Process for producing liquid organic hydrogen carriers (LOHC)

Abstract

A method of producing a liquid organic hydrogen carrier (LOHC). The method includes delivering a hydrocarbon feed stream rich in aromatic hydrocarbons to a selective hydrogenation reactor configured to selectively saturate olefins without saturating aromatic hydrocarbons to produce a hydrotreated feed stream; delivering the hydrotreated feed stream to a fractionation unit to form a light fraction stream and a heavy fraction stream at a cut point of 218 °C to 250 °C; and delivering the light fraction stream to an aromatic hydrocarbon extraction unit to form an aromatic compound stream. The method further includes delivering the non-aromatic compound stream to a naphthene separator to produce a naphthene stream; delivering the aromatic compound stream, the naphthene stream, and an input hydrogen stream to a hydrogenation unit to form a hydrotreated effluent stream; and delivering the hydrotreated effluent stream to a separator to remove unsaturated compounds, thereby isolating saturated compounds as a LOHC stream.

Description

Cross-references to related applications

[0001] This application claims the benefit of U.S. Patent Application Serial No. 18 / 538,307, filed December 13, 2023, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0002] The embodiments disclosed herein generally relate to methods and systems for transporting hydrogen atoms in the presence of chemical bonds between hydrogen atoms and hydrocarbons, and more specifically, to methods and systems for producing liquid organic hydrogen carriers for transporting hydrogen gas. Background Technology

[0003] Hydrogen is increasingly in demand as an environmentally friendly precursor chemical and fuel. Hydrogen production and utilization technologies are relatively mature. However, hydrogen storage and transportation technologies remain insufficient to meet the needs of the hydrogen energy industry. Typically, hydrogen is stored and transported in the form of compressed gaseous hydrogen molecules (e.g., above 5000 psi). However, these conventional gaseous hydrogen transportation technologies are costly and inefficient. For example, the compression process consumes a significant amount of energy (estimated to be 30% or more of the hydrogen's energy content). Furthermore, the transportation and storage of compressed hydrogen requires expensive pressure vessels. Some hydrogen molecules can even escape through the walls of the hydrogen container. Hydrogen also causes embrittlement of storage and transportation containers. Therefore, storing and transporting hydrogen in its liquid phase offers significant advantages, as it provides a much higher storage capacity than gaseous cylinders.

[0004] Liquid organic hydrogen carriers (LOHCs) are an excellent example of hydrogen storage through hydrogenation and dehydrogenation cycles due to their higher density. Using LOHCs offers several advantages. One advantage is that LOHCs can store hydrogen at high densities, making them easier to transport and use. This is because hydrogen is gaseous under ambient conditions, easily dissipates, and has a low energy density. Another advantage is that LOHCs are expected to be used in a wide range of applications due to their excellent long-term storage performance and stability at room temperature. Several examples of LOHC compounds have been identified as promising and cost-effective candidates, such as methanol, toluene, monobenzyltoluene, and dibenzyltoluene. Summary of the Invention

[0005] The embodiments of this disclosure simultaneously address the growing demand for hydrogen and the challenges of its transportation. Liquid organic hydrogen carriers (LOHCs) enable improved hydrogen storage through hydrogenation and dehydrogenation cycles. Using LOHCs offers several advantages. One advantage is that LOHCs can store hydrogen at high densities, making them easier to transport and use. This is because hydrogen is gaseous under ambient conditions, easily dissipates, and has low energy density, making large-scale transportation challenging. Another advantage is that LOHCs are expected to be used in a wide range of applications due to their excellent long-term storage performance and stability at room temperature. Several examples of LOHC compounds have been identified as promising and cost-effective candidates for hydrogen transportation, such as methanol, toluene, monobenzyltoluene, and dibenzyltoluene. Embodiments of this disclosure provide a method for producing liquid organic hydrogen carriers from existing hydrocarbon streams in refineries. Thus, the surge in existing streams is advantageously utilized to generate LOHCs for the transportation and / or storage of hydrogen.

[0006] According to one or more embodiments of this disclosure, a method for producing liquid organic hydrogen carriers (LOHC) is provided. The method includes: feeding a hydrocarbon feed stream to a selective hydrogenation reactor to generate a hydrotreated feed stream, wherein the hydrocarbon feed stream comprises at least 30% by weight of aromatic hydrocarbons and cycloalkanes, the selective hydrogenation reactor being configured to selectively saturate olefins without saturating aromatic hydrocarbons; feeding the hydrotreated feed stream to a fractionation unit to form a light fraction stream and a heavy fraction stream, wherein the fractionation unit separates the light fraction stream and the heavy fraction stream at a cut point in the range of 218°C to 250°C; and feeding the light fraction stream to an aromatic hydrocarbon extraction unit to form an aromatic compound stream and a non-aromatic compound stream. The method further includes conveying the non-aromatic compound stream to a cycloalkane separator to generate a cycloalkane stream and a non-cycloalkane stream; conveying the aromatic compound stream, the cycloalkane stream, and the input hydrogen stream to a hydrogenation unit to form a hydrotreated effluent stream, wherein the hydrotreated effluent stream contains saturated and unsaturated compounds; and conveying the hydrotreated effluent stream to a separator to remove the unsaturated compounds, thereby separating the saturated compounds as a LOHC stream.

[0007] These and other embodiments are described in more detail in the Detailed Description. It should be understood that the foregoing general description and the following detailed description present embodiments of the technology disclosed herein and are intended to provide an overview or framework for understanding the nature and features of the claimed technology. The included drawings provide a further understanding of the technology disclosed herein and are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments and, together with the description, serve to explain the principles and operation of the technology disclosed herein. Furthermore, the drawings and description are intended to be illustrative only and are not intended to limit the scope of the claims in any way. Attached Figure Description

[0008] The following detailed description of specific embodiments of this disclosure is best understood when read in conjunction with the following drawings, wherein similar structures are indicated by similar reference numerals, and wherein: Figure 1 A system diagram for producing liquid organic hydrogen carriers according to one or more embodiments described in this disclosure is schematically shown; Figure 2 A system diagram schematically illustrating the production of liquid organic hydrogen carriers according to one or more embodiments described in this disclosure is shown; and Figure 3 A system diagram for producing liquid organic hydrogen carriers according to one or more embodiments described in this disclosure is schematically shown.

[0009] For the purpose of illustrating the simplified schematic diagrams in the accompanying drawings, numerous valves, temperature sensors, electronic controllers, etc., that may be used in certain chemical processing operations and are well known to those skilled in the art are not included. Furthermore, typical ancillary components commonly included in typical chemical processing operations, such as air supply systems, catalyst hoppers, and flue gas treatment systems, are not necessarily shown. However, operating components (such as those described in this disclosure) may be added to the embodiments described herein.

[0010] It should also be noted that the arrows in the accompanying drawings represent process streams. However, arrows can equivalently refer to conveyor lines used to transfer process streams between two or more system components. Furthermore, arrows connecting multiple system components define the inlet or outlet in each given system component. The direction of the arrow generally corresponds to the primary direction of movement of the material in the stream contained within the physical conveyor line represented by the arrow. Additionally, arrows not connecting two or more system components indicate product streams leaving the illustrated system or system inlet streams entering the illustrated system. Product streams may be further processed in an associated chemical processing system or may be commercialized as a final product. System inlet streams may be streams transferred from associated chemical processing systems or may be untreated feed streams. Some arrows may represent recirculated streams, which are outflow streams from system components that are recycled back into the system. However, it should be understood that in some embodiments, any represented recirculated stream may be replaced by a system inlet stream of the same material, and a portion of the recirculated stream may leave the system as a system product.

