,.~, ~',' ' ..
~.. . .
.
':~
~' .
kinematic centispokes 133.3 _9_ . ~
10!~491 The above feed stock was passed through a reaction sequence as shown in the attached drawing, with the operating conditions in the first hydrocracking tower being as follows:
Pressure = 2000 psig Temperature = 450C
Space velocity = 1.0 hr (4500 gms/hr) Hot separator temperature = 450C
Hydrogen = 5000 c.ft/bbl Recycle oil = 9060 gms/hr The second stage catalytic hydrocracking was ; simulated using a bench scale reactor unit. The reactor contained as catalyst a product available from Harshaw Chemical Co. under - the designation Ho. HT 400 E. It contains 3 wt. % CoO and 15 wt % MoO3 supported on an alumina base. The operating conditions in the reactor were as follows:
~- Pressure = 2000 psig Temperature = 400 to 450C
Space velocity = 1 hr 20, Hydrogen = 5000 c.ft/bbl The gas stream collected from separator 15 and fed to the catalytic hydrocracking reactor had the following properties:
Boiling range = IBP to 950F
Specific gravi-ty 60/60F = 0.872 Sulphur, wt % = 1.97 Nitrogen, ppm = lg50 .
., , 1094~1 \
Distilled Fractions:
Naphtha (IBP to 400F) Content, vol % = 32.7 Specific gravity, 60/60F = 0.768 Sulphur, wt % = 0.88 Nitrogen, ppm = 575 Light Gas Oil (400 to 650F) Content, vol % = 46.0 Specific gravity, 60!60F = 0.897 Sulphur, wt ~ = 2.18 Nitrogen, ppm = 1404 Heavy Gas Oil (650 to 950F) Content, vol % = 21.3 ; Specific gravity, 60/60F = 0-991 Sulphur, wt % = 2.82 Nitrogen, ppm = 4542 The liquid product from the bench scale reactor (from separator 22 and collected by line 23 in the actual process) had the following properties:
Specific gravity, 60/60F = 0-825 Sulphur, wt % = 0-15 Nitrogen, ppm = 15 Distilled Fractions: -Naphtha (IBP - 400F) Content, vol % = 40-6 Specific gravity, 60/60F = 0-764 Sulphur, wt % = 0.04 ; Nitrogen, ppm = 0-5 109~
Light Gas Oil (400 - 650F) Content, vol % = 52.8 Specific gravity, ; 60/60F = 0.867 Sulphur, wt % = 0.06 Nitrogen, ppm = 10 Heavy Gas Oil (650 - 950F) Content, vol % = 6.6 Specific gravity, 60160F = O. 901 Sulphur, wt % = --~~~
rogen, pp~ = 99 ,~ .
1 :
~, :
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~ ~:
:
,.~, ~',' ' ..
~.. . .
.
':~
~' .
Claims (9)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFIEND AS FOLLOWS:
1. A process for hydrocracking a heavy hydrocarbon oil, at least about 50 volume percent of which boils above 975°F which comprises:
(a) passing said heavy hydrocarbon oil in the presence of 500 to 50,000 s.c.f. of hydrogen per barrel of said hydrocarbon oil upwardly through a first vertical empty column hydrocracking zone in the absence of catalyst, said hydrocracking zone being maintained at a temperature between about 400 and about 470°C, a pressure between about 500 and 2,500 p.s.i.g.
and a space velocity between about 0.5 and 1.5 volume of hydro-carbon oil per hour per volume of hydrocracking zone capacity, (b) removing from the top of said hydrocracking zone a mixed effluent containing a gaseous phase comprising hydrogen and vaporous hydrocarbons and a liquid phase comprising heavy hydrocarbons, (c) separating said effluent into a gaseous stream containing wide boiling range material from naphtha to heavy gas-oil and a liquid stream, containing heavy hydrocarbons, (d) recycling at least a portion of said liquid stream as heavy hydrocarbon oil feed to said first hydrocracking zone, (e) passing said gaseous stream together with added hydrogen upwardly through a second vertical hydrocracking zone containing a hydrogenating catalyst, said second hydrocracking zone being maintained at the same pressure as the first stage reactor, a temperature between about 400 and 470°C and a space velocity between about 0.5 and 1.5 volume of hydrocarbon oil per hour per volume of hydrocracking zone capacity, (f) removing from the top of said second hydro-cracking zone a second mixed effluent containing a gaseous phase comprising hydrogen and vaporous hydrocarbons and a liquid product phase, and (g) separating said second effluent in a low tem-perature-high pressure separator into a liquid product and a gaseous phase comprising hydrogen with minor amounts of gaseous hydrocarbons and impurities.
