SE543084C2

SE543084C2 - Method for co-processing waste plastic derived liquids and end-life-tire derived liquids with crude oils

Info

Publication number: SE543084C2
Application number: SE1951472A
Authority: SE
Inventors: Blanka Toukoniitty; Pekka Aalto; Ville Paasikallio
Original assignee: Neste Oyj
Priority date: 2018-12-28
Filing date: 2019-12-16
Publication date: 2020-10-06
Also published as: DK201970766A1; DK181062B1; NL2024523A; FR3091294A1; NO347068B1; DE102019133911B4; ES2769963A1; FR3091294B1; ES2769963B2; FI128635B; SE1951472A1; NO20191514A1; GB201918837D0; GB2580539A; BE1026853A1; DE102019133911A1; GB2580539B; BE1026853B1; NL2024523B1; FI20186136A1

Abstract

The present invention relates to methods for co-processing waste plastic (WP) derived liquids and end-life-tire (ELT) derived liquids with crude oils (CO) in conventional oil refinery settings comprising desalting (10) and distilling (20).

Description

METHOD FOR CO-PROCESSING WASTE PLASTIC DERIVED LIQUIDS ANDEND-LIFE-TIRE DERIVED LIQUIDS WITH CRUDE OILS FIELDThe present invention relates to methods for co-processing, in particular co-processing waste plastic derived liquids and end-life-tire derived liquids with crudeoils in conventional oil refinery settings.BACKGROUND Recycled-type raw materials or reduced-carbon feedstocks are feeds created by theprocessing of fossil-based wastes like waste plastics (WP) or end-of-life tires (ELT).The attractive feature of these raw materials from the viewpoint of the refinery is thatthey are quite similar compared to traditional refinery feeds, i.e. crude oil. WP/ELT-derived oils contain primarily hydrocarbons, and their oxygen content is clearly lower compared to biomass-based oils.

WP pyrolysis derived oils contain different elemental impurities dependent mostlyon the original raw material, but also on the pyrolysis technology employed. Thethree most relevant impurities in plastic pyrolysis oils are nitrogen, sulphur andchlorine, which have a detrimental effect on the direct utilization of the pyrolysis oil.These impurities are primarily present in organic form, which means that they arestructurally associated with hydrocarbon chains of varying size and complexity.Furthermore, metal impurities originating from additives and contamination can also be detected in these oils.

ELT pyrolysis oils tend to have much lower Cl content compared to WP pyrolysisoils, and therefore in co-processing of ELT pyrolysis oils this issue may be managedvia simple dilution. On the other hand, ELT pyrolysis oils contain other impuritieswhich can be detrimental in refining operations. These oils contain solid impuritiesmainly in the form of carbon black, which is used as a reinforcing filler in tireformulations, as well as some oil-soluble metallic impurities. ELT pyrolysis oil alsocontain substantial amounts of sulfur and nitrogen, both of which can be found in conventional crude oils as well. 2 Even if the WP/ELT derived oil has very low impurity concentration and/or it isutilized in very low concentrations, the impurities can still cause various issues overtime. Thus, the WP/ELT-derived oil should be introduced to the refinery in a manner that minimizes the potential effect of these impurities.

There are numerous pieces of art disclosing processes and equipment suitable forpreparation, purification and cracking of waste plastic and/or ELT pyrolysis oils. Forexample, US2016045841 discloses a specific reactor suitable for desaltingcombined hydrocarbon streams including crude oils and pyrolytic oils.WO2018025103A1 combination with a zeolitic catalyst and a stripping for chlorine removal from discloses utilization of a 'devolatilization' extruder inhydrocarbon streams or hydrocarbon stream precursors. JP4382552 B2 disclosesa method for processing plastic cracked light oil. However, it is specified that 90%of the plastic pyrolysis oil must be within a boiling point range of 100-300 °C.

JPH1161148 A discloses a method for co-processing WP derived liquid withhydrocarbon oil in petroleum refining plant, the method comprising admixing theWP-derived liquid and crude oil to form an admixture and distilling the admixture.

JP2002060757 A discloses thermal decomposition of WP and a production of acracked distillate and mixing the cracked distillate with crude oil. The document discloses also refining and purifying the mixture in petroleum refining processes.

