SE1951501A1 - Method for upgrading waste oil - Google Patents

Abstract

The present invention relates to a method comprising subjecting a feedstock having an oxygen content of at most 5.0 wt.-% (on a dry basis) to a heat treatment, separating solids from the heat-treated material to produce a metal-depleted feed, subjecting the metal-depleted feed, optionally together with a co-feed, to hydrocracking and recovering at least one hydrocarbon fraction boiling in the liquid fuel range from the hydrocracked material.

Description

METHOD FOR UPGRADING WASTE OIL Technical Field The present invention relates to a method for producing fuel componentsfrom waste oil, a fuel component obtainable by the method and the use ofthe fuel component.

Technical background Mobility and logistics are an essential part of life, economy and society today.To meet the growing energy needs of traffic and transport it is important toseek sustainable fuel solutions. Decarbonizing the transport sector is a majorchallenge and fossil fuels should slowly be replaced by more sustainable fuels.Liquid fuel has benefits compared to gases and electricity in traffic solutionsdue to existing infrastructure and fuel logistics. The energetic content of liquidfuels is also superior, which is essential since energy needs to be carried on- board in vehicles.

In addition to biofuels, there is increasing interest towards utilizing recycledfossil-based materials such as used lubricant oils (ULO) or other waste oilsfor production of transportation fuels. In contrast to most biomass-derivedliquids, ULO and other fossil waste oils have a distinct benefit of containingvery little oxygen. On the other hand, ULO and other waste oils do contain aplurality of other impurities (metals, phosphorus, silicon, chlorine) whichoriginate primarily from the additives that have been used in the productionprocess. However, the hydrocarbons that are contained in recycled fossil-based materials such as ULO and other waste oils are largely paraffinic, andthey fall within a boiling point range that is suitable for catalytic cracking.Waste oils such as these therefore offer an alternative for conventionalcracking feeds like vacuum gas oil (VGO).

Furthermore, starting from 2020 in the European Union, the new renewable energy directive (RED II) may include some form of incentives fortransportation fuels prepared from fossil-based recycled feeds. Thus, even though ULO and other waste oils are a highly challenging feedstock in terms 2/24 of purification, they are regarded as an alternative refinery feed with goodpotential. One method for purification of waste oils is distillation; itsimultaneously separates most of the metallic impurities / phosphorus andthe heaviest hydrocarbons into the distillation bottoms, thus rendering the resulting distillates into a more readily utilizable form.

An alternative approach for upgrading waste oils, such as ULO is to re-refinethe hydrocarbons into base oil components, e.g. by hydrotreatment, andsubsequently use them in the formulation of new lubricants. In this approach,it is essential to avoid the cracking of base oil hydrocarbon chains duringpurification and hydrotreatment. Because of this, distillation technologieswhich are particularly suitable for thermally unstable materials are often utilized for fractionating ULO.

Further, US 4,512,878 A discloses a method for recycling waste oils comprising a heat soaking step, a distillation step and a hydro-refining step.

US 4411774 A discloses heat treatment of ULO in the presence of a pre-treatment chemical to remove contaminants, followed by filtration, and re- using the thus treated liquids as lubricant oils.

US 3980551 A discloses demetallization of ULO in an ebullated bed reactor,followed by vacuum distillation to produce a clean fraction and a heavyfractions containing sludge and metals.

Summary of the inventionIt is an object of the present invention to provide an improved method for treatment of waste oils.

The inventors of the present invention surprisingly found that a heattreatment step is suited to reduce the metal content of a waste oil materialto such an extent that the heat-treated material, after removal of solidsubstance formed during heat treatment, can be subjected to a metal- 3/24 tolerant hydrocracking process without any further purification, such as distillation. More specifically, the inventors found that a heat-treatedfeedstock possesses suitable properties that would allow its direct forwardinginto hydrocracking without a further need for distillation, thus significantlyimproving the yield of the pre-cracking purification process as well as the overall yield.

That is, one distinct disadvantage of distillation, though providing quite purematerial, is the significant loss of hydrocarbon material into the distillationbottoms. Moreover, although the majority of the metals is fractionated intothe distillation bottoms, the resulting distillates do not necessarily meet thestringent contaminant specification of fixed-bed hydrotreating/hydrocrackingunits. In practice, this means that a secondary means of purification has tobe employed in order to further reduce the contaminant concentrations of thewaste oil distillates. Depending on the distillation characteristics of the wasteoil sample and the distillation methodology, the hydrocarbons that areseparated into the distillation bottoms may correspond to e.g. vacuumresidue (VR) type material which has a boiling point of > 550 °C and contains significant amounts of metal impurities.

Thus, since an adequate level of metal removal can be achieved without distillation, the present invention provides a process which achievesexceptionally high yields as compared to conventional techniques employing distillation to provide a feed suitable for hydrotreatment.