(a) passing said heavy hydrocarbon oil in the presence of 500 to 50,000 s.c.f. of hydrogen per barrel of said hydrocarbon oil upwardly through a first vertical empty column hydrocracking zone in the absence of catalyst, said hydrocracking zone being maintained at a temperature between about 400 and about 470°C, a pressure between about 500 and 2,500 p.s.i.g.
and a space velocity between about 0.5 and 1.5 volume of hydro-carbon oil per hour per volume of hydrocracking zone capacity, (b) removing from the top of said hydrocracking zone a mixed effluent containing a gaseous phase comprising hydrogen and vaporous hydrocarbons and a liquid phase comprising heavy hydrocarbons, (c) separating said effluent into a gaseous stream containing wide boiling range material from naphtha to heavy gas-oil and a liquid stream, containing heavy hydrocarbons, (d) recycling at least a portion of said liquid stream as heavy hydrocarbon oil feed to said first hydrocracking zone, (e) passing said gaseous stream together with added hydrogen upwardly through a second vertical hydrocracking zone containing a hydrogenating catalyst, said second hydrocracking zone being maintained at the same pressure as the first stage reactor, a temperature between about 400 and 470°C and a space velocity between about 0.5 and 1.5 volume of hydrocarbon oil per hour per volume of hydrocracking zone capacity, (f) removing from the top of said second hydro-cracking zone a second mixed effluent containing a gaseous phase comprising hydrogen and vaporous hydrocarbons and a liquid product phase, and (g) separating said second effluent in a low tem-perature-high pressure separator into a liquid product and a gaseous phase comprising hydrogen with minor amounts of gaseous hydrocarbons and impurities.
2. The process according to claim 1 wherein the heavy hydrocarbon oil contains a wide boiling range of materials through naphtha, kerosene, gas oil and tar.
3. The process according to claim 2 wherein the heavy hydrocarbon oil is a bitumen extracted from tar sands.
4. The process according to claim 1 wherein the effluent from the first hydrocracking zone is separated in a hot separator maintained at the same temperature as the first hydrocracking zone.
5. The process according to claim 4 wherein the effluent from the second hydrocracking zone is separated in a low temperature - high pressure separator.
6. The process according to claim 5 wherein the liquid product from the low temperature - high pressure separator is fractionated.
7. The process according to claim 6 wherein the liquid product is fractionated into a naphtha fraction, a light gas-oil fraction and a heavy gas-oil fraction.
8. A process for hydrocracking a heavy hydrocarbon oil, at least about 50 volume percent of which boils above 975°F which comprises:
(a) passing said heavy hydrocarbon oil in the presence of 500 to 50,000 s.c.f. of hydrogen per barrel of said hydrocarbon oil upwardly through a first vertical empty column hydrocracking zone in the absence of catalyst, said hydrocracking zone being maintained at a temperature between about 400 and about 470°C, a pressure between about 500 and 2,500 p.s.i.g. and a space velocity between about 0.5 and 1.5 volume of hydrocarbon oil per hour per volume of hydrocracking zone capacity, (b) removing from the top of said hydrocracking zone a mixed effluent containing a gaseous phase comprising hydrogen and light hydrocarbons and a liquid phase comprising heavy hydrocarbons, (c) passing said mixed effluent together with added hydrogen upwardly through a second vertical hydrocracking zone containing a hydrogenating catalyst, said second hydrocracking zone being maintained at the same pressure as the first stage reactor, a temperature between about 400 and 470°C and a space velocity between about 0.5 and 1.5 volume of hydrocarbon oil per hour per volume of hydrocracking zone capacity, (d) removing from the top of said second hydro-cracking zone a second mixed effluent containing a gaseous phase comprising hydrogen and light hydrocarbons and a liquid product phase comprising heavy hydrocarbons, (e) separating said second effluent in to a gaseous product and a liquid component and passing said liquid component through a fractionator.