JP2005105027 A discloses a manufacturing method comprising mixing naphthafraction with plastic cracked oil followed by subjecting the resultant mixture to hydrorefining.

Accordingly, there is still need for more robust methods for processing WP and ELT derived liquids.SUMMARY The following presents a simplified summary in order to provide a basicunderstanding of some aspects of various embodiments of the invention. Thesummary is not an extensive overview of the invention. lt is neither intended to identify key nor critical elements of the invention, nor to delineate the scope of the 3 invention. The following summary merely presents some concepts of the inventionin a simplified form as a prelude to a more detailed description of exemplifyingembodiments of the invention. lt was observed that when WP/ELT-derived liquids were admixed with crude oilfollowed by distillation, certain impurities of the WP/ELT-derived liquids could beremoved or concentrated to fractions where they could be more easily managed.Also, the problems related to reactivity of WP/ELT-derived oils could be avoided or at least alleviated. ln accordance with the invention, there is provided a new method for co-processingwaste plastic (WP) derived liquid and/or end-life-tire (ELT) derived liquids with crudeoil and/or desalted crude oil, wherein the method comprises following steps a) providing crude oil, b) providing waste plastic (WP) derived liquid and/or end-life-tire (ELT) liquid,c) admixing the WP-derived liquid and/or ELT-derived liquid and the crude oil to form an admixture,d) desalting the admixture, ande) distilling the admixture.

A number of exemplifying and non-limiting embodiments of the invention aredescribed in accompanied dependent claims.

Various exemplifying and non-limiting embodiments of the invention and to methodsof operation, together with additional objects and advantages thereof, are bestunderstood from the following description of specific exemplifying embodimentswhen read in connection with the accompanying figures.

The verbs “to comprise” and “to include” are used in this document as openlimitations that neither exclude nor require the existence of also unrecited features.The features recited in depending claims are mutually freely combinable unlessotherwise explicitly stated. Furthermore, it is to be understood that the use of "a" or "an", i.e. a singular form, throughout this document does not exclude a plurality.

BRIEF DESCRIPTION OF FIGURES 4 The exemplifying and non-limiting embodiments of the invention and their advantages are explained in greater detail below with reference to the accompanying figures, in which figures 1-3 shows g exemplary non-limiting methods for co-processing waste plastic (WP) derived liquids and/or end-life-tire (ELT) derived liquids with crude oil (CO) according to the present invention-and DESCRIPTION The present invention is related to co-processing of WP derived liquids and ELT-derived liquids preferably in conventional oil refinery setting using existingprocessing units. The principle of the present method is shown in figures 1-1-4.

According to the embodiment shown in figure 1, the process comprises co-introducing the WP and/or ELT-derived liquid and crude oil (CO) into the oil refineryvia a crude oil desalting unit 10, and a subsequent crude oil distillation unit (CDU)20. The distillation produces one or more distillates, i.e. distillation fractions and adistillation residue, i.e. a distillation bottom. According to this embodiment, thequality of the WP and/or ELT-derived liquid is not determined, but the liquids are fedto the desalting unit together with the crude oil.

According to a preferable embodiment the distillates and distillate bottoms areprocessed further. Thus, the distillates can be directed into one or morehydrodesulfurization units marked with reference numbers 30 and 40. Thedistillation residues from the crude oil distillation unit 20 can be directed to asubsequent vacuum distillation unit 50, to give rise to vacuum gas oil (VGO) andvacuum residue (VR). The VGO and/or the VR may be further processed utilizing e.g. fluid cata|ytic cracking, hydrocracking and residue hydrocracking processes 60.

Thus, the present invention concerns a method for co-processing waste plastic (WP)derived liquid and/or end-Iife-tire (ELT) derived liquid with crude oil comprising thefollowing steps: a) providing crude oil, c) admixing the WP-derived liquid and/or the ELT-derived liquid withcrude oil to form an admixture,d) desalting the admixture ande) distilling the admixtureï; As defined herein the waste plastic derived liquid or waste plastic derived oil (usedherein and throughout the description interchangeably) should be understood asmeaning any liquid comprising oil derived from thermal conversion of waste plastics,and the end-life-tire derived liquid or end-life-tire derived oil (used herein andthroughout the description interchangeably) should be understood as meaning anyliquid comprising oil derived from thermal conversion of end-life-tires. lt is understood that their composition may vary based on the thermal conversion technology used as well as on the nature of the raw materials.