[0011] Furthermore, the arrows in the accompanying drawings may schematically represent process steps for transferring material from one system component to another. For example, an arrow pointing from one system component to another may represent "transferring" the effluent from one system component to another, which may include "draining" or "removing" the contents of the process material from one system component and "introducing" the contents of that product stream into another system component. It should be understood that the arrows in the relevant accompanying drawings do not represent necessary or required steps.

[0012] It should be understood that, according to the embodiments shown in the relevant figures, the arrow between two system components may indicate that the logistics is unprocessed between the two system components. In other embodiments, the logistics represented by the arrow may have substantially the same composition throughout the transport between the two system components. Furthermore, it should be understood that in one or more embodiments, the arrow may indicate that at least 75 wt%, at least 90 wt%, at least 95 wt%, at least 99 wt%, at least 99.9 wt%, or even 100 wt% of the logistics has been transported between the system components. Thus, in some embodiments, less than the total logistics represented by the arrow may be transported between the system components, for example, if side-stream logistics are present.

[0013] It should be understood that when two or more pipelines intersect in the schematic flow diagram of the relevant figures, two or more process streams are "mixed" or "combined". Mixing or combining may also include mixing by directly introducing the two streams into similar reactors, separation units, or other system components. For example, it should be understood that when the two streams are described as being combined directly before entering a separation unit or reactor, in some embodiments, the streams may be equivalently introduced into the separation unit or reactor and mixed in the reactor.

[0014] Reference will now be made in more detail to various embodiments, some of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings to refer to the same or similar parts. Detailed Implementation

[0015] Embodiments of this disclosure relate to methods for producing liquid organic hydrogen carriers (LOHC). Generally, these methods are described herein within the context of one or more systems shown in the accompanying drawings. As discussed herein, the methods utilized in systems for producing LOHC include: feeding a hydrocarbon feed stream to a selective hydrogenation reactor to generate a hydrotreated feed stream; feeding the hydrotreated feed stream to a fractionation unit to form light and heavy fraction streams; feeding the light fraction stream to an aromatics extraction unit to form an aromatic and non-aromatic compound stream; feeding the non-aromatic compound stream to a cycloalkane separator to generate a cycloalkane and non-cycloalkane streams; hydrotreating the aromatic and cycloalkane streams to form a hydrotreated effluent stream; and feeding the hydrotreated effluent stream to a separator to separate the liquid organic hydrogen carrier as the LOHC stream from the remainder of the hydrotreated effluent stream. A further embodiment of the method for producing LOHC includes: feeding a second hydrocarbon stream together with the aromatic and cycloalkane streams to the hydrogenation unit. Further implementations of the method for producing LOHC include: transporting the LOHC stream from a first hydrocarbon processing facility to a second hydrocarbon processing facility, and conveying the LOHC stream to a dehydrogenation unit to form a dehydrogenated hydrocarbon stream and a hydrogen product stream. Figure 1-3 The implementation schemes are similar or identical in many respects, but include differences as described herein. As those skilled in the art will understand, Figure 1-3 The description of the embodiments disclosed herein is generally applicable to embodiments in other figures. For example, the embodiments disclosed herein are applicable to… Figure 1 The concept can be equally applied to Figure 2 Conversely, the same applies, even if this is not explicitly stated in this article.

[0016] As used in this disclosure, "catalyst" means any substance that increases the rate of a particular chemical reaction. The catalysts described in this disclosure can be used to promote a variety of reactions, such as, but not limited to, hydrotreatment and dehydrogenation reactions. As used in this disclosure, a "hydrotreatment catalyst" increases the rate of a hydrotreatment reaction. As used in this disclosure, a "dehydrogenation catalyst" increases the rate of a dehydrogenation reaction. The methods described herein should not necessarily be limited to specific catalytic materials unless explicitly stated otherwise.

[0017] As used in this disclosure, "separation unit" means any separation apparatus or system that at least partially separates one or more chemicals mixed in a process stream from each other. For example, a separation unit may selectively separate different chemicals, phases, or materials of different sizes from each other to form one or more chemical fractions. Examples of separation units include, but are not limited to, distillation columns, flash tanks, separators, centrifuges, cyclone separators, filtration devices, traps, scrubbers, expansion devices, membranes, solvent extraction equipment, etc. It should be understood that the separation processes described in this disclosure may not completely separate all one chemical component from all another chemical component. It should be understood that the separation processes described in this disclosure "at least partially" separate different chemical components from each other, and even if not explicitly stated, separation may include only partial separation.

[0018] As used in this disclosure, "cracking" refers to a chemical reaction in which molecules having carbon-carbon bonds break into more than one molecule by cleaving one or more carbon-carbon bonds; a chemical reaction in which compounds containing cyclic moieties (such as aromatics) are converted into compounds without cyclic moieties; or a chemical reaction in which molecules having carbon-carbon double bonds are reduced to carbon-carbon single bonds. Some catalysts may exhibit multiple forms of catalytic activity, and naming a catalyst by one particular function does not preclude it from being catalytically active for other functions. Generally, "hydrocracking" refers to cracking in the presence of hydrogen.

[0019] As used in this disclosure, "hydrocarbon" refers to a compound composed of hydrogen atoms and carbon atoms.

[0020] Hydrocarbon feedstream 102 may contain a variety of different hydrocarbons. In various embodiments, hydrocarbon feedstream 102 is selected from one or more of fluidized catalytic cracking (FCC) gasoline blending components, delayed coking naphtha, pyrolysis fuel oil, hydrotreated naphtha, reformate, or cracked gasoline. FCC gasoline is a naphtha-range material with an octane number and vapor pressure close to the quality specifications of finished gasoline. Delayed coking naphtha is a naphtha-range product from a coking unit. Hydrotreated naphtha is a naphtha-range material that has been hydrotreated to remove impurities such as sulfur and / or nitrogen. Cracked gasoline (pygas or pyrolysis gasoline line) is a mixture of naphtha-range materials with a high octane number containing aromatic hydrocarbons, olefins, and alkanes in the C5 to C12 range. Cracked gasoline is a byproduct of the high-temperature cracking of naphtha, propane, and / or gas oil during ethylene and propylene production. Therefore, it should be understood that hydrocarbon streams generated as products or effluents of various existing refining processes can be used as hydrocarbon feedstream 102.

[0021] In one or more preferred embodiments, the hydrocarbon feed stream 102 comprises pyrolysis fuel oil. Pyrolysis fuel oil (PFO) is a heavy liquid product generated during the steam cracking of crude oil fractions. The composition of PFO depends on the feedstock and reaction conditions used in the steam cracking process. PFO derived from naphtha and vacuum gas oil has been found to have high aromatic hydrocarbon content, a hydrogen-to-carbon (H / C) molar ratio of less than 1, and contains a large number of compounds with typical asphaltenes and coke solubility characteristics. Furthermore, PFO typically includes bicyclic aromatic hydrocarbons as the dominant chemical family.

[0022] It should be understood that, according to one or more embodiments of this disclosure, an initial substantial presence of aromatic hydrocarbons in the hydrocarbon feed stream 102 is desirable because aromatic compounds are used as liquid organic hydrogen carriers. In various embodiments, the hydrocarbon feed stream 102 may contain at least 30 wt% (wt%) of aromatic and cycloalkanes based on the total weight of the hydrocarbon feed stream 102, such as at least 35 wt%, at least 40 wt%, at least 45 wt%, at least 50 wt%, at least 55 wt%, at least 60 wt%, at least 70 wt%, or at least 5 wt% of aromatic and cycloalkanes.

