AU613714B2 - Treating a temperature-sensitive hydrocarbonaceous waste stream to produce a hydrogenated distillable and reusable hydrocarbonaceous product stream - Google Patents

Description

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-U LII*III i 6 13 COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952-69 COMPLETE SPECIFICATION

(ORIGINAL)

Class Application Number: Lodged: Form Int. Class Complete Specification Lodged: Accepted: Published: Priority: Related Art s SName of Applicant Address of Applicant Actual Inventor: Address for Service

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25 East Algonquin Road, Des United States of America Plaines, Illinois 60017, TOM N. KALNES and ROBERT B. JAMES, JR.

EDWD. WATERS SONS, 50 QUEEN STREET, MELBOURNE, AUSTRALIA, 3000.

Complete Specification for the invention entitled: TREATING A TEMPERATURE-SENSITIVE HYDROCARBONACEOUS WASTE STREAM TO PRODUCE A HYDROGENATED DISTILLABLE AND REUSABLE HYDROCARBONACEOUS PRODUCT STREAM The following statement Is a full description of this invention, including the best method of performing it known to US 1.

a.

"TREATING A TEMPERATURE-SENSITIVE HYDROCARBONACEOUS WASTE STREAM TO PRODUCE A HYDROGENATED DISTILLABLE AND REUSABLE HYDROCARBONACEOUS PRODUCT STREAM" FIELD OF THE INVENTION The field of art to which this invention 1 pertains is the production of a hydrogenated distillable and reusable hydrocarbonaceous product stream from a temperature-sensitive hydrocarbonaceous waste stream containing a non-distillable component. More specifically, the invention relates to a process using a combination of flash vaporization and selective hydrogenation for treating a temperature-sensitive hydrocarbonaceous waste stream containing a nondistillable component to produce a hydrogenated distillable and reusable hydrocarbonaceous product stream and a heavy non-distillable product while minimizing thermal degradation of the hydrocarbonaceous waste stream.

SBACKGROUND OF THE INVENTION With the advent of recognition of the dangers associated with disposal of waste streams containing hazardous materials, there has been a steadily increasing demand for technology which is capable of treating a temperature-sensitive hydrocarbonaceous waste stream containing a non-distillable component to produce a distillable and reusable hydrocarbonaceous product and a heavy non-distillable product while minimizing thermal degradation of the hydrocarbonaceous feed stream. Such treatment has always been in demand for the preparation and production of various hydrocarbonaceous products but with the increased environmental emphasis for the treatment and recycle of waste hydrocarbonaceous products there is an increased need for improved processes to separate heavy non-distillable components from a t 2 distillable hydrocarbonaceous product. For example, during the disposal or recycle of potentially environmentally harmful hydrocarbonaceous waste streams, an important step in the total solution to the problem is the pretreatment or conditioning of a hydrocarboanceous stream which facilitates the ultimate resolution to provide product streams which may subsequently be handled in an environmentally acceptable manner. Therefore, those skilled in the art have sought to find feasible techniques to remove heavy non-distillable components from a o temperature-sensitive hydrocarbonaceous waste stream to o provide a distillable hydrocarbonaceous product. Previous techniques which have been employed include filtration, I vacuum wiped film evaporation, solvent extraction, S0 15 centrifugation, and vacuum distillation.

BRIEF SUMMARY OF THE INVENTION o The invention provides an improved process for the production of a hydrogenated distillable and reusable a hydrocarbonaceous product from a temperature-sensitive hydrocarbonaceous waste stream containing a nondistillable component by means of contacting the hydrocarbonaceous feed stream with a hot hydrogen-rich gaseous stream to increase the temperature of the feed stream to vaporize at least a portion of the distillable hydrocarbonaceous compounds thereby producing a distillable hydrocarbonaceous product which is immediately hydrogenated in an integrated hydrogenation zone.

Important elements of the improved process are the relatively short time that the feed stream is maintained at elevated temperature, the avoidance of heating the feed stream via indirect heat exchange to preclude the coke formation that could otherwise occur and the minimization of utility costs due to the integration of the hydrogenation zone.

9 J 3 In its broadest aspect the invention may be characterized as a process for treating a temperature-sensitive hydrocarbonaceous waste stream containing a rtendistillable component to produce a hydrogenated distillable hydrocarbonaceous product and a heavy product comprising the non-distillable component while minimizing thermal degradation of the hydrocarbonaceous waste stream, which process comprises the steps of: contacting the waste stream with a hot first hydrogen-rich gaseous stream having a temperature greater than the waste stream in a flash zone at flash conditions thereby increasing the temperature of the waste stream and vaporizing at least a portion thereof to provide a vapor stream comprising hydrogen and hydrocarbonaceous compounds and a heavy product stream comprising the nondistillable component; contacting the vapor stream with a hydrogenation catalyst in a hydrogenation reaction zone at hydrogenation conditions to increase the hydrogen content of the hydrocarbonaceous compounds contained in the vapor stream; (c) condensing at least a portion of the resulting effluent stream from the hydrogenation reaction zone to provide a second hydrogen-rich gaseous stream and a liquid stream comprising hydrogenated distillable hydrocarbonaceous compounds; and recovering a hydrogenated distillable hydrocarbonaceous product from the liquid stream.