The present invention is defined in the independent claims. Further beneficialembodiments are set forth in the dependent claims. Specifically, the present invention relates to one or more of the following items: 1. A method comprising the following steps: subjecting a feedstock to a heat treatment (heat treatment step) toproduce a heat-treated material comprising liquid components and solidcomponents, 4/24 separating solids from the heat-treated material to produce a metal-depleted feed, subjecting the metal-depleted feed, optionally together with a co-feed,to hydrocracking (hydrocracking step) to form a hydrocracked material, recovering at least one hydrocarbon fraction boiling in the liquid fuelrange from the hydrocracked material; wherein the feedstock has an oxygen content of at most 5.0 wt.-% on a dry basis. 2. The method according to item 1, wherein the feedstock has an oxygencontent, on a dry basis, in the range of 0.1 wt.-% to 5.0 wt.-°/0, preferably atmost 4.0 wt.-°/o, at most 3.5 wt.-% or at most 3.0 wt.-%, and/or at least 0.2 wt.-°/o, at least 0.3 wt.-%, at least 0.4 wt.-% or at least 0.5 wt.-°/o. 3. The method according to item 1 or 2, wherein the total content of hydrogen(H) and carbon (C) in the feedstock, on a dry basis, is at least 80 wt.-°/0,preferably at least 85 wt.°/0, at least 90 wt.-°/0, at least 92 wt.-°/0, at least 94wt.-°/0, at least 95 wt.-°/0, at least 96 wt.-%, at least 97 wt.-°/0, at least 98wt.-°/0, or at least 99 wt.-°/0. 4. The method according to any one of the preceding items, furthercomprising a pre-treatment step of de-watering a crude feed to prepare thefeedstock.

. The method according to any one of the preceding items, wherein the metal-depleted feed is subjected to hydrocracking together with a co-feed. 6. The method according to any one of the preceding items, wherein the co-feed is a fossil-based feed, a renewable feed or a combination of both. /24 7. The method according to item 6, wherein the fossil-based feed is a fraction from crude oil and/or the renewable feed is a material derived by deoxygenation of a renewable material. 8. The method according to any one of the preceding items, wherein themetal content of the metal-depleted feed is lower than the metal content ofthe feedstock. 9. The method according to any one of the preceding items, wherein themetal content of the metal-depleted feed is at most 60 wt.-% of the metalcontent of the feedstock, preferably at most 50 wt.-°/0, at most 40 wt.-°/0, atmost 30 wt.-%, at most 20 wt.-%, at most 15 wt.-%, at most 10 wt.-% , atmost 8 wt.-% , at most 7 wt.-% , at most 6 wt.-% , at most 5 wt.-% , at most 4 wt.-% , or at most 3 wt.-% of the metal content of the feedstock.

. The method according to any one of the preceding items, wherein theheat treatment is carried out at a temperature of at least 290°C, preferablyat least 300°C, or at least 310°C. 11. The method according to any one of the preceding items, wherein theheat treatment is carried out at a temperature of at least 320°C or at least330°C. 12. The method according to any one of the preceding items, wherein theheat treatment is carried out at a temperature of at most 450°C, preferablyat most 400°C, at most 380°C, at most 370°C, at most 360°C, at most350°C, at most 340°C, or at most 335°C. 13. The method according to any one of the preceding items, wherein theheat treatment is carried out for at least 1 minute, preferably at least 2minutes, at least 5 minutes, at least 10 minutes, at least 20 minutes, at least30 minutes, at least 40 minutes, at least 50 minutes, at least 60 minutes, atleast 80 minutes or at least 100 minutes. 6/24 14. The method according to any one of the preceding items, wherein theheat treatment is carried out at a pressure of 1.0 bar or more, preferably 1.2 bar or more, 1.5 bar or more, 2.0 bar or more or 3.0 bar or more.

. The method according to any one of the preceding items, wherein thefeedstock contains at most 20.0 wt.-% water, preferably at most 15.0 wt.-%, at most 12.0 wt.-%, at most 10.0 wt.-%, at most 8.0 wt.-%, at most 7.0wt.-°/0, at most 6.0 wt.-%, at most 5.0 wt.-%, at most 4.0 wt.-%, at most3.0 wt.-°/o, at most 2.0 wt.-°/0, at most 1.5 wt.-%, at most 1.0 wt.-°/0, at most 0.7 wt.-%, or at most 0.5 wt.-% water. 16. The method according to any one of the preceding items, wherein thehydrocracking step is carried out at a temperature in the range of 300°C to500°C. 17. The method according to any one of the preceding items, wherein thehydrocracking step is carried out at a temperature of at least 310°C, at least320°C, at least 330°C, at least 340°C, or at least 350°C, and/or at most490°C, at most 480°C, at most 470°C, at most 460°C, at most 450°C, atmost 440°C, or at most 430°C. 18. The method according to any one of the preceding items, wherein themetal-depleted feed is subjected to hydrocracking in the presence of a solid catalyst. 19. The method according to item 18, wherein the solid catalyst contains atleast one non-noble Group VIII metal and at least one Group VIB metal anda carrier.

. The method according to item 19, wherein the carrier comprises silica,alumina or clay. 7/24 21. The method according to items 18 or 19, wherein the carrier comprisesBrönsted-acid component. 22. The method according to item 21, wherein the Brönsted-acid componentis zeolite or amorphous silica-alumina. 23. The method according to item 22, wherein the zeolite is Y-zeolite, beta-zeolite or any other 12-member ring zeolite. 24. The method according to items 19 to 23, wherein the Non-noble GroupVIII metal is Co or Ni and Group VIB metal is Mo or W.

