CA1239888A - Stripping of diluent from the d.c. tailings of a hot water process - Google Patents
Stripping of diluent from the d.c. tailings of a hot water processInfo
- Publication number
- CA1239888A CA1239888A CA000478757A CA478757A CA1239888A CA 1239888 A CA1239888 A CA 1239888A CA 000478757 A CA000478757 A CA 000478757A CA 478757 A CA478757 A CA 478757A CA 1239888 A CA1239888 A CA 1239888A
- Authority
- CA
- Canada
- Prior art keywords
- naphtha
- stripping
- carrier gas
- tailings
- process according
- 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
Links
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
- C10G1/00—Production of liquid hydrocarbon mixtures from oil-shale, oil-sand, or non-melting solid carbonaceous or similar materials, e.g. wood, coal
- C10G1/04—Production of liquid hydrocarbon mixtures from oil-shale, oil-sand, or non-melting solid carbonaceous or similar materials, e.g. wood, coal by extraction
- C10G1/045—Separation of insoluble materials
-
- 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
- C10G1/00—Production of liquid hydrocarbon mixtures from oil-shale, oil-sand, or non-melting solid carbonaceous or similar materials, e.g. wood, coal
- C10G1/04—Production of liquid hydrocarbon mixtures from oil-shale, oil-sand, or non-melting solid carbonaceous or similar materials, e.g. wood, coal by extraction
- C10G1/047—Hot water or cold water extraction processes
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Life Sciences & Earth Sciences (AREA)
- Wood Science & Technology (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A novel process for recovering naphtha diluent and bitumen from dilution centrifuge tailings comprises passing the tailings into a stripping cell which receives a carrier gas, preferably inert, for stripping the naphtha from the tailings and also For forming an essentially naphtha-free bitumen froth which is skimmed from the cell and preferably added to a primary bitumen froth stream, the stripped naphtha vapours being collected together with the carrier gas and recovered in a substantially pure form. This recovery of expensive naphtha is effected in a single step while concurrently providing a useful bitumen froth and thus the process significantly contributes to the efficiency of the Hot Water extraction process.
A novel process for recovering naphtha diluent and bitumen from dilution centrifuge tailings comprises passing the tailings into a stripping cell which receives a carrier gas, preferably inert, for stripping the naphtha from the tailings and also For forming an essentially naphtha-free bitumen froth which is skimmed from the cell and preferably added to a primary bitumen froth stream, the stripped naphtha vapours being collected together with the carrier gas and recovered in a substantially pure form. This recovery of expensive naphtha is effected in a single step while concurrently providing a useful bitumen froth and thus the process significantly contributes to the efficiency of the Hot Water extraction process.
Description
~ 70607-30 The present invention relates to the stripping and recovery of a diluent which is used in the dilution centrifuging of bitumen Eroth in the Hot Water extraction process of an oil sands treatment plant. In particular, the invention addresses the problem of naphtha diluent recovery from dilution centriEuging (D.C.) tailin~s.
In the well known Hot Water extraction process for the recovery o-E bitumen from oil sands, the latter is conditioned into a slurry by the addition of~ for example, steam and hot water and other additives before introduction to a primary separation vessel in which a percentage of the bitumen floats to the surface as a primary froth. A first tailings stream is withdrawn from the bottom oE the primary separation vessel, these tailings consisting essentially of water, sands and some bitumen. A stream of middlings is drawn off the primary separation vessel and passed to one or a series of flotation cells from which a second tailings stream is withdrawn. Froth from the flotation cell(s) is typi-cally then passed to a sett]ing vessel from which a second bitumen froth is withdrawn~ These stages of the overall extraction process comprise the extraction plant.
The aforementioned first and second froths are then deaerated and pumped to the froth treatment plant wherein the froth is sub~ected to centrifugation, typically initially in a scroll-type centrifuge and then in a disc-type centrifuge. Flow-ever, beEore sueh centrifu~ation treatment the froth is diluted usually with naphtha ko reduce the bitumen density and viscosity, and to facilitate the separation of water and solids from the -- '!' ' 8~
bitumen by centriEugation.
