CN1143383A - Removing contaminants from oil - Google Patents

Abstract

A process comprising combining the heavy oil still residue and propane in conduits (146) and pumping mixture through static mixer (300). The mixture is then passed through heat exchanger (301) and flows via (302) to an extraction vessel (304). The residum/oil mixture then leaves via outlet (308) and asphalt pump (309).

Description

Removal of pollutants in oil

field of invention

The present invention relates to the removal of contaminants from crude or processed mineral oils, and in particular to the removal of contaminants from waste motor oils. The present invention relates to a method and apparatus for removing contaminants from mineral oil.

current technology

It is known in the prior art that there are a large number of methods for removing pollutants in mineral oils and waste lubricating oils. Indeed, these plethora of prior art documents have also illustrated that people are looking for a low-cost method for removing pollutants from oils. Continuing efforts to address pollutants.

Undesirable contaminants in crude oil often include a complex mixture of high molecular weight alkanes (including naphthenes), known as bitumen, which is recovered as a viscous residue in vacuum distillation of petroleum and is known to degrade the distillation process. efficiency. It is well known in the art to remove or reduce bitumen by solvent extraction of crude oil with a liquid solvent such as propane or butane.

Waste motor oil contains a wide variety of undesirable contaminants such as carbon, some asphaltene compounds and added "potpourri" which include organometallic compounds such as rust inhibitors, antioxidants, antiwear agents, detergents Agents - dispersants and antifoam agents as well as synthetic polymeric pour point depressants and viscosity index improvers. In waste motor oils, dissolved and undissolved metal values include lead (from gasoline), iron (from engine wear) and varying amounts of calcium from added "chowder" other than nitrogen-containing organic compounds , phosphorus, sulfur, zinc, sodium and magnesium.

Since organometallic and polymeric compounds dissolve in the solvent used in the solvent extraction recovery process and start to distill at temperatures similar to lubricant base oils, it is very difficult to remove the added "chowder" from waste motor oil .

Water and stable oil/water emulsions are contaminants in marine slop recovery from ship bilges and cannot be removed economically. Therefore, marine waste oil cannot be used as a feedstock for refineries due to the risk of refining operation problems and the uneconomical use of conventional propane extraction in relatively small volumes.

US Patent No. 2196989 discloses a method of separating asphaltenes from crude oil to produce lubricating oil. In this method, crude oil is mixed with a light hydrocarbon solvent such as liquid propane or butane, an inert gas such as methane, ethane, hydrogen, carbon dioxide, nitrogen or ammonia, and the gas is used to dissolve Precipitating agent for oily substances in solvents.

At elevated temperature and pressure, the bituminous oil is contacted with a liquid solution of oil and propane, where most of the oil is dissolved in the liquid propane melt and small droplets of undissolved bitumen impurities fall into the reaction vessel bottom of. A gas soluble in liquid propane but insoluble in mineral oil is introduced into the oil/propane liquid solution near the top of the vessel under elevated pressure. The precipitant gas dissolves in the propane solution and dilutes it, thereby reducing the solubility of residual bitumen impurities, eventually precipitating the bitumen and most of the oil from solution.

Precipitation of oily impurities from propane solution by precipitant gas is said to be based on the principle of different solubility between different components.

US Patent No. 3870628 describes a process for removing bitumen from residual oil from vacuum distillation of petroleum. This method can also be used to recover waste lubricating oil.

The waste oil or distillation residue is pulsed into liquid propane under pressure to facilitate the dispersion of the oil into fine oil droplets in the solvent. The pulsed oil feed flows countercurrent to the liquid propane which dissolves the portion of the oil that can be used as a lubricant and precipitates the insoluble material. Applying mechanical vibration to the device is said to increase the output of the device.

US Patent No.4265734 is an improvement of the above-mentioned patent No.3870625 method. In an initial step, the contaminated oil is injected into a reservoir containing propane to form a mixture of contaminated oil and liquid propane in a volume ratio of 0.25:5 to 1:5. Let the mixture sit for about 1 hour to allow most of the impurities in the contaminated oil to settle to the bottom of the reservoir. The oil/propane solution is then drawn off and treated as in the aforementioned patent No. 3870625.

US Patent No. 5,286,380 to Mellen, of which Mellen is a co-inventor, relates to the removal of pollutants from spent motors.

In the '380 patent, spent motor oil is fed into an empty reaction vessel, and then a liquid aliphatic solvent, such as liquid propane, is introduced into the reaction vessel from the bottom of the reaction vessel so that the oil and solvent are mixed in a volume ratio of 1:10 , where the pollutants are precipitated out. The oil/solvent solution is then percolated through a bed of activated carbon to remove lead and other metal contaminants. Glass or plastic containers are preferred.

Traditional propane extraction for deasphalting crude oil relies on huge product upgrades, such as the production of light feedstock, to justify the high capital investment and high operating costs.

In crude asphalt extraction and waste motor oil reprocessing, the method of using propane as a solvent must use propane and oil in a ratio of 10:1-15:1 to reduce the viscosity and specific gravity of the solution, thereby fully making the suspended Fine solids settle under gravity. The high ratio of propane to oil needs to make the recovery of propane require a very large amount of energy and a very large settling vessel to ensure that very fine particles have sufficient settling retention time.

Another method of reprocessing waste motor oil, which is now popular in the United States, is water treatment after vacuum distillation.

In this process, slop oil is heated to about 150°C to remove any water and light hydrocarbons. The dehydrated oil stock, also containing additives, is then heated to about 260°C to remove any diesel components.

Next, the oil/additive mixture is heated to about 370° C. in a distillation column at about 5 mm Hg (abs.) to separate the base oil from the additive, and the base oil fraction is subjected to water treatment to improve color and odor. A water treatment step may also remove some of the residual polyaromatic hydrocarbons.

While generally effective for its purpose, the thin film vacuum distillation process described above suffers from a number of drawbacks.

The main problem with this distillation method is that the additive components are not removed until the final distillation step. At this stage, the oil (and additives) has been heated above 370°C, at this high temperature, thermal cracking of polymeric compounds and thermal decomposition of organometallic compounds will occur, causing severe coking in the distillation column and auxiliary equipment and corrosion. Coking and corrosion of equipment not only interfered with output efficiency, but also made the quality of lube oil fractions worse than in any other case.

While it is possible to pre-treat slop oil with sodium hydroxide to reduce coking and corrosion in areas downstream of the equipment, this would require expensive metallurgical upgrades in the upstream equipment to reduce corrosion in this area.