[0023] In one or more embodiments, the hydrocarbon feed stream 102 contains less than 0.1 wt% sulfur based on the total weight of the hydrocarbon feed stream 102. Elevated sulfur levels can lead to corrosion of equipment and catalyst poisoning in downstream processes. In various further embodiments, the hydrocarbon feed stream 102 contains less than 0.08 wt% sulfur, less than 0.06 wt% sulfur, less than 0.02 wt% sulfur, less than 0.02 wt% sulfur, or less than 0.01 wt% sulfur.

[0024] In one or more embodiments, the hydrocarbon feed stream 102 contains less than 400 ppm of nitrogen by weight, based on the total weight of the hydrocarbon feed stream 102. Elevated nitrogen levels may affect catalyst performance and cause problems during refining. In various further embodiments, the hydrocarbon feed stream 102 contains less than 300 ppm of nitrogen, less than 250 ppm of nitrogen, less than 100 ppm of nitrogen, less than 200 ppm of nitrogen, or less than 50 ppm of nitrogen.

[0025] In one or more embodiments, the hydrocarbon feed stream 102 contains less than 50 ppm of oxygen by weight, based on the total weight of the hydrocarbon feed stream 102. The presence of oxygen in the hydrocarbon feed stream 102 can lead to oxidation, reduce the stability of the hydrocarbon, and cause problems in downstream processes. In various further embodiments, the hydrocarbon feed stream 102 contains less than 40 ppm of oxygen, less than 30 ppm of oxygen, less than 25 ppm of oxygen, less than 20 ppm of oxygen, or less than 10 ppm of oxygen.

[0026] In one or more embodiments, the hydrocarbon feed stream 102 contains less than 0.1 wt% water, less than 0.05 wt% water, or less than 0.02 wt% water.

[0027] In one or more embodiments, the hydrocarbon feed stream 102 contains less than 10 ppm of chlorine, less than 8 ppm of chlorine, less than 6 ppm of chlorine, less than 5 ppm of chlorine, or less than 1 ppm of chlorine.

[0028] Table 1 provides example compositions of hydrocracking heavy naphtha provided as hydrocarbon feed stream 102 according to one or more embodiments of this disclosure. The compositions in Table 1 are exemplary in nature, and it should be understood that one or more embodiments cover hydrocarbon feed streams 102 with higher and / or lower percentages of each component.

[0029] Table 1 - Composition of an exemplary hydrocarbon feed stream

[0030] Hydrocarbon feed stream 102 is supplied to selective hydrotreating reactor 110. Selective hydrotreating reactor 110 is configured to selectively saturate olefins without saturating aromatic hydrocarbons, producing hydrotreating feed stream 112. This selective saturation is achieved because olefins are more easily saturated based on equilibrium at lower hydrogen pressures. Olefin saturation is desirable because this operation prevents or reduces olefin polymerization and gum formation, which can deactivate downstream catalysts or cause problems during storage and transportation.

[0031] In various embodiments, the selective hydrogenation reactor 110 can operate at reaction temperatures ranging from 100°C to 200°C, such as 100°C to 190°C, 100°C to 180°C, 110°C to 200°C, 110°C to 190°C, 110°C to 180°C, 120°C to 200°C, 120°C to 190°C, 120°C to 180°C, or any subset thereof. Unbound by theory, it is believed that higher temperatures may lead to runaway reactions and melt reactor components, thus requiring lower temperatures or less active catalysts to control the reaction rate.

[0032] In various embodiments, the selective hydrogenation reactor 110 can operate at pressures from 1 bar to 100 bar, such as 1 bar to 80 bar, 10 bar to 100 bar, 10 bar to 80 bar, 20 bar to 100 bar, 20 bar to 80 bar, 30 bar to 100 bar, 30 bar to 80 bar, 40 bar to 100 bar, 40 bar to 80 bar, or any subset thereof. Excessive pressure will saturate aromatic hydrocarbons to cycloalkanes. Insufficient pressure will prevent olefin saturation.

[0033] In various implementation schemes, the selective hydrogenation reactor 110 can operate at 40 to 80 bar for 0.5 h. -1 Up to 5 hours -1 Operating at a liquid hourly space velocity (LHSV), for example, 1 h -1 Up to 5 hours -1 2 h -1 Up to 3 hours -1 0.5 h -1 up to 4 hours -1 0.5 h -1 Up to 3 hours -1 0.5 h -1 Up to 2 hours -1 , or any subset thereof.

[0034] In one or more embodiments, the hydrotreating feed stream 112 is fed to a fractionation unit 120. Specifically, in one or more embodiments, the hydrotreating feed stream 112 is fed to the fractionation unit 120 to form a light fraction stream 122 and a heavy fraction stream 124. Fractionation of the hydrotreating feed stream 112 allows selection of components considered most promising LOHC candidates from the hydrotreating feed stream 112. Specifically, substances known as LOHCs can be selected, while substances known not to be LOHCs are removed.

[0035] Fractionation unit 120 may comprise any unit operation or system known to those skilled in the art for separating hydrocarbon streams by vapor pressure. One example of fractionation unit 120 is an atmospheric distillation unit. Atmospheric distillation units utilize fractional distillation to separate feed streams by heating the feed to a temperature at which one or more fractions in the mixture vaporize while other fractions remain liquid. Furthermore, in various embodiments, fractionation unit 120 may be a simple flash distillation column or a true boiling point distillation column with at least 15 theoretical plates.

[0036] In one or more embodiments, fractionating unit 120 separates light distillate stream 122 and heavy distillate stream 124 at cut points in the range of 115°C to 150°C. In various further embodiments, fractionating unit 120 separates light distillate stream 122 and heavy distillate stream 124 at cut points in the ranges of 115°C to 140°C, 115°C to 130°C, 120°C to 150°C, 125°C to 150°C, 120°C to 140°C, or 120°C to 130°C. It should be understood that maintaining the cut point above 115°C ensures that toluene with a boiling point of 110.6°C is retained in light distillate stream 122. Toluene is considered a substance used as an LOHC, which is hydrogenated to produce methylcyclohexane and dehydrogenated back to toluene, thereby storing and releasing hydrogen. A specific cut point of the fractionation unit 120 can be adjusted to modify the composition of the light distillate stream 122, so that it contains desired substances and excludes undesirable substances, which are included in the heavy distillate stream 124.

[0037] In one or more embodiments, the fractionation unit 120 may also generate an ultralight distillate stream (not shown) containing hydrocarbons with boiling points below the desired range for LOHC formation. In one or more embodiments, such ultralight distillates may be recycled as feed back to the selective hydrotreating reactor 110 for further processing. In one or more embodiments, such separation may be achieved via a separate gas-liquid separator (not shown).

[0038] In one or more embodiments, the fractionation unit 120 includes a plurality of separation units. For ease of illustration, the provided... Figure 1-3 A single unit operation is shown, but it should be understood that such unit operations may include multiple independent separator units to generate the disclosed product stream.

[0039] In one or more embodiments, the aromatic hydrocarbon extraction unit 130 separates the light distillate stream 122 into an aromatic compound stream 132 and a non-aromatic compound stream 134. The aromatic compound stream 132 is fed to the hydrogenation unit 140 for hydrogenation treatment and further selection as LOHC. The non-aromatic compound stream 134 is fed to the cycloalkane separator 160 for the separation and recovery of cycloalkane compounds.

