Arsenic removal in renewable fuel production

Abstract

The present invention relates to the removal of heteroatoms such as arsenic in the processing of renewable feedstocks.

Description

[Technical Field]

[0001] Technical Field The present invention relates to the removal of arsenic in the processing of renewable feedstocks. [Background technology]

[0002] background A particular, previously unrecognized issue is that some renewable feedstocks, especially those produced from residues and waste, may contain certain heteroatom contaminants, such as arsenic (As), that are not common in first-generation vegetable oil-based renewable feedstocks. Arsenic is known to be a serious catalyst poison, and efficient hydroprocessing methods require complete removal of As prior to hydroprocessing. Furthermore, due to its high toxicity, arsenic is undesirable in biofuel product streams. Therefore, arsenic must be removed when processing renewable feedstocks, especially sewage sludge.

[0003] On the other hand, arsenic removal is less of an issue in fossil-fuel-based refining processes, as the arsenic content in the feedstock is typically much lower. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] PCT / EP2021 / 068656 [Non-patent literature]

[0005] [Non-Patent Document 1] Robert Brown “Heterodoxy in Fast Pyrolysis of Biomass”: https: / / dx.doi.org / 10.1021 / acs.energyfuels.0c03512 Summary of the Invention [Problem to be solved by the invention]

[0006] Commercial plants processing fossil-based or first-generation renewable feedstocks traditionally remove arsenic, along with other potential heteroatoms such as phosphorus (P), silicon (Si), iron (Fe), nickel (Ni), vanadium (V), halides, or combinations thereof, as a first step before the hydrotreating step. This is essential in conventional processes because these heteroatoms rapidly deactivate conventional hydrotreating catalysts, dramatically shortening cycle lengths. Refineries processing arsenic-containing fossil feedstocks require arsenic removal because it is a serious catalyst poison, even when present at ppb levels. This deactivation effect forces refineries processing renewable feedstocks to increase feedstock inputs to protect the hydrotreating catalyst. When processing renewable feedstocks, the hydrotreating method involves both an initial stabilization process of the liquid oil feed and subsequent catalytic hydroprocessing. [Means for solving the problem]

[0007] summary The inventors have discovered that arsenic can be effectively removed from a liquid oil feedstock after it has been stabilized through a stabilization step and before the step involving catalytic hydroprocessing. The arsenic is captured using a guard material. This method allows arsenic removal between the initial stabilization and catalytic hydroprocessing. Surprisingly, when processing renewable feedstocks with high arsenic content, unlike conventional methods, it is not necessary to remove arsenic before hydroprocessing. Because some of the organically bound arsenic may be transformed within the stabilization reactor, it is beneficial to provide the stabilization reactor with a top layer (e.g., with an open structure) suitable for capturing solid heteroatom products.

[0008] Accordingly, a first aspect of the present invention relates to a method for removing arsenic in the processing of renewable feedstocks, said method comprising using a system comprising: - Liquid oil feed derived from renewable feedstocks; - stabilization reactor; - Guard material; - at least a first hydroprocessing reactor; wherein the method comprises the following steps: - providing the liquid oil feed to the stabilization reactor to provide a stabilized liquid oil feed; - feeding at least a portion of the stabilized liquid oil feed to the guard material and capturing arsenic within the guard material to provide a liquid oil feed having a reduced arsenic content; - feeding the low-arsenic liquid oil feed to the hydroprocessing reactor and subjecting it to catalytic hydroprocessing to provide one or more hydroprocessed product streams.

[0009] Additional aspects of the present invention are set forth in the following description, drawings and claims.

[0010] Figure legend The technique is illustrated by the following schematic diagram. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 shows a simplified layout of one embodiment of the system of the present invention. [Figure 2] FIG. 2 illustrates one embodiment of the system of the present invention. [Figure 3] FIG. 3 shows another embodiment of the system of the present invention. [Figure 4] Figure 4 shows a third embodiment of the system of the present invention. Embodiments that combine the features of Figures 2 to 4 are also included in the present invention. [Figure 5] FIG. 5 shows the sulfur (S) content in ppm in the product stream as a function of time in normalized hours on stream for the example. DETAILED DESCRIPTION OF THE INVENTION

[0012] Detailed Disclosure A "unit" performs a process that changes the chemical composition of the feed and may also include elements such as heat exchangers, mixers, compressors, etc. that do not change the chemical composition of the feed or stream.

[0013] In a first aspect, a method for removing arsenic in the processing of renewable feedstocks is provided, the method comprising using a system comprising: - Liquid oil feed derived from renewable feedstocks; - stabilization reactor; - Guard material; - at least one first hydroprocessing reactor;

[0014] Aspects relating to the method In certain embodiments, providing the liquid oil feed to the stabilization reactor can include contacting it with a stabilization hydrotreating catalyst, which contains less than 10 wt. % Ni, e.g., less than 8 wt. %, less than 5 wt. %, or no Ni, which has the advantage of catalyzing the stabilization reaction without arsenic scavenging or deactivation.

