EP4638657A1

EP4638657A1 - Method for suppressing catalyst poisoning by pyrolysis oils in contact with steel containments

Info

Publication number: EP4638657A1
Application number: EP23820953.0A
Authority: EP
Inventors: Mathias Haake; Mathias Feyen; Jochen Wagner; Aleksandra Martyna GAJDA; Monica Haag; Felix HUELSMANN
Original assignee: BASF SE
Current assignee: BASF SE
Priority date: 2022-12-19
Filing date: 2023-12-12
Publication date: 2025-10-29
Also published as: WO2024132668A1; CN120380111A; KR20250127281A

Abstract

The present invention concerns pyrolysis oils, mixtures and blends of pyrolysis oils comprising at least one catalyst poisoning suppressant,, wherein the catalyst poisoning suppressant is selected from amphiphilic compounds, the amphiphilic compounds comprising at least one nonpolar residue selected from C6 to C26 alkyl and/or alkylene and at least one polar residue, the at least one polar residue comprising at least one nitrogen atom. The invention further con- cerns a method for suppressing catalyst poisoning and/or fouling during thermal processes and the use of catalyst poisoning suppressants selected from amphiphilic compounds, the am- phiphilic compounds comprising at least one nonpolar residue selected from C6 to C26 alkyl and/or alkylene and at least one polar residue, the at least one polar residue comprising at least one nitrogen or oxygen atom. The poisoning of heterogeneous catalysts and/or fouling during thermal processes used in the purification, upgrading and/or conversion of pyrolysis oils derived from plastic waste, rubber materials, and mixtures/blends of such pyrolysis oils is reduced in the presence of at least one catalyst poisoning suppressant.

Description

Method for suppressing catalyst poisoning by pyrolysis oils in contact with steel containments

Technical Area

The present invention relates to pyrolysis oils comprising at least one catalyst poisoning suppressant, a method for reducing catalyst poisoning and/or fouling during thermal processes in purification, blending, upgrading and/or conversion of pyrolysis oils and the use of catalyst poisoning suppressants in pyrolysis oils to reduce poisoning of heterogeneous catalysts and/or fouling during thermal processes.

Background of the Invention

Liquids derived from feedstocks such as mixed waste plastics, rubber materials, and textiles by a pyrolysis reaction (denoted pyrolysis oils) are highly corrosive towards containments made of steel, especially containments made of carbon-steels and low-alloyed steels.

The reasons for the undesired corrosiveness of pyrolysis oils are manifold. In comparison with oils from fossil sources such as crude oil, pyrolysis oils have a higher content of components such as water, oxygenates, halogen(s) and sulfur e.g., bound in organic compounds. In addition, the total acid number (TAN) of pyrolysis oils is higher than in oils from fossil sources such as crude oil. Said differences in composition lead to an increased corrosion of pyrolysis oils towards containments (e.g., vessels, pipes, reactors, heat exchangers and the like) made of steel, especially containments made of carbon-steels and low-alloyed steels during storage, transport, handling and conversion of the pyrolysis oils.

For economic reasons cheaper steel materials and less corrosion-resistant steels such as carbon-steel (including construction steel) and low-alloyed steels are preferred containment materials. Hence, the increased corrosiveness of pyrolysis oils towards such materials in comparison to oils from fossil sources is a major problem.

One negative aspect of said increased corrosive behavior leads to an enrichment of metal ions and metal compounds in the pyrolysis oil during storage, transportation, handling and/or conversion in containments such has storage vessels, mixing vessels and pipes. The metal ions and metal compounds transferred from the containment material into the pyrolysis oil comprise Fe²⁺, Fe³⁺ and Ni²⁺ ions as well as soluble and insoluble compounds of such metal ions such as the respective metal hydroxides, oxides and hydroxy-oxides. Pyrolysis oils require designated purification and/or upgrading steps prior to further use in e.g., a steam cracking unit, a catalytic cracking unit, a fluid catalytic cracking unit, a partial oxidation unit and further downstream unit operations to obtain chemical products from such pyrolysis oils. Such purification and/or upgrading steps are required for example to remove all the various unwanted components such as water, oxygenates, halogen(s) and sulfur.

Catalyst poisons such as sulfur e.g., bound in organic compounds and chloride compounds present in the pyrolysis oil can be removed or their concentration reduced with conventional methods such as extraction, hydrotreatment, adsorption and de-chlorination which are for example disclosed in EP 3907267 A1.

Some of the purification/upgrading methods applied use one or more catalysts, having active sites and/or pores which can be poisoned and/or subjected to fouling by Fe²⁺, Fe³⁺ and Ni²⁺ ions as well as soluble and insoluble compounds of such metal ions such as the respective metal hydroxides, oxides and hydroxy-oxides.

The metal ions transferred from the containment material into the pyrolysis oil as well as soluble and insoluble compounds of such metal ions are not substantially removed from the pyrolysis oil during said purification and/or upgrading steps because none of the purification and/or upgrading steps is particularly directed to the removal of these metal ions and/or respective metal compounds.

Accordingly, the metal ions and metal compounds remain in the pyrolysis oil and act as catalyst poisons towards heterogeneous catalysts and thereby reduce the activity and lifetime of the catalysts used in later process steps. The catalyst poisons partially or totally deactivate a heterogeneous catalyst by e.g., decreasing the total number of active sites.

Metal ions such as Fe²⁺, Fe³⁺ and Ni²⁺ and compounds of said metal ions such as hydroxides, oxides and hydroxy-oxides are permanent poisons for precious metal and base metal catalysts applied for purification and upgrading of pyrolysis oils which is necessary before further use of a pyrolysis oil as e.g. a feedstock for steam cracking, fluid catalytic cracking, catalytic cracking, partial oxidation and other downstream processes.

Said metal ions also tend to be adsorbed onto the walls of the containment (such as vessels, pipes, reactors) from where they may be slowly re-released to poison also future charges of catalysts. For example, Ni²⁺ ions are a poison when deposited on a catalyst surface as they can act as a strong dehydrogenation catalyst which contributes to undesired carbon deposition. The effect of Ni²⁺ ions is well documented in units for fluid catalytic cracking where Ni²⁺ ions also increase the unwanted “light ends” gas production.