[0040] In one or more embodiments, the aromatic hydrocarbon extraction unit 130 may be an extraction separation unit. In the extraction separation unit, liquid-liquid extraction is performed to remove one or more compounds (such as aromatic compounds) from the bulk feedstock into a solvent. Specifically, the aromatic hydrocarbon extraction unit 130 may utilize solvent extraction to separate the aromatic compound stream 132 and the non-aromatic compound stream 134 based on the absorption of one or more components in the solvent. The solvent can then be separated in any suitable separation unit, such as, but not limited to, a series of flash tanks or fractionators / distillation columns based on boiling point separation of the feedstock, to remove the separated compounds. The aromatic hydrocarbon extraction unit 130 may include any suitable separation unit, such as, but not limited to, a series of flash tanks or fractionators / distillation columns based on boiling point separation of the feedstock, or separation based on molecular size using molecular sieves.

[0041] In one or more embodiments, the solvent used in the aromatic hydrocarbon extraction unit 130 comprises an organic molecule having an aldehyde side group. Specifically, the use of organic molecules with aldehyde side groups to separate aromatic hydrocarbons is associated with a particular class of compounds called aldehyde solvents. Examples of aldehyde solvents are aldehyde-amine solvents, particularly those containing aldehyde functional groups such as benzaldehyde. Aldehyde functional groups can form complexes with aromatic compounds, enhancing their solubility in the solvent. The selective interaction between the aldehyde side group and the aromatic compound makes it possible to separate aromatic hydrocarbons from other hydrocarbons. The advantages of these solvents include selectivity, enhanced solubility, and customizability, as the selection of aldehydes can be tailored to the specific characteristics of the hydrocarbon mixture and the desired separation results.

[0042] In one or more embodiments, the weight ratio of the light distillate stream 122 to the solvent in the aromatic hydrocarbon extraction unit 130 is in the range of 0.5 to 10. In a further embodiment, the weight ratio of the light distillate stream 122 to the solvent in the aromatic hydrocarbon extraction unit 130 is in the range of 0.75 to 10, 1.0 to 10, 1.25 to 10, 1.5 to 10, 0.5 to 5, 1.0 to 5, or 1.5 to 5. Excess solvent may lead to increased operating costs, reduced efficiency, and potential difficulties in separating and recovering excess solvent from the extract. Excess solvent may also affect the quality of the final product.

[0043] In one or more embodiments, the aromatic hydrocarbon extraction unit 130 includes multiple separation units. For ease of illustration, the provided... Figure 1-3 A single unit operation is shown, but it should be understood that such unit operations may include multiple independent separator units to generate the disclosed product stream.

[0044] In one or more embodiments, the cycloalkane separator 160 can separate the non-aromatic compound stream 134 into a cycloalkane stream 162 and a non-cycloalkane stream 164. The cycloalkane separator 160 can be any separation unit capable of separating the cycloalkane stream 162 from the non-aromatic compound stream 134. In one or more embodiments, the cycloalkane separator 160 can be an extraction separation unit. As previously described, in an extraction separation unit, liquid-liquid extraction is performed to remove one or more compounds from the bulk feedstock into a solvent. The solvent can then be separated in any suitable separation unit. Furthermore, in one or more embodiments, the cycloalkane separator 160 can include any suitable separation unit, such as, but not limited to, a series of flash tanks or fractionators / distillation columns for separating the feedstock based on boiling point.

[0045] In one or more embodiments, the solvent used in the cycloalkane separator 160 includes polar solvents. Examples of such polar solvents include aliphatic polyamines such as ethylenediamine, diethylenetriamine, triethylenetetramine, phenol, furfural, acetonitrile, sulfolane, dimethyl sulfoxide (DMSO), and N-methylpyrrolidone (NMP), and mixtures thereof.

[0046] In one or more embodiments, the weight ratio of the non-aromatic compound stream 134 to the solvent in the cycloalkane separator 160 is in the range of 0.5 to 10. In further embodiments, the weight ratio of the non-aromatic compound stream 134 to the solvent in the cycloalkane separator 160 is in the range of 0.75 to 10, 1.0 to 10, 1.25 to 10, 1.5 to 10, 0.5 to 5, 1.0 to 5, or 1.5 to 5. Excess solvent may lead to increased operating costs, reduced efficiency, and potential difficulties in separating and recovering excess solvent from the extraction product. Excess solvent may also affect the quality of the final product.

[0047] In one or more embodiments, the noncycloalkane stream 164 may primarily comprise noncycloalkanes (such as straight-chain hydrocarbons), with a small amount of aromatics due to imperfect separation in the aromatic hydrocarbon extraction unit 130. In one or more embodiments, the noncycloalkane stream 164 may contain at least 50% by weight, at least 60% by weight, at least 70% by weight, at least 80% by weight, at least 90% by weight, or at least 95% by weight of noncycloalkane stream 164 based on the total weight of the noncycloalkane stream 164.

[0048] In one or more embodiments, the cycloalkane stream 162 may comprise non-aromatic cyclic hydrocarbons. In some embodiments, the non-aromatic cyclic hydrocarbons in the cycloalkane stream 162 may be saturated cyclic hydrocarbons, such as monocyclic cycloalkanes, including cyclohexane, methylcyclohexane, dimethylcyclohexane, or methylethylcyclohexane. In various embodiments, the cycloalkane stream 162 may comprise at least 50% by weight, at least 60% by weight, at least 70% by weight, at least 80% by weight, at least 90% by weight, or at least 95% by weight of non-aromatic cyclic hydrocarbons based on the total weight of the cycloalkane stream 162.

[0049] In one or more embodiments, the cycloalkane separator 160 includes multiple separation units. For ease of illustration, the provided... Figure 1-3 A single unit operation is shown, but it should be understood that such unit operations may include multiple independent separator units to generate the disclosed product stream.

[0050] According to one or more embodiments, an aromatic compound stream 132, a cycloalkane stream 164, and an input hydrogen stream 144 may be conveyed to a hydrogenation unit 140. The aromatic compound stream 132 and the cycloalkane stream 164 may be combined before being conveyed to the hydrogenation unit 140, or they may be combined within the hydrogenation unit 140. Similarly, the input hydrogen stream 144 may be combined with the aromatic compound stream 132, the cycloalkane stream 164, or both, before being conveyed to the hydrogenation unit 140, or they may be combined within the hydrogenation unit 140.

[0051] The input hydrogen stream 144 may contain hydrogen. In one or more embodiments, the input hydrogen stream 144 may contain at least 80% by weight, at least 90% by weight, at least 95% by weight, at least 99% by weight, or at least 99.9% by weight of hydrogen, based on the total weight of the input hydrogen stream 144.

[0052] Hydrotreating unit 140 can hydrogenate aromatic compound stream 132 and cycloalkane stream 162. Hydrotreating refers to the process of contacting hydrocarbons with a hydrotreating catalyst in the presence of hydrogen, thereby hydrogenating the hydrocarbons. Typically, hydrotreating does not crack hydrocarbons. Instead, hydrotreating can saturate hydrocarbons without reducing their chain length. In addition, hydrotreating can also be used to remove contaminants such as sulfur and metals from hydrocarbons.

[0053] In one or more embodiments, the hydrogenation unit 140 may utilize a hydrotreating catalyst. Any hydrotreating catalyst known to those skilled in the art may be used, depending on the composition of the feed provided to the hydrogenation unit 140, which comprises an aromatic compound stream 132 and a cycloalkane stream 162. In various embodiments, the hydrotreating catalyst may comprise cobalt, molybdenum, tungsten, nickel-tungsten, nickel-cobalt, or nickel-molybdenum supported on an alumina, silica-alumina, or zeolite support.