[0015] In another particular embodiment, the guard material comprises more than 10% Ni by weight, such as more than 12% Ni by weight, which has the advantage of having a high concentration of Ni that is beneficial for arsenic capture as a guard.

[0016] renewable feedstock In a first embodiment, the method includes a liquid oil feed derived from a renewable feedstock. In one embodiment, the renewable feedstock includes: - Lignocellulosic-based biomass, e.g. wood products, algae, grasses, forestry waste and / or agricultural residues; - Municipal waste, in particular its organic fraction. Municipal waste here means feedstocks containing items discarded by the general public, such as mixed municipal waste as defined in Annex IX, Part A of Directive 2018 / 2001 (RED II). - Nitrogen-enriched renewable feedstocks, e.g., compost, sewage sludge.

[0017] In one embodiment, the proportion of renewable feedstock derived from renewable sources is 5-60% by mass, e.g., 10 or 50% by mass. In another embodiment, the proportion of renewable feedstock derived from renewable sources is greater than 60% by mass, e.g., 70-90% by mass. When the renewable source is recycled waste, some of the waste may be non-biological, such as waste plastic, and therefore can be characterized by its content of biological material. Objectively, 14 The amount of biogenic matter can be measured by its C-isotope content, as this isotope is virtually absent in fossil materials. Therefore, a biogenically rich renewable feedstock is one in which at least 20% of the carbon is 14 C. An example of waste is municipal waste, which is rich in biological material, including items discarded by the general public, such as municipal waste as defined in Annex IX Part A of EU Directive 2018 / 2001 (RED II).

[0018] The renewable feedstock may require cracking to produce the liquid oil feed. Thus, in one embodiment, the method further comprises the step of thermal cracking of the renewable feedstock to produce the liquid oil feed, wherein the thermal cracking comprises a pyrolysis step and / or a hydrothermal liquefaction step.

[0019] The pyrolysis step can include the use of a pyrolysis unit, such as a fluidized bed, transport bed, or circulating fluidized bed, as known in the art. For example, the pyrolysis step can include the use of a pyrolysis unit (also referred to herein as a pyrolysis reactor), a cyclone to remove particulate solids such as char, and a cooling device, thereby producing an off-gas stream (i.e., pyrolysis off-gas) and the liquid oil stream, i.e., condensed pyrolysis oil. The off-gas stream includes light hydrocarbons, such as C1-C4 hydrocarbons, CO, and CO2. 。The liquid oil stream, also referred to as pyrolysis oil or bio-oil, is a liquid substance rich in a mixture of molecules, typically more than 200 different compounds, including aldehydes, ketones, and / or other compounds, such as compounds such as furfural, which have carbonyl groups, and compounds resulting from the depolymerization of pyrolysis products. Thus, liquid oil feeds derived from renewable feedstocks can be pyrolysis oil or bio-oil.

[0020] In one embodiment, the pyrolysis step comprises fast pyrolysis (also referred to in the art as flash pyrolysis). Fast pyrolysis refers to the thermal decomposition of solid renewable feedstock in the absence of oxygen, at a temperature ranging from 350 to 650°C (e.g., about 500°C) for a reaction time of 10 seconds or less (e.g., less than 10 seconds, e.g., 5 seconds or less, e.g., about 2 seconds), i.e., a vapor residence time of 10 seconds or less, e.g., 2 seconds or less, e.g., about 2 seconds). This provides sufficient heat to the reaction to at least partially decompose large organic compounds, such as polymers, present in the renewable feedstock. Because the reaction proceeds under oxygen-deficient conditions, the elevated temperatures do not result in combustion of the renewable feedstock.

[0021] Conventionally, fast pyrolysis can also be carried out by autothermal operation, for example, in a fluidized bed reactor. The latter, also known as autothermal pyrolysis, is characterized by using air as a fluidizing gas, optionally mixed with an inert gas or recycled gas, or a mixture of air and an inert gas or recycled gas. This allows the partial oxidation of pyrolysis compounds produced in the pyrolysis reactor (autothermal reactor) to serve as the energy source for pyrolysis, while simultaneously improving heat transfer. For more details about autothermal pyrolysis, see, for example, Robert Brown, "Heterodoxy in Fast Pyrolysis of Biomass," https: / / dx.doi.org / 10.1021 / acs.energyfuels.0c03512. In one embodiment, the pyrolysis step includes autopyrolysis.

[0022] In one embodiment, the pyrolysis step comprises catalytic fast pyrolysis (CFP). Such catalytic fast pyrolysis steps involve the use of a catalyst, such as an acid catalyst, e.g., a zeolite catalyst. Catalytic fast pyrolysis can be operated both in situ, where the catalyst is located within the pyrolysis unit, and ex-situ, where the catalyst is located in a separate reactor.