. The method according to any one of the preceding items, wherein thehydrogen partial pressure in the hydrocracking step is in the range of 70 to200 bar. 26. The method according to any one of the preceding items, wherein thehydrocracking step is carried out in an ebullated bed reactor, slurry reactor or a fixed bed reactor. 27. The method according to any one of the preceding items, wherein thetotal content of metals and phosphorous in the feedstock is in the range of500 mg/kg to 10 000 mg/kg, preferably 1000 mg/kg to 8000 mg/kg. 28. The method according to any one of the preceding items, wherein thefeedstock is liquid at 25°C. 29. The method according to any one of the preceding items, wherein thetemperature during de-watering is lower than the (highest) temperature in the heat treatment step.

. The method according to any one of the preceding items, wherein thestep of removing insoluble components (the step of separating solids from 8/24 the heat-treated material) comprises at least one of centrifugation, Filtration, and sedimentation, preferably at least centrifugation. 31. The method according to any one of the preceding items, wherein theheat treatment step is carried out for 100 hours or less, preferably 50 hoursor less, 40 hours or less, 30 hours or less, 20 hours or less, 10 hours or less, or 5 hours or less. 32. The method according to any one of the preceding items, wherein a metalremoval additive is admixed with the feedstock in advance of or during theheat treatment step, the metal removal additive preferably being at least oneselected from the group consisting of ammonium sulphate, ammoniumbisulphate, diammonium phosphate, ammonium dihydrogen phosphate,calcium hydrogen phosphate, phosphoric acid, magnesium sulphate, calciumsulphate, aluminium sulphate and sodium sulphate. 33. A fuel component obtainable by the method according to any one of the preceding items. 34. The fuel component according to item 33, comprising the recoveredhydrocarbon fraction, wherein the fraction is preferably a fraction boiling in the gasoline range, or a fraction boiling in the middle distillate range.

. A use of the recovered hydrocarbon fraction obtained by the method according to any one of items 1 to 32 for producing a fuel or a fuel component.

The oxygen content in the feedstock can be determined by elementalanalysis. In the present invention, the oxygen content is determined on a dry basis of the feedstock (excluding water, if present in the feedstock).

Brief description of the drawingFig. 1 is a schematic illustration of the process according to the present invenüon. 9/24 Detailed description of the inventionTheembodiments. It is to be noted that any feature of the embodiments may be invention is now explained in detail with reference to specificcombined with any feature of another embodiment provided that such a combination does not result in a contradiction.

The present invention relates to a method comprising a heat treatment step,a solids separation step, a hydrocracking step and a recovering step. The heattreatment step is a step of subjecting a feedstock to a heat treatment toproduce a heat-treated material comprising liquid components and solidcomponents. The feedstock has an oxygen content of at most 5.0 wt.-°/0 ona dry basis (i.e. excluding water). The solids separation step is a step ofseparating solids from the heat-treated material to produce a metal-depletedfeed. The hydrocracking step is a step of subjecting the metal-depleted feed,optionally together with a co-feed, to hydrocracking to form a hydrocrackedmaterial. The recovering step is a step of recovering at least one hydrocarbonfraction boiling in the liquid fuel range from the hydrocracked material.

The present inventors surprisingly found that heat treatment of the feedstockand subsequent solids removal is sufficient to provide a feed suited for metal-tolerant hydrocracking units, such as residue hydrocracking (RHC) units.Specifically, the inventors found that distillation of the heat treated materialis not necessary and thus the significant loss of valuable hydrocarbon material in the distillation bottoms can be avoided.

Further, the heat treatment may reduce fouling tendencies of the crackingcatalyst and thus increase catalyst life. Although it is not desired to be boundto theory, it is assumed that the heat treatment causes reactive componentsin the feedstock to undergo a reaction and thus to end up as a solid materialwhich can be removed e.g. by filtration or centrifugation. It is assumed thatsuch reactive components are responsible for coke formation (fouling) in the hydrocracking step. /24 The feedstock of the present invention encompasses any material of fossil orrenewable (biomass-based) origin having an oxygen content of at most 5 wt.-% on a dry basis. In a preferred embodiment, the feedstock is waste oil orde-watered waste oil. Employing a waste material (pre-used material) in thepresent invention provides a sustainable process of re-introducing fossil orrenewable carbon material into the value chain and thus reducing the needfor exploiting natural recourses. Since the feedstock has an oxygen contentof at most 5 wt.-°/o, unprocessed bio-based oils such as crude vegetable oil,fats and the like are not included, because these materials have a highRather, the containing mainly hydrocarbons as well as contaminants, e.g. contaminants content of oxygen. invention is concerned with materialincluded as a result of the production method of the material or as a result of the primary use of the material.

In the present invention, the total content of metals (not including metalloids,such as Si) and phosphorous in the feedstock is preferably in the range of500 mg/kg to 10000 mg/kg, preferably 1000 mg/kg to 8000 mg/kg. In otherwords, the feedstock of the present invention is preferably a contaminatedmaterial, such as a waste material. The content of metals in the feedstockcan be determined using e.g. inductively coupled plasma atomic emissionspectrometry based on standard ASTM D5185. For the purpose of the presentinvention, the total content of metals preferably refers to the total (summed)content of Al, Cr, Cu, Fe, Na, Ni, Pb, Sn, V, Ba, Ca, Mg, Mn, and Zn.