Another example is iron oxide (formed from Fe²⁺/Fe³⁺ ions and oxygen present e.g., in the “water impurity part” of the pyrolysis oil and/or oxygen bound to organic residues such as Fe- carboxylates) which is a known poison for several types of hydrocarbon processing catalysts which increases undesired deposition of carbon on the surface of such heterogeneous catalysts.

Finely divided iron oxide is reactive with catalyst components containing sodium and/or silicon and thereby accumulates on the catalyst surface and can form new low temperature phases. Such new low temperature phases can grow and cause masking of the existing active sites of the catalyst and/or plugging pores which both reduce the activity of the catalyst.

Adsorption of Fe²⁺, Fe³⁺ and Ni²⁺ ions and compounds thereof onto the surface of catalysts also decreases the activity of catalysts used for HDS (hydrodesulfurization) processes which are a common purification step before utilizing pyrolysis oils as a cracker feedstock.

Several approaches to prevent corrosion of a containment material and undesired transfer of Fe²⁺, Fe³⁺ and Ni²⁺ ions and compounds thereof into the pyrolysis oil are known in the art.

A pyrolysis reactor bed made of ceramic to prevent corrosion is disclosed in JP 2002060541 A. Such ceramic beds can suppress the release of Fe²⁺, Fe³⁺ and Ni²⁺ ions and compounds thereof into the pyrolysis oil but are very expensive and prone to mechanical damage e.g., during temperature cycling, for example between loading the reactor and the pyrolysis reaction at a temperature of several hundred °C.

The addition of a sorbent to the plastic waste prior to the pyrolysis reaction is disclosed in US 2015/0135583 A1. Such a sorbent may remove some of the impurities present in the pyrolysis oil but is not suitable to suppress the release of Fe²⁺, Fe³⁺ and Ni²⁺ ions and compounds thereof into the pyrolysis oil from a containment material. The addition of an alkaline substance to waste plastics comprising PVC prior to the pyrolysis reaction is disclosed in JP 2002179837 A. Acids such as benzoic acid formed during the pyrolysis reaction are neutralized and thereby the corrosion of equipment made of metal is reduced. Acids and the resulting low pH value of pyrolysis oils are only one reason for the release of Fe²⁺, Fe³⁺ and Ni²⁺ ions and compounds thereof into the pyrolysis oil. Other reasons for release of Fe²⁺, Fe³⁺ and Ni²⁺ ions and compounds thereof into the pyrolysis oil such as the higher water content in respect to oils of fossil origin and the high oxygen content are not solved by this method.

Document WO 2013/188021 A1 discloses a method comprising blending pyrolysis oil with alcohols having a carbon number of 8, crude jatropa oil, castor oil which both comprise oleic fatty acid. The composition is then filtered.

Document WO 2020/178599 A1 discloses a method comprising blending pyrolysis oil with an upgrading solution which may be C10 alcohol, C10 carbonate, C10 amide. The composition is then separated from the pyrolysis oil.

Accordingly, a more feasible way to suppress the release of Fe²⁺, Fe³⁺ and Ni²⁺ ions and compounds thereof into the pyrolysis oil while in contact with containment materials such as steel, more particularly carbon-steels and low-alloy steels is needed to suppress or reduce the poisoning of catalysts and/or fouling during thermal processes.

Summary of the Invention

It is a first objective of the present invention to reduce the poisoning of heterogeneous catalysts and/or fouling during thermal processes used in the purification and/or upgrading of pyrolysis oils derived from plastic waste, rubber materials, mixtures of pyrolysis oils and blends of at least one pyrolysis oil with other hydrocarbon liquids such as naphtha. Preferably said purification, upgrading and/or conversion is a hydrotreatment method in the presence of hydrogen and at least one heterogeneous catalyst.

It is a second objective of the present invention to provide a method for suppressing fouling during thermal processes used in the conversion of pyrolysis oils derived from plastic waste, rubber materials, mixtures of pyrolysis oils and blends of at least one pyrolysis oil with other hydrocarbon liquids such as naphtha. Preferably said conversion is a thermal process selected from the group consisting of steam cracking and partial oxidation. Most preferably, the fouling during steam cracking and partial oxidation is reduced. It is a third objective of the present invention to provide a pyrolysis oil in which upon physical and/or chemical contact with a containment material metal ions such as Fe²⁺, Fe³⁺ and Ni²⁺ and compounds of such metal ions are not enriched or at least less enriched in the pyrolysis oil, mixtures of pyrolysis oils and blends of at least one pyrolysis oil with other hydrocarbon liquids such as naphtha.

It is a fourth objective of the present invention to provide additives for the use in pyrolysis oils, mixtures of pyrolysis oils and blends of at least one pyrolysis oil with other hydrocarbon liquids such as naphtha to suppress the release of Fe²⁺, Fe³⁺ and Ni²⁺ ions and compounds thereof from containment materials such as steel, particularly carbon-steels and low-alloy steels.

These objectives are solved by a pyrolysis oil, mixture of at least two pyrolysis oils or blend comprising at least one pyrolysis oil, containing at least one catalyst poisoning suppressant selected from amphiphilic compounds, the amphiphilic compounds comprising at least one nonpolar residue selected from C6 to C26 alkyl and/or alkylene and at least one polar residue, the at least one polar residue comprising at least one nitrogen atom.

These objectives are further solved by a method for suppressing catalyst poisoning for upgrading and/or fouling during a thermal process for converting of a pyrolysis oil, a mixture of at least two pyrolysis oils and a blend comprising at least one pyrolysis oil, comprising the steps

(i) providing a pyrolysis oil, a mixture of at least two pyrolysis oils or a blend comprising at least one pyrolysis oil in a steel containment, wherein the pyrolysis oil, the mixture of at least two pyrolysis oils or the blend comprising at least one pyrolysis oil is in physical and/or chemical contact with said steel containment,

(ii) adding at least one catalyst poisoning suppressant to said pyrolysis oil, the mixture of at least two pyrolysis oils or the blend comprising at least one pyrolysis oil, wherein the at least one catalyst poisoning suppressant is selected from the group consisting of amphiphilic compounds, the amphiphilic compounds comprising at least one nonpolar residue selected from C6 to C26 alkyl and/or alkylene and at least one polar residue, the at least one polar residue comprising at least one heteroatom selected from the group consisting of nitrogen and oxygen, (iii) contacting said pyrolysis oil, mixture of at least two pyrolysis oils or blend comprising at least one pyrolysis oil, comprising said at least one catalyst poisoning suppressant with at least one heterogeneous catalyst or subjecting said pyrolysis oil, mixture of at least two pyrolysis oils or blend comprising at least one pyrolysis oil, comprising said at least one catalyst poisoning suppressant to a thermal process.