[0054] In various embodiments, the hydrogenation unit 140 can operate at reaction temperatures from 150°C to 300°C, such as 150°C to 275°C, 150°C to 250°C, 175°C to 300°C, 175°C to 275°C, 175°C to 250°C, 200°C to 300°C, 200°C to 275°C, 200°C to 250°C, or any subset thereof.

[0055] In various implementations, the hydrogenation unit 140 can operate at pressures from 1 bar to 50 bar, such as 1 bar to 40 bar, 1 bar to 35 bar, 5 bar to 50 bar, 5 bar to 35 bar, 10 bar to 50 bar, 10 bar to 35 bar, 15 bar to 50 bar, 15 bar to 35 bar, or any subset thereof.

[0056] In various implementation schemes, the hydrogenation unit 140 can be completed in 0.5 h. -1 Up to 5 hours -1 Operating at a liquid hourly space velocity (LHSV), for example, 1 h -1 Up to 5 hours -1 2 h -1 Up to 3 hours -1 0.5 h -1 up to 4 hours -1 0.5 h -1 Up to 3 hours -1 0.5 h -1 Up to 2 hours -1 , or any subset thereof.

[0057] Hydrotreating unit 140 can be an existing unit operation or reactor in an existing refinery. For example, hydrotreating unit 140 can be configured as a batch reactor, a semi-batch reactor, a continuous fluidized bed reactor, a continuous fixed bed reactor, or a combination thereof. Examples of hydrotreating units 140 that can be utilized in an existing refinery architecture include hydrotreating processors, hydrocrackers, hydrodesulfurization units, ammonia production units (such as Haber-Bosch reactors), and units that produce methanol from syngas and / or CO2. Hydrotreating unit 140 is typically used for processing natural gas, naphtha, full-range naphtha, light naphtha, heavy naphtha, kerosene, jet fuel, distillate fuels, diesel, fuel oil, vacuum gas oil (VGO), gasoline, atmospheric residue and vacuum residue, CO2, nitrogen, or mixtures thereof.

[0058] Still referencing Figure 1Hydrogenation unit 140 produces hydroprocessing effluent 142. Hydroprocessing effluent 142 contains saturated and unsaturated compounds. It should be understood that hydroprocessing effluent 142 also contains unreacted hydrogen. Unreacted hydrogen can be recycled or used as feedstock for any other existing process within the refinery. Unsaturated LOHCs comprise organic molecules having C-C double or triple bonds, and hydrogenation unit 140 saturates such LOHCs, resulting in the addition of hydrogen atoms and the breaking of C-C double and triple bonds. Therefore, the selection of LOHCs can be determined based on the selection of compounds that are successfully hydrogenated and saturated in hydrogenation unit 140. Thus, saturated compounds in hydroprocessing effluent 142 are considered LOHCs sought according to this disclosure.

[0059] The hydrotreated effluent 142 contains the hydrotreated aromatic compound stream 132. Because the hydrogenation of the aromatic compound stream 132 produces saturated compounds that are considered saturated liquid organic hydrogen carriers, the hydrogen-to-carbon ratio of the hydrotreated effluent 142 can be higher than that of the aromatic compound stream 132. For example, the hydrocarbon saturation in the hydrotreated effluent 142 can be higher than that in the aromatic compound stream 132.

[0060] In one or more embodiments, processing the aromatic compound stream 132 in the hydrogenation unit 140 reduces or eliminates the presence of sulfur-containing and nitrogen-containing compounds. The hydrogenation effluent stream 142 may contain less than 1% by weight, for example less than 0.5% by weight, less than 0.1% by weight, less than 0.01% by weight, or even less than 0.001% by weight of the total weight of sulfur and nitrogen.

[0061] As described herein, in some embodiments, the hydrotreating effluent 142 may be fed to a separator 150. The separator 150 may remove unsaturated compounds from the hydrotreating effluent 142, thereby separating saturated compounds as a LOHC stream 152. Unsaturated compounds are removed as a non-LOHC stream 154. The separator 150 may be any separation unit capable of separating the liquid organic hydrogen carrier from the remainder of the hydrotreating effluent 142. The non-LOHC stream 154, containing the unsaturated compounds removed from the hydrotreating effluent 142, may be further processed to recover the unsaturated compounds from the non-LOHC stream 154.

[0062] In one or more embodiments, separator 150 may utilize molecular sieve separation to generate LOHC stream 152 based on the adsorption of unsaturated compounds in the hydrotreated effluent 142 onto a support. In various embodiments, the support for adsorbing the unsaturated compounds in the hydrotreated effluent 142 may include molecular sieves, zeolite catalysts, activated carbon, or amorphous silica. For example, zeolites with mesopores to macropores, such as ZSM-5 with 8-12 membered rings, preferentially adsorb smaller molecules such as olefins while allowing larger saturated hydrocarbons to pass through.

[0063] In one or more embodiments, the adsorption in separator 150 for the removal of unsaturated compounds from hydrotreated effluent 142 is carried out at a temperature of 10°C to 80°C. In various further embodiments, the adsorption in separator 150 for the removal of unsaturated compounds from hydrotreated effluent 142 is carried out at temperatures of 10°C to 80°C, 10°C to 70°C, 10°C to 60°C, 10°C to 50°C, 10°C to 40°C, 20°C to 80°C, 20°C to 60°C, or 20°C to 40°C. The separation is intentionally carried out under mild operating conditions to improve separation and obtain LOHC effluent 152, thereby minimizing the inclusion of substances that would not be LOHC. Specifically, as those skilled in the art will understand, at elevated temperatures, molecular sieves and other supports may release the adsorbed substances, resulting in a decrease in the purity of the effluent. Furthermore, adsorption at high temperatures may lead to decomposition of the adsorbed substances or undesirable reactions.

[0064] In one or more embodiments, separator 150 may be an extraction separation unit. Specifically, separator 150 may utilize solvent extraction to separate saturated and unsaturated compounds in the hydrotreated effluent 142 based on the absorption of one or more components in the solvent. The solvent may then be separated in any suitable separation unit, such as, but not limited to, a series of flash tanks or fractionators / distillation columns based on boiling point separation of the feedstock, to remove the separated compounds.

[0065] In one or more embodiments, the solvent used in separator 150 is selected from those commonly used in refining or petrochemical processes to selectively dissolve unsaturated hydrocarbons such as olefins. For example, liquid propane can be used to selectively dissolve unsaturated hydrocarbons.

[0066] In one or more embodiments, the weight ratio of the hydrotreated effluent 142 to the solvent in separator 150 is in the range of 0.5 to 10. In a further embodiment, the weight ratio of the hydrotreated effluent 142 to the solvent in separation unit 150 is in the range of 0.75 to 10, 1.0 to 10, 1.25 to 10, 1.5 to 10, 1.75 to 10, 2.0 to 10, or 2.5 to 10.

[0067] In one or more embodiments, the separator 150 includes a plurality of separation units. For ease of illustration, the provided... Figure 1-3 A single unit operation is shown, but it should be understood that such unit operations may include multiple independent separator units to generate the disclosed product stream.

[0068] In one or more embodiments, the second hydrocarbon stream 108 may be supplied to the hydrogenation unit 140 together with the aromatic compound stream 132 and the cycloalkane stream 162. (Reference) Figure 2 The diagram illustrates one or more general embodiments of this disclosure, showing a second hydrocarbon stream 108 introduced into the hydrogenation unit 140 as a separate stream from the aromatic compound stream 132 and the cycloalkane stream 162, with any mixing occurring within the hydrogenation unit 140. However, it should be understood that the second hydrocarbon stream 108, the aromatic compound stream 132, and the cycloalkane stream 162 may be combined in any combination prior to introduction into the hydrogenation unit 140.