In the present invention, the oxygen content “on a dry basis”means that theoxygen content is determined under the assumption that all of the water isremoved before determining the content. The oxygen content on a dry basiscan be determined by drying the feedstock and determining the oxygencontent (e.g. by elemental analysis). Alternatively, the oxygen content on a dry basis can be determined from a wet feedstock as follows: 11/24 oxygen content (dry basis) = 100% * {(tota| oxygen content of the wetfeedstock, e.g. by elemental analysis) - (oxygen contained in the wetfeedstock in the form of water)} / {(mass of wet feedstock) - (mass of water in the wet feedstock)} The content (mass) of water contained in the wet feedstock can bedetermined by any suitable means (e.g. Karl-Fisher titration according toASTM D6304, or distillation according to ASTM D95).

The feedstock may comprise waste oil, such as used lubricant oil (ULO).Specifically, waste oils in accordance with the present invention include anyfossil (mineral based) or renewable (biomass-based) lubrication or industrialoils which have become unfit for the use for which they were originallyintended, and in particular used combustion engine oils and gearbox oils and also mineral lubricating oils, oils for turbines and hydraulic oils.

The feedstock is preferably liquid at 25°C. Thus, the feedstock can be easilyhandled and does not require excessive heating during storage and/ortransportation.

In the method of the present invention, the feedstock preferably has anoxygen content, on a dry basis, in the range of 0.1 wt.-% to 5.0 wt.-°/0, morepreferably at most 4.0 wt.-%, at most 3.5 wt.-% or at most 3.0 wt.-%, and/orat least 0.2 wt.-%, at least 0.3 wt.-%, at least 0.4 wt.-% or at least 0.5 wt.-%.

In other words, it is preferred that the feedstock is a material containing only low amounts of oxygen.

Further, it is preferred that the total content of hydrogen (H) and carbon (C)in the feedstock, on a dry basis, is at least 80 wt.-°/0, preferably at least 85wt.%, at least 90 wt.-%, at least 92 wt.-%, at least 94 wt.-%, at least 95 12/24 wt.-°/0, at least 96 wt.-%, at least 97 wt.-°/0, at least 98 wt.-°/0, or at least 99wt.-%. It is preferred that the total content of hydrogen (H) and carbon (C)in the feedstock, on a dry basis, be at least 90 wt.-°/0. The contents ofhydrogen and carbon in the feedstock can be determined by elementalanalysis using e.g. ASTM D5291.

That is, the feedstock of the present invention is preferably composedpredominantly of hydrocarbon material (consisting of C and H) with lowcontents of heteroatoms which may be contained as inorganic impuritiesand/or in the form of non-hydrocarbon organic material.

The method of the present invention may further comprise a pre-treatmentstep of de-watering a crude feed to provide the feedstock. In view ofefficiency, the de-watering step needs not be carried out if the material to beprocessed already contains a low amount of water and thus the material canbe directly used as the feedstock.

De-watering may be achieved by any suitable chemical and/or physicalmethod. For example, an absorbent or adsorbent for water may be contactedwith the crude feed or water may be removed thermally by evaporation(distillation). The temperature during de-watering is usually lower than in theheat treatment step. The water removal step is preferably carried out at atemperature of less than 150°C, preferably 130°C or less. Further, it ispreferably that de-watering is carried out at ambient pressure so as to keep processing equipment simple.

De-watering the crude feed allows better performance in subsequent steps,especially in the heat treatment step. In particular, stable pressure conditionscan be achieved by removing water (and optionally further light components)before the heat treatment step.

On the other hand, a certain amount of water may be present in the feedstockof the present invention. Depending on circumstances, it may be favourable 13/24 to employ a water-containing feedstock without subjecting it to a water-removal step. In any case, the feedstock of the present invention preferablycontains at most 20.0 wt.-% water, more preferably at most 15.0 wt.-%, atmost 12.0 wt.-%, at most 10.0 wt.-%, or at most 8.0 wt.-%. Even loweramounts of water are desirable but may cause additional efforts for removingwater. Nevertheless, the feedstock may have a water content of at most 7.0wt.-°/0, at most 6.0 wt.-%, at most 5.0 wt.-%, at most 4.0 wt.-%, at most3.0 wt.-°/o, at most 2.0 wt.-°/0, at most 1.5 wt.-%, at most 1.0 wt.-°/0, at most 0.7 wt.-%, or at most 0.5 wt.-% water.

The method of the present invention comprises a step of removing so|ids(insoluble components) before performing hydrocracking. The insolublecomponents include anything which is insoluble in the liquid phase havingbeen subjected to the heat treatment. More specifically, the insolublecomponents include particulate so|ids, precipitates, sludge, including (highly)viscous liquids which are immiscible with the liquid phase (which becomesthe metal-depleted feed). By reducing the content of insoluble components(or by completely removing the so|ids) before hydrocracking, the foulingtendency can be reduced and the handling properties can be improved.Suitable methods for removing so|ids include, but are not limited tocentrifugation, filtration and sedimentation and it is preferred that the processof the present invention comprises at least centrifugation as the only so|ids removal steps or as at least one of multiple so|ids removal steps.