Tailings are withdrawn -Erom the scroll- and disc-type centri~uges and comprise water, so]ids, bitumen and diluent in the following approximate composition (~ weight): bitumen 3%; naphtha
In the well known Hot Water extraction process for the recovery o-E bitumen from oil sands, the latter is conditioned into a slurry by the addition of~ for example, steam and hot water and other additives before introduction to a primary separation vessel in which a percentage of the bitumen floats to the surface as a primary froth. A first tailings stream is withdrawn from the bottom oE the primary separation vessel, these tailings consisting essentially of water, sands and some bitumen. A stream of middlings is drawn off the primary separation vessel and passed to one or a series of flotation cells from which a second tailings stream is withdrawn. Froth from the flotation cell(s) is typi-cally then passed to a sett]ing vessel from which a second bitumen froth is withdrawn~ These stages of the overall extraction process comprise the extraction plant.
The aforementioned first and second froths are then deaerated and pumped to the froth treatment plant wherein the froth is sub~ected to centrifugation, typically initially in a scroll-type centrifuge and then in a disc-type centrifuge. Flow-ever, beEore sueh centrifu~ation treatment the froth is diluted usually with naphtha ko reduce the bitumen density and viscosity, and to facilitate the separation of water and solids from the -- '!' ' 8~
bitumen by centriEugation.
Tailings are withdrawn -Erom the scroll- and disc-type centri~uges and comprise water, so]ids, bitumen and diluent in the following approximate composition (~ weight): bitumen 3%; naphtha
2%; solids 15%; water 80%.
Thus, it can be seen that there is a considerable loss of bitumen but, more notably, also a 105s of naphtha. ~rom an economic standpoint this is important since the diluent is consi-derably more expensive than the bitumen.
As tau~ht in Canadian Patents ~los. 993,392, 1,013,695 and 1,027,501, the D.C. tailings are passed to a steam stripping column or a flash vacuum vessel from which most of the expensive diluent vaporizes off and is collected, the remainder o the tailings being simply discarded or sub~ected to further treatment.
The use of a steam stripping column is energy intensive and accordingly expensive.
Alternatively, Canadian Patents Nos. 1,081,642 and 1,094,484 teach that the D.C. tailings are passed through an induced-ga.s flotation cell wherein both the naphtha diluent and bitumen are recovered as a froth which can then be further treated to separate out more water and solids from the naphtha and bitumen, optionally by the addition of more naphtha to the froth followed by centrifugation. After this centrifugation stage, the naphtha has to be separated from the bitumen by conventional means of vacuum flashin~ and steam stripping. It should be noted that this flotation process does not separate the naphtha from the bitumen or from the tailings.
~ 3~
The present invention is directed to a process which effectively recovers the expensive naphtha diluent ~rom the D~C.
tailings with much reduced energy requirements. Furthermore, the process of the present invention si~ultaneously permits recovery of most of the bitumen from the D.C. tailings.
According to the present invention, there is now provided a process for stripping naphtha diluent and the formation of an essentially naphtha-free bitumen froth from D.C. tailings ~Jhich comprises: a) passing said tailings into at least one stripping cell which receives a carrier gas supply for stripping the naphtha from the tailings and for forming the essentially naphtha-free bitumen froth which is removed from the cell, the stripping cell being adapted to confine and withdraw vapourized naphtha and said carrier gas from the cell, and b) treating the vapourized naphtha and carrier gas to recover the naphtha.
It is important to note that in the process of the present invention the stripping cell effectively strips off the naphtha while forming a bitumen froth in a form eminently suitable Eor bitumen recovery.
Thus, in con-trast to some conventional D.C. tailings treatments in which, for naphtha recovery, at least two energy intensive stages are involved (air Elotation cell and stripping column), the present invention efEectively recovers over 90% of naphtha in a single principal stage.
In general terms, the D.C. tailings from the scroll- and disc-type centrifuges enter one or more stripping cells at a temperature of approximately 75C.