These objectives are further solved by the use of at least one additive, said at least one additive selected from amphiphilic compounds comprising at least one nonpolar residue selected from C6 to C26 alkyl and/or alkylene and at least one polar residue comprising at least one heteroatom selected from the group consisting of nitrogen and oxygen as a catalyst poisoning suppressant in a pyrolysis oil, a mixture of at least two pyrolysis oils or a blend comprising at least one pyrolysis oil to suppress enrichment of a catalyst poison selected from the group comprising Fe²⁺ ions, Fe³⁺ ions, Ni²⁺ ions and compounds of said metal ions in said pyrolysis oil, mixture of at least two pyrolysis oils or blend comprising at least one pyrolysis oil.

Thereby, the poisoning of heterogeneous catalysts and/or fouling of adsorbents and/or membranes is reduced and the lifetime of heterogeneous catalysts and/or adsorbents and/or membranes used in later process steps is increased and their activity is maintained for a longer time and/or throughput.

Detailed Description of the Invention

“Blend” is defined herein as a blend comprising at least one pyrolysis oil blended (mixed) with at least one other hydrocarbon liquid such as naphtha or high vacuum residue (also known as “HVR”, “vac resid” and “residuum” which is the heaviest of the distillation cuts and can be obtained from the bottom cut of a vacuum distillation tower of a refinery). Blending is for example used to alter physical properties such as reducing the viscosity and/or chemical properties such as reducing the concentration of certain ingredients e.g., sulfur by diluting the one or more pyrolysis oils with at least one other hydrocarbon liquid.

“Catalyst” is defined herein as heterogeneous catalysts which are solid materials comprising a surface and having active sites mandatory for the desired catalytic properties of such a catalyst.

“ppm” is defined herein as a parts-per-million notation referring to a mass fraction.

In the context of the present description and the accompanying claims, the term “about” preferably means a deviation of the thus described value of ±15%. In the context of the present invention, the term “combinations thereof’ is inclusive of one or more of the recited elements.

In the context of the present invention, the term “mixture thereof’ is inclusive of one or more of the recited elements.

Pyrolysis oil can be manufactured by a pyrolysis reaction from feedstocks such as plastic waste, mixed plastic waste, rubber waste, textiles, mixtures thereof. Pyrolysis oils can also be manufactured from mixtures of the aforementioned feedstocks with other kinds of waste and impurities.

Examples of waste plastics include pure plastic waste, mixed plastic waste, film waste, including soiling, adhesive materials, fillers, residues etc., industrial plastic waste and municipal plastic waste. Mixed plastic waste is composed of different types of polymers.

Examples of rubber waste include end-of-life tires, rubber waste produced during manufacturing processes and discarded rubber containing products such as latex examining gloves. End-of-life tires comprise further ingredients such as textiles and organic and inorganic additives which may be separated from the rubber portion of end-of-life tires prior to pyrolysis.

Preferably, the pyrolysis oil, to which at least one catalyst poisoning suppressant is added is manufactured by pyrolysis from a feedstock comprising rubber waste.

Preferably, at least one of the pyrolysis oils in the mixture comprising two pyrolysis oils to which the at least one catalyst poisoning suppressant is added is manufactured by pyrolysis from a feedstock comprising rubber waste.

Preferably, at least one of the pyrolysis oils in the blend comprising at least one pyrolysis oils to which the at least one catalyst poisoning suppressant is added is manufactured by pyrolysis from a feedstock comprising rubber waste.

Most preferably, the pyrolysis oil to which at least one catalyst poisoning suppressant is added is manufactured by pyrolysis from a feedstock comprising end-of-life tires or parts thereof such as the rubber components. The pyrolysis reaction is a thermal decomposition or degradation of such feedstocks under inert conditions and results in a gaseous fraction, a liquid fraction and a solid char fraction. During the pyrolysis, the feedstocks are converted into a great variety of chemicals including a) gases such a H2, Ci-C4-alkanes, C2-C4-alkenes, ethyne, propyne, 1-butyne, b) pyrolysis oil having a boiling temperature in the range of 25 to 500 °C and c) char.

Pyrolysis processes as such are known. They are described, e.g., in EP 0713906 A1 and WO 95/03375 A1. Suitable pyrolysis oils are also commercially available. The pyrolysis oil is typically a liquid at 15°C. "Liquid at 15°C" in the terms of the present invention means that the pyrolysis oil has a density of at most 1 .3 g/ml, e.g., a density in the range from 0.65 to 0.98 g/ml, at 15 °C and 1013 mbar, as determined according to DIN EN ISO 12185.

The pyrolysis oils obtained from a pyrolysis reaction comprise:

- at least 30 mg/l sulfur, preferably 100 to 5000 mg/l sulfur, more preferably 200 to 4000 mg/l sulfur (determined in accordance with ASTM D 5453);

- at least 30 mg/l nitrogen, preferably 100 to 4000 mg/l nitrogen, more preferably 200 to 4000 mg/l nitrogen (determined in accordance with ASTM D 6069);

- at least 5 mg/l halogen, preferably 10 to 1000 mg/l halogen, more preferably 20 to 800 mg/l halogen (determined in accordance with ASTM D 5808);

- at least 0.01 wt.-% water, preferably 0.1 to 5 wt.-% water, more preferably 0.2 to 3 wt.-% water (determined in accordance with ASTM E 1064);

- at least 100 ppm oxygenates; preferably 200 to 5000 ppm oxygenates, more preferably 300 to 1800 ppm oxygenates (determined in accordance with ASTM 5291);

- at least 2 wt.-% alkenes, preferably 2.1 to 15 wt.-% alkenes, more preferably 2.3 to 10 wt.-% alkenes (determined by gas chromatography);

- a total acid number (TAN) of 0.1 to 18 (determined by titration with a KOH solution and given as amount of KOH in milligrams that is needed to neutralize the acids in one gram of pyrolysis oil);

- a pH value in the range of about 2 to about 5.

Examples of sulfur-containing compounds include thioles, sulfides, disulfides, sulfoxides, sulfones, sulfinic acids, sulfonic acid, sulfonic acid amides, sulfonate ester, ester of sulfuric acid, thioketones, thiocarboxylic acids, thioesters, dithiocarboxylic acids, thiocyanates, sulfonic acid amides etc.