In the present invention, the metal content of the metal-depleted feed islower than the metal content of the feedstock. In other words, metals in thefeedstock accumulate in the so|ids and are separated after the heattreatment. As a result, the metal content is reduced. In the present invention,the “metals content” does not include the content of metalloids (e.g. Si, B).At this time, the content of other contaminants (such as metalloids, phosphorous, sulphur and chlorine) may be reduced as well. 14/24 The metal content of the metal-depleted feed is preferably at most 60 wt.-%of the metal content of the feedstock, preferably at most 50 wt.-°/0, at most40 wt.-%, at most 30 wt.-°/o, at most 20 wt.-%, at most 15 wt.-%, at most10 wt.-% , at most 8 wt.-% , at most 7 wt.-% , at most 6 wt.-% , at most 5wt.-% , at most 4 wt.-% , or at most 3 wt.-% of the metal content of thefeedstock. The metal content may be determined by any suitable means, suchas atomic spectroscopy (e.g. AAS, AES, AFS, ICP-MS), e.g. inductivelycoupled plasma atomic emission spectrometry based on standard ASTMD5185.

The more the metal content is reduced by the heat treatment and subsequentsolids removal, the more metal-depleted feed can be employed in thesubsequent hydrocracking step without being concerned about catalyst poisoning or other negative effects of metal impurities.

In the present invention, the heating temperature during the heat treatmentstep is preferably at least 290°C. In this respect, balance between heatingtemperature and heating time (residence time) influences the efficiency ofthe method of the present invention. Generally, the lower the heat treatmenttemperature is, the longer the heat treatment time should be in order toachieve the best results.

The heat treatment temperature is preferably at least 300°C, or at least310°C and may be at least 320°C or at least 330°C.

It is particularly preferable that the heat treatment temperature is the highesttemperature among all temperatures of the method of the present inventionpreceding the hydrocracking step.

In the present invention, the heat treatment temperature refers to the temperature of the material to be treated (i.e. of the feedstock). /24 If the heat treatment temperature is at least 290°C, a considerable metaldepletion can be achieved. In this respect, although a reduction of metalcontent can be achieved even at lower temperatures, this requires very longheating times which is not therefore not preferable. On the other hand, heattreatment temperatures of much more than 400°C are usually not necessaryto achieve the object of the present invention so that the heat treatmenttemperature is preferably 450°C or less, more preferably 440°C or less. Theheat treatment temperature may further be 430°C or less, 420°C or less,410°C or less, 400°C or less, 390°C or less, 380°C or less, 370°C or less,360°C or less, 350°C or less, 340°C or less, or 335°C or less.

The heat treatment duration (heat treatment time / residence time)influences the efficiency of the method of the present invention as well.Generally, it is preferable that the heat treatment step is carried out for atleast 1 minute so as to achieve sufficient metal reduction (solids formation)and to further enable good process control. The heat treatment time ispreferably at least 2 minutes, at least 5 minutes, at least 10 minutes, at least20 minutes, at least 30 minutes, or at least 40 minutes. The heat treatmenttime may further be at least 50 minutes, at least 60 minutes, at least 80minutes or at least 100 minutes. Generally, there is no upper limit for theheat treatment time. However, in view of process efficiency, the heattreatment time if preferably no upper limit 100 hours or less, more preferably50 hours or less, 40 hours or less, 30 hours or less, 20 hours or less, 10 hoursor less, or 5 hours or less.

If the heat treatment is carried out in a batch reactor, the heat treatmenttime corresponds to the temperature holding time. In a continuous reactor,the heat treatment time corresponds to the residence time.

Preferably, the heat treatment step is carried out at a pressure of 0.5 bar ormore, more preferably 0.8 bar or more, 1.0 bar or more, 1.2 bar or more,1.5 bar or more, 2.0 bar or more, 3.0 bar or more, 4.0 bar or more, 5.0 baror more, 6.0 bar or more, 8.0 bar or more, 10.0 bar or more, 12.0 bar or 16/24 more, or 14.0 bar or more. An elevated pressure during the heat treatmentstep can reduce the evaporation tendency and thus ensure an efficient heattreatment. The pressure should be 200 bar or less, preferably 100 bar or less, more preferably 50 bar or less in order to keep technical equipment simple.

If not indicated to the contrary, a pressure referred to in the present inventionmeans absolute pressure. The pressure values above refer to the highestpressure occurring in the heat treatment step, i.e. measured at the point/timeof highest pressure. In particular, it is preferable that the heat treatment isnot carried out under reduced pressure, but rather under ambient pressureor elevated pressure. Specifically, higher pressure reduces the volatilisationtendency and thus possible product loss or boiling effects (e.g. in continuous processes).

A metal removal additive may be present during the heat treatment step. Themetal removal additive may be added before starting the heat treatmentand/or may be added during heat treatment. Suitable metal removaladditives are those mentioned in US 4411774 A, but are not limited to those.Specifically, the metal removal additive in the present invention may be oneor more selected from the group consisting of ammonium sulphate,ammonium bisulphate, diammonium phosphate, ammonium dihydrogenphosphate, calcium hydrogen phosphate, phosphoric acid, and magnesiumsulphate and/or one or more selected from the group consisting of calciumsulphate, aluminium sulphate and sodium sulphate. The total added amountof the metal removal additive is preferably at least 0.1 wt.-%, morepreferably at least 0.5 wt.-% or at least 1.0 wt.-% relative to the dry weightof the feedstock (total weight on a dry basis). The total added amount refersto the summed amount of all added metal removal additives (but notincluding solvents, if any, which are added together with the metal removaladditives). If the metal removal additive is one or more selected from thegroup consisting of calcium sulphate, aluminium sulphate and sodiumsulphate, the added amount is preferably at least 2.0 wt.-°/0, more preferablyat least 3.0 wt.-% and even more preferably at least 4.0 wt.-% so as to 17/24 improve filterability. However, metal removal efficiency is improved with any(even low) amount of metal removal additive as compared to a process employing no additive at all.

In the present invention, the type of hydrocracking is not particularly limitedas long as it can tolerate the metal content of the metal-depleted feed(optionally in admixture with a co-feed). A conventional hydrocrackingprocess may be employed and applicable hydrocracking process types includefixed-bed ebullated bedhydrocracking. hydrocracking, hydrocracking, and slurry The hydrocracking may be carried out in the presence of a solid catalyst. Thesolid catalyst may be a bifunctional catalyst. When using a catalyst, the cracking effect can be achieved at lower cracking temperature.

The solid catalyst preferably contains at least one non-noble Group VIIImetal, at least one Group VIB metal and a carrier. Preferably both the non-noble Group VIII metal and the at least one Group VIB metal are supportedon the carrier. Any suitable carrier may be used and a carrier comprisingsilica, alumina or clay is preferred. Further, a carrier comprising a Brönsted-acid component is preferred. The Brönsted-acid component may preferablybe zeolite or amorphous silica-alumina. A suitable zeolite is Y-zeolite, beta-zeolite or any other 12-member ring zeolite. The non-noble Group VIII metalis preferably Co or Ni. The group VIB metal is preferably Mo or W. Specifically,the following types of catalysts are preferred, especially when supported ona carrier as mentioned above: Co-Mo, Co-W, Ni-Mo, Ni-W.

The cracking temperature is not particularly limited and any suitabletemperature may be employed. Specifically, a temperature within the rangeof 300°C to 500°C may be employed. The cracking temperature is preferablyat least 310°C, at least 320°C, at least 330°C, at least 340°C, or at least350°C. The cracking temperature may be at most 490°C, at most 480°C, atmost 470°C, at most 460°C, at most 450°C, at most 440°C, or at most430°C. 18/24 In the hydrocracking step, the hydrogen partial pressure in the hydrocrackingstep is preferably in the range of 70 to 200 bar.

The hydrocracking step may be carried out in any suitable reactor andpreferable is an ebullated bed reactor, a s|urry reactor or a fixed bed reactor.

The feed of the hydrocracking step may comprise one or more co-feeds inaddition to the meta|-dep|eted feed of the present invention. The co-feed maybe a fossil-based feed, a renewable feed or a combination of both.

The feed of the hydrocracking step preferably comprises a renewable feedcomponent (biomass-based feed component) as a co-feed in addition to themeta|-dep|eted feed (component). By combining the meta|-dep|eted feedwith a biomass-based feed, the method of the present invention can be evenmore sustainable. The feedstock, and even more the meta|-dep|eted feedproduced therefrom, comprises mainly hydrocarbons (compounds consistingof carbon atoms and hydrogen atoms) and thus the oxygen content and otherproperties can be finely adjusted by combining the biomass-based feed andthe meta|-dep|eted feed.

The renewable feed may be a material derived by deoxygenation of a renewable material.

Further, the feed of the hydrocracking step may comprise a fossil feedcomponent in addition to the meta|-dep|eted feed. The fossil feed may be asuitable feed other than the meta|-dep|eted feed and may be a fraction fromcrude oil (e.g. a fraction from crude oil distillation or a fraction obtained byprocessing crude oil). Specifically, the fossil feed may be a conventionalcracking feed, such as vacuum gas oil (VGO), or vacuum residue (VR).

By combining the meta|-dep|eted feed with another feed (co-feed), the hydrocracking properties can be finely adjusted and the desired product 19/24 distribution can be adjusted more easily. Preferably, the content of the metal-depleted feed in the (total) feed of the hydrocracking step is 50 wt.-% or less,more preferably 40 wt.-% or less, 30 wt.-% or less or 20 wt.-% or less. Inorder to efficiently increase the use of waste oil components, the content ofthe metal-depleted feed in the feed of the hydrocracking step is preferably 1wt.-% or more, more preferably 2 wt.-% or more, 5 wt.-% or more or 8 wt.-% or more. By limiting the content of the metal-depleted feed in the (overall)hydrocracking feed, the metal content can be limited while still achieving asustainable effect. Limited metal content allows selection of less metal-tolerant catalysts and/or can improve catalyst life.

The method of the present invention further comprises a step of recoveringat least one hydrocarbon fraction from the hydrocracked material (theproduct of the hydrocracking step/ hydrocracking product). This step can beachieved by fractionating the hydrocracked material and recovering the atleast one fraction. Fractionation can be carried out with any known meansand preferably results in the production of at least a gasoline range fractionand/or a middle distillate range fraction.

The procedure of the present invention is schematically shown in Fig. 1. Asillustrated in Fig. 1, water may be removed in a de-watering step (optional),insoluble components (precipitates) are removed e.g. in a centrifugation step.

The resulting metal-depleted feed is then subjected to hydrocracking.

The present invention further relates to a fuel component obtainable by themethod of the present invention.

As can be seen from the results of the Examples, the method of the presentinvention enables efficient production of fuel components, especially in thegasoline and middle distillate range, in high yield.