(a) passing said heavy hydrocarbon oil in the presence of 500 to 50,000 s.c.f. of hydrogen per barrel of said hydrocarbon oil upwardly through a first vertical empty column hydrocracking zone in the absence of catalyst, said hydrocracking zone being maintained at a temperature between about 400 and about 470°C, a pressure between about 500 and 2,500 p.s.i.g. and a space velocity between about 0.5 and 1.5 volume of hydrocarbon oil per hour per volume of hydrocracking zone capacity, (b) removing from the top of said hydrocracking zone a mixed effluent containing a gaseous phase comprising hydrogen and light hydrocarbons and a liquid phase comprising heavy hydrocarbons, (c) passing said mixed effluent together with added hydrogen upwardly through a second vertical hydrocracking zone containing a hydrogenating catalyst, said second hydrocracking zone being maintained at the same pressure as the first stage reactor, a temperature between about 400 and 470°C and a space velocity between about 0.5 and 1.5 volume of hydrocarbon oil per hour per volume of hydrocracking zone capacity, (d) removing from the top of said second hydro-cracking zone a second mixed effluent containing a gaseous phase comprising hydrogen and light hydrocarbons and a liquid product phase comprising heavy hydrocarbons, (e) separating said second effluent in to a gaseous product and a liquid component and passing said liquid component through a fractionator.
9. A process for hydrocracking a heavy hydrocarbon oil, at least about 50 volume percent of which boils above 975°F which comprises: (a) passing said heavy hydrocarbon oil in the presence of 500 to 50,000 s.c.f. of hydrogen per barrel of said hydrocracking oil upwardly through a first vertical empty column hydrocracking zone in the absence of catalyst, said hydrocracking zone being maintained at a temperature between about 400 and about 470°C, a pressure between about 500 and 2,500 p.s.i.g. and a space velocity between about 0.5 and 1.5 volume of hydro-carbon oil per hour per volume of hydrocracking zone capacity, (b) removing from the top of said hydrocracking zone a mixed effluent containing a gaseous phase comprising hydrogen and vaporous hydrocarbons and a liquid phase comprising heavy hydrocarbons, and characterized by further reacting the mixed effluent by either (c) separating said effluent into a gaseous stream containing wide boiling range material from naphtha to heavy gas-oil and a liquid stream, containing heavy hydrocarbons, (d) recycling at least a portion of said liquid stream as heavy hydrocarbon oil feed to said first hydrocracking zone, (e) passing said gaseous stream together with added hydrogen upwardly through a second vertical hydrocracking zone containing a hydrogenating catalyst, said second hydrocracking zone being maintained at the same pressure as the first stage reactor, a temper-ature between about 400 and 470°C and a space velocity between about 0.5 and 1.5 volume of hydrocarbon oil per hour per volume of hydrocracking zone capacity, (f) remov-ing from the top of said second hydrocracking zone a second mixed effluent containing a gaseous phase compris-ing hydrogen and vaporous hydrocarbons and a liquid product phase, and (g) separating said second effluent in a low temperature-high pressure separator into a liquid product and a gaseous phase comprising hydrogen with minor amounts of gaseous hydrocarbons and impurities, or (h) passing said mixed effluent together with added hydrogen upwardly through a second vertical hydrocracking zone containing a hydrogenating catalyst, said second hydrocracking zone being maintained at the same pressure as the first stage reactor, a temperature between about 400 and 470°C and a space velocity between about 0.5 and 1.5 volume of hydrocarbon oil per hour per volume of hydrocracking zone capacity, (i) removing from the top of said second hydrocracking zone a second mixed effluent containing a gaseous phase comprising hydrogen and light hydrocarbons and a liquid product phase compris-ing heavy hydrocarbons, (j) separating said second effluent in to a gaseous product and a liquid component and passing said liquid component through a fractionator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA275,103A CA1094491A (en) | 1977-03-30 | 1977-03-30 | Two-stage thermal and catalytic hydrocracking of heavy oils |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA275,103A CA1094491A (en) | 1977-03-30 | 1977-03-30 | Two-stage thermal and catalytic hydrocracking of heavy oils |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1094491A true CA1094491A (en) | 1981-01-27 |
Family
ID=4108280
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA275,103A Expired CA1094491A (en) | 1977-03-30 | 1977-03-30 | Two-stage thermal and catalytic hydrocracking of heavy oils |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1094491A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2499584A1 (en) * | 1981-02-12 | 1982-08-13 | Ca Minister Energy | METHOD FOR SIMULTANEOUS DEMETALLIZATION AND HYDROCRACKING OF HEAVY HYDROCARBON OILS |
-
1977
- 1977-03-30 CA CA275,103A patent/CA1094491A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2499584A1 (en) * | 1981-02-12 | 1982-08-13 | Ca Minister Energy | METHOD FOR SIMULTANEOUS DEMETALLIZATION AND HYDROCRACKING OF HEAVY HYDROCARBON OILS |
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