[0069] The hydrocarbon feed to the hydrogenation unit 140 may contain aromatic compound stream 132 and cycloalkane stream 162 in amounts ranging from 0.1 wt% to 100 wt%, with the remainder comprising a second hydrocarbon stream 108. In various embodiments, the hydrocarbon feed to the hydrogenation unit 140 may comprise 0.1 wt% to 100 wt% of aromatic compound stream 132 and cycloalkane stream 162, 20 wt% to 100 wt% of aromatic compound stream 132 and cycloalkane stream 162, 40 wt% to 100 wt% of aromatic compound stream 132 and cycloalkane stream 162, 60 wt% to 100 wt% of aromatic compound stream 132 and cycloalkane stream 162, 80 wt% to 100 wt% of aromatic compound stream 132 and cycloalkane stream 162, or substantially 100 wt% of aromatic compound stream 132 and cycloalkane stream 162. In one or more embodiments, the second hydrocarbon stream 108 may be a heavy naphtha stream or a rich aromatic hydrocarbon stream.

[0070] In one or more embodiments, the second hydrocarbon stream 108 may be provided together with the hydrotreating feed stream 112 to the fractionation unit 120. (Reference) Figure 3 The diagram illustrates one or more general embodiments of this disclosure, showing the second hydrocarbon stream 108 being combined with the hydrotreating feed stream 112 before being introduced into the fractionation unit 120. However, it should be understood that the second hydrocarbon stream 108 and the hydrotreating feed stream 112 may be provided to the fractionation unit 120 as separate streams.

[0071] The hydrocarbon feed to fractionating unit 120 may contain hydrotreated feed stream 112 at a concentration ranging from 0.1 wt% to 100 wt%, with the remainder comprising a second hydrocarbon stream 108. In various embodiments, the hydrocarbon feed to fractionating unit 120 may comprise 0.1 wt% to 100 wt% hydrotreated feed stream 112, 20 wt% to 100 wt% hydrotreated feed stream 112, 40 wt% to 100 wt% hydrotreated feed stream 112, 60 wt% to 100 wt% hydrotreated feed stream 112, 80 wt% to 100 wt% hydrotreated feed stream 112, or substantially 100 wt% hydrotreated feed stream 112. In one or more embodiments, the second hydrocarbon stream 108 may be a heavy naphtha stream or an aromatic hydrocarbon-rich stream.

[0072] When provided as a second hydrocarbon stream 106, the heavy naphtha stream may refer to a hydrocarbon fraction, such as a crude oil fraction. The initial boiling point (IBP) of the heavy naphtha stream may be from 80°C to 100°C, for example, 80°C to 95°C, 85°C to 100°C, 88°C to 100°C, 80°C to 92°C, or 88°C to 92°C. The final boiling point (FBP) of the heavy naphtha stream may be from 180°C to 220°C, for example, 180°C to 215°C, 180°C to 210°C, 180°C to 205°C, 185°C to 220°C, 190°C to 220°C, 195°C to 220°C, 185°C to 215°C, 190°C to 210°C, 195°C to 205°C, or any subset thereof. The heavy naphtha stream may contain hydrocarbons or be composed of hydrocarbons.

[0073] When provided as a second hydrocarbon stream 108, the aromatic hydrocarbon stream may contain at least 50% by weight of an aromatic compound based on the total weight of the aromatic hydrocarbon stream, such as at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, at least 99%, or even at least 99.9% by weight of an aromatic compound. In one or more embodiments, the aromatic hydrocarbon stream may contain at least 50% by weight of a C9+ aromatic compound (an aromatic compound having at least 9 carbon atoms). Suitable C9+ aromatic compounds may include, but are not limited to, benzyltoluene, dibenzyltoluene, methylindole, phenazine, and ethylcarbazole. Furthermore, in one or more embodiments, suitable C9+ aromatic compounds include any bicyclic or polycyclic aromatic hydrocarbons. In various implementations, the aromatic hydrocarbon stream may contain at least 50% by weight, for example at least 60% by weight, at least 70% by weight, at least 80% by weight, at least 90% by weight, at least 95% by weight, at least 99% by weight, or even at least 99.9% by weight of C9+ aromatic compounds based on the total weight of the aromatic hydrocarbon stream.

[0074] Now for reference Figure 1-3Each of these systems, wherein system 10 for producing liquid organic hydrogen carriers may include at least a first hydrocarbon processing facility 100 and a second hydrocarbon processing facility 200, wherein the first hydrocarbon processing facility 100 and the second hydrocarbon processing facility 200 are located in different geographical locations, as described herein. Typically, a single hydrocarbon processing facility, such as the first hydrocarbon processing facility 100 and the second hydrocarbon processing facility 200, is a processing facility that is only locally integrated with other processing facilities, and generally refers to an integrated complex capable of converting its respective hydrocarbon feedstock into its respective product. For example, a single hydrocarbon processing facility may be under the control of a single entity, such as a single control room or manager. In one or more embodiments, the first hydrocarbon processing facility 100 and the second hydrocarbon processing facility 200 may each be an independent refinery. For example, the first hydrocarbon processing facility 100 and the second hydrocarbon processing facility 200 may be refineries in different geographical regions. A geographical region may refer to a portion of the Earth's surface defined by physical features (such as a hemisphere, continent or part thereof, climate, altitude, proximity to mountains or bodies of water) or socio-political features (such as a dominant language, nation-state, province, or city). The first hydrocarbon processing facility 100 and the second hydrocarbon processing facility 200 may be separated from each other, and their distance or other obstacles may make it challenging or impractical to transport products between the first hydrocarbon processing facility 100 and the second hydrocarbon processing facility 200 under normal circumstances. For example, the first hydrocarbon processing facility 100 and the second hydrocarbon processing facility 200 may be at least 1 km apart, such as at least 100 km, at least 200 km, at least 500 km, or at least 1000 km. In one or more embodiments, the first hydrocarbon processing facility 100 and the second hydrocarbon processing facility 200 may be located at different latitudes or in different time zones.

[0075] It should be understood that the distance or other obstacles between the first hydrocarbon processing facility 100 and the second hydrocarbon processing facility 200, which may be considered challenging or impractical under normal circumstances, may depend on the specific substance to be transported. For example, the physical distance between the first hydrocarbon processing facility 100 and the second hydrocarbon processing facility 200 may make the routine transport of hydrogen between them difficult. Using this method and system, the transport of hydrogen between the first hydrocarbon processing facility 100 and the second hydrocarbon processing facility 200 can be made cheaper and more efficient, thereby enabling operators to utilize cheaper and / or renewable power sources available near the first hydrocarbon processing facility 100. In some embodiments, the first hydrocarbon processing facility 100 and the second hydrocarbon processing facility 200 may be located at different latitudes, which can allow operators to take advantage of variations in energy production, such as the increased power output of a given solar panel when placed closer to the equator.

[0076] like Figure 1-3As shown, the first hydrocarbon processing facility 100 may include a heat treatment unit 110, a fractionation unit 120, an aromatic hydrocarbon extraction unit 130, a cycloalkane separator 160, at least one hydrogenation unit 140, and a separator 150 (if present). Furthermore, the second hydrocarbon processing facility 200 may include a dehydrogenation unit 210.