A second embodiment of the Invention may be characterized as a process for treating a temperature-sensitive hydrocarbonaceous waste stream containing a nondistillable component to produce a hydrogenated distillable hydrocarbonaceous product and a heavy product comprising the non-distillable component while minimizing thermal degradation of the hydrocarbonaceous waste stream which process comprises the steps of: contacting the waste stream with a hot first hydrogen-rich gaseous stream having a temperature greater than the waste stream In a flash zone at flash conditions thereby increasing the temperature of the waste stream and vaporizing at least a portion thereof to provide a vapor stream comprising hydrogen and hydrocarbonaceous compounds and a heavy product stream comprising the non-distillable component; contacting the vapor stream with a hydrogenation catalyst In a hydrogenation reaction zone at hydrogenation conditions to increase the hydrogen content of the hydrocarbonaceous compounds contained In the vapor stream; condensing at least a portion of the resulting effluent stream from the hydrogenation reaction zone to provide a second hydiogen-rich gaseous stream suitable for recycle to step and a liquid stream comprising fuel gas and hydrogenated ;rN 4',5 distillable hydrocarbonaceous compounds; and 51 J- 'ic i 3a recovering from said liquid stream a hydrogenated distillable hydrocarbonaceous product stream and a fuel gas stream; and heating at least a portion of said second hydrogen-rich gaseous stream recovered in step and passing the resulting heated stream back to step A third embodiment of the invention may be characterized as a process for treating a temperature-sensitive hydrocarbonaceous waste stream containing a nondistillable component to produce a hydrogenated distillable hydrocarbonaceous product and a heavy product comprising the non-distillable component while minimizing thermal degradation of said hydrocarbonaceous stream which process comprises the 1 0 steps of: contacting the waste stream with a first hydrogen-rich gaseous stream having a temperature greater than the waste stream in a flash zone at flash conditions thereby increasing the temperature of ri i I i

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4 the waste stream and vaporizing at least a portion thereof to provide a hydrocarbonaceous vapor stream comprising hydrogen and a heavy product comprising the nondistillable component; immediately thereafter, contacting the vapor stream with a hydrqgenation catalyst in a hydrogenation reaction zone at hydrogenation conditions to increase the hydrogen content of the hydrocarbonaceous compounds contained in the hydrocarbonaceous vapor stream; condensing at least a portion of the resulting effluent from the hydrogenation reaction zone to provide a second hydrogen-rich gaseous stream suitable for recycle to step and a first liquid stream comprising fuel gas and hydrogenated distillable hydrocarbonaceous compounds; and separating fuel gas from the first liquid stream to provide a second hydrocarbonaceous vapor stream comprising normally gaseous hydrocarbons and a normally liquid hydrogenated distillable hydrocarbonaceous product.

o ot embodiment of the invention may be 1 characterized as a process for treating a temperaturesensitive hydrocarbonaceous waste stream containing a nondistillable component to produce a hydrogenated distillable and reusable hydrocarbonaceous product and a theavy product comprising the non-distillable component while minimizing thermal degradation of the Shydrocarbonaceous stream which process comprises the steps ijof: contacting the waste stream with a first hydrogen-rich gaseous stream having a temperature greater !than the waste stream in a flash zone at flash conditions thereby increasing the temperature of the waste stream and vaporizing at least a portion thereof to provide a hydrocarbonaceous vapor stream comprising hydrogen and a heavy product comprising the non-distillt.le component; contacting the vapor stream with a hydrogenation catalyst in a hydrogenation rection zone at hydrogenation Sconditions to simultaneously increase the hydrogen content I H hyrocrbos ad a ormllyliqid hdroenaed of the hydrocarbonaceous compounds contained in the vapor stream and to generate at least one water-soluble inorganic compound produced from the reaction of the hydrocarbonaceous compounds and the hydrogen; (c) contacting the resulting effluent from the hydrogenation zone with a fresh aqueous scrubbing solution; (d) introducing a resulting admixture of the effluent from the hydrogenation zone and the aqueous scrubbing solution into a separation zone to provide a second hydrogen-rich gaseous stream suitable for recycle to step a first oo00o0 liquid stream comprising fuel gas and hydrogenated o distillable hydrocarbonaceous compounds and a spent oo aqueous scrubbing solution containing at least a portion of the water-soluble inorganic compound; and (e) °o0 15 separating fuel gas from the first liquid stream to 0, °provide a second hydrocarbonaceous vapor stream comprising normally gaseous hydrocarbons and a normally liquid hydrogenated distillable hydrocarbonaceous product.