According to one embodiment, WP-derived liquid is admixed with crude oil, and theadmixture desalted and distilled. According to this embodiment, the co-processingdoes not include ELT-derived liquid, and the quality of the WP-derived liquid is not determined.

According to another embodiment, ELT-derived liquid is admixed with crude oil, andthe admixture is desalted and distilled. According to this embodiment, the co-processing does not include WP-derived liquid, and the quality of the ELT-derivedliquid is not determined.

According to another embodiment, WP- and ELT-derived liquid is admixed withcrude oil, and the admixture is desalted and distilled. According to this embodiment,the quality of the WP- and ELT-derived liquid is not determined.

According to another embodiment, quality of WP-derived liquid is analyzed, and itsquality was observed to be below predetermined value. According to thisembodiment, the co-processing does not include ELT-derived liquid. Thus, the WP- 7 derived liquid is admixed with crude oil to form an admixture which is desalted anddistilled.

According to another embodiment, quality of ELT-derived liquid is analyzed, and itsquality is observed to be below predetermined value. According to this embodiment,the co-processing does not include WP-derived liquid. Thus, the ELT-derived liquidis admixed with crude oil to form an admixture which is desalted and distilled.

According to another embodiment, quality of ELT-derived liquid and WP-derivedliquid is analyzed, and quality of ELT-derived liquid and quality ofWP-derived liquidis observed to be below predetermined value. Thus, the ELT-derived liquid and WP-derived are admixed with crude oil to form an admixture which is desalted anddistilled.

According to another embodiment, quality of ELT-derived liquid and quality ofWP-derived liquid is determined, and quality of the ELT-derived liquid and quality of theWP-derived is observed to be above and below predetermined value, respectively.Thus, the WP-derived liquid is admixed with crude oil to form an admixture which isdesalted, and the desalted admixture is distilled with the ELT-derived liquid.

According to another embodiment, quality of ELT-derived liquid and WP-derivedliquid are determined, and quality of WP-derived liquid and quality of the ELT-derived was observed to be above and below predetermined value, respectively.Thus, the ELT-derived liquid is admixed with crude oil to form an admixture which isdesalted, and the desalted admixture is distilled with the WP-derived liquid.

The quality of the ELT- and WP-derived liquids can be determined using methods known in the art. Exemplary methods are titration and gas chromatography.Exemplary impurities to be determined comprise one or more of: inorganic halogencompounds, inorganic sulfur compounds, water soluble oxygen compounds. An exemplary impurity is inorganic chlorine, in form of HCI. According to an exemplary 8 embodiment the impurity is inorganic chlorine and it is determined by titration withAgNOs.

The predetermined level of quality can be specified as required. According to anexemplary embodiment the WP and/or ELT-derived liquid is co-desalted with crude oil if its Cl content is 200 mg/kg or more.

According one embodiment, the WP and/or ELT-derived liquid is admixed with crudeoil to form an admixture. According to a particular embodiment the admixture isproduced by admixing 1 part by weight WP-derived liquid and/or ELT-derived liquidand 1 - 1000 parts by weight crude oil. According to an exemplary embodiment theadmixture comprises a 1:10 mixture by weight WP- and/or ELT derived liquid andcrude oil. lt is obvious for a skilled person that also different ratios of WP- and/orELT derived liquid and crude oil can be used. Further exemplary WP/ELT:CO ratiosare 1:1, 1:2, 1:3, 1:5, 1:25, 1:50, 1:100, 1:500, and 1:1000 by weight. desalted-The desalting can be done by any desalting methods known in the art.

Exemplary desalting methods include chemical and electrostatic separation,chemical desalting, and electric desalting. ln chemical and electrostatic separation washing of the salt from the admixture iscarried out using water. The oil and water phases are separated in a settling tank by adding chemicals to assist in breaking up emulsion, by the application of 9 electrostatic field to Collapse the droplets of saltwater more rapidly, or by acombination of the aforementioned two techniques. ln chemical desalting water and chemical surfactant (demulsifiers) are added to theadmixture, and the admixture is heated so that salts and other impurities dissolve into the water or attach to the water, and then held in a tank where they settle out.