[0077] In one or more embodiments, and with reference to Figure 1-3 LOHC stream 152 or a portion thereof may be transported from the first hydrocarbon processing facility 100 to the second hydrocarbon processing facility 200. Transport may refer to the process of physically moving hydrocarbons from the first hydrocarbon processing facility 100 to the second hydrocarbon processing facility 200, the process of preparing hydrocarbons for physical movement from the first hydrocarbon processing facility 100 to the second hydrocarbon processing facility 200, and the storage of hydrocarbons before, during, or after the physical movement. In the case of transporting hydrogen, hydrogen may be transported in the form of hydrogen atoms covalently bonded to hydrocarbon molecules. In one or more embodiments, transporting LOHC stream 152 or a portion thereof may include transporting LOHC stream 152 or a portion thereof from the first hydrocarbon processing facility 100 to the second hydrocarbon processing facility 200 by tanker, train, ship, and / or pipeline. In one or more embodiments, hydrocarbons may be transported from the first hydrocarbon processing facility 100 to the second hydrocarbon processing facility 200 by tanker, train, and / or ship. The time between the hydrogenation of aromatic compound stream 132 and the dehydrogenation of LOHC stream 152 may be at least 2 weeks, for example at least 1 month, at least 2 months, or at least 6 months. The transport steps may include storing hydrocarbons in a first hydrocarbon processing facility 100, a second hydrocarbon processing facility 200, an intermediate storage or processing facility, or in the transport container itself. The time difference between the hydrotreating and dehydrogenation steps allows operators to store intermittent electricity in the form of hydrogen for use during periods of high demand, such as storing summer solar power for winter use.

[0078] Still referencing Figure 1-3LOHC stream 152 or a portion thereof may be fed to dehydrogenation unit 210 to form hydrogen product stream 212 and dehydrogenated LOHC stream 214. Dehydrogenation unit 210 may be any refining process unit capable of removing hydrogen atoms from hydrocarbon molecules to form hydrogen. Refining process units suitable for use as dehydrogenation unit 210 include, for example, steam crackers, catalytic reformers, aromatization units, etc. For example, dehydrogenation unit 210 may be any single, independent dehydrogenation unit, such as a propane-to-propylene unit. In the case where dehydrogenation unit 210 is a catalytic reformer that contacts hydrocarbons with a catalyst, the catalyst may comprise iron (iron oxide (III)), potassium oxide, potassium chloride, a noble metal (Pt or Re) supported on a silica or silica-alumina matrix, or a combination thereof. The catalytic reformer can operate at reaction temperatures ranging from 50°C to 700°C, such as 100°C to 700°C, 200°C to 700°C, 300°C to 700°C, 400°C to 700°C, 50°C to 600°C, 200°C to 600°C, 300°C to 600°C, 400°C to 600°C, or any subset thereof; reaction pressures ranging from 1 bar to 50 bar, such as 1 bar to 30 bar, 1 bar to 20 bar, 1 bar to 10 bar, 5 bar to 50 bar, 10 bar to 50 bar, 20 bar to 50 bar, 30 bar to 50 bar, or any subset thereof; and a liquid hourly space velocity (LHSV) of 0.5 h⁻¹. -1 Up to 5 hours -1 For example, 0.5 h -1 up to 4 hours -1 0.5 h -1 Up to 3 hours -1 0.5 h -1 Up to 2 hours -1 0.5 h -1 up to 1 hour -1 1 h -1 Up to 5 hours -1 2h -1 Up to 5 hours -1 3 h -1 Up to 5 hours -1 4 h -1 Up to 5 hours -1 , or any subset thereof.

[0079] In one or more embodiments, dehydrogenated LOHC stream 214 may contain hydrocarbons and have a lower hydrogen-to-carbon ratio than LOHC stream 152. For example, dehydrogenated LOHC stream 214 may have a lower degree of saturation than LOHC stream 152.

[0080] In one or more embodiments, hydrogen product stream 212 may contain hydrogen, for example, at least 80% by weight, at least 90% by weight, at least 99% by weight, at least 99.9% by weight, at least 99.99% by weight, or 99.999% by weight, based on the total weight of hydrogen product stream 212. Hydrogen product stream 212 may contain less than 500 ppm (by weight), less than 250 ppm, less than 100 ppm, less than 50 ppm, less than 20 ppm, or less than 10 ppm, less than 5 ppm, less than 2.5 ppm, or less than 1 ppm of sulfur and carbon monoxide, respectively. A practical and growing application of hydrogen is in fuel cells. Typically, cryogenic fuel cells use precious metal catalysts, which are susceptible to poisoning by sulfur and CO in their hydrogen fuel. Therefore, it is desirable for hydrogen product stream 212 to contain relatively low amounts of sulfur and CO.

[0081] It should now be understood that various aspects of the methods and related systems for producing liquid organic hydrogen carriers (LOHC) have been described, and these aspects can be used in combination with various other aspects.

[0082] According to a first aspect, a method for producing liquid organic hydrogen carriers (LOHC) includes: conveying a hydrocarbon feed stream to a selective hydrogenation reactor to generate a hydrotreated feed stream, wherein the hydrocarbon feed stream comprises at least 30% by weight of aromatic hydrocarbons and cycloalkanes, the selective hydrogenation reactor being configured to selectively saturate olefins without saturating aromatic hydrocarbons; and conveying the hydrotreated feed stream to a fractionation unit to form a light fraction stream and a heavy fraction stream, wherein the fractionation unit separates the light fraction stream and the heavy fraction stream at a cut point in the range of 218°C to 250°C. The light distillate stream is fed to an aromatic hydrocarbon extraction unit to form an aromatic compound stream and a non-aromatic compound stream; the non-aromatic compound stream is fed to a cycloalkane separator to generate a cycloalkane stream and a non-cycloalkane stream; the aromatic compound stream, the cycloalkane stream, and the input hydrogen stream are fed to a hydrogenation unit to form a hydrogenation effluent stream, wherein the hydrogenation effluent stream contains saturated and unsaturated compounds; and the hydrogenation effluent stream is fed to a separator to remove the unsaturated compounds, thereby separating the saturated compounds as a LOHC stream.

[0083] The second aspect includes the method of the first aspect, wherein the hydrocarbon feed stream comprises pyrolytic fuel oil.

[0084] The third aspect includes the method of the first or second aspect, wherein the selective hydrogenation reactor operates at an operating temperature of 100°C to 200°C and a pressure of 1 bar to 100 bar.

[0085] The fourth aspect includes a method of any one of the first to third aspects, wherein the aromatic hydrocarbon extraction unit utilizes solvent extraction to separate the aromatic compound stream and the non-aromatic compound stream based on the absorption of one or more components in the solvent.

[0086] The fifth aspect includes the method of the fourth aspect, wherein the solvent used in the aromatic hydrocarbon extraction unit comprises an organic molecule having an aldehyde side group.

[0087] The sixth aspect includes the method of the fourth or fifth aspect, wherein the weight ratio of the light distillate stream to the solvent in the aromatic hydrocarbon extraction unit is in the range of 1.5 to 10.

[0088] The seventh aspect includes a method of any one of the first to sixth aspects, wherein the cycloalkane separator utilizes solvent extraction to separate the cycloalkane stream and the non-cycloalkane stream based on the absorption of one or more components in the solvent.

[0089] The eighth aspect includes the method of the seventh aspect, wherein the solvent used in the cycloalkane separator includes a polar solvent.

[0090] The ninth aspect includes the method of any one of the first to eighth aspects, wherein the hydrogenation unit operates under reaction conditions of 150°C to 300°C and a pressure of 1 bar to 50 bar.