Examples of nitrogen-containing compounds include amines, imines, amides, imides, azides, azo compounds, oximes, hydrazones, hydrazines, cyanates, nitrates, nitriles, nitrite, nitro compounds, nitroso compounds, oximes, N-containing heteroaromates, carbamate ester, sulfonic acid amides, thiocyanates, sulfonic acid amides.

Examples of halogen are halogen-containing compounds including aliphatic halides, (het- ero)aromatic halides, aliphatic- aromatic halides, acyl halides, etc. Halogens may also be present in the pyrolysis oils as anions such as F^_, Ck, Br and k.

Examples of oxygenates are compounds containing oxygen as a part of their chemical structure. Oxygenates comprise compounds such as alcohols, ethers, aldehydes, ketones and car- boxylates/carboxylic acids.

Examples of carboxylic acids include formic acid, acetic acid, higher carboxylic acids, carboxylic acids having at least two carboxylic acid residues, benzoic acid and salts thereof.

The pyrolysis oils obtained from a pyrolysis reaction preferably further has a bromine number of about 2 g Br2/100g to about 150 g Br2/100g (determined by ASTM 1159) and/or a C5 hydrocarbon content of about 0.03 wt.-% to about 12.2 wt.-% (determined by ASTM D 5134) and/or a naphthalene content of about 0.5 wt.-% to about 18.4 wt.-% (determined by ASTM D 5134) and/or a styrene content of about 0.02 wt.-% to about 29.5 wt.-% (determined by ASTM D 5134) and/or a toluene content of about 4.3 wt.-% to about 71.5 wt.-% (determined by ASTM D 5134). Such pyrolysis oils are particularly suited as pyrolysis oil(s), for the method and the use according to the present invention.

Mixtures of pyrolysis oils can be obtained by mixing two or more pyrolysis oils made from different feedstocks and/or made with different pyrolysis reaction conditions and/or made in different batches from the same feedstock and pyrolysis reaction conditions.

Blends comprising at least one pyrolysis oil can be obtained by blending at least one pyrolysis oil with at least one other hydrocarbon liquid such as naphtha, high vacuum residues (HVR) etc. Other hydrocarbon liquids suitable for blending with at least one pyrolysis oil are known to the skilled person.

In one embodiment of the present invention at least one pyrolysis oil is blended with one or more other hydrocarbon liquids such as naphtha and/or high vacuum residue. Such blends comprise for example about 30 wt.-% of one or more pyrolysis oils and about 70 wt.-% of one or more other hydrocarbon liquids; about 50 wt.-% of one or more pyrolysis oils and about 50 wt.- % of one or more other hydrocarbon liquids; or about 70 wt.-% of one or more pyrolysis oils and about 30 wt.-% of one or more other hydrocarbon liquids. Such blends may comprise in addition water. The resulting blends comprise for example about 30 wt.-% of one or more pyrolysis oils, 30 wt.-% of one or more other hydrocarbon liquids and about 30 wt.-% of water.

The pyrolysis oil and/or mixture of at least two different pyrolysis oils and/or blend is in physical and/or chemical contact with containments during the pyrolysis reaction, storage, transport, handling, purification, upgrading, mixing with other pyrolysis oils and blending of at least one pyrolysis oil with at least one other hydrocarbon liquid such as naphtha etc.

The temperature of the pyrolysis oil, mixture of two or more pyrolysis oils or blend comprising at least one pyrolysis oils when in physical and/or chemical contact with a containment ranges from low temperatures such as room temperature or the temperature outside of a building where the pyrolysis oil may be stored and/or transported to the temperature applied during the pyrolysis reaction of several hundred °C. The temperature of the pyrolysis oil, mixture of two or more pyrolysis oils or blend comprising at least one pyrolysis oils may be elevated to e.g., 50 °C or 70 °C during transport in a pipe or other handling operations to obtain a reduced viscosity and thereby more favorable fluidic properties. The temperature of the pyrolysis oil, mixture of two or more pyrolysis oils or blend comprising at least one pyrolysis oils ranges from about -10 °C to about 100 °C during storage, transport and/or handling. The temperature of the pyrolysis oil, mixture of two or more pyrolysis oils or blend comprising at least one pyrolysis oils may be elevated to about 270 °C or even higher such as 300 °C, 400 °C, 500 °C in thermal processes such as pre-heating before the pyrolysis oil is, for example, fed into a steam cracking reactor or into a partial oxidation reactor, steam cracking or partial oxidation. During all said temperatures, the pyrolysis oil, mixture of two or more pyrolysis oils or blend comprising at least one pyrolysis oils is preferably in contact with a steel containment.

The thermal process in step (iii) is most preferably selected from the group consisting of preheating for steam cracking, steam cracking, pre-heating for partial oxidation and partial oxidation.

Accordingly, the temperature ranges from about 10 to about 300 °C. This temperature range also applies to blends comprising at least one pyrolysis oil and mixtures of pyrolysis oils comprising at least two pyrolysis oils.

“Containment” is defined herein as a means for storing, transporting, directing, handling and thermal processing of a pyrolysis oil, a mixture comprising at least two pyrolysis oils or a blend comprising at least one pyrolysis oils. A containment can also be a reactor wherein a) the pyrol- ysis oil is made by a pyrolysis reaction and/or b) the pyrolysis oil or parts thereof is/are chemically and/or physically converted, for example in/during a thermal process. “Containment” includes but is not limited to stationary vessels, movable vessels, pipes, reactors, heat exchangers, valves and the like.

Containments according to the present invention are made of or comprise steel materials. Said steel materials are in physical and/or chemical contact with the pyrolysis oil, a mixture comprising at least two pyrolysis oils or a blend comprising at least one pyrolysis oils.

The steel materials can be in principle any kind of materials referred to as steel such as stainless steels, high-alloyed steels, low-alloyed steels, carbon-steels etc. For economic reasons the steel material is preferably selected from carbon-steels or a low-alloy steels. Carbon-steels and low-alloyed steels are cheaper than e.g., stainless steels but are less resistant against corrosion caused by a pyrolysis oil.

“Carbon-steel” is defined herein as a steel comprising C in the range of about 0.05 to about 2.0 wt.-%.