Other embodiments of the present invention o o0 20 encompass further details such as preferred feedstocks, hydrogenation catalysts, aqueous scrubbing solutions and operating conditions, all of which are hereinafter disclosed in the following discussion of each of these facets of the invention.

C a 0 BRIEF DESCRIPTION OF THE DRAWING The drawing is a simplified process flow diagram of a preferred embodiment of the present invention.

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1 A 6 DETAILED DESCRIPTION OF THE INVENTION The present invention provides an improved integrated process for the removal of heavy nondistillable components from a temperature-sensitive hydrocarbonaceous waste stream and the subsequent hydrogenation of the distillable hydrocarbonaceous stream.

A wide variety of temperature-sensitive hydrocarbonaceous waste streams are candidates for treatment in accordance with the process of the present invention. Examples of hydrocarbonaceous streams which are suitable for treatment by the process of the present invention are dielectric fluids, hydraulic fluids, heat transfer fluids, used lubricating oil, used cutting oils, used solvents, still bottoms from solvent recycle operations, coal tars, atmospheric residuum, oils contaminated with polychlorinated biphenyls (PCB), halogenated wastes and other hydrocarbonaceous industrial waste. Many of these hydrocarbonaceous streams may contain non-distillable S 20 components which include, for example, organometallic compounds, inorganic metallic compounds, finely divided particulate matter and non-distillable hydrocarbonaceous compounds. The present invention is particularly advantageous when the non-distillable components comprise sub-micron particulate matter and the conventional techniques of filtration or centrifugation tend to be highly ineffective.

The presence of a non-distillable component including finely divided particulate matter in a hydrocarbonaceous feed to a hydrogenation zone greatly increases the difficulty of the hydrogenation. A non- .0 distillable component tends 1) to foul the hot heat exchange surfaces which are used to heat the feed to hydrogenation conditions, 2) to form coke or in some other manner deactivate the hydrogenation catalyst thereby shortening its active life and 3) to otherwise hinder a

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7 smooth and facile hydrogenation operation. Particulate matter in a feed stream tends to deposit within the hydrogenation zone and to plug a fixed hydrogenation catalyst bed thereby abbreviating the time on stream.

Once the temperature-sensitive hydrocarbonaceous waste feed stream is separated into a distillable hydrocarbonaceous stream and a heavy non-distillable product, the resulting distillable hydrocarbonaceous stream is introduced into a hydrogenation zone. If the feed stream contains metallic compounds such as those that contain metals such as zinc, copper, iron, barium, phosphorus, magnesium, aluminum, lead, mercury, cadmium, cobalt, arsenic, vanadium, chromium, and nickel, these compounds will be isolated in the relatively small volume of recovered non-distillable product which may then be treated for metals recovery or otherwise disposed of as desired. In the event that the feed stream contains distillable hydrocarbonaceous compounds which include sulfur, oxygen, nitrogen, metal or halogen components, the resulting recovered distillable hydrocarbonaceous stream is hydrogenated to remove or convert such components as desired. In a preferred embodiment of the present invention, the hydrogenation of the resulting distillable hydrocarbonaceous stream is preferably conducted immediately after flashing the feed without intermediate separation or condensation. The advantages of the integrated process of the present invention will be readily apparent to those skilled in the art and include the economy of greatly reduced utility costs.

In accordance with the subject invention, a temperature-sensitive hydrocarbonaceous waste stream 01 containing a non-distillable component is contacted with a hot hydrogen-rich gaseous stream having a temperature greater than the hydrocarbonaceous stream in a flash zone at flash conditions thereby increasing the temperature of the hydrocarbonaceous stream and vaporizing at least a 1 J 1- 8 portion thereof to provide a hydrocarbonaceous vapor stream comprising hydrogen and a heavy non-distillable product. The hot hydrogen-rich gaseous stream preferably comprises more than about 70 mole hydrogen and more preferably more than about 90 mole hydrogen. The hot hydrogen-rich gaseous stream is multi-functional and serves as 1) a heat source used to directly heat the Shydrocarbonaceous feed stream to preclude the coke formation that could otherwise occur when using an indirect heating apparatus such as a heater or heatexchanger, 2) a diluent to reduce the partial pressure of the hydrocarbonaceous compounds during vaporization in the I flash zone, 3) a possible reactant to minimize the formation of hydrocarbonaceous polymers at elevated i 15 temperatures, 4) a stripping medium and 5) at least a portion of the hydrogen required in the hydrogenation {i reaction zone. In accordance with the subject invention, j the temperature-sensitive hydrocarbonaceous feed stream is preferably maintained at a temperature less than about 482 0 F (250 0 C) before being introduced into the flash zone Sin order to prevent or minimize the thermal degradation of the feed stream. Depending upon the characteristics and composition of the hydrocarbonaceous feed stream, the hot hydrogen-rich gaseous stream is introduced into the flash zone at a temperature greater than the hydrocarbonaceous feed stream and preferably at a temperature from about 200°F (93 0 C) to about 1200 0 F (649 C).