The present invention further relates to a use of the recovered hydrocarbonfraction for producing a fuel or a fuel component. /24 ExamplesThe present invention is further illustrated by way of Examples. However, itis to be noted that the invention is not intended to be limited to the exemplary embodiments presented in the Examples.

Example 1 Used Iubricant oil (ULO) was used as a feedstock. The ULO contained 17.0wt.-% water and had a high amount of metal impurities (3181 mg/kg on awet basis = 3833 mg/kg on a dry basis; detected metals: Al, Cr, Cu, Fe, Na,Ni, Pb, Sn, V, Ba, Ca, Mg, Mn, Zn).The content of Si was detected as well andwas 84 mg(kg (wet) and thus 101 mg/kg (dry). The oxygen content (on adry basis) was 1.0 wt.-°/0.

The ULO was de-watered in a rotary evaporator at 100°C and 80 mbar. As aconsequence, water (and light ends) were removed. The de-watered ULO wasthen subjected to heat treatment in a batch reactor at 320°C for 1 hour. Thepressure at the beginning of the heat treatment was 1 bar and the pressureincreased to approximately 23 bar as a consequence of heating in the closedvessel. The heat-treated material was cooled down to 50°C and centrifugedat 4300 rpm for 30 minutes and the liquid parts (excluding solids and sludge) were recovered as a metal-depleted feed ready to be fed to hydrocracking.

The yield of the respective process steps (wt.-% of original ULO) and themetal contents of the feedstock (ULO) and the metal-depleted feed (after centrifugation) are given in Table 1 below. 21/24 Table 1:Process step Stream Yield (wt.- Yield (wt.- Metals Si P% wet % dry mg/kg mg/kg mg/kgfeedstock) feedstock) (dry (dry (drybasis) basis) basis)-- ULO 100 -- 3833 101 1705Water +_ 18.9 -- -- -- --De-Watering |l9ht5Dry ULO 80.2 96.6 -- -- --solids(and 6.5 7.8 -- -- --Heatsludge)treatment +solids removal metahdepleted 73.4 88.4 48 17 20feed As can be seen from Table 1, the method of the present invention achieves asignificant reduction of metals content (and of metalloids content) suitable to be fed to a metal-tolerant hydrocracking process.

Comparative Example 1: The metal depleted feed of Example 1 was further subjected to thin filmevaporation at 0.1 mbar (270-281°C). As a result, the total metals contentof the distillate (b.p. < 560°C) further decreased to 2 mg/kg whereas the Sicontent and the P content remained almost unchanged. On the other hand,another 6 wt.-% of product (relative to dry basis of feedstock) was lost asdistillation bottoms.

Example 2 Another batch of used lubricant oil (ULO-2) was used as a feedstock. TheULO-2 contained 2.6 wt.-% water and had a high amount of metal impurities(2155 mg/kg on a wet basis; detected metals: Al, Cr, Cu, Fe, Na, Ni, Pb, Sn,V, Ba, Ca, Mg, Mn, Zn).The content of Si was 278 mg/kg (wet) and the 22/24 content of P was 455 mg/kg (wet). The oxygen content (on a dry basis) was1.0 wt.-%.

The ULO-2 was de-watered in a rotary evaporator at 100°C and 80 mbar. Asa consequence, water (and light ends) were removed. One part of the de-watered ULO-2 was then admixed with 3000 ppm (relative to de-wateredULO-2) of 85 wt.-% H3PO4 as a metal removal enhancer was then subjectedto heat treatment in a batch reactor at 320°C for 1 hour.

Another part of the de-watered ULO-2 was subjected to heat treatment in abatch reactor at 320°C for 1 hour without additive.

In each case, the pressure at the beginning of the heat treatment was 1 barand the pressure increased to approximately 6-7 bar as a consequence ofheating in the closed vessel. The heat-treated material was cooled down to50°C and solids were removed and the liquid parts (excluding solids andsludge) were recovered as a metal-depleted feed ready to be fed to hyd rocracking.

Solids removal was effected using centrifugation at 4300 rpm for 30 minutes.In a further experiment, solids removal was effected with filtration instead of centrifugation.

The yield of the respective process steps (wt.-% of original ULO) and themetal contents of the feedstock (ULO-2) and the metal-depleted feed (aftercentrifugation) are given in Table 2 below. 23/24 Table 2:Process step Stream Yield (wt.- Yield (wt.- Metals Si P% wet % dry mg/kg mg/kg mg/kgfeedstock) feedstock) (dry (dry (drybasis) basis) basis)-- ULO 100 -- 2213 285 467Water +4.6 -- -- -- --De-Watering lightsDry ULO 95.4 97.9 -- -- --solidsHeat(and 7.3 7.5 -- -- --treatmentsludge)with additive+ metal-centrifugation depleted 88.1 90.5 111 133 69feedsolidsHeat (and 7.6 7.8 -- -- --treatment sludge)with additive meta-+ flltfatm” depleted 87.8 90.1 31 71 14feed As can be seen from Table 2, the method of the present invention achieves asignificant reduction of metals content (and of metalloids content) suitable tobe fed to a metal-tolerant hydrocracking process. Further, it can be seen thatmetal removal efficiency is significantly improved when employing a metalremoval additive in combination with filtration as the solids removal step(preferably at least as the first stage of the metal removal step or as the only metal removal step).