Even in the middle diesel fraction column, maintenance of the equipment is very expensive since the column packing has to be replaced every 6-8 months.

In general, thin film evaporators used in the above processes are expensive to construct and operate per unit of output capacity. Moreover, in this process, about 2% of the light oil (diesel) fraction is lost in the water removal stage, and about 3% is lost in the final distillation stage due to remaining at the bottom where there is still bitumen. Useful base oil is lost.

US Patents 4,624,763, 4,624,764, 4,661,226, 4,634,510, 4,627,901, 4,622,119 and 4,622,118 all relate to the removal of wax from lubricating oils by introducing high voltage charges into the oil/solvent mixture to nucleate wax particles prior to precipitation.

Australian Patent No.605288 discloses a method for extracting oil from a stable oil/water emulsion, which is to add a liquefied hydrocarbon solvent in the emulsion, separate part of the oil that forms an oil solvent phase when standing, and then reduce The pressure of the residual two-phase system to volatilize the pressurized liquid solvent, wherein the emulsion separates into oil and water phases.

Summary of the invention and its purpose

It is an object of the present invention to provide novel methods and apparatus for removing contaminants from oil which overcome or substantially alleviate at least some of the problems associated with prior methods and/or apparatus.

According to one aspect of the present invention, there is provided a method for removing pollutants from oil plants, the method comprising the steps of:

forming a solution of the contaminated oil in a liquid aliphatic solvent in a first pressure vessel;

introducing gas in the form of fine gas bubbles in the lower region of said first pressure vessel, wherein said solution is agitated by gas bubbles rising from the solution and contaminants are separated from the solution by flocculation;

Separation of flocculated contaminants from liquid solution; and

The solvent is separated from this solution to obtain an oil substantially free of contaminants.

Suitable solvents include C ₁ -C ₇ alkanes.

The solvent preferably comprises liquid propane or butane or mixtures thereof.

The flocculation enhancer may be selected from water and/or electrolyte solutions.

Water is suitably present in the solution of oil and solvent during the flocculation reaction in an amount of at least 2% v/v.

During the flocculation reaction, the amount of water present in the solution of oil and solvent is preferably at least 3% v/v.

The concentration of water in the oil and solvent solution is most preferably about 3% to 6% v/v.

As flocculation enhancer, alternatively and in addition to water, electrolytes can also be used as flocculation enhancer.

Suitable electrolytes include strong acids or bases.

The electrolyte can be selected from _H2SO4 , HCl, NaOH or KOH _.

If desired, the flocculation reaction can be carried out in the presence of physical contact between the conductive element and the solution of oil and solvent.

Gases may include polar or non-polar gases.

Suitably, the gas is selected from CO ₂ , N ₂ or C ₁ -C ₄ alkanes.

Preferably, the gas comprises propane or butane or mixtures thereof.

Most preferably, when the aliphatic solvent is propane, the gas comprises propane.

The temperature for carrying out the flocculation reaction is between 15°C and 45°C.

The suitable temperature for carrying out the flocculation reaction is between 15°C and 30°C.

The most preferred temperature for carrying out the flocculation reaction is between 18°C and 25°C.

The method for removing pollutants from oil can also include the following steps:

Transporting the oil and solvent solution from which pollutants have been flocculated from the first pressure vessel to the second pressure vessel;

Settling residual pollutants out of the solution of oil and solvent;

delivering a substantially contaminant-free oil and solvent solution to a solvent stripper; and

Solvent removal from a solution of oil and solvent yields an oil fraction that is substantially free of contaminants.

This substantially contaminant-free oil fraction can be further purified by a distillation step, if desired.

Preferably, the distillation step is performed under reduced pressure.

Prior to distillation, the substantially contaminant-free oil fraction may be subjected to a stripping step to remove residual solvent and petroleum ether fraction therefrom.

If desired, the contaminant residues from the first and/or second pressure vessel may be subjected to a stripping step to remove water and residual solvent.

Preferably, the contaminant residue from which water and residual solvents have been removed is mixed with hot oil to obtain a flowable bitumen extender.

Most preferably, the thermal oil comprises distillation residue from the distillation step.

Contaminated oils can include automotive drain oil.

Additionally, contaminated oil may include crude oil.

Contaminated oils may include residues from petroleum cracking and/or distillation steps.

In addition, contaminated oil may include waste oil from bilge tanks.

Furthermore, contaminated oil may include oil/water mixtures and/or oil/water emulsions obtained during petroleum extraction.

According to another aspect of the present invention, there is provided a method of refining crude oil to obtain a clear petroleum product, the method comprising removing contaminants from the crude feedstock according to the first method of the present invention, and then making the substantially contaminant-free oil feedstock Subsequent refining steps.

According to a further aspect of the present invention there is provided a method of utilizing distillation residues in petroleum refining processes, the method comprising treating the distillation residues according to the first aspect of the invention and then extracting from the contaminated residue thus formed Separate lighter fractions.

According to a further aspect of the present invention there is provided a method of utilizing aqueous petroleum residues from petroleum production, the method comprising treating the aqueous residues according to the first aspect of the present invention to extract oil therefrom substantially free of contaminants fractions.

According to a further aspect of the present invention, there is provided a method of utilizing waste oil from bunkers, the method comprising treating waste oil from bunkers according to the method of the first aspect of the invention to extract therefrom a fuel oil fraction substantially free of pollutants .

Preferably, when utilizing water-containing petroleum residues and/or waste oil from oil tanks in the oil extraction process, the water content of the oily residues to be treated will first undergo a water extraction step to reduce the water content in the materials to be treated. to less than 10%.

According to a second aspect of the present invention, there is provided a device for removing pollutants from oil, said device comprising:

a first pressure vessel in fluid communication with a source of contaminated oil and solvent, and, optionally, a source of flocculation enhancer containing water and/or electrolyte;

a source of pressurized gas optionally introduced through an inlet adjacent the lower portion of said first pressure vessel to disperse fine gas bubbles in the oil/solvent/flocculant contained in the vessel;

an outlet in fluid communication with said inlet to circulate gas introduced into said first pressure vessel;

a decant port to selectively remove substantially contaminant-free oil/solvent solution from said first pressure vessel; and

A contaminant outlet adjacent a lower portion of the first pressure vessel for selectively removing flocculated contaminants settled in the lower region.