During the contacting, the flash zone is preferably maintained at flash conditions which include a I 30 temperature from about 150 0 F (65 0 C) to about 860 0

F

(460 a pressure from about atmospheric to about 2000 psig (13788 kPa gauge), a hydrogen circulation rate of about 1000 SCFB (168 normal m 3 /m 3 to about 30,000 SCFB (5056 normal m/m3i) based on the temperature-sensitive hydrocarbonaceous feed stream and an average residence time of the hydrogen-containing, hydrocarbonaceous vapor J 9 stream in the flash zone from about 0.1 seconds to about seconds. A more preferred average residence time of the hydrogen-containing, hydrocarbonaceous vapor stream in the flash zone is from about 1 second to about 10 seconds.

The resulting heavy non-distillable portion of the feed stream is removed from the bottom of the flash zone as required to yield a heavy non-distillable product.

The heavy non-distillable product may contain a relatively small amount of distillable components but since essentially all of non-distillable components contained in the hydrocarbonaceous feed stream are recovered in this product stream, the term "heavy non-distillable product" is nevertheless used for the convenient description of this product stream. The heavy non-distillable product preferably contains a distillable component of less than abotit 10 weight percent and more preferably less than about 5 weight percent. Under certain circumstances with a feed stream not having an appreciable amount of liquid non-distillable components, it is contemplated that an additional liquid may be utilized to flush the heavy nondistUllables from the flash zone. An example of this situation is when the hydrocarbonaceous feed stream comprises a very high percentage of distillable hydrocarbonaceous compounds and relatively small quantities of finely divided particulate matter (solid) and essentially no liquid non-dis4illable component for use as a carrier for the solids. Such a flush liquid may, for example, be a high boiling range vacuum gas oil having a boiling range from about 700OF (371°C) to about 1000OF (538 0 C) or a vacuum tower bottoms stream boiling at a temperature greater than about 1000°F (538 0 The selection of a flush liquid depends upon the composition of the hydrocarbonaceous feed stream and the prevailing flash conditions in the flash separator, and the volume of the flush liquid is preferably limited to that required for removal of the heavy nen-distillable component.

I j The resulting hydrogen-containing, hydrocarbonaceous vapor stream is removed from tLr flash zone and is immediately introduced into a catalytic hydrogenation zone containing hydrogenation catalyst and maintained at hydrogenation conditions. The catalytic hydrogenation zone may contain a fixed, ebullated or fluidized catalyst bed. This reaction zone is preferably maintained under an imposed pressure from about atmospheric (0 kPa gauge) to about 2000 psig (13790 kPa gauge) and more preferably under a pressure from about 100 psig (689.5 kPa gauge) to about 1800 psig (12411 kPa gauge). Suitably, such reaction is conducted with a maximum catalyst bed temperature in the range of about S' 122 0 F (50 0 C) to about 850°F (454 0 C) selected to perform o" 15 the desired hydrogenation conversion to reduce or eliminate the undesirable characteristics or components of the hydrocarbonaceous vapor stream, In accordance with the present invention, it is contemplated that the desired hydrogenation conversion includes, for example, S, 20 dehalogenation, desulfurization, denitrification, olefin saturation, oxygenate conversion and hydrocracking.

Further preferred operating conditions include liquid hourly space velocities in the range from about 0.05 hr 1 to about 20 hr" 1 and hydrogen circulation rates from about 200 standard cubic feet per barrel (SCFB) (33.71 normal m3/m 3 to about 50,000 SCFB (8427 normal 3/m3), preferably from about 300 SCFB (50.6 normal m 3 /m 3 to about 20,000 SCFB (3371 normal m 3 /m 3 In the event that the temperature of the hydrogen-containing, hydrocarbonaceous vapor stream which is removed from the flash zone is not deemed to be exactly the temperature selected to operate the catalytic hydrogenation zone, the temperature of the hydrogencontaining, hydrocarbonaceous stream may be adjusted either upward or downward by any means known to those of skill in the art in order to achieve the desired 1 0 temperature in the catalytic hydrogenation zone. such a -temperature adjustment may be accomplished, for example, by the addition of either cold or hot hydrogen.