~L2~
Although air or stack gas can be used as a carrier gas which is passed into the stripping cell, an inert gas such as nitrogen or carbon dioxide, can also be used. Preferably, the carrier gas is preheated to about 100 C before introduction to the stripping cell where it is mixed well with the tailings. An im-peller in the strippiny cell ensures good gas-to-liquid contact which is important for the stripping process. Between about 60 to 97~ of naphtha in the D.C. tailings vapourizes off with the carrier gas and also a small amount of water. This gas mixture may then be preferably passed through a cold water condenser wherein naphtha condenses out and the ca~ier gas is recycled to the strip-ping cell via a blower and preferably an auxiliary heater. Steam can be added directly to the carrier gas to heat up the gas and/
or raise the tailings temperature. However, if the carrier gas or tailings are heated to too high a temperature then it in-creases the quantities of water which vapourize off with the nap-htha and carrier gas. Preferably, therefore, the carrier gas is heated up to a temperature between about 30 C to 120 C and more preferably, to about 95 C prior to entry into the stripping cell.
As an alternative to the preferred preheating of carrier gas, the D.C. tailings may be preheated in order to provide opti-mum temperature conditions within the strippiny cell. However, since the hydrocarbons are concentrated in the froth, it is pre-ferable to heat up only the froth within the stripping cell. This is done by providing a part of the hot carrier gas or steam, at or , ~
just below the froth level, or by contacting the froth with heat-ing elements.
Bitumen froth is withdrawn from the stripping cell and can be -treated further before joining the plant bitumen main stream.
The present invention will now be further described, by way of example only, with reference to the following examples and figures, in which:
~ 4a -8~3 E`igure 1 is a diagramrnatic representation of the ~.C.
tailings treatment plant according to the present invention, an~
Figure 2 graphically illustrates the e~fect of residence time in the stripping cell on diluent recovery.
Turning firstly to Figure 1, D.C. tailings 1 enter a stripping vessel 2 into which a carrier gas is blown at 3 by carrier gas blower 4. The carrier gas is passed through a heater 5 before entry to the stripping cell 2. A gas mixture consisting of naphtha, carrier gas and some steam exits the stripping cell 2 and passes through a condenser unit 6 before passing into a sepa-rator 7. In the condenser 6 naphtha diluent and water condense out and are then separated from each other in separator 7.
Carrier gas passes from the separator back to the gas blower 4, preferably past a gas make-up line 8. ~n optional vacuum producing system can be typically installed between the condenser and the separator.
In the stripping vessel 2 an essentially naphtha-free bitumen froth is formed which is passed to a froth cleaner 9 wherein solids and water are removed. ~ollowing deaeration the bitumen product is then preferably pumped back to the plant bitumen froth stream. ~ailings, which consist essentially of water and solids are removed from the stripping cell 2 and froth cleaner 9.
Steam can optionally be added to the carrier gas line at 10.
The condenser 6 and separa-tor 7 units can be replaced by any other diluent vapour recovery process such as an adsorption tower, which can optionally be added on the carrier gas recycle line.
The stripping vessel 2, of which only one is illus-trated, can be operated at sub-atmospheric pressure (vacuum).
This accelerates the naphtha diluent evaporation rate. PreEerably mixing within the stripping cell 2 is enhanced by an impeller so that there is good gas-to-liquid contact Eor efficient stripping of the naphtha.
The following example is a scaled down naphtha stripping and recovery from D.C. tai]inqs.
Example Batches of about 1300 grams of D.C. tailings samples were taken from a ~5 gallon drum containing a sample of froth treatment (centriEugation) plant tailings. The samples consisted of the following:
~ Weight Bitumen 2.52 Naphtha 1.78 Solids 13.03 Water 82.67 A sea]ed stripping cell was used with a Denver flotation machine shaft and impeller. The carrier gas used was nitrogen which could be heated up to about 120C before entry to the stripping cell. Gases vapouriziny from the strippiny cell were collected and passed through a water-cooled condenser wherein the condensed naphtha accumulated in a graduated trap.