[0023] The pyrolysis step can include in-situ catalytic fast pyrolysis. In one embodiment, a catalyst is placed in the pyrolysis unit, and deoxygenation (DO) (e.g., via decarboxylation, decarboxylation with an acid-based catalyst, such as a zeolite catalyst) occurs in the pyrolysis reactor immediately after the pyrolysis vapor is generated. Suitable catalysts for CFP include alumina and zeolite catalysts, including all types of zeolite catalysts typically used in hydrocracking (HCR) and cracking in refinery processes, such as HZSM-5. Alternatively, in another embodiment, a hydrotreating catalyst, such as a hydrodeoxygenation catalyst, is placed in the pyrolysis unit, and the pyrolysis vapor is immediately hydrodeoxygenated in the pyrolysis reactor upon formation. This method is referred to as in-situ HDO (also referred to as reactive catalytic fast pyrolysis, or RCFP). Suitable catalysts for HDO include metal-based catalysts such as reduced forms of Ni, Mo, Co, Pt, Pd, Re, Ru, and Fe, e.g., CoMo or NiMo catalysts, as well as sulfide forms such as CoMoS, NiS, NiMoS, NiWS, and RuS. The catalyst support is similar to that used in conventional HDO refinery processes and is typically a refractory support such as alumina, silica, titania, or a combination thereof.

[0024] Liquid pyrolysis oil products derived from renewable feedstocks have not been found to contain significant arsenic, such as greater than 1 ppb by mass, greater than 5 ppb by mass, greater than 50 ppb by mass, greater than 500 ppb by mass, or greater than 5 ppm by mass, and no specific advice exists regarding the treatment process for arsenic-containing pyrolysis oil. Bio-based pyrolysis oils have been found to contain higher arsenic than, for example, pyrolysis oils derived from recycled plastics. Therefore, the presented method is likely to be applicable to general pyrolysis oils, but is expected to be particularly effective for bio-based pyrolysis oils.

[0025] The use of a catalyst in the pyrolysis reactor can significantly reduce the temperature required to carry out the pyrolysis. Furthermore, it can also increase the selectivity to the desired pyrolysis oil compounds. When operating catalytic fast pyrolysis with arsenic-containing feeds, it is preferable that the catalyst in the pyrolysis section be a Mo, CoMo, or acid catalyst rather than a nickel-containing catalyst, as these catalysts are less inhibited by arsenic in this location than nickel-based catalysts.

[0026] In one embodiment, the pyrolysis step is fast pyrolysis, and the vapor residence time is 10 seconds or less, such as less than 10 seconds, such as 5 seconds or less, such as about 2 seconds, or 1 second, or in the range of 1 to 5 seconds, selected from: simple fast pyrolysis; in situ catalytic fast pyrolysis (in-situ CFP); ex-situ catalytic fast pyrolysis (ex-situ CFP); reactive catalytic fast pyrolysis (RCFP); hydropyrolysis (hydrothermolysis) (HP); catalytic fast hydropyrolysis (CHP).

[0027] As an alternative to fast pyrolysis, intermediate and / or slow pyrolysis may also be used and may be preferred in some cases.

[0028] In one embodiment, the pyrolysis step is intermediate pyrolysis, with vapor residence times ranging from 10 seconds to 5 minutes, e.g., 11 seconds to 3 minutes. Similar to fast pyrolysis, temperatures range from 350 to 650°C, e.g., about 500°C. This pyrolysis is often carried out in a pyrolysis reactor that processes different types of waste, with the vapors being combusted after the pyrolysis reactor. Typical reactors are: Herreshoff furnaces, rotary drums, Amaron, CHOREN paddle pyrolysis kilns, auger reactors, and vacuum pyrolysis reactors.

[0029] In another embodiment, the pyrolysis step is slow pyrolysis, with solids residence times ranging from 5 minutes to 2 hours (e.g., 10 minutes to 1 hour). Temperatures of around 300°C are suitable. This pyrolysis results in high carbonization yields, and the resulting carbon can be used as fertilizer or charcoal; pyrolysis still produces some gas and bio-crude, and if the carbon is used as fertilizer, the greenhouse gas (GHG) emissions of the final bio-oil exceed 100%, making it carbon negative. Typical reactors are auger reactors, but with different residence times than intermediate pyrolysis, and include fixed-bed reactors, kilns, Lambiot SIFIC / CISR retorts, Lurgi process reactors, wagon reactors, and Carbotwin retorts.