Comparative Example 2 ULO-2 was subjected to heat treatment in the same manner as in Example 2but without metal removal additive and to subsequent centrifugation. Theheat-treated sample was then subjected to distillation under the conditions used in Comparative Example 1. The results are shown in Table 3 below. 24/24 Table 3:Process step Stream Yield (wt.- Yield (wt.- Metals Si P% wet % dry mg/kg mg/kg mg/kgfeedstock) feedstock) (dry (dry (drybasis) basis) basis)-- ULO 100 -- 2213 285 467Water +4.6 -- -- -- --De-watering lightsDry ULO 95.4 97.9 -- -- --solidsHeat(and 9.6 9.9 -- -- --treatmentsludge)withoutadditive + heat-centrifugation treated 85.7 88.0 801 123 308materialHeat bottoms 14.4 14.8 -- -- --treatment +centrifugation+ dlstlllatmn distillate 71.3 73.2 4 116 10 As can be seen from Table 3, the metal removal efficiency of distillation ishigher than when using only centrifugation or filtration after heat treatment.However, the content of Si is even higher (presumably because volatile Sicompounds are evaporated even from the sludge) than for the technique ofthe present invention. In addition, a significant amount of product is lost asdistillation bottoms.

Claims (14)

1. A method comprising the following steps: subjecting a feedstock to a heat treatment (heat treatment step) toproduce a heat-treated material comprising liquid components and solidcomponents, separating solids from the heat-treated material to produce a metal-depleted feed, subjecting the metal-depleted feed, optionally together with a co-feed,to hydrocracking (hydrocracking step) to form a hydrocracked material, recovering at least one hydrocarbon fraction boiling in the liquid fuelrange from the hydrocracked material; wherein the feedstock has an oxygen content of at most 5.0 wt.-°/0 on a drybasis, and wherein the step of separating solids from the heat-treatedmaterial (the step of removing insoluble components) comprises at least one of centrifugation, filtration, and sedimentation.

2. The method according to claim 1, wherein the feedstock has an oxygencontent, on a dry basis, in the range of 0.1 wt.-°/0 to 5.0 wt.-%, preferably atmost 4.0 wt.-°/o, at most 3.5 wt.-% or at most 3.0 wt.-%, and/or at least 0.2wt.-°/o, at least 0.3 wt.-%, at least 0.4 wt.-% or at least 0.5 wt.-°/o.

3. The method according to claim 1 or 2, wherein the total content ofhydrogen (H) and carbon (C) in the feedstock, on a dry basis, is at least 80wt.-°/0, preferably at least 85 wt.%, at least 90 wt.-°/0, at least 92 wt.-°/0, atleast 94 wt.-%, at least 95 wt.-%, at least 96 wt.-%, at least 97 wt.-°/o, at least 98 wt.-%, or at least 99 wt.-°/0.

4. The method according to any one of the preceding claims, wherein themetal-depleted feed is subjected to hydrocracking together with a co-feed, 2/3 wherein the co-feed is preferably a fossil-based feed, a renewable feed or a combination of both.

5. The method according to any one of the preceding claims, wherein themetal content of the metal-depleted feed is at most 60 wt.-% of the metalcontent of the feedstock, preferably at most 50 wt.-°/0, at most 40 wt.-°/0, atmost 30 wt.-%, at most 20 wt.-%, at most 15 wt.-%, at most 10 wt.-% , atmost 8 wt.-% , at most 7 wt.-% , at most 6 wt.-% , at most 5 wt.-% , at most 4 wt.-% , or at most 3 wt.-% of the metal content of the feedstock.

6. The method according to any one of the preceding claims, wherein theheat treatment is carried out at a temperature of at least 290°C, preferablyat least 300°C, at least 310°C, at least 320°C, or at least 330°C.

7. The method according to any one of the preceding claims, wherein theheat treatment is carried out for at least 1 minute, preferably at least 2minutes, at least 5 minutes, at least 10 minutes, at least 20 minutes, at least30 minutes, at least 40 minutes, at least 50 minutes, at least 60 minutes, atleast 80 minutes or at least 100 minutes.

8. The method according to any one of the preceding claims, wherein thehydrocracking step is carried out at a temperature in the range of 300°C to500°C.

9. The method according to any one of the preceding claims, wherein themetal-depleted feed is subjected to hydrocracking in the presence of a solidcatalyst and the solid catalyst preferably contains at least one non-nobleGroup VIII metal and at least one Group VIB metal and a carrier.

10. The method according to claim 9, wherein the carrier comprises silica,alumina or clay and/or wherein the carrier comprises a Brönsted-acidcomponent, wherein the Brönsted-acid component is preferably zeolite oramorphous silica-alumina. 3/3

11. The method according to any one of the preceding claims, wherein thehydrocracking step is carried out in an ebullated bed reactor, slurry reactor or a fixed bed reactor.

12. The method according to any one of the preceding claims, wherein thetotal content of metals and phosphorous in the feedstock is in the range of500 mg/kg to 10 000 mg/kg, preferably 1000 mg/kg to 8000 mg/kg.

13. The method according to any one of the preceding claims, wherein thestep of separating so|ids from the heat-treated material (removing insoluble components) comprises at least centrifugation.

14. A use of the recovered hydrocarbon fraction obtained by the methodaccording to any one of claims 1 to 13 for producing a fuel or a fuel component.