[0091] The tenth aspect includes the method of any one of the first to ninth aspects, wherein the hydrogenation unit includes a hydrogenation treatment catalyst comprising cobalt, molybdenum or tungsten supported on an alumina support.

[0092] The eleventh aspect includes the method of any one of the first to tenth aspects, wherein the separator utilizes molecular sieve separation to generate the LOHC stream based on the adsorption of unsaturated compounds in the hydrogenation effluent on a support.

[0093] The twelfth aspect includes the method of the eleventh aspect, wherein adsorption is carried out at a temperature of 10°C to 80°C.

[0094] The thirteenth aspect includes a method of any one of the first to tenth aspects, wherein the separator utilizes solvent extraction to generate the LOHC stream based on the absorption of unsaturated compounds in the hydrotreated effluent stream by the solvent.

[0095] The fourteenth aspect includes a method of any one of the first to thirteenth aspects, wherein the method further includes conveying a second hydrocarbon stream together with the aromatic compound stream and the cycloalkane stream to the hydrogenation unit.

[0096] The fifteenth aspect includes the method of the fourteenth aspect, wherein the second hydrocarbon stream comprises a rich aromatic hydrocarbon stream.

[0097] The sixteenth aspect includes a method of any one of the first to fifteenth aspects, wherein the method further includes: transporting the LOHC stream from a first hydrocarbon processing facility to a second hydrocarbon processing facility; and conveying the LOHC stream to a dehydrogenation unit to form a dehydrogenated hydrocarbon stream and a hydrogen product stream, wherein the first hydrocarbon processing facility and the second hydrocarbon processing facility are at least 1 km apart.

[0098] The seventeenth aspect includes the method of the sixteenth aspect, wherein the dehydrogenation unit is a catalytic reformer.

[0099] The eighteenth aspect includes the method of any one of the first to seventeenth aspects, wherein the hydrocarbon feed stream contains less than 0.1% by weight of sulfur.

[0100] The nineteenth aspect includes the method of any one of the first to eighteenth aspects, wherein the hydrocarbon feed stream contains less than 400 ppm of nitrogen by weight.

[0101] The twentieth aspect includes the method of any one of the first to nineteenth aspects, wherein the hydrocarbon feed stream contains less than 50 ppm by weight of oxygen.

[0102] For the purpose of describing and defining this disclosure, it should be noted that the terms “about” or “approximately” are used in this disclosure to indicate the degree of uncertainty that may be attributable to any quantitative comparison, numerical value, measurement, or other expression. The terms “about” and / or “approximately” are also used in this disclosure to indicate the extent to which a quantitative expression may deviate from the reference without altering the essential function of the subject matter.

[0103] Ranges are provided throughout this disclosure. It is contemplated that each discrete value covered by these ranges will also be included. Furthermore, it is also contemplated that ranges may be formed by each discrete value covered by the explicitly disclosed ranges. For the sake of brevity, this is not explicitly stated after each disclosed range, but rather this general description is provided herein.

[0104] It should be noted that one or more of the following claims use the term "wherein" as a transitional phrase. To define this technology, it should be noted that this term is introduced in the claims as an open-ended transitional phrase to introduce a statement of a series of structural features, and should be interpreted in a similar manner to the more commonly used open-ended prepositional phrase "comprising."

[0105] Any quantitative value expressed in this application may be regarded as including open-ended embodiments consistent with the transitional phrases “comprising” or “including”, and closed or partially closed embodiments consistent with the transitional phrases “consisting of” and “substantially consisting of”.

[0106] It should also be noted that statements in this article regarding “at least one” components, elements, etc., should not be used to infer that the alternative use of the article “a or an” should be limited to a single component, element, etc.

Claims

1. A method for producing liquid organic hydrogen carrier (LOHC), the method comprising: The hydrocarbon feed stream is fed to a selective hydrotreating reactor to generate a hydrotreating feed stream, wherein: The hydrocarbon feed stream contains at least 30% by weight of aromatic hydrocarbons and cycloalkanes; and The selective hydrogenation reactor is configured to selectively saturate olefins without saturating aromatic hydrocarbons. The hydrotreating feed stream is conveyed to the fractionation unit to form a light distillate stream and a heavy distillate stream, wherein: The fractionation unit separates the light distillate stream and the heavy distillate stream at a cutting point in the range of 218°C to 250°C. The light distillate stream is transported to the aromatic hydrocarbon extraction unit to form an aromatic compound stream and a non-aromatic compound stream; The non-aromatic compound stream is fed to a cycloalkane separator to generate cycloalkane and non-cycloalkane streams; The aromatic compound stream, the cycloalkane stream, and the input hydrogen stream are fed to the hydrogenation unit to form a hydrogenation treatment effluent stream, wherein: The hydrotreated effluent contains saturated and unsaturated compounds; and The hydrotreated effluent is fed to a separator to remove the unsaturated compounds, thereby separating the saturated compounds as the LOHC stream.

2. The method according to claim 1, wherein the hydrocarbon feed stream comprises pyrolytic fuel oil.

3. The method according to claim 1 or 2, wherein the selective hydrogenation reactor operates at an operating temperature of 100°C to 200°C and a pressure of 1 bar to 100 bar.

4. The method according to any one of claims 1 to 3, wherein the aromatic hydrocarbon extraction unit utilizes solvent extraction to separate the aromatic compound stream and the non-aromatic compound stream based on the absorption of one or more components in the solvent.

5. The method of claim 4, wherein the solvent used in the aromatic hydrocarbon extraction unit comprises an organic molecule having an aldehyde side group.

6. The method according to claim 4 or 5, wherein the weight ratio of the light distillate stream to the solvent in the aromatic hydrocarbon extraction unit is in the range of 1.5 to 10.

7. The method according to any one of claims 1 to 6, wherein the cycloalkane separator utilizes solvent extraction to separate the cycloalkane stream and the non-cycloalkane stream based on the absorption of one or more components in the solvent.

8. The method of claim 7, wherein the solvent used in the cycloalkane separator comprises a polar solvent.

9. The method according to any one of claims 1 to 8, wherein the hydrogenation unit is operated under reaction conditions of 150°C to 300°C and a pressure of 1 bar to 50 bar.

10. The method according to any one of claims 1 to 9, wherein the hydrogenation unit comprises a hydrogenation treatment catalyst, the hydrogenation treatment catalyst comprising cobalt, molybdenum or tungsten supported on an alumina support.

11. The method according to any one of claims 1 to 10, wherein the separator utilizes molecular sieve separation to generate the LOHC stream based on the adsorption of unsaturated compounds in the hydrotreated effluent on a support.

12. The method according to claim 11, wherein the adsorption is carried out at a temperature of 10°C to 80°C.

13. The method according to any one of claims 1 to 10, wherein the separator utilizes solvent extraction to generate the LOHC stream based on the absorption of unsaturated compounds in the hydrotreated effluent stream by the solvent.

14. The method according to any one of claims 1 to 13, further comprising conveying the second hydrocarbon stream together with the aromatic compound stream and the cycloalkane stream to the hydrogenation unit.

15. The method according to any one of claims 1 to 14, further comprising: The LOHC stream is transported from the first hydrocarbon processing facility to the second hydrocarbon processing facility; as well as The LOHC stream is transported to a dehydrogenation unit to form a dehydrogenated hydrocarbon stream and a hydrogen product stream, wherein the first hydrocarbon processing facility and the second hydrocarbon processing facility are at least 1 km apart.

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