[0030] Thus, the liquid oil feed includes compounds formed at moderately elevated temperatures (>80°C), but below temperatures that result in substantially complete hydrotreating. The liquid oil feed can include: i) feeds rich in conjugated diolefins or styrene and its homologues derived from the thermochemical decomposition of plastic waste, municipal waste, waste-derived fuels, and solid recovered fuels; ii) feeds rich in carbonyl compounds and sugars derived from the thermochemical decomposition of lignocellulosic biomass; and / or iii) nitrogen-enriched feedstocks, e.g., nitrogen-enriched feeds derived from the thermochemical decomposition of fertilizer, sewage sludge, and / or similar compositions from other sources. In one embodiment, the liquid oil feed can include compounds resulting from the thermochemical decomposition (e.g., compounds i)-iii) that can subsequently react, i.e., react between identical (e.g., diolefins with diolefins) or different (e.g., aldehydes with phenols) reactive functional groups to provide larger compounds. Such larger compounds can cause complete or partial blockage of reactors, tubes, heaters, heat exchangers, and catalysts involved in subsequent process steps.

[0031] Stabilization of liquid oil feed In a first embodiment, the method includes using a system including a stabilization reactor, the method including providing a liquid oil feed to the stabilization reactor and providing a stabilized liquid oil feed.

[0032] The purpose of the method steps is to provide a stabilized liquid oil feed, characterized as a feed having a lower content of reactive compounds than the liquid oil feed. This can be achieved by modifying the chemical composition of the liquid oil and / or removing destabilizing components from the liquid oil. The stabilized liquid oil feed can have a lower vapor pressure than the liquid oil feed. In this way, the method steps provide a less reactive liquid oil, such as the stabilized liquid oil, which can be used as a feed for a subsequent process step.

[0033] In one embodiment, the method comprises reacting the liquid oil feed with hydrogen in the presence of a catalyst in a stabilization reactor, wherein the catalyst comprises at least one metal selected from Ni, Co, Mo, W, Cu, Pt, Pd, Ru, for example, the catalyst comprises nickel-molybdenum molybdenum (Ni-Mo), cobalt-molybdenum (Co-Mo), nickel-tungsten (NiW), nickel-copper (NiCu), Pt, Pd, or Ru, thereby obtaining at least one stabilized liquid oil feed.

[0034] In one embodiment, the method includes operating the stabilization reactor at a temperature of 100 to 230°C and a pressure of 20 to 200 barg. The temperatures include the inlet temperature of the liquid oil stream and the outlet temperature of the stabilized liquid oil stream. The barg unit refers to pressures above atmospheric pressure (atmospheric pressure is approximately 1 bar), and may also be referred to as "hydrogen pressure." The method may be carried out at a hydrogen to liquid oil ratio of 500 to 10,000 NL / L, e.g., 2,000 to 5,000 NL / L, specifically 2,500, 3,000, 3,500, 4,000, or 4,500 NL / L. As used herein, "hydrogen to liquid oil ratio" or "H2 / oil ratio" refers to the volumetric ratio of hydrogen to the flow rate of the liquid oil stream. The unit NL refers to "standard" liters, i.e., the amount of gas that occupies this volume at 0°C and 1 atmosphere. Liquid volumes are treated as standard amounts at 15°C and 1 atmosphere.

[0035] According to this method, the process steps result in the modification of the liquid oil feed composition through hydrogenation to remove destabilizing components from the liquid oil feed, thereby converting reactive compounds present in the liquid oil feed to less reactive compounds under low-temperature conditions. In one embodiment, the liquid oil feed contains at least 0.5 wt% oxygen (O), e.g., at least 4 wt% O, e.g., at least 20 wt% O, e.g., at least 30 wt% O, or at least 45 wt% O. Pyrolysis oils derived from recycled plastics typically contain 0.5-4 wt% oxygen, while pyrolysis oils derived from biological materials typically contain 5-50 wt% oxygen. Oxygen can be present as reactive compounds such as furfural, furan, aldehydes, ketones, and acids, which can be converted to alcohols, for example, by efficiently converting carbonyl groups to alcohols. The conversion of carbonyls to alcohols is carried out at a reactor temperature of approximately 200°C. The alcohols can be further converted to saturated organic compounds during stabilization and / or in subsequent hydroprocessing process steps such as hydrodeoxygenation (HDO).

[0036] In certain embodiments, a step of the method comprises hydrotreating a liquid oil stream in a continuous operation in a fixed bed reactor, i.e., hydrotreating the liquid oil stream in the presence of a nickel-molybdenum (Ni-Mo) based catalyst at an inlet temperature of 100-230°C, a pressure of 100-200 barg, a liquid hourly space velocity (LHSV) of 0.1-1.1 h -1、 and hydrotreating the liquid oil stream by a continuous operation of reacting the liquid oil stream under conditions of a hydrogen to liquid oil ratio of 500 to 10,000 NL / L (e.g., 2,000 to 5,000 NL / L), defined as the volume ratio of hydrogen to the liquid oil stream, thereby forming a stabilized liquid oil stream.

[0037] The combination of the above features, i.e. low temperature, high pressure, low LHSV and high H2 / liquid oil ratio, allows for liquid oil stabilization, specifically converting carbonyl groups to alcohols, extending the run time before plugging issues (if they occur) occur, while also reducing catalyst coking and subsequent catalyst deactivation and avoiding hydrogen starvation.