Suitably, said apparatus comprises a second pressure vessel for storing the substantially contaminant-free oil solvent solution decanted from said first pressure vessel, said second pressure vessel comprising a An outlet for substantially continuously withdrawing a substantially contaminant-free oil/solvent solution, and an outlet in the lower portion of said second pressure vessel for removal of accumulated flocculated contaminants settled therein.

The apparatus may include a solvent stripping vessel to remove solvent from the substantially contaminant-free oil/solvent solution extracted from said first and/or second pressure vessel, the solvent thus extracted being returned to said solvent source.

Suitably, the apparatus includes a further stripping vessel to remove any residual solvent and light fuel oil fractions from the desolventized feed conveyed from said stripping vessel.

If desired, said apparatus may include a distillation column to remove base oil product from said stripped solvent and light oil fractions conveyed from said further stripping vessel.

Preferably, said apparatus includes a residual oil collector to collect contaminants from said first and second pressure vessels.

Suitably, the residual oil collector is capable of separating water and/or residual solvent from the collected residual oil.

If desired, the apparatus may further include a resid disposal vessel including heating means to provide a resid material that is flowable.

Suitably, said resid processing vessel includes a mixing means to mix oil with said resid to provide a flowable product.

Preferably, said means is in fluid communication with said distillation column to provide an oil distillation residue admixed with said raffinate.

According to another aspect of the present invention, there is provided an apparatus for producing bright oil from crude oil, said apparatus comprising a decontamination apparatus according to the second aspect of the present invention, for pre-treating crude oil upstream of a conventional crude oil processing facility.

According to a further aspect of the present invention there is provided an apparatus for processing distillation residues in a conventional petroleum distillation plant, said apparatus comprising an apparatus according to the second aspect of the invention to extract valuable of petroleum distillates.

The present invention also provides another apparatus for utilizing aqueous crude oil obtained from oil extraction.

Furthermore, the present invention also provides a device for utilizing oil tank waste oil obtained from the bottom of a ship.

In another aspect, the present invention provides an apparatus for treating oily residues from commercial and institutional establishments to separate oil from waste water and/or storm water sources, if desired.

The present invention has overcome or The problems in the prior art are basically alleviated.

In one embodiment, oil is pumped from an oil storage tank to a solvent mixing tank, where the oil is mixed with an aliphatic solvent, such as methane, ethane, propane, butane, pentane, from a solvent storage tank via another pump. Alkanes, hexanes, heptanes, etc., and then add an appropriate amount of flocculation enhancer. Advantageously, before entering the solvent mixing tank, the solvent, reagent and oil are first mixed at room temperature or at a temperature elevated to about 25°C-40°C to form a mixture of oil, reagent and solvent. The mixture is then agitated by dispersing a gas, preferably propane, into the bottom of the solvent mixing tank. This agitation can be allowed to occur for a certain period of time, after which time the gas is turned off and the mixture separates by gravity.

The oil/propane solution is delivered to the second tank using the pressure differential between the two tanks as the driving force. Water, asphalt residue and some solvents are sent from the solvent mixing tank to the residue and water separation tank.

When all the materials, ie oil solvent/reagent solution as well as water and residual oil, have been transferred from the solvent mixing tank, the tank accepts the next batch, such as waste oil and propane solvent. The oil/solvent solution in the solution feed tank can separate the residual oil that has not been separated in the solvent mixing tank, but the solution feed tank is mainly a containment tank to continuously send the oil/solvent solution to solvent oil recovery District (this will be explained later), like this, can complete a continuous action. The oil/solvent solution is pumped by the stripper booster pump, which increases the pressure to the pressure at which the solvent stripper operates. The residual oil that settles out in the solution feed tank is sent to the asphalt mixing tank. This transfer is done by the pressure difference between the two tanks.

The residual oil and water separator is used to separate the oil/solvent solution delivered from the bottom of the solvent mixing tank from the residual oil and also from the water. Therefore, this is a three-phase (oil, water and residual oil) separator. The determination of each phase boundary is done by pumping through a glass liquid level gauge with a sight port through the pump from a specific horizontal position, and then by observing the color difference between the water and residual oil or other suitable observation methods. Once a horizontal position is observed, the water is drained and discarded, or a portion of this water can be used as a flocculation enhancer if desired. The solid resid, with some propane and water remaining in the solid, is conveyed to the asphalt mixing tank where it is heated and mixed with the heavy oil from the bottom of the vacuum distillation column.

The solvent stripper recovers more than 95% of all propane solvent injected into the solvent mixing tank. The remaining propane solvent will be recovered in the distillation pre-flash or petroleum ether flash tank. The oil/solvent solution from the solution feed tank enters the solvent stripper at high pressure, which is facilitated by the vane pump. The oil/solvent solution is then introduced into a packed column in the solvent stripper, where the oil and propane mixture flows through the packed bed, where propane vapor from the reboiler of the solvent stripper strips the propane solvent from the oil remove. Propane exits the top of the column and is then condensed by the condenser. From this condenser, the propane solvent is reintroduced into the solvent storage tank for future reuse.

The oil falls to the bottom of the solvent stripper and enters the reboiler. This reboiler uses a hot oil stream from the bottom of the distillation column. The heat is provided by a furnace. The hot oil stream is then pumped through the reboiler to heat the oil mixture to about 260°C.

This hot oil is sent to a light oil flash tank operating at lower pressure. In the petroleum ether flash tank, low pressure and high temperature vaporize the petroleum ether fraction and any propane that may remain in the oil.

The vaporized petroleum ether fraction and propane solvent enter an overhead condenser where all the petroleum ether fraction is condensed. The petroleum ether fraction and propane mixture then enters the petroleum ether separation drum, from which the petroleum ether is pumped through a pump to the petroleum ether storage facility. The propane gas enters a two-stage compressor with an intercooler where the propane solvent is compressed and sent back to the solvent storage tank.

The unflashed oil in the petroleum ether flash tank is sent to the vacuum distillation column. By reducing the pressure of the oil, the still liquid diesel and lubricating oils are vaporized and enter the upper part of the distillation column. At this time, the unvaporized liquid falls to the bottom of the tower, where it is heated to about 350°C for further vaporization to vaporize more oil. The unvaporized liquid is pumped to the hot oil loop, which provides heat to the solvent stripper and asphalt mixing tank mentioned above. When the oil is cooled by providing these measures in the hot oil ring, it is returned to the furnace where it is heated to about 350°C and returned to the bottom of the distillation column.