The D.C. tailings sample in the strippiny cell was heated up to a speciEied temperature while being mixed by the impeller which rotated at approximately 500 rpms. The carrier gas was heated to a predetermined temperat-1re and then bubbled through the tailings in the stripping cell at which time the mixing velocity of the impeller was increased to approximately 1000 rpms.
The carrier gas flow was adjusted and set at 0.4 cu. m. min/cu. m.
cell. The volume of the naphtha diluent gas condensed in the graduated trap was recorded with time up to twenty minutes.
~fter the carrier gas flow had been terminated, the bitumen froth in the stripping cell was skinned off, weighed and analyzed. The tailings from the stripping cell were also weighed and analyzed.
Two series of readings were taken, the first with the nitrogen carrier gas being preheated to 25C and the second with the nitrogen carrier gas being preheated to between 95 and 100C.
In each case, the D.C. tailings fed to the stripping cell were heated to 75C.
Nitrogen Gas at 25C
Residence Time Naphtha Recovery in Minutes ~ weight, evaporated _nd_ ondensed 22~5 ~1.6 59.8 77.2 The bitumen recovery in the froth amounted to 32.6% by weight, the froth composition (% weight) being: bitumen 11.6, naphtha 1.7, solids 29.3, and water 57.4.
The tail.ings composition from the stripping cell in ~
weight was: bitumen 0.5, naphtha 0.1, solids 9.7 and water ~9.7.
Nitrogen Gas at 95-100C
Residence Tlme Naphtha Recovery in Minutes % weight, evaporated and condensed ~8.9 8~.4 92.5 9~.7 The bitumen recovery in the froth was 77.8 weight %.
The composition of the froth in % weight was: bitumen 12.9, naphtha 0.3, solids 34.9, and water 51.9.
The tailings composition (% weight) was: hitumen 0.67, naphtha 0.01, solids 9.39 and water 89.92.
It can thus be seen from the above results -that the amount of naphtha stripped from the D.C. tailings is increased when the temperature of the carrier gas is increased to 95-100~C.
Furthermore, as can also be seen from Figure 2, the amount of naphtha recovered increases when the stripping time is increased.
In both cases, up to about 30% recovery, the evaporation rates are almost linear with time, however, the use of heated gas (95~C) increases the diluent evaporation rate by a :Eactor o~ two. This substantially reduces the residence time required to achieve a specified recovery and conse~uently the size or number of stripping vessels. Operating the vessel under sub-atmospheric pressures (vacuum), such as 34.5 kPa(a) (5 psia)l may further increase the diluent evaporation rate and should reduce the 8~8 required flow of strlpping gas. The optimum operating conditions such as: tailings temperature, stripp.ing gas temperature and flow rate, mixing velocity, operat.ing pressure and residence time are usually determined on a pilot scale development unit, and any variations thereof frQm the values exemplified in this specifica-tion are within the scope of the present invention.
Thus, it can be seen that there is a considerable loss of bitumen but, more notably, also a 105s of naphtha. ~rom an economic standpoint this is important since the diluent is consi-derably more expensive than the bitumen.
As tau~ht in Canadian Patents ~los. 993,392, 1,013,695 and 1,027,501, the D.C. tailings are passed to a steam stripping column or a flash vacuum vessel from which most of the expensive diluent vaporizes off and is collected, the remainder o the tailings being simply discarded or sub~ected to further treatment.
The use of a steam stripping column is energy intensive and accordingly expensive.
Alternatively, Canadian Patents Nos. 1,081,642 and 1,094,484 teach that the D.C. tailings are passed through an induced-ga.s flotation cell wherein both the naphtha diluent and bitumen are recovered as a froth which can then be further treated to separate out more water and solids from the naphtha and bitumen, optionally by the addition of more naphtha to the froth followed by centrifugation. After this centrifugation stage, the naphtha has to be separated from the bitumen by conventional means of vacuum flashin~ and steam stripping. It should be noted that this flotation process does not separate the naphtha from the bitumen or from the tailings.