[0038] The temperature range of 100-230°C includes the inlet temperature of the liquid oil stream and the outlet temperature of the stabilized liquid oil stream. For example, the inlet temperature can be 100, 110, 120, or 130°C. The higher the inlet temperature, e.g., 130°C, the easier it is to ignite the process and initiate the exothermic reaction. The outlet temperature can be, for example, 200, 215, or 230°C. More generally, the temperature at a given step or reactor (unit) refers to the inlet temperature in an adiabatic step or the reaction temperature in an isothermal step. Thus, a temperature of 100-230°C appropriately refers to the inlet temperature. The term continuous operation, as known to those skilled in the art, refers to a constant flow of incoming liquid oil during a given production cycle, and a stabilized liquid oil stream is withdrawn as the discharged product. This is in contrast to batch, or discontinuous, operation, as is well known in the art. In batch operation, the total amount of liquid oil and catalyst is introduced at the beginning of the process, and the discharged product is withdrawn after a certain time.

[0039] Therefore, operation at low temperatures (100-230°C) not only results in stabilization of the liquid oil, avoiding the problem of clogging, but also allows stabilization without catalyst deactivation or the risk of hydrogen starvation. Surprisingly, it has been found that under low-temperature conditions, arsenic does not significantly interact or react with materials such as the catalyst in the stabilization reactor, and does not deactivate the catalyst. This allows arsenic to be removed from the stabilized liquid oil feed using guard materials in subsequent steps.

[0040] Capture of arsenic and any additional heteroatom(s) In a first aspect, a method for arsenic removal in renewable feedstock processing is provided, the method comprising feeding at least a portion of a stabilized liquid oil feed to a guard material and capturing the arsenic within the guard material to obtain a liquid oil feed having a low arsenic content. The low arsenic content may be measured on an absolute basis (e.g., less than 1 ppb mass%, less than 5 ppb mass%, less than 50 ppb mass%) or on a relative basis (e.g., less than 10%, less than 1% of the arsenic content in the feedstock).

[0041] The liquid oil feed may contain arsenic (As) in an amount ranging from 5 ppb-50 ppm by mass. The arsenic content may vary significantly depending on the feedstock. For example, the As content may be greater than 5 ppb. The ppm units are given by mass (weight basis), i.e., ppm-mass. In one embodiment, the method further comprises trapping one or more additional heteroatoms in the guard material. The heteroatoms are selected from one or more of phosphorus (P), silicon (Si), iron (Fe), nickel (Ni), vanadium (V), halides, or combinations thereof. The heteroatoms may be advantageously trapped within the guard material because they can be solidified as sulfides or other solid compounds.

[0042] The arsenic-trapping guard material can be a metal guard bed. By metal guard bed, we mean a fixed bed of material active in hydrometallation (HDM) and / or hydrodeoxygenation (HDO). The hydrodemetallation (HDM) process is intended to include a pretreatment step to generate free metals and convert them to metal sulfides. Hydrodemetallation differs from, for example, hydrodesulfurization (HDS), in which heteroatoms (S) are removed in a gaseous state. In addition to removing arsenic and other heteroatoms, such as P, Si, Fe, Ni, V, halides, and combinations thereof, the guard material can also be provided with deoxygenation activity.

[0043] A suitable guard layer can be a porous material comprising alumina, the alumina comprising alpha (α)-alumina. The alumina can further comprise, for example, 0-50 wt. % theta (θ)-alumina, and optionally, a lesser amount, for example, 0-10 wt. % gamma (γ)-alumina, as determined by XRD. The porous material has a BET specific surface area of ​​1-110 m2, as measured according to ASTM D4567-19 (i.e., single-point measurement of surface area by the BET equation). 2 The porous material may have a pore size distribution (PSD) of 0.50 to 0.80 ml / g, suitably a total pore volume of 0.50 to 0.80 ml / g as measured by mercury penetration according to ASTM D4284. The pore size distribution (PSD) of the porous material may be such that at least 30% by volume of the total pore volume is pores with a radius of >400 Å, preferably pores with a radius of >500 Å (e.g., pores with a radius of up to 5000 Å). Pores with a radius of 500 Å, e.g., pores with a radius of up to 5000 Å, are preferred; for example, as described in the applicant's co-pending patent application PCT / EP2021 / 068656. The porous material may further comprise one or more metals selected from Co, Mo, Ni, W, and combinations thereof, preferably Ni. Ni may be combined with at least one other metal. The content of the one or more metals is 0.25 to 20% by weight, e.g., 0.25 to 15%, 0.25 to 10%, or 0.25 to 5% by weight. In one embodiment, at least one metal is in the form of an oxide or sulfide.