A certain amount of heavy oil product that has not been vaporized in the distillation column is pumped to the asphalt mixing tank. Also the hot oil above dissolves the residual oil from the solvent mixing tank and the solution feed tank.

The oil vaporized in the distillation column passes through the distillation column and rises to a section of the column where it is condensed and pumped to an oil storage tank. The still vaporizing petroleum ether fraction rises to the upper packed section of the column where it is condensed and pumped away. Substances that are still not condensable at this point are pumped via a sliding vane vacuum pump to the furnace where the vapors are burned off.

These and other objects and features of the present invention will become apparent from the detailed description and accompanying drawings.

Brief description of the drawings

For a fuller understanding of the various aspects of the invention, which may be put into practice, reference is now made to a preferred embodiment which is shown in the accompanying drawings in which:

Fig. 1 is the schematic diagram of settling reaction vessel;

Figure 2 is a flow diagram representing an apparatus for removing contaminants from oils according to both the method and apparatus aspects of the present invention;

FIG. 3 is an enlarged schematic view of the bitumen extraction system shown in FIG. 2 .

Detailed description of the illustrated embodiment scheme

Figure 1 shows the laboratory standard reaction vessel used to generate the experimental data discussed hereinafter.

In Figure 1, a container 201 comprises a transparent cylindrical acrylic plastic wall 202 with a top closure member 203 and a generally frustoconical bottom closure member 204. The expanded mild steel mesh pipe 205 is located inside the container 201 and is movable, the function of which will be explained later.

At the base of the container 200 is an asphalt valve 206 to remove asphalt residue 207 that collects in this area, while another valve 208 is provided on a conduit 209 communicating with a source of waste oil and other additives (not shown).

Two-way valve 209 communicates with conduit 210 that provides a source (not shown) of liquid propane or compressed gas such as _CO2 or _N2 . The valve 209 is also in communication with the gas recirculation system comprising a conduit 211 connected to the upper part of the vessel 1 in a fluid communication system, an isolation valve 212 , a gas compressor 213 and a heat exchanger 214 . The gas is dispersed in the vessel 201 through a spray manifold 217 having a plurality of nozzles 218 to disperse the gas into fine bubbles.

Outflow conduit 215 with isolation valve 216 is connected to a solvent stripper/recovery system (not shown).

The method according to a preferred aspect of the present invention comprises mixing the contaminated oil containing water and/or electrolytes with liquid propane in a ratio of 1:3-1:6 and spraying the mixture with fine bubbles of propane for 10-20 minutes at room temperature, The mixture was then allowed to settle for about 10-20 minutes.

The mixture separates into three distinct layers, a clear oil/propane layer, a water layer and a residue layer. The layers were collected and propane was removed from the clear oil fraction. Example

The reaction vessel of Fig. 1 is filled with 1000ml oil plant, then mixed into liquid propane in a ratio of 1:6. Agitate the propane/oil mixture by pumping propane gas as fine bubbles into the liquid mixture for 10 minutes.

The spray produces high-velocity air bubbles with a diameter of 1-3 mm and provides relatively gentle but turbulent mixing. After stirring for 10 minutes, the mixture was allowed to settle, and the settling rate was measured.

When the suspended solids had completely settled, the clear oil/propane mixture layer was removed and propane was extracted from the mixture under reduced pressure. The remaining residue was removed and the entrained propane was boiled off at atmospheric pressure.

The oil used in the tests was used car oil with an initial water content of 3.8%. The oil is heated to 140°C for dehydration, so that the water content is less than 0.2%, and the specific gravity is 0.887kg/m ³ .

Dilute the oil in hexane according to the ratio of oil to solvent of 1:10, and measure the transparency of the removed oil.

The residue from the test was weighed and viscosities and flow characteristics were compared visually, and the water content of the residue was determined by the standard ASTM method.

All liquid additives in oil, such as H ₂ O, 97% H ₂ SO ₄ , 35% HCl and red water are in v/v, while 45% KOH, CH ₃ COOH, clay and sodium hexametaphosphate The additions are all in wt/v.

In the tests performed, flocs were formed during agitation with bubbling flow. After the gas spray has ceased, the flocs may continue to grow as light mixing of the liquid mixture/floc suspension continues due to entrained gas bubbles passing through the liquid.

The table below shows the effect of different concentrations of water in oil/propane mixtures, and the effect of electrolytes and other chemicals in the settling properties of treated oil and residues.

Table I

Effect of water content in dehydrated oil (with metal sieve) Water content (%) Sedimentation rate (min) oil paint Residue (gm) Water in residue (%) <0.2 very slow 14-18 8.0 No solid residue 25mm oil/sludge N/A 1.0 slow 8-9 7.5 No solid residue 12mm oil/sludge N/A 2.0 slow 8-9 7.0 No solid residue 12mm oil/sludge N/A 3.0 Moderate 5-6 7.0 40-51 40 5.0 Moderate 5-6 7.0 45-66 70 20.0 Moderate 5-6 7.0 7200 64

Table IA

Efficacy of water content in dewatered oils (removal of metal sieves) Water content (%) Sedimentation rate (min) oil color Residue (gm) Water in residue (%) 5.0 very very slow >30 7.5 No solid residue 50mm oil/sludge N/A

Table II

The effect of KOH in dehydrated oil (with metal sieve) KOH(%) Sedimentation rate (min) oil paint Residue (gm) Water in residue (%) <0.2 very fast 2-3 5.5 28 sticky 12 0.5 very fast 2-3 4.5 36 sticky 16 0.5 Fast 3-4 5.5 19 sticky 30

Table IIA

Efficacy of KOH in dehydrated oil (removal of metal sieve) KOH(%) Sedimentation rate (min) oil paint Residue (gm) Water in residue (%) 0.5 very fast 2-3 7.5 65 viscosity 12

Table III

Efficacy of Acids in Dehydrated Oils concentration(%) Sedimentation rate (min) oil paint Residue (gm) Water in residue (%) _0.2H2SO4 ( ₉₈ %) very fast 2-3 4.5 21 very very sticky 6 _0.5H2SO4 ( ₉₈ %) Fast 3-4 4.5 30 very very sticky 9 0.5HCl (35%) Medium 8-10 4.0 39 very sticky twenty one 0.5CH ₃ COOH Slow 10-12 6.5 29 Sticky 3.5

Table IV

Efficacy of different chemicals in dehydrating oilseeds concentration(%) Sedimentation rate (min) oil paint Residue (gm) Water in residue (%) 1% Calgon + 1% water Fast 3-4 5.5 120 sticky 30 0.5% hexametaphosphate + 2% water very slow 20-25 - 34 Sticky 27 5% red water Slow 8-10 7.5 47 Sticky - 5% _CH3OH very slow 10-25 10 no solid residue N/A 5% clay Slow 8-10 7.5 65* 13

* Some clay settles first, followed by clay and residue in soft lumps.