Electric desalting comprises treating the admixture under charge condition so thatpolar molecules get oriented and get separated.

The desalting can also be done by extracting with water or water-containing fluid.The desalting with water removes or at least decreases the amounts of water-soluble impurities in the admixture. An exemplary water-to oil ration in the extractionis 1:1. Naturally, the impurities which are removed are not necessarily actual salts; According to one embodiment, a desalted admixture comprising the WP- and/orELT-derived liquid is distilled to give rise to one or more distillation fractions, i.e.distillates and typically also a distillation residue, i.e. a distillation bottom. Accordingto an exemplary embodiment the distillation provides two distillates and a distillatebottom. According to another exemplary embodiment the distillation provides eightdistillates and a distillate bottom.

According to an exemplary embodiment, the distillation provides three fractions,namely a first distillation fraction, a second distillation fraction and a distillationresidue. The distillates can be further divided into sub-distillates, which may be withdrawn from the distillation column as discrete products.

According to one embodiment the distillation is performed at atmospheric pressure.According to a particular embodiment the distillation is performed at atmosphericpressure producing a first distillation fraction, a second distillation fraction and a thirddistillation fraction. According to an exemplary embodiment, at least 90 wt-% of thefirst distillation fraction boils at a temperature of 170 °C under atmospheric pressure.According to the same exemplary embodiment, at least 80 vvt-% of the seconddistillation fraction boils at a temperature range of 170 to 360 °C at atmosphericpressure. Furthermore, according to the same exemplary embodiment, at least 90 wt-% of the third distillation fraction boils at a temperature of above 360 °C atatmospheric pressure.

According to a particular embodiment the one or more distillates are subjected toone or more further distillations to provide two or more sub-fractions of the one or more distillates.

According to a particular embodiment the first disti||ate or one or more of its sub-fractions, and/or the second disti||ate or one or more of its sub-fractions is fed to ahydrodesulfurization unit wherein a hydrodesulfurization reaction is performed.Hydrodesulfurization (HDS) is a catalytic chemical process used to remove sulfurfrom the distillates. The purpose of removing the sulfur and creating products suchas ultra-low-sulfur diesel, is to reduce the sulfur dioxide emissions that result fromusing those fuels in automotive vehicles, aircraft, railroad locomotives, ships, gas oroil burning power plants, residential and industrial furnaces, and other forms of fuel combustion.

For hydrodesulfurization, there are various types of catalysts employed. Mostlythese are different combinations of oxides and sulfides of cobalt, molybdenum,nickel, iron, and wolfram on v-alumina or alumina/silica/zeolite support, or on their mixture.

According to one embodiment the hydrodesulfurization of the first disti||ate or one ormore of its sub-fractions produces a gasoline component or an intermediate suitablefor further processing to a gasoline component.

According to another embodiment the hydrodesulfurization of the second disti||ateor one or more of its sub-fractions produces a diesel component, or an intermediatesuitable for further processing to a diesel component.

Exemplary HDS catalysts are CoMolAlgOg, NiMolAlzOa and CoMoNilAlzOs.

According to an exemplary embodiment the hydrodesulfurization is performed at280-320 °C in 20-35 bar in the presence of hydrogen and a hydrodesulfurizationcatalyst such as ColvlolAlzOs or NiMolAlzOs. 11 Exemplary process parameters for the middle distillate are temperature: 320-380 °C; pressure: 35-80 bar in the presence of hydrogen and a hydrodesulfurizationcatalyst such as CoMolAlzOs or NiMolAlzOa. LHSV is preferably 1.5-3.0 h* andH2/feed ratio is preferably 300-450 N m3/m3.

Exemplary process parameters for naphtha fraction are CoMolAlzOs or NiMolAlzOscatalyst at 280-320°C temperature, 20-35 bar pressure, 3.0-5.0 h* liquid hourspace velocity (LHSV: flow of feedstock in m3 through 1 m3 catalyst during 1 hcatalyst at normal condition of 20°C and 101.3 kPa), and 100-250N m3/m3 hydrogen/hydrocarbon ratio.

According to another embodiment the disti||ation residue is subjected to vacuumdisti||ation typically at 370-410 °C and 1-10 kPa producing vacuum gas oil (VGO)and vacuum residue (VR).

According to a particular embodiment the VGO is further processed utilizing one or more of fluid catalytic cracking (FCC), hydrocracking (HC) and residue hydrocracking processes. ln the FCC process, the VGO is heated to a high temperature and moderatepressure, and brought into contact with a hot, powdered catalyst. An exemplary FCCcatalyst has four major components: crystalline zeolite, matrix, binder, and filler.Zeolite is the primary active component and can range from about 15 to 50 weightpercent of the catalyst. The catalyst breaks the long-chain molecules of the high-boiling hydrocarbon liquids into much shorter molecules, which are collected as aare then separated via disti||ation in the FCC main fractionator. The main products from the FCC process are gasoline and liquefied petroleum gas (LPG). ln the HC process, catalytic cracking of the VGO is assisted by the presence ofadded hydrogen gas. The HC is preferably facilitated by a bifunctional catalyst thatis capable of rearranging and breaking hydrocarbon chains as well as addinghydrogen to aromatics and olefins that may be present in the VGO. The productsHC are saturated hydrocarbons. The major products from hydrocracking are jet fueland diesel, but low sulphur naphtha fractions and LPG are also produced. All these products have typically very low content of sulphur and other contaminants. 12 According to another particular embodiment the VR is further processed utilizingone or more of fluid catalytic cracking, hydrocracking and residue hydrocrackingprocesses.

The method of the present invention a||eviates problems which would beencountered if impure WP/ELT-derived liquids were disti||ed in a stand-alonedistillation unit, and the resulting distillates would be co-processed directly in e.g.refinery hydrodesulfurization units. When utilizing this latter approach, i.e. stand-alone distillation and co-processing of distillates, the distillates will contain varyingamounts of heteroatoms such as N and Cl. Upon hydrotreating, these will beremoved in the form of NH3 and HCl. This process will consume hydrogen and theresulting gases can form deposits of NH4CI which are problematic e.g. in heatexchangers and recycle gas compressors. Thus, it would be beneficial to lower theconcentration of these heteroatoms prior to hydrotreating operations.

Processing the WP/ELT-derived oils according to the method of the presentinvention has the following benefits: Water-soluble impurities are removed in the desalting unit. These impurities mayinclude e.g. HCl, oxygenated organic molecules and certain nitrogen-containing organic molecules. lt is known that WP/ELT-derived liquids may include organic chlorides. Whensubjected to high temperatures used in CDU preheating units the chlorides arereleased as HCl. The gaseous HCl that is released in the distillation will be carriedto the top of the distillation column and to the overhead condenser, where it willsubsequently condense along with the steam that is fed into the distillation column,thus forming aqueous hydrochloric acid. However, certain measures such as NaOHaddition downstream of the desalter unit or use of a neutralizing amine can be usedto control and limit corrosion at the top of the distillation column and in the overheadcondenser. lt is less challenging to have HCl released in the CDU than in adownstream hydrotreating unit which does not have similar readiness for corrosion control. 13 lf the WP/ELT-derived oil contain non-volatile impurities such as metals, co-processing the oil in a CDU has the benefit of concentrating the metals into a heavierhydrocarbon fractions which already have higher metal content to begin with.Depending of the impurities which are present in the WP/ELT-derived oil and thedistillation configuration that is utilized, the metallic impurities can e.g. concentratein vacuum gas oil or vacuum residue. These fractions can then be further processedin refining units which have a higher tolerance for metals. Such refining units caninclude e.g. fluid catalytic cracking or residue hydrocracking in an ebullated bed reactor.

WP/ELT-derived oils are more reactive than typical crude oil. Accordingly, thereactivity is reduced by diluting with crude oil which allows further processing ofWP/ELT-derived oils in reactors such as HDS reactors designed for crude oil.

ExperimentalExample 1: Removal of water-soluble impurities from WP-derived liquids The WP/ELT-derived liquids (pyrolysis oils) which are utilized in these examples were purchased from Ecomation Oy (Salo, Finland).

A waste plastic derived liquid was washed with water at ambient temperature toremove water-soluble impurities. The washing was carried out using a water-to-oilratio of 1:1 (weight/weight) by agitating the mixture in a separation funnel. The oiland the water were separated, and the oil was analysed for heteroatom (N, S, Cl,Br) content. The results are shown in Table 1.

Table 1. Results from water-washing of waste plastic derived liquid at roomtemperature using water-to-oil ratio of 1:1.

Original oil Water-washed oil removal-%N (mg/kg) 790 650 18S (mg/kg) 984 880 11Cl (mg/kg) 585 468 20Br (mg/kg) 291 249 14 14 Although the procedure itself may differ from an actual desalting process, the resultsshow that a certain amount of impurities can be removed from waste plastic derivedliquids by essentially washing the sample with water. The impurities/heteroatomswhich are removed are not necessarily actual salts - some of the compounds mayalso be water-soluble organic compounds. One skilled in the art can also appreciatethat the amount of water-soluble impurities in the waste plastic derived liquid willalso vary depending of the feedstock and the pyrolysis process. Furthermore, theconditions (temperature, residence time, diluting with crude oil) that are used in theactual desalting process can also influence the removal of impurities.

Example 2: Concentration of metallic impurities in the distillation of ELT-derivedliquid The example shows the metallic impurities beneficially concentrate into thedistillation bottoms when an ELT-derived liquid is distilled into three separatefractions. lron (Fe) and zinc (Zn) were the most abundant impurities in the originalELT-derived liquid. As the results in Table 2 show, both of these impurities wereeffectively concentrated into the distillation bottoms, which in this case isrepresented by the fraction with a boiling point range of >360 °C. Thus, the distillatefractions which would be subsequently fed into e.g. fixed-bed hydrotreating reactors, no longer contain any Fe or Zn.

Table 2. Distillation yields and distribution of main metallic impurities in distillation ofELT-derived liquid.

Original o" <170 °C 170-360 °C >360 °Cfraction fraction fraction Yield in distillation - 21 52 27 (wt-%) Fe (mg/kg) 4.2 <0.1 <0.1 17 Zn (mg/kg) 4.1 <0.1 <0.1 13 ln this example, the ELT-derived liquid was distilled in neat form, i.e. without anyconventional crude oil. ln the processing concept that was presented in Figure 1,the >360 °C fraction of the ELT-derived liquid would exit the CDU in the atmospheric residue stream, which would then be subjected to vacuum distillation. Thus, thecontaminant metals of the ELT-derived liquid might further concentrate into thedistillation bottoms of the vacuum distillation unit, i.e. vacuum residue. Furthermore,all the distillate fractions that are obtained from the WP/ELT-derived liquid would be diluted with the co-processed crude oil.

The specific examples provided in the description given above should not be construed as limiting the scope and/or the applicability of the appended claims.

Claims

16 What is claimed is

1. A method for co-processing waste plastic (WP) derived liquid and/or end-Iife-tire (ELT) derived liquid with crude oil, the method comprising a) providing WP-derived liquid and/or ELT-derived liquid, b) providing crude oil, c) admixing the WP-derived liquid and/or the ELT-derived liquid and the crude oil to form an admixture,d) desalting the admixture, ande) distilling the admixture. _ The method according to claim 1, wherein step c) comprises admixing 1 part by weight WP-derived liquid and/or ELT-derived liquid and 1 - 1000 parts by weightcrude oil. _ The method according to claim 1 or 2, wherein the desalting comprises treating with water. _ The method according to any one of claims 1-3, wherein the distilling produces one or more distillates and a distillate bottom. _ The method according to claim 4 comprising subjecting at least one of the one or more distillates to hydrodesulfurization reaction. _ The method according to claim 5 wherein the subjecting is at 280-320 °C in 20- 35 bar in the presence of hydrogen and a hydrodesulfurization catalyst such asC0|V|0/A|2O3 Or Ni|V|0/A|2O3_ _ The method according to claim 5 wherein the subjecting is at 320-380 °C in 35- 80 bar in the presence of hydrogen and a hydrodesulfurization catalyst such asC0|V|0/A|2O3 Or Ni|V|0/A|2O3_ _ The method according to claim 4 comprising subjecting the distillate bottom to vacuum distillation. _ The method according to claim 8, wherein the vacuum distillation produces vacuum gas oil and/or vacuum residue. 17 10.The method according to claim 9 wherein the vacuum gas oil and/or the vacuumresidue is subjected to one or more of ﬂuid catalytic cracking, hydrocracking andresidue hydrocracking.