[0044] In one embodiment, a suitable guard bed is a catalyst comprising molybdenum supported on alumina, i.e., Mo / Al2O3 catalyst. In yet another embodiment, a suitable catalyst is a catalyst having demetallization activity and moderate hydrodesulfurization activity, such as the commercially available NiMo / Al2O3 catalyst. Thus, in one aspect, when the guard material is a metal guard bed, e.g., Mo / Al2O3 and / or Ni / Al2O3, 、 The method includes trapping arsenic in the guard material.

[0045] The guard material intended to capture arsenic preferably contains a large amount of Ni, for example, 10 to 20 mass %, and further advantageously contains a small amount of Mo, for example, less than 1 mass %, less than 0.5 mass %, or no Mo.

[0046] The use of porous materials with pores greater than 400 Å improves the permeability of the stabilized liquid oil feed, thereby allowing the penetration of arsenic-containing molecules. The porous material may exhibit a broad peak, e.g., a unimodal pore system, or may exhibit a bimodal or trimodal pore system, with particularly small pores potentially imparting hydrotreating activity to the porous material.

[0047] It is advantageous for the guard material to have hydrotreating activity, such as deoxygenation activity. This avoids coking and high exothermicity when the feed contacts the primary downstream catalyst layer for hydrotreating. The most reactive molecules in the feed are converted, thereby reducing the risk of excessive temperature rise that could cause gumming. The hydrotreating activity can be achieved by the presence of one or more metals selected from Co, Mo, Ni, W, and combinations thereof, preferably Ni, present in the porous material at a content of 0.25 to 20% by weight, e.g., 0.25 to 15% by weight, 0.25 to 10% by weight, or 0.25 to 5% by weight. Furthermore, the low-arsenic-content liquid oil feed is preheated before being fed to the hydroprocessing reactor for catalytic hydroprocessing. This preheating has the advantage of allowing the hydroprocessing reactor to operate at a higher temperature than the stabilization reactor. In one embodiment, the method includes operating the guard material, optionally as a guard material unit, at a temperature above 250° C., for example 250-360° C., which allows for optimal capture of arsenic within the guard material through the process of hydrodemetallation.

[0048] The guard material can be positioned in a variety of ways. In one embodiment, at least a portion of the guard material is positioned within the first catalytic hydroprocessing reactor upstream of the hydroprocessing catalyst. This is advantageous because the first catalytic hydroprocessing reactor is heated to high temperatures, e.g., above 250°C, and therefore the guard material can be operated at temperatures above 250°C without additional placement.

[0049] In some embodiments, the guard material is disposed in a unit, and the method includes using one or more guard material units. In embodiments using one or more guard material units, the method can include using one or more guard material units arranged in parallel. Alternatively, or additionally, the method can include using multiple guard material units arranged in series. The use of multiple guard material units allows the unit (e.g., reactor) to be replaced without making other additional modifications to the system, and preferably without stopping the method during the replacement.

[0050] Partial conversion of organically bound arsenic and / or other heteroatoms may occur in the stabilization reactor. For this reason, it is advantageous to additionally capture heteroatoms, such as solid heteroatom products, at the inlet of the stabilization reactor, for example, in a guard material. Therefore, in one embodiment, the method is further characterized in that the stabilization reactor further comprises a top layer (e.g., having an open structure) suitable for capturing solid heteroatom products.

[0051] In some embodiments, the arsenic-depleted liquid oil provided by the arsenic-scavenging method step is then provided as a feed to said hydroprocessing reactor and subjected to catalytic hydroprocessing.

[0052] Catalytic Hydroprocessing In a first aspect, the method includes using a system including at least a first hydroprocessing reactor, feeding the low-arsenic content liquid oil feed to the hydroprocessing reactor and subjecting it to catalytic hydroprocessing to obtain one or more hydroprocessed product streams, whereby the method includes at least one catalytic hydroprocessing step.

[0053] In one embodiment, the process is carried out in one or more hydroprocessing reactors and comprises one or more hydroprocessing steps selected from hydrodeoxygenation (HDO), hydrotreating, hydrodenitrogenation (HDN), hydrodesulfurization (HDS), aromatic ring saturation (HDA), hydrocracking, and / or isomerization. Hydrodeoxygenation (HDO) refers to the removal of oxygen from a liquid oil feed, primarily as HO.

[0054] Catalytically active materials for hydroprocessing (e.g., HDO) typically contain an active metal (a base metal sulfide, e.g., nickel, cobalt, tungsten, or molybdenum, or an elemental noble metal, e.g., platinum or palladium) and a refractory support (e.g., alumina, silica, titania, or a combination thereof). Hydroprocessing, e.g., HDO, conditions involve temperatures in the range of 250-400°C, pressures in the range of 30-200 bar, and liquid hourly space velocities (LHSV) in the range of 0.1-2, optionally with intermediate cooling by cold hydrogen, mass, or product quenching.