~ 3~
The present invention is directed to a process which effectively recovers the expensive naphtha diluent ~rom the D~C.
tailings with much reduced energy requirements. Furthermore, the process of the present invention si~ultaneously permits recovery of most of the bitumen from the D.C. tailings.
According to the present invention, there is now provided a process for stripping naphtha diluent and the formation of an essentially naphtha-free bitumen froth from D.C. tailings ~Jhich comprises: a) passing said tailings into at least one stripping cell which receives a carrier gas supply for stripping the naphtha from the tailings and for forming the essentially naphtha-free bitumen froth which is removed from the cell, the stripping cell being adapted to confine and withdraw vapourized naphtha and said carrier gas from the cell, and b) treating the vapourized naphtha and carrier gas to recover the naphtha.
It is important to note that in the process of the present invention the stripping cell effectively strips off the naphtha while forming a bitumen froth in a form eminently suitable Eor bitumen recovery.
Thus, in con-trast to some conventional D.C. tailings treatments in which, for naphtha recovery, at least two energy intensive stages are involved (air Elotation cell and stripping column), the present invention efEectively recovers over 90% of naphtha in a single principal stage.
In general terms, the D.C. tailings from the scroll- and disc-type centrifuges enter one or more stripping cells at a temperature of approximately 75C.
~L2~
Although air or stack gas can be used as a carrier gas which is passed into the stripping cell, an inert gas such as nitrogen or carbon dioxide, can also be used. Preferably, the carrier gas is preheated to about 100 C before introduction to the stripping cell where it is mixed well with the tailings. An im-peller in the strippiny cell ensures good gas-to-liquid contact which is important for the stripping process. Between about 60 to 97~ of naphtha in the D.C. tailings vapourizes off with the carrier gas and also a small amount of water. This gas mixture may then be preferably passed through a cold water condenser wherein naphtha condenses out and the ca~ier gas is recycled to the strip-ping cell via a blower and preferably an auxiliary heater. Steam can be added directly to the carrier gas to heat up the gas and/
or raise the tailings temperature. However, if the carrier gas or tailings are heated to too high a temperature then it in-creases the quantities of water which vapourize off with the nap-htha and carrier gas. Preferably, therefore, the carrier gas is heated up to a temperature between about 30 C to 120 C and more preferably, to about 95 C prior to entry into the stripping cell.
As an alternative to the preferred preheating of carrier gas, the D.C. tailings may be preheated in order to provide opti-mum temperature conditions within the strippiny cell. However, since the hydrocarbons are concentrated in the froth, it is pre-ferable to heat up only the froth within the stripping cell. This is done by providing a part of the hot carrier gas or steam, at or , ~
just below the froth level, or by contacting the froth with heat-ing elements.
Bitumen froth is withdrawn from the stripping cell and can be -treated further before joining the plant bitumen main stream.
The present invention will now be further described, by way of example only, with reference to the following examples and figures, in which:
~ 4a -8~3 E`igure 1 is a diagramrnatic representation of the ~.C.
tailings treatment plant according to the present invention, an~
Figure 2 graphically illustrates the e~fect of residence time in the stripping cell on diluent recovery.
Turning firstly to Figure 1, D.C. tailings 1 enter a stripping vessel 2 into which a carrier gas is blown at 3 by carrier gas blower 4. The carrier gas is passed through a heater 5 before entry to the stripping cell 2. A gas mixture consisting of naphtha, carrier gas and some steam exits the stripping cell 2 and passes through a condenser unit 6 before passing into a sepa-rator 7. In the condenser 6 naphtha diluent and water condense out and are then separated from each other in separator 7.
Carrier gas passes from the separator back to the gas blower 4, preferably past a gas make-up line 8. ~n optional vacuum producing system can be typically installed between the condenser and the separator.
In the stripping vessel 2 an essentially naphtha-free bitumen froth is formed which is passed to a froth cleaner 9 wherein solids and water are removed. ~ollowing deaeration the bitumen product is then preferably pumped back to the plant bitumen froth stream. ~ailings, which consist essentially of water and solids are removed from the stripping cell 2 and froth cleaner 9.