“Carbon-steel” also comprises steels having in addition to a C content in the range of about 0.05 to about 2.0 wt.-%. No minimum content is specified or required for Cr, Co, Mo, Ni, Nb, Ti, V, W and Zr or any other element to be added to obtain a desired alloying effect; the specified minimum for Cu does not exceed 0.4 wt.-%; or a maximum content for any of the following elements does not exceed the percentages noted: 1.65 wt.-% Mn; 0.6 wt.-% Si; 0.6 wt.-% Cu.

More preferably, the carbon-steel is a low-carbon-steel having a C content of about 0.05 to about 0.15 wt.-% and/or a medium-carbon-steel having a C content of about 0.3 to about 0.5 wt.-%.

“Low-alloy steel” is defined herein as a steel containing from about 1 to about 5 wt.-% of individual alloying elements and less than 10.5 wt.-% of all alloying elements together. Alloying elements include but are not limited to one or more of the following chemical elements: Co, Cr, Mo, Ni, Nb, Ti, V, W, Zr.

The specific composition of pyrolysis oils with a higher content of components such as sulfur, nitrogen, halogens, water, oxygenates, alkenes and a higher total acid number TAN compared to oils from fossil sources such as crude oil results in a (more) severe corrosive attack towards steel of containments, especially when made of or comprising carbon-steels and low-alloy steels. Thereby undesired metal ions such as Fe²⁺, Fe³⁺ and Ni²⁺ ions and/or compounds thereof are released from the containment material into the pyrolysis oil and cause poisoning of heterogeneous catalysts and/or fouling of adsorbents and/or membranes with which the pyrolysis oil is contacted in later process steps during e.g., purification and/or upgrading.

To prevent such poisoning of heterogeneous catalyst and/or fouling of adsorbents and/or membranes in later process steps, at least one catalyst poisoning suppressant is added to the pyrolysis oil, a mixture comprising at least two pyrolysis oils or a blend comprising at least one pyrolysis oils.

The pyrolysis oil, mixture of at least two pyrolysis oils or blend comprising at least one pyrolysis oil according to the present invention contains at least one catalyst poisoning suppressant selected from amphiphilic compounds, the amphiphilic compounds comprising at least one nonpolar residue selected from C6 to C26 alkyl and/or alkylene and at least one polar residue, the at least one polar residue comprising at least one nitrogen atom.

“Amphiphilic” is defined herein as molecules and/or ions comprising both hydrophilic (polar) and lipophilic (nonpolar) properties.

The at least one catalyst poisoning suppressant is preferably selected from the group comprising

- C6 to C26 fatty acids, saturated, mono-unsaturated and poly-unsaturated coupled by a C-C bond to a N-heterocyclic compound;

- nitrogen-compounds quaternized with a hydrocarbyl epoxide in combination with a free hy- drocarbyl-substituted polycarboxylic acid; and

- mixtures thereof.

Suitable adducts of a C6 to C26 fatty acid, saturated, mono-unsaturated and poly-unsaturated coupled by a C-C bond with a N-heterocyclic compound comprise 2-(2-heptadec-8-enyl-2- imidazolin-1-yl)ethanol (CAS-No. 95-38-5) which can be obtained by heating oleic acid with 2- (2-aminoethylamino)ethanol up to 270 °C for five hours and removal of the water formed by azeotropic distillation with xylol. Suitable nitrogen-compounds quaternized with a hydrocarbyl epoxide in combination with a free hydrocarbyl-substituted polycarboxylic acid comprise C16-alkyl-N(CH₃)2 quaternized with propyleneoxide in the presence of polyisobythylene succinic acid. Other suitable nitrogencompounds quaternized with a hydrocarbyl epoxide in combination with a free hydrocarbyl- substituted polycarboxylic acid and the synthesis methods for obtaining such quaternized compounds are disclosed in WO 2014/195464 A1 and WO 2015/113681 A1 which are both incorporated by reference.

The term “and mixtures thereof’ in respect to the at least one catalyst poisoning suppressant is to be understood that said suppressant contains for example one or more C6 to C26 fatty acids, saturated, mono-unsaturated and poly-unsaturated coupled by a C-C bond to a N-heterocyclic compound or for example a combination of one or more C6 to C26 fatty acids, saturated, monounsaturated and poly-unsaturated coupled by a C-C bond to a N-heterocyclic compound with for example one or more nitrogen-compounds quaternized with a hydrocarbyl epoxide in combination with a free hydrocarbyl-substituted polycarboxylic acid.

The concentration of the at least one catalyst poisoning suppressant in the pyrolysis oil ranges from 5 to 20000 ppm, preferably from 10 to 15000 ppm and more preferably from 20 to 10000 ppm.

The at least one catalyst poisoning suppressant can also be used in mixtures of at least two pyrolysis oils and blends comprising at least one pyrolysis oil.

The concentration of the at least one catalyst poisoning suppressant in a mixture of at least two pyrolysis oils ranges from 5 to 20000 ppm, preferably from 10 to 15000 ppm and more preferably from 20 to 10000 ppm.

The concentration of the at least one catalyst poisoning suppressant in a blend comprising at least one pyrolysis oil ranges from 5 to 20000 ppm, preferably from 10 to 15000 ppm and more preferably from 20 to 10000 ppm.

The at least one catalyst poisoning suppressant can also be used in a method for suppressing catalyst poisoning for upgrading of and/or fouling during a thermal process for converting of a pyrolysis oil, a mixture of at least two pyrolysis oils and a blend comprising at least one pyrolysis oil, comprising the steps (i) providing a pyrolysis oil, a mixture of at least two pyrolysis oils or a blend comprising at least one pyrolysis oil in a steel containment, wherein the pyrolysis oil, the mixture of at least two pyrolysis oils or the blend comprising at least one pyrolysis oil is in physical and/or chemical contact with said steel containment,

(ii) adding at least one catalyst poisoning suppressant to said pyrolysis oil, the mixture of at least two pyrolysis oils or the blend comprising at least one pyrolysis oil, wherein the at least one catalyst poisoning suppressant is selected from the group consisting of amphiphilic compounds, the amphiphilic compounds comprising at least one nonpolar residue selected from C6 to C26 alkyl and/or alkylene and at least one polar residue, the at least one polar residue comprising at least one heteroatom selected from the group consisting of nitrogen and oxygen,

(iii) contacting said pyrolysis oil, mixture of at least two pyrolysis oils or blend comprising at least one pyrolysis oil, comprising said at least one catalyst poisoning suppressant with at least one heterogeneous catalyst or subjecting the said pyrolysis oil, mixture of at least two pyrolysis oils or blend comprising at least one pyrolysis oil, comprising said at least one catalyst poisoning suppressant to a thermal process.