[0055] Hydrodearomatization (HDA) refers to a hydrotreating process that uses hydrogen under heat, pressure, and the presence of a catalyst to saturate aromatic hydrocarbons, resulting in a low aromatic hydrocarbon content in the product. Catalytically active materials for this process typically include an active metal (typically an elemental noble metal, e.g., platinum and / or palladium, but also sulfurized base metals, e.g., nickel, cobalt, tungsten, and molybdenum) and a refractory support (e.g., amorphous silica-alumina, alumina, silica, titania, or combinations thereof). Dearomatization reaction conditions include temperatures ranging from 200 to 350 °C, pressures ranging from 20 to 200 bar, and liquid hourly space velocities (LHSVs) ranging from 0.5 to 8.0.

[0056] Hydrocracking refers to a bifunctional catalytic process that combines catalytic cracking and hydrogenation, in which a liquid oil feed undergoes cracking in the presence of hydrogen. Materials catalytically active in hydrocracking have similar properties to those catalytically active in isomerization, typically including an active metal (typically an elemental noble metal, e.g., platinum and / or palladium, or a sulfide-based metal, e.g., nickel, cobalt, tungsten, and / or molybdenum), an acidic support (typically a molecular sieve with a topology such as MFI, BEA, or FAU that exhibits high cracking activity), and a refractory support (e.g., alumina, silica, titania, or a combination thereof). The difference from materials catalytically active in isomerization typically lies in the nature of the acidic support, which may have a different structure (e.g., amorphous silica-alumina) or a different acidity, such as a silica:alumina ratio. Hydrocracking conditions involve temperatures in the range of 250-400°C, pressures in the range of 30-200 bar, and liquid hourly space velocities (LHSV) in the range of 0.5-8.0, with intermediate cooling by cold hydrogen, mass, or product quenching as needed.

[0057] Isomerization processes (including hydrodewaxing) aim to improve the flow index of liquid oil feeds. Catalytically active materials in isomerization typically include an active metal (an elemental noble metal, e.g., platinum and / or palladium, or a sulfide-based metal, e.g., nickel, cobalt, tungsten, and / or molybdenum), an acidic support (usually a molecular sieve exhibiting high shape selectivity, with topologies such as MOR, FER, MRE, MWW, AEL, TON, or MTT), and a refractory support (alumina, silica, titania, or a combination thereof). Isomerization conditions include temperatures ranging from 250 to 400°C, pressures ranging from 20 to 200 bar, and liquid hourly space velocities (LHSV) ranging from 0.5 to 8.0.

[0058] Specific Embodiments of the Invention Figure 1 shows a schematic diagram of a process for heteroatom removal according to the present invention. A liquid oil feed (1) is fed to a stabilization reactor (10) to produce a stabilized liquid oil feed (11). The stabilized liquid oil feed (11) is fed to a guard material (20), where the heteroatoms are captured by the guard material, thereby producing a liquid oil feed (21) with reduced heteroatom content. This liquid oil feed (21) with reduced heteroatom content is fed to a hydroprocessing reactor (30), which may contain one or more catalysts of the same or different nature, and undergoes catalytic hydroprocessing to provide a hydroprocessed product stream (31).

[0059] Figure 2 shows a layout similar to Figure 1, with two or more guard material units (20a, b, c) arranged in parallel. Figure 3 shows a layout similar to Figure 1, with two or more guard material units (20a, b, c) arranged in series. Figure 4 shows a layout similar to Figure 1, with guard material (20) arranged upstream of the hydroprocessing catalyst in the first catalytic hydroprocessing reactor (30). [Example]

[0060] example Arsenic uptake was measured in two studies with and without the use of guard materials.

[0061] Liquid oil feeds derived from different batches of sewage sludge (arsenic content: approximately 6 ppm by weight, sulfur content: approximately 1% by weight, and oxygen content: approximately 6% by weight) were processed in a pilot plant system consisting of two reactors in series, followed by a gas-liquid separation section. In Test 1, 115 ml of a commercially available Ni-Mo-based catalyst was loaded into the first reactor for stabilization, and 115 ml of a commercially available high-activity Ni-Mo-based catalyst was loaded into the second reactor for hydroprocessing. In Test 2, the first reactor was loaded the same as in Test 1, and the second reactor was loaded with 57.5 ml of guard catalyst on top of 115 ml of the same hydroprocessing catalyst loaded in Test 1. The guard catalyst was a Ni-based alumina catalyst.

[0062] Tests 1 and 2 were carried out at a hydrogen to liquid oil ratio of 4000 Nl / l, a pressure of 70 barg and a feed flow rate of 57.5 ml / h. In both tests the temperature of the first reactor was kept constant at 220°C. In test 1 the second reactor was operated at the following reactor temperatures: 330°C, 340°C, 360°C, 380°C. In test 2 the following reactor temperatures were used for the second reactor: 330°C, 340°C, 360°C, 380°C, 400°C.