Steam can optionally be added to the carrier gas line at 10.
The condenser 6 and separa-tor 7 units can be replaced by any other diluent vapour recovery process such as an adsorption tower, which can optionally be added on the carrier gas recycle line.
The stripping vessel 2, of which only one is illus-trated, can be operated at sub-atmospheric pressure (vacuum).
This accelerates the naphtha diluent evaporation rate. PreEerably mixing within the stripping cell 2 is enhanced by an impeller so that there is good gas-to-liquid contact Eor efficient stripping of the naphtha.
The following example is a scaled down naphtha stripping and recovery from D.C. tai]inqs.
Example Batches of about 1300 grams of D.C. tailings samples were taken from a ~5 gallon drum containing a sample of froth treatment (centriEugation) plant tailings. The samples consisted of the following:
~ Weight Bitumen 2.52 Naphtha 1.78 Solids 13.03 Water 82.67 A sea]ed stripping cell was used with a Denver flotation machine shaft and impeller. The carrier gas used was nitrogen which could be heated up to about 120C before entry to the stripping cell. Gases vapouriziny from the strippiny cell were collected and passed through a water-cooled condenser wherein the condensed naphtha accumulated in a graduated trap.
The D.C. tailings sample in the strippiny cell was heated up to a speciEied temperature while being mixed by the impeller which rotated at approximately 500 rpms. The carrier gas was heated to a predetermined temperat-1re and then bubbled through the tailings in the stripping cell at which time the mixing velocity of the impeller was increased to approximately 1000 rpms.
The carrier gas flow was adjusted and set at 0.4 cu. m. min/cu. m.
cell. The volume of the naphtha diluent gas condensed in the graduated trap was recorded with time up to twenty minutes.
~fter the carrier gas flow had been terminated, the bitumen froth in the stripping cell was skinned off, weighed and analyzed. The tailings from the stripping cell were also weighed and analyzed.
Two series of readings were taken, the first with the nitrogen carrier gas being preheated to 25C and the second with the nitrogen carrier gas being preheated to between 95 and 100C.
In each case, the D.C. tailings fed to the stripping cell were heated to 75C.
Nitrogen Gas at 25C
Residence Time Naphtha Recovery in Minutes ~ weight, evaporated _nd_ ondensed 22~5 ~1.6 59.8 77.2 The bitumen recovery in the froth amounted to 32.6% by weight, the froth composition (% weight) being: bitumen 11.6, naphtha 1.7, solids 29.3, and water 57.4.
The tail.ings composition from the stripping cell in ~
weight was: bitumen 0.5, naphtha 0.1, solids 9.7 and water ~9.7.
Nitrogen Gas at 95-100C
Residence Tlme Naphtha Recovery in Minutes % weight, evaporated and condensed ~8.9 8~.4 92.5 9~.7 The bitumen recovery in the froth was 77.8 weight %.
The composition of the froth in % weight was: bitumen 12.9, naphtha 0.3, solids 34.9, and water 51.9.
The tailings composition (% weight) was: hitumen 0.67, naphtha 0.01, solids 9.39 and water 89.92.
It can thus be seen from the above results -that the amount of naphtha stripped from the D.C. tailings is increased when the temperature of the carrier gas is increased to 95-100~C.
Furthermore, as can also be seen from Figure 2, the amount of naphtha recovered increases when the stripping time is increased.
In both cases, up to about 30% recovery, the evaporation rates are almost linear with time, however, the use of heated gas (95~C) increases the diluent evaporation rate by a :Eactor o~ two. This substantially reduces the residence time required to achieve a specified recovery and conse~uently the size or number of stripping vessels. Operating the vessel under sub-atmospheric pressures (vacuum), such as 34.5 kPa(a) (5 psia)l may further increase the diluent evaporation rate and should reduce the 8~8 required flow of strlpping gas. The optimum operating conditions such as: tailings temperature, stripp.ing gas temperature and flow rate, mixing velocity, operat.ing pressure and residence time are usually determined on a pilot scale development unit, and any variations thereof frQm the values exemplified in this specifica-tion are within the scope of the present invention.