The preferred catalytic composite disposed within the hereinabove described hydrogenation zone can be characterized as containing a metallic component having hydrogenation activity, which component is combined with a suitable refractory inorganic oxide carrier material of either synthetic or natural origin. The precise composition and method of manufacturing the carrier material is not considered essential to the present invention. Preferred carrier materials are alumina, silica and mixtures thereof. Suitable metallic components having hydrogenation activity are those selected from the group comprising the metals of Groups VI-B and VIII of the Periodic Toble, as set forth in the Periodic Table of thl- Elements, E.H. Sargent and Company, 1964. Thus, the catalytic Composites may comprise one or more metallic components from the group of molybdenum, tungsten, chromium, iron, cobalt, nickel, platinum, palladium, iridium, osmium, rhodium, ruthenium, and mixtures thereof.

The concentration of the catalytically active metallic component, or components, is primarily dependent upon a particular metal as well as the physical and/or chemical characteristics of the particular hydrocarbon feedstock.

For excample, the metallic components of Group VI-B are generally present in an amount within the range of from about I to about 20 weight percent, the iron-group metals in an amount within the range uf about 0. 2 to about weight percent, whereas the noble metals of Group TVIII are preferably present in an amount within the range of from about 0.3. to about 5 weight percent, all of which are calculated as if these components existed within the catalytic composite in the elemental state. In addition, any catalyst employed commercially for hydrogenating middle distillate hydrocarbonaceous compounds to remove 12 nitrogen and sulfur may function effectively in the hydrogenation zone of the present invention. It is further contemplated that hydrogenation catalytic composites may comprise one or more of the following components: cesium, francium, lithium, potassium, rubidium, sodium, copper, gold, silver, cadmium, mercury and zinc.

The hydrocarbonaceous effluent stream from the hydrogenation zone is preferably subjected to coolingj conditions sufficient to condense at least a portion thereof and thereafter contacted with an aqueous scrubbing solution. In some cases, the aqueous scrubbing solution may be used to accomplish a portion of the desired condensation step. The resulting admixture is admitted to a separation zone in order to separate a spent aqueous stream, a hydrogenated hydrocarbonaceous liquid phase and a. hydrogen-rich gaseous phase. The contact of the hydrocarbonaceous effluent from the hydrogenation zone with the aqueous scrubbing solution may be performed in any convenient manner and is preferably conducted by cocurrent, in-line. mixing which may be promoted by inherent turbulence, mixing orifices or any other suitable mixing means. The aqueous scrubbing solution is preferably introduced in an amount from about 1 to about 100 volume percent based on the hydrocarbonaceous effluent from the hydrogenation zone. The aqueous scrubbing solution is selected depending on the characteristics of the hydrocarbonaceous vapor stream introduced into the hydrogenation zone. For example, if the hydrocarbonaceous stream to thie hydrogenation zone comprises halogenated compounds, the aqueous scrubbing solution preferably contains a basic compound such as calcium hydroxide, potassium hydroxide or sodium hydroxide in order to neutralize the acid such as hydrogen chloride, hydrogen bromide and hydrogen fluoride, for example, which is formed during the hydrogenation of the halogen The following statement is a full description of this invention, including the best method of performing it known to US 1.

13 compounds. In the event that the hydrocarbonaceous vapor stream contains only sulfur and nitrogen compounds, water may be a suitable aqueous scrubbing solution to dissolve the resulting hydrogen sulfide and ammonia. The resulting hydrogenated hydrocarbonaceous liquid phase is recovered and the hydrogen-rich gaseous phase may be recycled to the hydrogenation zone if desired.

The resulting hydrogenated hydrocarbonaceous liquid phase is preferably recovered from the hydrogenrich gaseous phase in a separation zone which is maintained at essentially the same pressure as the hydrogenation reaction zone and as a consequence contains dissolved hydrogen and low molecular weight normally gaseous hydrocarbons if present. In accordance with the present invention, it is preferred that the hydrogenated hydrocarbonaceous liquid phase comprising the hereinabove mentioned gases be stabilized in a convenient manner, such as, for example, by stripping or flashing to remove the normally gaseous components to provide a stable hydrogenated distillable hydrocarbonaceous product.

In the drawing, the process of the present invention is illustrated by means of a simplified flow diagram in which such details as pumps, instrumentation, heat-exchange and heat-recovery circuits, compressors and similar hardware have been deleted as being non-essential to an understanding of the techniques involved. The use of such miscellaneous appurtenances are well within the purview of one skilled in the art.

With reference now to the drawing, a liquid hydrocarbonaceous feed waste stream having a nondistillable component is introduced into the process via conduit 1 and is contacted with a hot gaseous hydrogenrich recycle stream which is provided via conduit 10 from a source hereinafter described. The liquid hydrocarbonaceous feed waste stream and the hydrogen-rich recycle stream are intimately contacted in hot hydrog'n I 14 flash separator 2. A hydrocarbonaceous vapor stream compri.sing hydrogen is removed from hot hydrogen flash separator 2 via conduit 3 and immediately introduced into hydrogenation reaction zone 5 which is maintained at hydrogenation conditions without intermediate separation thereof. A heavy non-distillable stream is removed from the bottom of hot hydrogen flash separator 2 via conduit 4 and recovered. The resulting hydrogenated hydrocarbonaceous vapor stream is removed from hydrogenation reaction zone 5 via conduit 6 and is contacted with an aqueous scrubbing solution which is introduced via conduit 7 to cause condensation of at least a portion of the vapor stream. The resulting admixture of the hydrogenated~ hydroc'arbonaceous effluent and the aqueous crubbing solution is passed via conduit 6 and if cooled in Aleat-exchanger 8 to cause a further portion of the vapor otream to bea condensed. The resulting cooled ef fluent from heat-exchanger 8 is passed via conduit 6 into high pressure vapor/liquid separator 9. A hydrogenrich gaseous stream is removed from high pressure vapor/liquid separator 9 via conduit 10, heated to a suitable temperature in heat-exchanger 12 and, utilized to contact the waste oil feed stream as hereinabove described. since hydrogen is lost in the process by means 2l 25 of a portion of the hydrogen being dissolved in the exiting liquid hydrocarbon and hydrogen being consumed during the hydrogenation reaction, it is necessary to supplant the hydrogen-rich gaseous stream with make-up hydrogen from some suitable external source, for example, a catalytic reforming unit or a hydrogen plant. Make-up hydrogen may be introduced into the system at any convenient and suitable point, and is introduced in the drawing via conduit 11. A liquid hydrogenated hydrocarbonaceous stream comprising hydrogen in solution is removed from high pressure vapor/liquid separator 9 v3ia conduit 14 and is introduced into low pressure

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vapor/liquid separator 15. A spent aqueous scrubbing solution is removed from high pres6X- vapor/liquid separator 9 via conduit 13 and recovered. A gaseous stream comprising hydrogen and any normally gaseous hydrocarbons present is removed from low pressure vapor/liquid separator 15 via conduit 17 and recovered. A normally licliid distillable hydrogenated hydrocarbon aceou s product is removed from low pressure vapor/liquid separator 15 via conduit 16 and recovered. In the event that the waste oil feed stream contains water, this water is recovered from high pressure vapor/liquid separator 9 via conduit 13 together with the spent aqueous scrubbing solution as hereinabove described.

The process of the present invention is further demonstrated by the following illustrative embodiment.

This illustrative embodiment is however not presented to unduly limit the process of this invention, but to further illustrate the advantages of the hereinabove described embodiments. The following data are considered reasonably illustrative of the expected performance of the invention.

ILLUSTRATIVE EMBODIMENT A waste lube oil having the characteristics presented in Table 1 and contaminated with 1020 ppm by weight of polychlorinated biphenyl (PCB) was charged in admixture with a hot hydrogen stream at a rate of 100 mass units per hour to a hot hydrogen flash separation zone.

The hot hydrogen was introduced into the hot hydrogen flash separation zone at a rate of 31 mass units per hour.

16 TABLE 1 WASTE LUBE OIL FEEDSTOCK PROPERTIES (5375-45) Specific Gravity 60°F (15 0 C) 0.8827 Vacuum Distillation Boiling Range, F (OC I (ASTM D-1160) IBP 338 (170) 516 (269) 628 (331) 30% 690 (367) 730 (388) 750 (399) 800 (421) 831 (444) 80% 882 (474) %Over Bottoms Sulfur, weight percent Polychlorinated Biphenyl Concentration, wppm 1020 Lead, wppm 863 Zinc, wppm 416 Cadmium, wppm 1 Copper, wppm 21 Chromium, wppm The waste lube oil was preheated to a temperature of <482°F (<250 0 C) before introduction into the hot hydrogen flash separation zone which temperature precluded any significant detectable thermal degradation.

The waste lube oil was intimately contacted in the hot flgsh separation zone with a hot hydrogen-rich gaseous stream having a temperature upon introduction into the hot hydrogen flash separation zone of >748°F (>398 0 In addition, the hot hydrogen flash separation zone was operated at conditions which included a temperature of 17 748 0 F (398 0 a pressure of 500 psig (3447 kPa gauge), a hydrogen circulation rate of 18000 SCFB (3034 normal

M

3 /m 3 and an average residence time of the vapor stream of 5 seconds. A hydrocarbonaceous vapor stream comprising hydrogen was recovered from the hot hydrogen flash separation zone, and directly and immediately introduced without separation into a hydrogenation reaction zone containing a hydrogenation catalyst comprising alumina, cobalt and molybdenum. The hydrogenation reaction is conducted with a catalyst peak temperature of 700OF (371 0 C) a pressure of 500 psig (3447 kPa gauge), a liquid hourly space velocity of 0.5 based on hydrocarbon feed to 0000 cc 10the hydrogenation reaction zone and a hydrogen circulation 00 3 h yroeae 00rate of 18,000 SCFB (3034 normal m .Tehdoeae a00C0 15 effluent from the hydrogenation reaction zone including Q000 0 hydrogen chloride is contacted with an aqueous scrubbing solution containing sodium hydroxide, cooled to about 100OF (38 0 and sent to a vapor-liquid high pressure 0000 separator wherein a gaseous hydrogen-rich stream is 0: 0 20 separated from the normally liquid hydrocarbonaceous a* products and spent aqueous scrubbing solution containing 00 0 sodium and chloride ions. The resulting gaseous hydrogena 0 0 rich stream is heated and then recycled to the hot hydrogen flash separation zone together with a fresh 0' 25 supply of hydrogen in an amount sufficient to maintain the 0 000 0 hydrogenation reaction zone pressure. A hydrogenated hydrocarbonaceous stream comprising dissolved hydrogen is removed from the vapor'-liquid high pressure separator and introduced into a product stabilizer which is maintained at a pressure of 10 psia (68.9 kPa absolute) and a temperature of 100OF (38 0 An overhead gaseous stream In an amount of <1 mass unit per hour and having the characteristics presented in Table 2 is recovered from the hereinabove mentioned product stabilizer.

18 TABLE 2 ANALYSIS OF PRODUCT STABILIZER OVERHEAD GAS STREAM Component Hydrogen Mole Percent '53.3 15.4 7.9 6.4 3.8 4.2

C

4

C

5

C

6 a 9 0 0f 00 0 o 0 0 0 0 00 0 0?0 0 0 0 0 0 00 f0 0 0 0 0 0 0 0 A hydrogenated hydrocarbonaceous liquid stream in an amount of 87.1 mass units per hour having the 15 characteristics presented in Table 3 is removed from the product stabilizer.

TABLE 3 ANALYSIS OF HYDROGENATED HYDROCARBONACEOUS LIQUID STREAM Specific Gravity 60°F (15 0

°C)

Vacuum Distillation Boiling Range, (ASTM D-1160) 10% 0.855 e F 430 725 890 Sulfur, weight percent Polychlorinated Biphenyl Concentration, wppm Lead, wppm Zinc, wppm Cadmium, wppm Copper, wppm Chromium, wppm (221) (384) (476) <0.1 <2 <0.03 <0.01 <0.02 <0.01 <0.6

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I 19 A non-distillable liquid stream is recovered from the bottom of the flash separation zone in an amount of 12 mass units per hour and having the characteristics I presented in Table 4.

i TABLE 4 ANALYSIS OF NON-DISTILLABLE STREAM Specific Gravity 60oF (15°C) >0.9 i 10 Polychlorinated Biphenyl Concentration, wppm 110 The foregoing description, drawing and illustrative embodiment clearly illustrate the advantages i encompassed by the process of the present invention and the benefits to be afforded with the use thereof.

Claims (9)

1. A process for treating a temperature-sensitive hydrocarbonaceous waste stream containing a non-distillable component to produce a hydrogenated distillable hydrocarbonaceous product and a heavy product, comprising the non-distillable component while minimizing thermal degradation of the hydrocarbonaceous waste stream, which process comprises the steps of: contacting the waste stream with a hot first hydrogen-rich gaseous stream having a temperature greater than the waste stream in a flash zone at flash conditions thereby increasing the temperature of said waste stream and vaporizing at least a portion thereof to provide a vapor stream comprising hydrogen and hydrocarbonaceous compounds and a heavy product stream, comprising the non-distillable component; contacting the vapor stream with a hydrogenation catalyst in a hydrogenation reaction zone at hydrogenation conditions to increase the hydrogen content of the hydrocarbonaceous compounds contained in the vapour stream; condensing at least a portion of the resulting effluent stream from the hydrogenation reaction zone to provide a second hydrogen-rich gaseous stream and a o liquid stream comprising hydrogenated distillable hydrocarbonaceous compounds; and recovering a hydrogenated distillable hydrocarbonaceous product from the liquid o o stream.

2. A process for treating a temperature-sensitive hydrocarbonaceous waste stream containing a non-distillable component to produce a hydrogenated distillable hydrocarbonaceous product and a heavy product comprising the non-distillable component while minimizing thermal degradation of the hydrocarbonaceous waste stream which process comprises the steps of: contacting the waste stream with a hot first hydrogen-rich gaseous stream having a temperature greater than the waste stream in a flash zone at flash conditions thereby increasing the temperature of the waste stream and vaporizing at least a portion thereof to provide a vapor stream comprising hydrogen and hydrocarbonaceous compounds and a heavy product stream comprising the non-distillable component; i 21 contacting the vapor stream with a hydrogenation catalyst in a hydrogenation reaction zone at hydrogenation conditions to increase the hydrogen content of the hydrocarbonaceous compounds contained in the vapor stream; condensing at least a portion of the resulting effluent stream from the hydrogenation reaction zone to provide a second hydrogen-rich gaseous stream suitable for recycle to step and a liquid stream comprising fuel gas and hydrogenated distillable hydrocarbonaceous compounds; and recovering from said liquid stream a hydrogenated distillable hydrocarbonaceous j product stream and a fuel gas stream; and heating at least a portion of said second hydrogen-rich gaseous stream recovered in step and passing the resulting heated stream back to step

3. The process of claim 1 or claim 2 wherein said temperature-sensitive hydrocarbonaceous waste stream comprises dielectric fluids, hydraulic fluids, heat transfer fluids, used lubricating oil, used cutting oils, used solvents, still bottoms from solvent recycle operations, coal tars, atmospheric residuum, PCB-contaminated oils, halogenated wastes or other hydrocarbonaceous Industrial waste, and wherein said non- j I distillable component comprises organometallic compounds, inorganic metallic compounds, finely divided particulate matter or non-distillable hydrocarbonaceous S compounds,

4, The process of claim 1 or claim 2 wherein said temperature.sensitive I hydrocarbonaceous waste stream Is Introduced Into said flash zone at a temperature less than 482F (250C), and wherein the temperature of said hot first hydrogen-rich stream Is from 200*F (93°C) to 1200 0 F (6490).

5, The process of claim 1 or claim 2 wherein said flash conditions Include a ti temperature from 150 0 F (650C) to 860°F (4601C), a pressure from atmospheric to 2000 psig (13788 kPa gauge), a hydrogen circulation rate of 1000 SCFB (168 normal m 3 /m 3 to 30,000 SCFB (5056 normal m 3 /m3) based on said temperature-sensitive hydrocarbonaceous waste stream, and an average residence time of said vapor stream In said flash zone of 0.1 seconds to 50 seconds. S iS 22

6. The process of claim 1 or claim wherein said hydrogenation reaction zone is operated at conditions which include a pressure from atmospheric (0 kPa gauge) to 2000 psig (13790 kPa gauge), a maximum catalyst temperature from 122 0 F (500C) to 850 0 F (454°C) and a hydrogen circulation rate from 200 SCFB (33.7 normal m 3 /m 3 to 50,000 SCFB (8427 normal std ms/ms).

7. The process of claim 1 or claim 2 wherein said hydrogenation catalyst comprises a refractory inorganic oxide and at least one metallic compound having hydrogenation activity selected from the metals of Group VIB and VIII of the Periodic Table.

8. The process of claim 1 or claim 2 wherein at least one water-soluble inorganic i compound is produced in hydrogenation reaction zone from the reaction of said hydrocarbonaceous compounds and said hydrogen; wherein the resulting effluent from said hydrogenation zone containing hydrogenated hydrocarbonaceous compounds and at least one water-soluble Inorganic compound is contacted with a fresh aqueous scrubbing solution; and wherein the resulting admixture of said effluent from said hydrogenation zone and said aqueous scrubbing solution Is passed into a separation zone to provide a second hydrogen-rich gaseous stream, a first liquid stream comprising fuel gas and hydrogenated distillable hydrocarbonaceous compounds and a spent aqueous scrubbing solution containing at least a portion of said water-soluble inorganic compound.

9. The process of claim 8 wherein said water-soluble Inorganic compound is selected from the group consisting of hydrogen sulfide, ammonia, hydrogen chloride, hydrogen bromide and hydrogen fluoride, and wherein said aqueous scrubbing solution comprises a compound selected from the group consisting of calcium hydroxide, potassium hydroxide and sodium hydroxide. SAITED this 3rd day of June, 1991. WATERMARK PATENT& TRADEMARK ATTORNEYS THE ATRIUM 290 BURWOOD ROAD HAWTHORN VICTORIA 3122 AUSTRAUA LCG/RHB/ML 4 /'t