The above results indicate that there are many factors that can play a role in the formation of large particles that settle rapidly in propane/oil mixtures. It also shows that there are many powerful mechanisms that can be used to elucidate the formation of large flocculant particles.

Without intending to limit the nature of the various powerful mechanisms to any hypotheses, the following discussion only attempts to explain the basics of the observed phenomena.

In addition to van der Waals attraction and electric double layer repulsion, the stability of complex surfactant mixtures/dispersions is also affected by various other factors, such as absorption energy, entropy energy, and bridging energy.

Provided there is no apparent condensation or settling of contaminants when the slop oil is simply mixed with liquid propane at a ratio of slop oil to liquid propane of about 1:3-1:4 v/v, the introduction of air bubbles, especially in the presence of water Or in the case of electrolytes, the destabilization of the solution/dispersion increases. This is completely opposite to the propane treatment method of the prior art. The method of the prior art requires that the ratio of oil/liquid propane is 1: 10-1: 15 to reduce the viscosity and specific gravity of the solution, so that fine particle solids and insoluble oil will go through a long process. Long settling time to precipitate.

In the process according to the invention, the ratio of oil/liquid propane does not change significantly due to the introduction of propane gas bubbles which are drawn from the upper region of the reaction vessel and recycled.

Experiments with other gases such as _CO2 and _N2 have shown that, although not as effective as propane, agitation of the oil/propane mixture by these gases can also induce coagulation or flocculation reactions in the presence of water and/or electrolytes. Therefore, the dispersion of fine air bubbles in the oil/propane mixture can generate triboelectric charges on the surface of the air bubbles in the form of an electric double layer.

If the waste oil is a mixture of ionic species such as organometallic compounds and non-ionic macromolecular species such as synthetic polymeric viscosity index improvers and polar and nonpolar molecular species, it is believed that the waste oil behaves like a lyophilic and lyophobic colloid system mixture. This is evidenced by the as yet unexplained role of metal sieves on solid formation and the role of strong electrolytes on the process. At equilibrium, the system behaves like a lyophobic colloidal system where flocculation occurs with the addition of relatively small amounts of electrolyte. Strictly speaking, although water is not an electrolyte, it is believed that the contaminated oil contains water-soluble impurities that act like electrolytes.

By examining the characteristics of the coagulation/flocculation reaction, the settling rate of solids and the nature of the solids obtained from various chemicals added to the dewatered oil can be obtained, and some understanding of the complexity of the process can be obtained. water

Water plays a vital role in forming large residue particles in the absence of any other chemicals. If the oil is dry (<0.2%), the insoluble residue formed is very small in size, does not flocculate and settles very slowly. The settled residue does not form a sticky mass that remains at the bottom of the column, but instead collects in the oil/propane mixture and redissolves in the oil when the propane is removed.

The ratio of propane to oil was 6:1 and at least 3% water was required in the oil before a significant change in the sedimentation rate was achieved. At this concentration, larger residue particles are formed and the residue can be easily separated from the oil/propane mixture. The residue is viscous and will have a tar-like structure. Viscosity measurements were not performed. The sedimentation rate of the residue remained approximately constant as the water content increased above 3%, but increased as the water content increased. This is mainly due to the increase in water bound in the residue.

For the formation of these larger particles, sufficient water in the form of droplets is required so that the precipitated insolubles can attach to them. The minimum water content found in this work may be due to the solubility of water in the propane-oil mixture, and if the water content in the oil is less than 3.0%, sufficient nuclei cannot be obtained. Although triboelectric bubbles can nucleate in their own right, it is believed that charge transfer can occur between the bubbles and water particles, which would explain why water/electrolyte nuclei can increase the rate of flocculation.

However, without the metal sieve in the reactor, the oil with 5.0% water did not form large particles and settled in a similar manner to the dry oil. The small particle size settles slowly and does not produce a residue that is easily separated from the oil-propane mixture.

It is believed that metal sieves provide a conductive matrix in a non-conductive medium, which facilitates charge transfer between gas bubbles and ionic and polar molecular species in aqueous electrolytes or mixtures.

The presence of water and metal (iron or copper) sieves is necessary for the formation of large particles since the insoluble residue produced in the dry oil does not form a rapidly settling residue. The most likely mechanism is that turbulent mixing from the propane spray creates a triboelectric charge on the water droplets, which attracts and attaches sediment residue to the droplet, or that air bubbles become charged and then transfer that charge Give water drops.

Mixing also provides greater droplet-particle contact, which helps overcome bilayer repulsion. Due to the presence of organometallics, the residues will have significant ionic charges, but these do not explain why the metal surface that the mixture contacts is required.

The metal remains inert throughout the process, and there are no visible signs that it has reacted or corroded. The test setup depicted in Figures 2 and 3 consisted of a mild steel reaction vessel and was run in the same manner as the laboratory tests with metal sieves. alkali

In the absence of water, the addition of a 45% KOH solution to dry oil produced a large, fast-settling residue. There is a marked improvement in color, faster settling and a markedly increased viscosity of the settled residue compared to oils prepared in the water-based process described above.

3% water plus 0.5% KOH slightly lowered the settling rate (but better than 3% water alone) and made the residue less viscous. The water content in the residue was reduced due to the presence of KOH.

When KOH was used, the formation of a rapidly settling residue was independent of the presence or absence of metal sieves. This suggests that a different mechanism than that of water alone is affecting the formation of large residue particles. An increase in the viscosity of the residue indicates that more bonding or crosslinking has occurred.

The strong base reacts with the residue so that the particles tend to attach to each other when brought into contact with each other due to intensive mixing. KOH and NaOH both work equally well, while ammonia and Ca(OH) ₂ don't, although it's not known exactly what reaction is going on.

Tests without a metal screen produced a greater amount of residue and the oil was darker in color. acid

In the absence of water, 0.2% or 0.5% sulfuric acid solutions produced a large settling residue. The oil color is the same as that of 0.5% KOH. But the residues are all by far the stickiest, suggesting considerable cross-linking. The presence of water in the oil reduces the depth of the reaction.