[0063] The sulfur content of the liquid product after the reactor system was measured using ASTM D-7039. Figure 5 shows the product sulfur content (ppm) in the liquid product as a function of time (hr). The legend indicates the reactor temperature used in the second reactor. Test 1, which did not use guard material, had significantly higher sulfur content in the product stream compared to Test 2, which used a guard catalyst under equivalent temperature conditions in the second reaction. Rapid deactivation of the hydroprocessing catalyst was observed in the absence of guard material. No deactivation of the hydroprocessing catalyst was observed in tests that included guard material.

[0064] The present invention has been described with reference to several embodiments and examples. Those skilled in the art can combine these embodiments and examples within the scope of the invention as defined by the claims. All documents cited herein are incorporated by reference.

Claims

1. A method for removing arsenic in the processing of renewable raw materials, using a system comprising: - Liquid oil supplies derived from renewable raw materials (1); - Stabilized reactor (10); - Guard material (20); - At least a first hydrogenation reactor (30); Here, the method is: - A step of supplying the liquid oil feed (1) to the stabilizing reactor (10) to contact the stabilizing hydrogenation catalyst and supplying the stabilized liquid oil feed (11); - A step of supplying at least a portion of the stabilized liquid oil supply (11) to the guard material (20), capturing arsenic within the guard material, and supplying a liquid oil supply (21) with a low arsenic content. - The process includes the step of supplying the liquid oil feed (21) with a low arsenic content to the hydrogenation reactor (30), subjecting it to catalytic hydrogenation, and supplying one or more hydrogenated product streams (31), - Here, the stabilized hydrogenation catalyst contains less than 10% by mass of Ni, for example, less than 8% by mass of Ni, less than 5% by mass of Ni, or does not contain Ni. - The guard material contains more than 10% by mass of Ni, for example, more than 12% by mass of Ni. The aforementioned method.

2. The aforementioned renewable raw materials are: - Lignocellulose-based biomass, e.g., wood products, algae, grass, forestry waste and / or agricultural residues; - Urban waste, especially its organic components, - Renewable raw materials for nitrogen enrichment, e.g., compost, sewage sludge The method according to claim 1, including the method according to claim 1.

3. The method according to claim 1 or 2, further comprising a pyrolysis step of a renewable feedstock for producing the liquid oil feed, wherein the pyrolysis includes a pyrolysis step and / or a hydrothermal liquefaction step.

4. The method according to claim 1 or 2, wherein the liquid oil supply contains at least 1% by mass of oxygen (O), for example at least 20% by mass of O, for example at least 30% by mass of O, or at least 45% by mass of O.

5. The method according to claim 1 or 2, wherein the method includes operating the stabilized reactor (10) at a temperature of 100 to 230°C and a pressure of 20 to 200 barg.

6. The method includes reacting the liquid oil feed (1) with hydrogen in the stabilizing reactor (10) in the presence of a stabilizing hydrogenation catalyst, The method according to claim 1 or 2, wherein the catalyst comprises at least one metal selected from Ni, Co, Mo, W, Cu, Pt, Pd, Ru, for example, the catalyst comprises nickel-molybdenum-molybdenum (Ni-Mo), cobalt-molybdenum (Co-Mo), nickel-tungsten (NiW), nickel-copper (NiCu), Pt, Pd, or Ru, and provides at least one stabilized liquid oil feed (11).

7. The method according to claim 1 or 2, wherein the stabilizing reactor further comprises a top layer suitable for capturing solid heteroatom products, for example, by having an open structure.

8. The method according to claim 1 or 2, wherein the guard material (20) is arranged in a unit, and the method includes the use of one or more guard material units (20a, b, c).

9. The method according to claim 7, wherein the method includes the use of two or more guard material units (20a, b, c) arranged in parallel.

10. The method according to claim 7, wherein the method includes the use of two or more guard material units (20a, b, c) arranged in series.

11. The method according to claim 1 or 2, wherein at least a portion of the guard material (20) is located upstream of the hydrogenation catalyst in the first catalyst hydrogenation reactor (30).

12. The method includes capturing arsenic within the guard material (20), wherein the guard material (20) is a metal guard floor, for example, Ni / Al ２ O ３ The method according to claim 1 or 2.

13. The method according to claim 1 or 2, wherein the method includes operating the guard material (20) at a temperature exceeding 250°C, for example, 250 to 420°C.

14. The method according to claim 1 or 2, wherein the method comprises capturing one or more further heteroatoms in the guard material (20), the heteroatom(s) being selected from one or more of phosphorus (P), silicon (Si), iron (Fe), nickel (Ni), vanadium (V), halides, or combinations thereof.

15. The method according to claim 1 or 2, wherein the one or more catalytic hydrogenation steps are selected from hydrogenation deoxygenation (HDO), hydrogenation treatment, hydrogenation denitrification (HDN), hydrogenation desulfurization (HDS), aromatic ring saturation (HDA), hydrogenation and / or isomerization.

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