Preferably, the at least one catalyst poisoning suppressant in this method is selected from the group comprising

- C6 to C26 fatty acids, saturated, mono-unsaturated and poly-unsaturated;

- dimerized fatty acids;

- copolymers of at least one ethylenically unsaturated, polymerizable polycarboxylic anhydride with at least one polymerizable alkene;

- alkenylsuccinic acid and alkenylsuccinic acid anhydride wherein the alkenyl-residue is selected from C6 to C26 alkenyl having one or more C=C bonds;

- mixtures thereof.

Preferably the pyrolysis oil according to the present invention and provided in step (i) contains at least 30 mg/l sulfur, at least 30 mg/l nitrogen, at least 5 mg/l halogen, and at least 100 ppm oxygenates. More preferably, the pyrolysis oil according to the present invention and provided in step (i) contains 100 to 5000 mg/l sulfur, 100 to 5000 mg/l nitrogen, 10 to 1000 mg/l halogen, and 200 to 5000 ppm oxygenates.

Preferably, the mixture of at least two pyrolysis oils according to the present invention and provided in step (i) contains at least 30 mg/l sulfur, at least 30 mg/l nitrogen, at least 5 mg/l halogen, and at least 100 ppm oxygenates.

More preferably, the mixture of at least two pyrolysis oils according to the present invention and provided in step (i) contains 100 to 5000 mg/l sulfur, 100 to 5000 mg/l nitrogen, 10 to 1000 mg/l halogen, and 200 to 100000 ppm oxygenates.

Preferably, the at least one pyrolysis oil in a blend according to the present invention and provided in step (i), the blend comprising at least one pyrolysis oil, contains at least 30 mg/l sulfur, at least 30 mg/l nitrogen, at least 5 mg/l halogen, and at least 100 ppm oxygenates.

More preferably, the at least one pyrolysis oil in a blend according to the present invention and provided in step (i), the blend comprising at least one pyrolysis oil, contains 100 to 5000 mg/l sulfur, 100 to 5000 mg/l nitrogen, 10 to 1000 mg/l halogen, and 200 to 100000 ppm oxygenates.

Preferably, the steel containment comprises one or more materials selected from the group comprising carbon-steel and low-alloy steel.

Preferably, the concentration of the at least one catalyst poisoning suppressant in the pyrolysis oil, the mixture of at least two pyrolysis oils or the blend comprising at least one pyrolysis oil ranges from 5 to 20000 ppm, more preferably from 10 to 15000 ppm and most preferably from 20 to 10000 ppm.

The at least one catalyst poisoning suppressant can be added to the pyrolysis oil after separating the gaseous and solid products formed by the pyrolysis reaction. The at least one catalyst poisoning suppressant can also be added to the pyrolysis oil at a later process step e.g., when or after filling the pyrolysis oil into a storage vessel or when or after filling the pyrolysis oil into a transport vessel and after filtration of the pyrolysis oil. The at least one catalyst poisoning suppressant can also be added to the pyrolysis oil before, during and/or after purifying the pyrolysis by one or more purification steps selected from extraction, distillation, hydrotreatment, absorp- tion and adsorption. The addition of the at least one catalyst poisoning suppressant to the pyrolysis oil is not limited to a particular process step or time.

The at least one catalyst poisoning suppressant can be added to a mixture of at least two pyrolysis oils prior to mixing to the individual pyrolysis oils, during mixing of the pyrolysis oils and/or after mixing of the pyrolysis oils.

The at least one catalyst poisoning suppressant can be added to a blend comprising at least one pyrolysis oil prior to blending into the at least one pyrolysis oil, during blending and/or after blending.

In one embodiment of the present invention the mixture of at least one catalyst poisoning suppressant and pyrolysis oil is formed by forced agitation such as by stirring or any other suitable means to obtain a homogeneous contribution of the at least one catalyst poisoning suppressant in the pyrolysis oil.

In another embodiment of the present invention the at least one catalyst poisoning suppressant is added to the pyrolysis oil without forced agitation.

Both forced agitation and no forced agitation can also be applied to mixtures of at least two pyrolysis oils and blends comprising at least one pyrolysis oil when at least one catalyst poisoning suppressant is added.

At least one additive selected from amphiphilic compounds, the amphiphilic compounds comprising at least one nonpolar residue selected from C6 to C26 alkyl and/or alkylene and at least one polar residue, the at least one polar residue comprising at least one heteroatom selected from the group consisting of oxygen and nitrogen can be used as a catalyst poisoning suppressant in a pyrolysis oil, a mixture comprising at least two pyrolysis oils or a blend comprising at least one pyrolysis oil to suppress enrichment of a catalyst poison selected from the group comprising Fe²⁺ ions, Fe³⁺ ions, Ni²⁺ ions and compounds of said metal ions in said pyrolysis oil, a mixture comprising at least two pyrolysis oils or a blend comprising at least one pyrolysis oil.

Preferably for said use, the at least one additive is selected from the group comprising

- C6 to C26 fatty acids, saturated, mono-unsaturated and poly-unsaturated;

- dimerized fatty acids; - copolymers of at least one ethylenically unsaturated, polymerizable polycarboxylic anhydride with at least one polymerizable alkene;

- nitrogen-compounds quaternized with a hydrocarbyl epoxide that is in combination with a free hydrocarbyl-substituted polycarboxylic acid;

- and mixtures thereof.

Preferably for said use, the concentration of the at least one additive in the pyrolysis oil, mixture comprising at least two pyrolysis oils or blend comprising at least one pyrolysis oil ranges from 5 to 20000 ppm, more preferably from 10 to 15000 ppm and most preferably from 20 to 10000 ppm.

Preferably for said use, said pyrolysis oil contains at least 30 mg/l sulfur, at least 30 mg/l nitrogen, at least 5 mg/l halogen, and at least 100 ppm oxygenates.

More preferably for said use, the pyrolysis oil contains 100 to 5000 mg/l sulfur, 100 to 4000 mg/l nitrogen, 10 to 1000 mg/l halogen, and 200 to 5000 ppm oxygenates.