Similarly, when 0.5% HCl was used, the sedimentation rate was moderate, but faster than when only water was present. Oil color, however, was the best of all tested. The water content for this work is 2% due to the acid 35% solution. It can be seen from previous work that this will reduce the settling velocity.

Weak acids such as acetic acid produce slow-settling residues that are difficult to separate from oil-propane mixtures.

Strong acids act in a similar way to strong bases, by reacting with residues to form species that tend to attach to other residue particles, or by creating cross-linking reactions between particles. Acids and bases can also increase the amount of insolubles by precipitating metal hydroxides and sulfates.

For this type of system, spraying of propane or another gas is not critical and similar results can be achieved by mechanical mixing. Dispersant

Calgon, a commercially available water treatment additive, and sodium hexametaphosphate showed varying effects. High concentrations (1%) of Calgon with 5% water produced a rapidly settling residue and a medium colored oil. Sodium hexametaphosphate in 2% water produced a slowly settling residue that, unlike the 2% water only test, could be separated from the propane-oil mixture.

Both compounds act as particle dispersants in aqueous systems, and they were tested in an attempt to prevent water from binding with the residue. This was only partially successful, and the presence of highly charged ions seemed to enhance the growth of residue particles. This may be due to the precipitation of metal phosphates. other chemicals

The addition of clay and red water did not significantly change the particle size and sedimentation rate of the residue. Clay improves settling properties by adsorbing some residues on its surface. The residue is drier and less fluid.

Whether used in automotive waste oil, crude crude oil, petroleum distillation residues, or bunker waste oil, etc., the process of the present invention has been found to remove up to 95% of the contaminants, including water, during the initial flocculation stage. During subsequent stripping and/or distillation stages, the light fuel oil fraction and the base oil fraction are found to be substantially free of contaminants.

Figure 2 schematically represents a commercial plant for the removal of contaminants from oil.

In Fig. 2, the apparatus comprises a first pressure vessel 10 for receiving a forming solution of solvent and contaminated oil, the first pressure vessel 10 having a top and a bottom 12 and 14, respectively, the bottom 14 being used for passing gas through a line 15 Dispersed into the solution in the first pressure vessel 10, and a recovery device in the form of a solvent stripper 16, at this, the solution is divided into vaporized solvent and oil, and the vaporized solvent passes through the line 15 from the bottom of the first pressure vessel 10 14 were reintroduced by spraying.

The apparatus also includes a supply 18 of contaminated oil, such as waste gasoline, in vapor communication with the first pressure vessel through a waste oil line 20 and a valve 22 , and a waste gasoline feed pump 24 pumps the waste gasoline into the first pressure vessel 10 . In addition, the device also includes a liquid solvent supply 26 introduced into the first pressure vessel 10 through a liquid solvent line 28 and a valve 30 , and a liquid solvent pump 32 is used to pump the liquid solvent from the supply 26 to the vessel 10 .

Advantageously, the intermediate portion of the feed lines 20 and 28 forms a third line 34 leading to the vessel 20, so that the third line 34 simultaneously introduces liquid solvent and waste gasoline into the vessel 10 to form a solution. Inlet 152 selectively introduces a flocculation enhancer.

Additionally, the apparatus includes a second pressure vessel 36 in fluid communication with the first vessel 10 via a line 38, the second vessel 36 comprising top and bottom portions 40 and 42, respectively. Advantageously, the solvent and oil in the solution are removed from the first vessel 10 and then introduced into the second vessel 36 by means of a pressure differential between the two vessels.

The apparatus further includes a solution, bitumen resid and water separation tank 44 which includes an inlet 46 in fluid communication with the vessel 10 where the solvent and oil in solution, bitumen resid and water are conveyed from the bottom 14 by a pump 48 To the separation tank 44. Separation tank 44 also includes a first outlet 50 through which water is removed from tank 44, a second outlet 52 through which bitumen residue is removed from tank 44, and a third outlet 54 through which solvent and Oil is returned to the first container 10 through this port. The inside of the tank 44 is provided with an overflow port 56 (not shown) and a water outlet 50 through which water and solvent flow.

The apparatus further includes a bitumen resid mixing tank 60 including an inlet 62 in fluid communication with the second outlet 52 of tank 44, through which the bitumen resid is collected via line 64, and an outlet 66 for removal of bituminous product. Advantageously, the bottom 42 of the vessel 36 is in fluid communication with the inlet 62 of the mixing tank 60 via a line 68 whereby additional bitumen residue is removed from the vessel 36 .

As noted above, the apparatus includes a solvent stripper 16 in fluid communication with the second vessel 36 via line 70 as a recovery unit. A feed pump 72 is included in the line 70 to facilitate delivery of solvent and oil solution to the stripper 16 . Also the feed pump 72 increases the pressure differential between the vessel 36 and the stripper 16 . Preferably, the stripper 16 includes a packed column 74 through which the solvent and oil solution flow. The column 74 has a top and a bottom 76 and 78, respectively. The top 76 includes an outlet 80 through which most of the heated vaporized solvent is discharged. discharged from the stripper 16. The stripper 16 further includes a reboiler 82 integrally connected to and fluidly connected to the bottom 78 of the column 74, the reboiler 82 including an outlet 84 through which the oil and remaining solvent are stripped from the discharged from column 16.

The apparatus also includes a condenser 86 which is in fluid communication with the top 76 of the packed column 74 and the solvent supply 26 via line 88, whereby the heated vaporized solvent is condensed into liquid form and returned to the solvent supply. 26 for future needs.

The apparatus further includes a gasoline flash drum 90 having a respective top and bottom 92 and 94, the top 92 including an outlet 96 and the bottom 94 including an outlet 98, the drum 90 being in fluid communication with the reboiler 82 via line 100 such that, The oil and residual solvent may be sent from the solvent stripper to the gasoline flash drum 90 .

The apparatus also includes another condenser 102 in fluid communication with the top 92 of the drum 90 via line 104 where vaporized gasoline is condensed to a liquid. The apparatus further includes a gasoline collection drum 106 having a top and a bottom 108 and 110, respectively, the top 108 including a solvent outlet 112 and the bottom 110 including an outlet 114 for liquid gasoline, the drum 106 being in fluid communication with the condenser 102 via a line 116 such that , gasoline and solvent can be sent from condenser 102 to drum 106 . The apparatus also includes a gasoline pump 114 in fluid communication with an outlet 114 of the drum 106 whereby refined gasoline product is pumped into a gasoline supply (not shown).