Claims (17)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for stripping naphtha diluent and for the formation of an essentially naphtha-free bitumen froth from D.C.
tailings which comprises:
a) passing said tailings into at least one stripping cell which receives a carrier gas supply for stripping the naphtha from the tailings and for forming the essentially naphtha-free bitumen froth which is removes from the cell, the stripping cell being adapted to confine and withdraw vapourized naphtha and said carrier gas from the cell, and b) treating the vapourized naphtha and carrier gas to recover the naphtha.
tailings which comprises:
a) passing said tailings into at least one stripping cell which receives a carrier gas supply for stripping the naphtha from the tailings and for forming the essentially naphtha-free bitumen froth which is removes from the cell, the stripping cell being adapted to confine and withdraw vapourized naphtha and said carrier gas from the cell, and b) treating the vapourized naphtha and carrier gas to recover the naphtha.
2. The process according to claim 1 wherein the essentially naphtha-free bitumen froth removed from the stripping cell is added to a bitumen froth stream in a Hot Water oil sands extrac-tion plant.
3. A process according to claim 1 wherein the carrier gas is heated prior to introduction to the tailings.
4. A process according to claim 3 wherein the carrier gas is heated up to about 200°C.
5. A process according to claim 3 wherein the carrier gas is heated to between about 90°C and 100°C.
6. A process according to claim 1, 2 or 3 wherein steam is injected to the stripping cell together with a carrier gas.
7. A process according to claim 1 wherein the carrier gas is selected from the group consisting of air, nitrogen, carbon dioxide, and stack gas.
8. A process according to claim 1 wherein the gas is an inert gas.
9. A process according to claim 1, 2 or 3 wherein the naphtha which is stripped from the D.C. tailings is recycled to a froth treatment plant.
10. A process according to claim 1, 2 or 3 wherein the stripping vessel is operated under sub-atmospheric pressure.
11. A process according to claim 1, 2 or 3 wherein the stripping gas is recycled.
12. A process according to claims 1, 2, 3 wherein the bitumen froth is further treated to recover the residual naphtha, by gas or steam stripping or by introducing the froth to a vacuum flush vessel.
13. A process according to claim 1, 2 or 3 wherein the carrier gas is mixed with tailings in the stripping cell at least in part by means of an induced gas flotation mixer.
14. A process according to Claim 1, 2 or 3 wherein the carrier gas is premixed under pressure with the tailings in a pre-chamber before entry to said stripping cell wherein the carrier gas is substantially released from said tailings.
15. A process according to Claim 1, 2 or 3 wherein a part of the carrier gas flow is introduced to the tailings to form the froth and the remaining carrier gas is provided in a separate flow to strip off the naphtha.
16. A process according to Claim 1, 2 or 3 wherein the froth in the stripping cell is heated by a separate stream of carrier gas or steam which is injected or dispersed into the froth or at a location just below the froth level.