Preferably for said use, the mixture of pyrolysis oils comprising at least two pyrolysis oil contains at least 30 mg/l sulfur, at least 30 mg/l nitrogen, at least 5 mg/l halogen, and at least 100 ppm oxygenates.

More preferably for said use, the mixture of pyrolysis oils comprising at least two pyrolysis oils contains 100 to 5000 mg/l sulfur, 100 to 5000 mg/l nitrogen, 10 to 1000 mg/l halogen, and 200 to 5000 ppm oxygenates.

Preferably for said use, the at least one pyrolysis oil in a blend comprising at least one pyrolysis oil contains at least 30 mg/l sulfur, at least 30 mg/l nitrogen, at least 5 mg/l halogen, and at least 100 ppm oxygenates.

More preferably for said use, the at least one pyrolysis oil in a blend comprising at least one pyrolysis oil contains 100 to 5000 mg/l sulfur, 100 to 5000 mg/l nitrogen, 10 to 1000 mg/l halogen, and 200 to 5000 ppm oxygenates. Preferably for said use, the pyrolysis oil, the mixture of pyrolysis oils comprising at least two pyrolysis oils or the blend comprising at least one pyrolysis oil is in physical and/or chemical contact with a steel containment comprising one or more materials selected from carbon-steels and low-alloy steels.

It is assumed that the at least one catalyst poisoning suppressant is capable to form a film on the surface of the containment by adsorption which includes interaction of the at least one catalyst poisoning suppressant and the surface of the containment by physisorption and/or chemisorption.

The pyrolysis oils, mixtures of pyrolysis oils comprising at least two pyrolysis oils or blends comprising at least one pyrolysis oil comprising at least one catalyst poisoning suppressant and the method for using such pyrolysis oil compositions reduce the undesired poisoning of heterogeneous catalysts used in or after purification, upgrading and/or blending of pyrolysis oils.

Examples of purification processes comprising heterogeneous catalysts are hydrotreating or hydroprocessing techniques for removing sulfur compounds (hydrodesulfurization, HDS) and nitrogen compounds (hydrodenitrogenation, HDN) from pyrolysis oils. Such catalysts typically comprise at least one group 6 metal component and at least one group 8, 9 and 10 metal component composited with a support. The catalysts employed in such purification methods are highly sensitive to poisoning by e.g., Fe²⁺ ions, Fe³⁺ ions, Ni²⁺ ions and compounds of said metal ions. The lifetime of said catalysts is increased and their activity is maintained over a longer time when using the pyrolysis oil compositions and methods according to the present invention.

Furthermore, undesired coking can occur in parts such as pipes made of steel, preferably carbon-steel or low-alloy steel, at elevated temperatures in presence of Fe²⁺ and or Fe³⁺ ions adsorbed to the steel surface. Such undesired coking can lead to blocking of parts such as pipes.

The pyrolysis oils, mixtures of pyrolysis oils comprising at least two pyrolysis oils or blends comprising at least one pyrolysis oil comprising at least one catalyst poisoning suppressant and the method for using such pyrolysis oil compositions also reduce the undesired fouling during thermal processes in or after purification, upgrading, blending and/or conversion of pyrolysis oils. The small amount of the at least one catalyst poisoning suppressant in the pyrolysis oil, mixtures of pyrolysis oils comprising at least two pyrolysis oils or blends comprising at least one pyrolysis oil of 5 to 20000 ppm, preferably of 10 to 15000 ppm and more of from 20 to 10000 ppm has no negative effects during purification, upgrading, blending and/or conversion processes.

The invention will be further explained by the following non-limiting examples.

Examples

The enrichment of metal ions such as Fe²⁺, Fe³⁺ and Ni²⁺ and compounds of such metal ions during storage in a steel containment material was tested with a pyrolysis oil by assessing the corrosive attack on steel fingers made of a carbon-steel (BS970-070M20; also denoted DIN 1.0402) after 4 h of immersion in the pyrolysis oil at 60 °C. The tests were conducted without and with addition of different amounts of a catalyst poisoning suppressant according to the present invention.

The pyrolysis oil was obtained from DRON Industries (manufactured by DRON Industries from end-of-life tires (ELT) with a proprietary pyrolysis process, the pyrolysis oil comprising 30 mg/l halogen and 1.2 g/l sulfur, TAN = 8.4). The corrosion observed on the steel fingers were then visually inspected and rated from 0 (no visible corrosion) to ++++ (severe corrosion).

Table 1 : Results from corrosion tests with steel fingers immersed for 4 h at 60 °C in the pyrolysis oil.

^1-4 available from BASF SE The examples and the results in Table 1 show that the corrosion of a carbon-steel is reduced or suppressed by adding at least one catalyst poisoning suppressant according to the present invention to the pyrolysis oil. Accordingly, metal ions such as Fe²⁺, Fe³⁺ and Ni²⁺ and compounds of such metal ions are not enriched or less enriched in the presence of at least one catalyst poisoning suppressant to the pyrolysis oil and catalyst poisoning and/or fouling of an adsorbent and/or a membrane are reduced.

A pyrolysis oil manufactured by BASF was used for the following examples and comparative examples. The pyrolysis oil was manufactured from plastic waste comprising polyolefins by a pyrolysis reaction. The pyrolysis oil was mixed with high vacuum residue (HVR) and water as follows: 166 g pyrolysis oil + 192 g HVR + 136 g water. The corrosion behavior of steel sheets made of 1.4541 (X6CrNiTi18-10) and 1.4571 (X6CrNiMoTi17-12-2) was tested 4 x 7 days with exchange of the mixture comprising the pyrolysis oil in between at T = 275 °C in sealed autoclaves made of a nickel alloy. The steel sheets made of 1.4551 and 1.4571 steel, respectively, had a size of 50 x 20 x 2 mm, comprised a welding seam and were coarsely sanded on one side. The steel sheets were immersed in the mixture comprising the pyrolysis oil during the test and the remaining autoclave volume was filled with nitrogen gas. The mixture comprising a pyrolysis oil was not agitated during the tests. The temperature of 275 °C is selected to simulate the conditions of pre-heating for steam cracking and pre-heating for partial oxidation.

The average linear corrosion velocity was determined and rated x (failed) or o (passed).

Table 2: results from corrosion tests at T = 275 °C.

Claims

1. Pyrolysis oil, mixture of at least two pyrolysis oils or blend comprising at least one pyrolysis oil, containing at least one catalyst poisoning suppressant selected from amphiphilic compounds, the amphiphilic compounds comprising at least one nonpolar residue selected from C6 to C26 alkyl and/or alkylene and at least one polar residue, the at least one polar residue comprising at least one nitrogen atom.

2. Pyrolysis oil, mixture of at least two pyrolysis oils or blend comprising at least one pyrolysis oil according to claim 1 wherein the at least one catalyst poisoning suppressant is selected from the group consisting of

- nitrogen-compounds quaternized with a hydrocarbyl epoxide in combination with a free hydrocarbyl-substituted polycarboxylic acid; and

- mixtures thereof.

3. Pyrolysis oil, mixture of at least two pyrolysis oils or blend comprising at least one pyrolysis oil according to any of claims 1 and 2 wherein the concentration of the at least one catalyst poisoning suppressant ranges from 5 to 20000 ppm.

4. Pyrolysis oil or mixture of at least two pyrolysis oils or the at least one pyrolysis oil in a blend according to any one of claims 1 to 3, having a bromine number of about

2 g Br2/100g to about 150 g Br2/100g (determined by ASTM 1159) and/or a C5 hydrocarbon content of about 0.03 wt.-% to about 12.2 wt.-% (determined by ASTM D 5134) and/or a naphthalene content of about 0.5 wt.-% to about 18.4 wt.-% (determined by ASTM D 5134) and/or a styrene content of about 0.02 wt.-% to about 29.5 wt.-% (determined by ASTM D 5134) and/or a toluene content of about 4.3 wt.-% to about 71.5 wt.-% (determined by ASTM D 5134).

5. Pyrolysis oil according to any of claims 1 to 4 wherein the pyrolysis oil, at least one pyrolysis oil in the mixture comprising at least two pyrolysis oils or at least one pyrolysis oils in the blend comprising at least one pyrolysis oils is obtained from rubber waste by a pyrolysis reaction.

6. Method for suppressing catalyst poisoning for upgrading of and/or fouling during a thermal process for converting of a pyrolysis oil, a mixture of at least two pyrolysis oils and a blend comprising at least one pyrolysis oil, comprising the steps

(ii) adding at least one catalyst poisoning suppressant to said pyrolysis oil, the mixture of at least two pyrolysis oils or the blend comprising at least one pyrolysis oil, wherein the at least one catalyst poisoning suppressant is selected from the group consisting of amphiphilic compounds, the amphiphilic compounds comprising at least one nonpolar residue selected from C6 to C26 alkyl and/or alkylene and at least one polar residue, the at least one polar residue comprising at least one hetroatom selected from the group consisting of nitrogen and oxygen,

7. Method according to claim 6 wherein the concentration of the at least one catalyst poisoning suppressant ranges from 5 to 20000 ppm.

8. Method according to any of claims 6 and 7 wherein said steel containment comprises one or more materials selected from the group comprising carbon-steels and low-alloy steels.

9. Method according to any one of claims 6 to 8 wherein the at least one catalyst poisoning suppressant is selected from the group consisting of

C6 to C26 fatty acids, saturated, mono-unsaturated and poly-unsaturated; dimerized fatty acids; copolymers of at least one ethylenically unsaturated, polymerizable polycarboxylic anhydride with at least one polymerizable alkene; alkenylsuccinic acid and alkenylsuccinic acid anhydride wherein the alkenyl-residue is selected from C6 to C26 alkenyl having one or more C=C bonds;

C6 to C26 fatty acids, saturated, mono-unsaturated and poly-unsaturated coupled by a C-C bond to a N-heterocyclic compound; nitrogen-compounds quaternized with a hydrocarbyl epoxide in combination with a free hydrocarbyl-substituted polycarboxylic acid; and mixtures thereof.

10. Method according to any one of claims 6 to 9 wherein the pyrolysis oil or the mixture of at least two pyrolysis oils or the at least one pyrolysis oil in a blend, comprising at least one pyrolysis oil, provided in step (i) has a bromine number of about 2 g Br2/100g to about 150 g Br2/100g (determined by ASTM 1159) and/or a C5 hydrocarbon content of about 0.03 wt.-% to about 12.2 wt.-% (determined by ASTM D 5134) and/or a naphthalene content of about 0.5 wt.-% to about 18.4 wt.-% (determined by ASTM D 5134) and/or a styrene content of about 0.02 wt.-% to about 29.5 wt.-% (determined by ASTM D 5134) and/or a toluene content of about 4.3 wt.-% to about 71.5 wt.-% (determined by ASTM D 5134).

11. Method according to any one of claims 6 to 10 wherein the thermal process in step (iii) is selected from the group consisting of pre-heating for steam cracking, steam cracking, preheating for partial oxidation and partial oxidation.

12. Use of at least one additive selected from amphiphilic compounds comprising at least one nonpolar residue selected from C6 to C26 alkyl and/or alkylene and at least one polar residue comprising at least one heteroatom selected from the group consisting of oxygen and nitrogen as a catalyst poisoning suppressant in a pyrolysis oil, a mixture of at least two pyrolysis oils or a blend comprising at least one pyrolysis oil to suppress enrichment of a catalyst poison selected from the group comprising Fe²⁺ ions, Fe³⁺ ions, Ni²⁺ ions and compounds of said metal ions in said pyrolysis oil, mixture of at least two pyrolysis oils or a blend comprising at least one pyrolysis oil.

13. Use according to claim 12 wherein the at least one additive is selected from the group comprising

14. Use according to claim 12 or 13 wherein the concentration of the at least one additive in the pyrolysis oil, mixture of at least two pyrolysis oils or blend comprising at least one pyrolysis oil ranges from 5 to 20000 ppm.

15. Use according to any one of claims 12 to 14 wherein the pyrolysis oil or mixture of at least two pyrolysis oils or the at least one pyrolysis oil in a blend, comprising at least one pyrolysis oil has a bromine number of about 2 g Br₂/100g to about 150 g Br₂/100g (determined by ASTM 1159) and/or a C5 hydrocarbon content of about 0.03 wt.-% to about 12.2 wt.-% (determined by ASTM D 5134) and/or a naphthalene content of about 0.5 wt.-% to about 18.4 wt.-% (determined by ASTM D 5134) and/or a styrene content of about

0.02 wt.-% to about 29.5 wt.-% (determined by ASTM D 5134) and/or a toluene content of about 4.3 wt.-% to about 71.5 wt.-% (determined by ASTM D 5134).