The apparatus further includes two sets of compressors and an intermediate cooler 122 in fluid communication with outlet 112 in drum 106 via line 124 such that the solvent in drum 106 is passed therethrough to be further compressed and cooled. Compressor and cooler 122 is in fluid communication with condenser 86 via line 126 so that solvent passing therethrough is condensed and returned to solvent supply 26 for future use. An intermediate suction scrubber (not shown) is adjacent to and in fluid communication with the cooler and compressor 122 such that liquid condensed there is returned to the drum 106 .

The apparatus also includes a vacuum distillation column 128 having top, middle, and bottom sections 130, 132, and 134, respectively, the top section 130 including an outlet 136 for a refined diesel fuel product, the middle section 132 including an outlet 138 for a refined lube oil product, and the bottom section 134 including an outlet 138 for a refined lube product. Outlet 140 for heavy oil and distillation residue, column 128 is in fluid communication with outlet 98 in drum 90 via line 142 . The apparatus further includes a furnace 144 for heating the oil in the column 128 . Also, column 128 is in fluid communication with inlet 62 of tank 60 via line 146 whereby the heated heavy oil distillation residue is introduced into tank 60 for mixing with the bitumen resid to form the final bitumen product. The bitumen pump 148 preferably circulates residual oil and oil stock to facilitate mixing. Line 150 is provided between tank 60 and condenser 102 so that excess solvent vapor and water can be removed from tank 60 .

The flocculation enhancer may be introduced into the first pressure vessel 10 from a suitable storage device (not shown) through the introduction port 152 . Flocculation enhancers may include aqueous solutions of water, strong electrolytes and strong acid or alkaline earth metal hydroxides or other suitable agents or mixtures thereof.

If desired, NaOH or KOH can be introduced through one or both of ports 152 and 156 to improve the color of the refined base oil product.

Long-running pilot operations have shown no reduction or change in the efficiency of the separation, stripping, reboiling, or vacuum distillation vessels, with little or no evidence of coking or corrosion.

Figure 3 shows an alternative embodiment of the bituminous resid processing system shown in Figure 2, with the same reference numerals used for clarity.

Since the residual oil from the propane extraction unit 44 is a solid substance containing water and entrained propane gas when cooled at atmospheric pressure, it is not suitable for sale as a by-product, and its disposal is difficult. difficulty.

The method according to the invention mixes the heavy oil residue with a mixture of viscous resid, water and propane, the former from vacuum distillation column 128, and the latter mixture from propane extraction vessel 44 and vessel 36 via conduits 146 and 64/68. The two streams are pumped by static pump 300 . The mixture then passes through heat exchanger 301 where the temperature of the mixture rises to about 150°.

The heated mixture flows through conduit 302 to inlet 303 which is connected to extraction vessel 304 . A spray head 305 in fluid communication with the inlet 303 sprays the mixture as a thin film on a shed tray 306 to increase the separation of propane and water vapor from the mixture. Outlet 307 is in fluid communication with conduit 150 (FIG. 2) to recover and separate propane and water vapor

The residual oil/oil mixture exits vessel 304 via outlet 308 and asphalt pump 309 and is dispersed by conduit 310 into a viscous liquid of anhydrous and propane, which can be used as a salable product such as asphalt fill for roofing or road paving etc. agent.

Although the method and apparatus of the present invention have been described with reference to the removal of contaminants from waste motor vehicle lubricating oil, or "waste oil," it will be apparent to those skilled in the art, with no or only some modifications, that Obviously the method and apparatus can also be used to remove contaminants from other oils.

For example, the process can be used upstream of a petroleum cracking/distillation unit to remove bitumen and other contaminants from the feed that can reduce cracking efficiency by poisoning catalysts, etc., or to reduce the efficiency of the vacuum distillation step, where the distillation Causes premature coking and corrosion in the column.

Likewise, residues from conventional cracking/distillation processes can also be treated according to the invention to extract valuable, but lighter fractions that cannot be economically extracted from the residue.

The present invention can also economically recover valuable hydrocarbons from bilge oil, oily wastes and emulsions from tertiary petroleum extraction, and petroleum wastes and emulsions from subsea crude oil extraction.

The by-products in the inventive method are marketable products such as bitumen extender, and heavy metals and other toxic substances have been extracted from the polluted oil, the bitumen extender material is a safe, non-water leachable bonding matrix, This avoids the necessity and high cost and hazards associated with other devices used to dispose of toxic pollutants.

The base oil products prepared according to the present invention can be upgraded, if desired, even further by known hydrotreating methods.

It will also be apparent to those skilled in the art that modifications and variations can be made in the method and apparatus of the invention without departing from the spirit and scope of the invention.

Claims (50)

1. A method for removing pollutants from oil plants, the method comprising the following steps: forming a solution of the contaminated oil in a liquid aliphatic solvent in the presence of a flocculation enhancer in a first pressure vessel; introducing gas in the form of fine gas bubbles in the lower region of said first pressure vessel, wherein said solution is agitated by gas bubbles rising from the solution and contaminants are separated from the solution by flocculation; Separation of flocculated contaminants from liquid solution; and The solvent is separated from this solution to obtain an oil substantially free of contaminants. 2. The method of claim 1, wherein the solvent comprises a C ₁ -C ₇ alkane. 3. A process as claimed in claim 2, wherein the solvent preferably comprises liquid propane or butane or mixtures thereof. 4. A method as claimed in any one of claims 1 to 3, wherein the flocculation enhancer is selected from water and/or electrolyte solutions. 5. A method as claimed in claim 4, wherein, during the flocculation reaction, water is present in the solution of oil and solvent suitably at least 2% v/v. 6. A method as claimed in claim 5, wherein, during the flocculation reaction, the amount of water present in the oil and solvent solution of oil and solvent is preferably at least 3% v/v. 7. The method of claim 6, wherein the concentration of water in the oil and solvent solution is in the range of about 3% - 6% v/v. 8. A method as claimed in any one of the preceding claims, wherein electrolytes are used as flocculation enhancers. 9. The method of claim 8, wherein the electrolyte comprises a strong acid or base. 10. The method of claim 9, wherein the electrolyte is selected from _H2SO4 , _HCl , NaOH or KOH. 11. A method as claimed in any one of the preceding claims, wherein the flocculation is carried out in the presence of physical contact between the electrically conductive element and the solution of oil and solvent. 12. A method as claimed in any preceding claim, wherein the gas may comprise a polar or non-polar gas. 13. The method of claim 12, wherein the gas is selected from _CO2 , _N2 or _C1 - _C4 alkanes. 14. The method of claim 13, wherein the gas comprises propane or butane or mixtures thereof. 15. The method of claim 14, wherein, when the aliphatic solvent is propane, the gas comprises propane. 16. A method as claimed in any preceding claim, wherein the flocculation reaction is carried out at a temperature between 15°C and 45°C. 17. The method of claim 16, wherein the flocculation reaction is carried out at a temperature between 15°C and 30°C. 18. The method of claim 18, wherein the flocculation reaction is carried out at a temperature between 18°C and 25°C. 19. A method as claimed in any one of the preceding claims, wherein the method of removing contaminants from the oil further comprises the step of: Transporting the oil and solvent solution from which pollutants have been flocculated from the first pressure vessel to the second pressure vessel; Settling any remaining contaminants from the oil and solvent solution; transferring the substantially contaminant-free oil and solvent solution from the second pressure vessel to the solvent stripper; and Solvent removal from a solution of oil and solvent yields an oil fraction that is substantially free of contaminants. 20. A process as claimed in any preceding claim, wherein the substantially contaminant-free oil fraction is further purified by a distillation step. 21. The method of claim 20, wherein the distilling step is performed under reduced pressure. 22. A process as claimed in claim 20 or 21 wherein, prior to distillation, the substantially contaminant-free oil fraction is subjected to a stripping step to remove residual solvent and petroleum ether fraction therefrom. 23. A process as claimed in any one of the preceding claims, wherein the contaminant residues from the first and/or second pressure vessel are subjected to a stripping step to remove water and any residual solvent. 24. A method as claimed in claim 23, wherein the contaminant residue from which water and residual solvent have been removed is mixed with hot oil to obtain a flowable bitumen extender. 25. The method of claim 24, wherein the thermal oil comprises distillation residue from the distillation step. 26. A method as claimed in any preceding claim, wherein the contaminated oil comprises automotive waste oil. 27. The method of any one of claims 1 to 25, wherein the contaminated oil stock comprises crude oil. 28. A method as claimed in any one of claims 1 to 25 wherein the contaminated oil comprises the residue of petroleum cracking and/or distillation steps. 29. A method as claimed in any one of claims 1 to 25, wherein the contaminated oil comprises bilge oil. 30. A method as claimed in any one of claims 1 to 25, wherein the contaminated oil comprises oil/water mixtures and/or oil/water emulsions obtained during petroleum extraction. 31. A process for refining crude oil to obtain a clear petroleum product, the process comprising removing contaminants from the crude feedstock according to the method of any one of claims 1 to 25, and then subjecting the substantially contaminant-free oil feedstock to subsequent refining steps. 32. A method of utilizing distillation residues in petroleum refining processes, the method comprising treating the distillation residues according to any one of claims 1 to 25 and then separating more light distillate. 33. A method of utilizing aqueous petroleum residues from petroleum extraction, the method comprising treating the aqueous residues according to any one of claims 1 to 25 to extract substantially contaminant-free oil distillates therefrom share. 34. A method of utilizing bunker waste oil, the method comprising treating bunker waste oil according to any one of claims 1 to 25 to extract therefrom a substantially contaminant-free fuel oil fraction. 35. A method as claimed in claim 33' or 34, wherein, preferably, when utilizing water-containing petroleum residues and/or waste oil from oil tanks in the oil extraction process, the water content of the oily residues to be treated is first passed A water extraction step to reduce the water content of the material to be treated to less than 10%. 36. An apparatus for removing pollutants from oil, said apparatus comprising: a first pressure vessel in fluid communication with a source of contaminated oil and solvent, and, optionally, a source of flocculation enhancer containing water and/or electrolyte; a source of pressurized gas optionally introduced through an inlet adjacent the lower portion of said first pressure vessel to disperse fine gas bubbles in the oil/solvent/flocculant contained in the vessel; an outlet in fluid communication with said inlet to circulate gas introduced into said first pressure vessel; a decant port to selectively remove substantially contaminant-free oil/solvent solution from said first pressure vessel; and A contaminant outlet adjacent a lower portion of the first pressure vessel for selectively removing flocculated contaminants settled in the lower region. 37. The apparatus of claim 36, comprising a second pressure vessel for holding the substantially contaminant-free oil solvent solution decanted from said first pressure vessel, said second pressure vessel comprising a an outlet in the vessel for substantially continuously withdrawing a substantially contaminant-free oil/solvent solution, and an outlet in the lower portion of said second pressure vessel for removing accumulated flocculated contaminants settled therein. 38. The apparatus of claim 37, further comprising a solvent stripping vessel for removing solvent from the substantially contaminant-free oil/solvent solution extracted from said first and/or second pressure vessel, such that The solvent is then returned to the solvent source. 39. Apparatus as claimed in claim 38 including a further stripping vessel for removing any residual solvent and light fuel fractions from the desolvated feed conveyed from said stripping vessel. 40. The apparatus of claim 39 including a distillation column for removing base oil product from said stripped solvent and light oil fractions conveyed from said further stripping vessel. 41. Apparatus as claimed in any one of claims 37 to 40 including a residual oil trap for collecting contaminants from said first and second pressure vessels. 42. The apparatus of claim 41, wherein the residual oil collector is operable to separate water and/or residual solvent from the collected residual oil. 43. The apparatus of claim 42, wherein said resid processing vessel includes heating means to provide a flowable resid material. 44. Apparatus as claimed in claim 43 wherein said resid processing vessel includes a mixing means for mixing oil with said resid to provide a flowable product. 45. The apparatus of claim 44 wherein said apparatus is in fluid communication with said distillation column to provide an oil distillation residue admixed with said raffinate. 46. A plant for the production of bright oil from crude oil, said plant comprising a decontamination unit as claimed in any one of claims 37 to 45 to pre-treat crude oil upstream of conventional crude oil processing facilities. 47. An apparatus for processing distillation residues in a conventional petroleum distillation plant, said apparatus comprising an apparatus according to any one of claims 37 to 46, to extract valuable petroleum fractions from petroleum distillation residues . 48. Apparatus according to any one of claims 337 to 45 for utilizing aqueous crude oil obtained from oil extraction. 49. Apparatus according to any one of claims 37 to 45 for use of oil tank waste obtained from the bottom of a ship. 50. Apparatus according to any one of claims 37 to 45 for use in the treatment of oily residues from commercial and institutional establishments to separate oil from waste water and/or stormwater sources.

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