17. A process according to Claim 1, 2 or 3 wherein the froth in the stripping cell is heated by a heating element which is brought into contact with the froth or by radiation.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000478757A CA1239888A (en) | 1985-04-10 | 1985-04-10 | Stripping of diluent from the d.c. tailings of a hot water process |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000478757A CA1239888A (en) | 1985-04-10 | 1985-04-10 | Stripping of diluent from the d.c. tailings of a hot water process |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1239888A true CA1239888A (en) | 1988-08-02 |
Family
ID=4130229
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000478757A Expired CA1239888A (en) | 1985-04-10 | 1985-04-10 | Stripping of diluent from the d.c. tailings of a hot water process |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1239888A (en) |
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6358404B1 (en) | 1999-05-13 | 2002-03-19 | Aec Oil Sands, L.P. | Method for recovery of hydrocarbon diluent from tailing |
| US6358403B1 (en) | 1999-05-14 | 2002-03-19 | Aec Oil Sands, L.P. | Process for recovery of hydrocarbon from tailings |
| WO2012126110A1 (en) * | 2011-03-18 | 2012-09-27 | Suncor Energy Inc. | Unit and process with scrubbing of entrained tailings particles from an overhead solvent stream |
| US8656996B2 (en) | 2010-11-19 | 2014-02-25 | Exxonmobil Upstream Research Company | Systems and methods for enhanced waterfloods |
| US8657000B2 (en) | 2010-11-19 | 2014-02-25 | Exxonmobil Upstream Research Company | Systems and methods for enhanced waterfloods |
| US8739869B2 (en) | 2010-11-19 | 2014-06-03 | Exxonmobil Upstream Research Company | Systems and methods for enhanced waterfloods |
| US8974661B2 (en) | 2010-12-30 | 2015-03-10 | Exxonmobil Upstream Research Company | Methods for separation of bitumen from oil sands |
-
1985
- 1985-04-10 CA CA000478757A patent/CA1239888A/en not_active Expired
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6358404B1 (en) | 1999-05-13 | 2002-03-19 | Aec Oil Sands, L.P. | Method for recovery of hydrocarbon diluent from tailing |
| US6358403B1 (en) | 1999-05-14 | 2002-03-19 | Aec Oil Sands, L.P. | Process for recovery of hydrocarbon from tailings |
| US8656996B2 (en) | 2010-11-19 | 2014-02-25 | Exxonmobil Upstream Research Company | Systems and methods for enhanced waterfloods |
| US8657000B2 (en) | 2010-11-19 | 2014-02-25 | Exxonmobil Upstream Research Company | Systems and methods for enhanced waterfloods |
| US8739869B2 (en) | 2010-11-19 | 2014-06-03 | Exxonmobil Upstream Research Company | Systems and methods for enhanced waterfloods |
| US8974661B2 (en) | 2010-12-30 | 2015-03-10 | Exxonmobil Upstream Research Company | Methods for separation of bitumen from oil sands |
| WO2012126110A1 (en) * | 2011-03-18 | 2012-09-27 | Suncor Energy Inc. | Unit and process with scrubbing of entrained tailings particles from an overhead solvent stream |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6358404B1 (en) | Method for recovery of hydrocarbon diluent from tailing | |
| US4139450A (en) | Solvent extraction of tar sand | |
| US6358403B1 (en) | Process for recovery of hydrocarbon from tailings | |
| US4514305A (en) | Azeotropic dehydration process for treating bituminous froth | |
| CA2055213C (en) | Process for increasing the bitumen content of oil sands froth | |
| JPS6158110B2 (en) | ||
| US3808120A (en) | Tar sands bitumen froth treatment | |
| US4875998A (en) | Hot water bitumen extraction process | |
| US5738762A (en) | Separating oil and water from emulsions containing toxic light ends | |
| CA1239888A (en) | Stripping of diluent from the d.c. tailings of a hot water process | |
| CA2400258A1 (en) | Bituminous froth inclined plate separator and hydrocarbon cyclone treatment process | |
| US4116809A (en) | Deaerator circuit for bitumen froth | |
| CA1144513A (en) | Closed-loop vacuum fractionation process | |
| JPS6131750B2 (en) | ||
| JPS6059952B2 (en) | Improved separation method for bituminous materials | |
| JPS5815932A (en) | Purification of aqueous over flow containing bisphenol a and phenol | |
| US4455234A (en) | Process of extracting a metal value | |
| CA1081642A (en) | Recovery of hydrocarbons from dilution centrifuging tailings | |
| WO1981002580A1 (en) | Method for treating coal to obtain a refined carbonaceous material | |
| US3573196A (en) | Use of light hydrocarbons in tar sand processing | |
| US4111789A (en) | Recovery of hydrocarbon from dilution centrifuging tailings | |
| US3169052A (en) | Low temperature purification of ethylene | |
| US2322881A (en) | Solvent treating | |
| JPS6329917B2 (en) | ||
| CA2936316C (en) | Process and apparatus for partially deasphalting bitumen |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |