Organic Chloride Removal Process

This application claims priority to U.S. Provisional Patent Application Ser. No. 63/643,160, filed on May 6, 2024, the entirety of which is incorporated herein by reference.

Pyrolysis oils derived from the thermal treatment of materials such as plastics, tires, and the like, may be converted into fuels and chemical intermediates including sustainable aviation fuel, sustainable diesel, and steam cracker feeds to produce olefins.

Pyrolysis oils may be fed to conventional petroleum-based hydroprocessing units before final placement as a fuel or a chemical intermediate. However, pyrolysis oils may contain significant concentrations of olefins, di-olefins, oxygenates, chlorides and metals that are catalytically and physically problematic for processing units, such as hydroprocessing units. For example, olefins, as measured by Bromine Number, increase hydrogen consumption, which increases the catalyst temperature rise potentially reducing the catalytic temperature cycle and catalyst cycle length. Di-olefins, as measured by diene value, increase the gumming potential of the feed and potentially can polymerize, increasing the pressure drop in equipment and catalyst beds. Oxygenates increase hydrogen consumption as well as increasing the catalyst temperature rise, potentially reducing the catalytic temperature cycle and catalyst cycle length.

Chlorides in the feed create corrosive hydrogen chloride, which is detrimental to the metallurgy in a hydroprocessing unit reactor circuit. For example, the total chloride in the feed to a hydroprocessing unit is generally limited to less than 5 ppmw, and more preferably less than 1 ppmw, based on the typical metallurgy used in hydroprocessing units.

The desired proportion of pyrolysis oil in a petroleum-based feed can be up to 10 to 20%. In this example, the pyrolysis oil will increase the feed blend chloride concentration by 40-60 ppmw. The chloride in pyrolysis oil, for example, from the thermal pyrolysis of poly-vinyl chloride plastic, is typically organically-bound. The organic chloride cannot be removed using an aqueous washing step, such as in a desalter operation, and economically efficient organic chloride adsorbents are not available.

The metals in pyrolysis oil can be present in concentrations up to 200 ppmw or more. The metals may be present in significant concentration as both organometallic and inorganic components. However, it is not practical to process the metals directly in the hydroprocessing unit or other processing units because the volume of filtration media required to remove the metals for the desired catalyst cycle length would displace a disproportionate amount of active catalyst. Both inorganic and Organometallic based components will significantly and permanently deactivate active hydroprocessing catalysts more rapidly, which decreases the catalyst cycle length and decreases on-stream efficiency. Inorganic metallic components in particular can rapidly foul catalyst beds and create a significant increase in pressure drop.

Attempts have been made to solve these problems. Proposed solutions include modifying the existing high-pressure unit in the reactor circuit with extensive metallurgical upgrades, adding an additional reactor and associated equipment for diene saturation, adding a significant volume of filtration media in the high-pressure reactor, and adding additional recycle gas compressor capacity to increase quench capacity to manage additional temperature rise and the like associated with co-processing the as-received pyrolysis oil. However, these solutions involve major changes to the existing high-pressure hydroprocessing unit, which may include expensive metallurgical upgrades.

Therefore, there is a need for a process which removes the undesirable components in pyrolysis oil efficiently and without requiring extensive upgrading to the metallurgy or expensive process changes.

The invention reduces and/or potentially avoids extensive metallurgical upgrades and major changes in the high-pressure hydroprocessing unit or other processing units. Loss of processing time is mitigated by avoiding extensive process modifications. Significantly higher catalyst temperature rise and hydrogen consumption are averted in an existing hydroprocessing unit, both of which reduce the catalyst cycle length and petroleum-based oil feed capacity. As a result, the invention improves the economics of processing organic chloride laden oils, such as pyrolysis oils, vegetable oils and fats.

Pyrolysis oil is the product of long chain polymers that undergo the process of pyrolysis. Pyrolysis is the reduction of the average molecular weight of long chain polymers utilizing heat and time in the absence of oxygen into lower carbon number molecules. Such long chain polymers can include polyolefins such as polyethylene, polypropylene, polyvinyl chloride (PVC), polystyrene, and the like. Other sources subject to pyrolysis are synthetic and/or natural rubber found in tires, and the like, or combinations thereof. The invention does not pertain to pyrolysis oils from the “fast” pyrolysis of lignocellulosic sources.

Vegetable oils and fats refer to triglycerides and free fatty acids from animal and plant sources.

The process is a pre-treatment process for processing units in situations where the feed to the processing unit should not contain high level of organic chlorides due to catalyst deactivation, incurring shorter catalyst cycles, or requiring extensive or capitally intensive processing unit modifications. The pre-treatment processing reduces the level of organic chloride so the catalyst is not deactivated as quickly and/or more extensive metallurgical upgrading is not required.

The processing unit could be any suitable processing unit. Suitable processing units include, but are not limited to, hydroprocessing units such as hydrotreating units and hydrocracking units, fluid catalytic cracking units, steam cracking units, and the like.

One aspect of the invention is a pre-treatment process for removing an organic chloride from an oil feed stream comprising pyrolysis oil, vegetable oils, fats, or combinations thereof and the organic chloride. In one embodiment, the pre-treatment process comprises combining the feed stream with a first hydrogen stream to form a combined feed stream. The combined feed stream is passed through a catalytic hydrodechlorination reaction zone comprising a catalytic hydrodechlorination reactor containing a hydrodechlorination catalyst. The catalytic hydrodechlorination reaction zone may comprise one or more catalytic hydrodechlorination reactors. In addition to hydrodechlorination reactions, olefins and di-olefins may be saturated, oxygenates may be converted to water, organic nitrogen compounds may be converted to form ammonia, organic sulfur components may be reacted to form hydrogen sulfide, aromatics may be saturated, and organometallic compounds may be converted to deposit metals onto a hydrodechlorination catalyst.

The effluent from the catalytic hydrodechlorination reaction zone comprises dechlorinated pyrolysis oil, or vegetable oil, or fat, or combinations thereof and a gas phase comprising HCl. A caustic solution is introduced to the effluent to form a mixture comprising the dechlorinated pyrolysis oil, or vegetable oil, or fat, or combinations thereof and a solution comprising a chloride salt.

The mixture is separated in a cold separator, typically at a temperature of less than 200° F., and desirably less than 150° F., into a spent caustic stream comprising the chloride salt solution, a gas stream comprising hydrogen and HCl, and a dechlorinated oil stream comprising the dechlorinated pyrolysis oil, or vegetable oil, or fat, or combinations thereof having less than 10 ppmw organic chloride. In some embodiments, the organic chloride level is less than 5 ppmw, or less than 2.5 ppmw, or less than 1 ppmw, or less than 0.8 ppmw, or less than 0.75 ppmw, or less than 0.6 ppmw, or less than 0.5 ppmw, or less than 0.4 ppmw, or less than 0.3 ppmw, or less than 0.2 ppmw, or less than 0.1 ppmw.

The dechlorinated oil stream is passed to a processing unit. In some embodiments, the only oil stream processed in the processing unit is the dechlorinated oil stream. In other embodiments, a mineral oil feed stream is also passed to the processing unit. Mineral oil commonly refers to petroleum or crude oil based oil streams and the two references can be used interchangeably. When mineral oil is coprocessed with the dechlorinated oil stream, the amount of the dechlorinated oil stream can be up to 99% or more of the total oil stream (i.e., mineral oil and dechlorinated oil stream), or 95% or more, or 90% or more, or 80% or more, or 70% or more, or 60% or more, or 50% or more, or 40% or more, or 30% or more, or 25% or more, or 20% or more, or 15% or more, or 10% or more, but is typically in the range of 10-20%. Any suitable processing unit can be used with the pretreatment process. Suitable processing units include, but are not limited to, hydroprocessing units, such as hydrotreating units and hydrocracking units, fluid catalytic cracking units, steam cracking units, and the like.

In some embodiments, the pre-treatment process further comprises filtering the feed stream to remove particulate matter before combining the feed stream with the first hydrogen stream. In one embodiment, plastics contain components that change the rigidity or flexibility of the plastic. Such components can comprise of metals, such as alkali, alkaline earth, silicon, and other metals that become metal-containing particulates in the pyrolysis oil after the pyrolysis process. In another embodiment, corrosion-based particulate matter can be carried in the pyrolysis oil from upstream piping and storage tanks transporting or storing the pyrolysis oil. In another embodiment, performance additives can be carried into the pyrolysis of tires or the like. The filtering system may be designed with a variety of filtering medium, fiber cloth, sintered metals with a plurality of filters with varying pore sizes. Parallel units or lead/lag design allows for on-line change out to extend run cycle. Other possible practices include using precoating on filter medium to increase filtering depth, applying gas or liquid back flush to establish a semi-continuous filtering cycles, or using porous solid sorbents beds as filtering medium.

In some embodiments, the process further comprises heating the combined feed stream to a temperature in a range of 285° C. to 375° C. before passing the combined feed stream to the catalytic hydrodechlorination reaction zone. The combined feed stream can be heated using any suitable method. Suitable methods include, but are not limited to, electric heaters, fired heaters, hot oil systems, heat exchange with process streams, such as the effluent from the catalytic hydrodechlorination reaction zone, or combinations thereof. The heat of reaction from the aforementioned reactions occurring across the dehydrochlorination reactor can increase the reactor effluent temperature over the reactor inlet temperature by 25 to 100° C. However, the preferred increase in temperature is less than 60° C. In one embodiment, the increase in reactor temperature is limited by providing recycle liquid flow from the cold separator to the feed surge drum, which is mixed with the organic-chloride laden oil.

The catalytic hydrodechlorination reaction zone is typically operated at a pressure in the range of 2.75 MPa to 4.5 MPa (400-650 psig).

In some embodiments, the process further comprises saturating dienes in the combined feed stream before passing the combined feed stream through the catalytic hydrodechlorination reaction zone. The diene saturation reaction typically takes place at temperatures less than 230° C.

In some embodiments. the process further comprises cooling the mixture before separating the mixture. The mixture is typically cooled to temperature of less than 93° C. (200° F.), and desirably less than 65° C. (150° F.).

The pre-treatment process can be integrated with the make-up hydrogen gas system for the processing unit. In some embodiments, it can be a once-through hydrogen make-up gas system.

Any suitable stream comprising hydrogen can be used. Suitable hydrogen streams include, but are not limited to, hydrogen containing streams from pressure swing adsorption units, reforming units, steam reforming units, blue hydrogen (hydrogen produced from the hydrogen forming process, such as steam reforming, with subsequent CO2 sequestration), green hydrogen (electrolytically produced hydrogen using renewable power sources), cold flash gas from hydroprocessing units, fluid catalytic cracking units dry gas, steam cracking units for the production of olefins, and the like.

In some embodiments, the process further comprises compressing a hydrogen feed stream to form a compressed hydrogen stream; and dividing the compressed hydrogen stream into the first hydrogen stream and a second hydrogen stream. The pressure of the hydrogen feed stream is typically in the range of 1.35 MPa to 2.1 MPa (200-300 psig). The compressed hydrogen stream is generally in the range of 3.0 MPa to 4.5 MPa (440-660 psig).

In some embodiments, the second hydrogen stream can be compressed, and the compressed second hydrogen stream is introduced into the processing unit through a hydrogen inlet. For example, there can be 1-3 additional compression stages be used, depending on the downstream pressure required. In other embodiments, the second hydrogen stream can be used without any additional compression.

In some embodiments, the process further comprises passing the gas stream from the cold separator through a bed comprising an HCl adsorbent to form a dechlorinated hydrogen stream. The pressure of the dechlorinated hydrogen stream is generally in the range of 1.6 MPa to 3.8 MPa (240-560 psig).

In some embodiments, the dechlorinated hydrogen stream can be combined with the second hydrogen stream. Alternatively, the dechlorinated hydrogen stream can be combined with the hydrogen feed stream. It some embodiments, part of the dechlorinated hydrogen stream is combined with the second hydrogen stream, and another part is combined with the hydrogen feed stream.

In some embodiments, the hydrogen stream is divided into three streams, and the third hydrogen stream is combined with the hydrogen feed stream.

In some embodiments, a portion of the dechlorinated oil stream is combined with the oil feed stream or the filtered oil feed stream as a diluent to manage fouling and the exotherm in the hydrodechlorination reactor.

Another aspect of the invention is an apparatus for removing an organic chloride from an oil feed stream comprising pyrolysis oil, or vegetable oil, or fat, or combinations thereof and the organic chloride. In one embodiment, the apparatus comprises an oil feed tank comprising an inlet and an outlet. There is a first hydrogen compressor comprising an inlet and an outlet, the first hydrogen compressor inlet in downstream fluid communication with a source of hydrogen. The apparatus comprises a catalytic hydrodechlorination reaction zone comprising a catalytic hydrodechlorination reactor containing a catalytic hydrodechlorination catalyst, the catalytic hydrodechlorination reaction zone having an inlet and an outlet, the inlet of the catalytic hydrodechlorination reaction zone being in downstream fluid communication with the oil feed tank outlet and the first hydrogen compressor outlet. The apparatus comprises a cold separator having an inlet, a gas stream outlet, an oil outlet, and a spent caustic outlet, the cold separator inlet being in downstream fluid communication with the catalytic hydrodechlorination reaction zone outlet. The apparatus comprises a source of caustic in fluid communication with a line between the catalytic hydrodechlorination reaction zone outlet and the cold separator inlet. The apparatus comprises processing unit comprising an oil inlet, the processing unit oil inlet being in downstream fluid communication with the cold separator oil outlet.

In some embodiments, the apparatus further comprises a heat source in thermal communication with a line between the oil feed tank outlet and the catalytic hydrodechlorination reaction zone inlet.

In some embodiments, the apparatus further comprises a diene saturation reactor positioned between the oil feed tank outlet and the catalytic hydrodechlorination reaction zone inlet.

In some embodiments, the apparatus further comprises a cooler positioned between the catalytic hydrodechlorination reaction zone outlet and the cold separator inlet.

In some embodiments, the apparatus further comprises a bed comprising an HCl adsorbent having an inlet and an outlet, the inlet in downstream fluid communication with the cold separator gas stream outlet.

In some embodiments, the first hydrogen compressor inlet is in downstream fluid communication with the HCl adsorbent bed outlet; or the processing unit further comprises a hydrogen inlet and wherein the processing unit hydrogen inlet is in downstream fluid communication with the HCl adsorbent bed outlet; or both.

In some embodiments, the apparatus further comprises a second compressor comprising an inlet and an outlet, the second compressor inlet being in downstream fluid communication with the first compressor outlet, and the processing unit further comprising a hydrogen inlet, the processing unit hydrogen inlet being in downstream fluid communication with the second compressor outlet.

In some embodiments, the apparatus further comprises a filter comprising an inlet and an outlet, the oil feed tank inlet being in downstream fluid communication with the filter outlet.

In some embodiments, the apparatus further comprises a mineral oil supply, the processing unit being in downstream fluid communication with the mineral oil tank outlet. The mineral oil supply can be a direct feed from an upstream mineral oil process, or there could be a surge tank between the upstream mineral oil process and the processing unit.

The invention pretreats a pyrolysis oil originated from long-chain polymer, a tire or the like, or vegetable oil or a fat, or combination of all types before a processing unit. The level of contaminant removal may be defined as an efficiency of the reduction of each contaminant, such as the efficiency of the reduction of a contaminants in mass fraction relative to its mass fraction in total feed. An efficiency that fulfills the objective of requiring little to no upgrades in the downstream processing unit maybe considered to be optimal. For an 75% Cl removal efficiency due to hydrochlorination pretreatment of a pyrolysis oil feed with 100 ppmw Cl, it allows for 25 parts in mass pyrolysis oil to be cofed with 80 parts in mass of a petroleum-based near Cl-free feed so that it stills maintains less than 5 ppmw combined feed to an existing hydroprocessing unit, FCC unit, steam cracking unit, or the like such that metallurgy upgrades are minimized or eliminated. The efficiency of removal can be greater than 40%, or greater than 50%, or greater than 60%, or greater than 70%, or greater than 80%, or greater than 90%, or greater than 95%, or greater than 98%, or greater than 99%, or greater than 99.5%, or greater than 99.7%, or greater than 99.8%, or greater than 99.9%, or greater than 99.95%, or greater than 99.99% for each contaminant individually, or combinations thereof. A range of efficiency for this invention may be 40-100% Cl removal in mass, or 40-100% oxygen removal in mass, or 40-100% total metal removal in mass, or 40-100% diene saturation, or 40-100% olefin saturation, respectively, or combinations thereof. The removal efficiency may be 40-99.9%, or 45-99.9%, or 50-99.9%, or 55-99.9%, or 60-99.9%, or 65-99.9%, or 70-99.9%, or 75-99.9%, or 80-99.9%, or 85-99.9%, or 90-99.9%, or 95-99.9% for each contaminant individually, or combinations thereof. The removal efficiency may be 40-99.5%, or 45-99.5%, or 50-99.5%, or 55-99.5%, or 60-99.5%, or 65-99.5%, or 70-99.5%, or 75-99.5%, or 80-99.5%, or 85-99.5%, or 90-99.5%, or 95-99.5% for each contaminant individually, or combinations thereof. The removal efficiency may be 45-100%, or 50-100%, or 55-100%, or 60-100%, or 65-100%, or 70-100%, or 75-100%, or 80-100%, or 85-100%, or 90-100%, or 95-100% for each contaminant individually, or combinations thereof. The removal efficiency may be 40-95%, or 40-90%, or 40-85%, or 40-80%, or 40-75%, or 40-70%, or 40-65%, or 40-60%, or 40-55%, or 40-50%, or 40-45% for each contaminant individually, or combinations thereof. All main contaminants are treated down to a level such that a petroleum-based downstream processing unit can blend in up to about 20% vol of pyrolysis oil with little to no upgrade or design changes, thus significantly reducing the cost or increasing the processability of co-processing.

The processis illustrated in the Figure. An organic-chloride laden oil streamfrom the pyrolysis of plastics or the like is filtered through a filtration bedto remove particulate matter. The filtration bed may be a single vessel, or it may be configured in a lead/lag configuration to allow changing the filtration media while maintaining the continuous processing of the organic chloride laden oil. Any suitable filtration media may be used. Suitable filtration media may include, but are not limited to, high surface area alumina, a reticulated porous ceramic media with significant internal porous volume, or an adsorbent such as sodium gamma-alumina. In another embodiment, the pyrolysis oil is filtered through cartridges or a back-washed filter containing a filtration media.

The filtered pyrolysis oil streamis sent to a feed surge drum. The filtered pyrolysis oil streamfrom the surge drumis sent to the organic chloride reaction section.

The hydrogen feed streamis sent to a first compressor. The compressed hydrogen streamis divided into a first hydrogen stream, a second hydrogen stream, and a third hydrogen stream. The first hydrogen streamis the treat gas for the reaction section.

The treat gas required for the reaction section and the chemical hydrogen that is consumed in the organic chloride reaction section is less than the makeup hydrogen required for the processing unit, such as hydroprocessing units, fluid catalytic cracking units, steam cracking units, that is processing the petroleum-based oil and the treated pyrolysis oil from the invention. In this way, the hydrogen flow required for the invention is provided in a once-through hydrogen configuration relative to the hydroprocessing or other unit. The invention treat gas rate is three to five times the required chemical hydrogen consumption in the organic chloride reaction section.

The organic chloride reaction section comprises a diene saturation reactorto saturate dienes and a catalytic hydrodechlorination reaction zone comprising a catalytic hydrodechlorination reactorto convert the organic chlorides into a hydrocarbon and hydrogen chloride and to saturate olefins. The pressure drop of the organic chloride reaction section (diene saturation reactorand catalytic hydrodechlorination reaction zone) is preferably less than 200 psi, or less than 150 psi.

The filtered pyrolysis oil streamfrom the surge drumis combined with the first hydrogen streamto form combined stream. The combined streamis sent through heat exchanger, and the heated pyrolysis oil streamis sent to the diene saturation reactorwhere the dienes in the pyrolysis oil are saturated.

The diene saturated pyrolysis oil streamis heat exchanged in heat exchanger, and the heated diene saturated pyrolysis oil streamis further heated in heater. The second heated saturated pyrolysis streamfrom heateris sent to catalytic hydrodechlorination reactorwhere hydrodechlorination and olefin saturation take place. Additional reactions including hydrodeoxygenation, denitrogenation, desulfurization, and demetallization of organometallic components may also occur in the diene saturation reactor and/or preferably in the hydrodechlorination reactor. The effluentfrom the catalytic hydrodechlorination reactorcomprises dechlorinated pyrolysis oil and a gas phase comprising HCl.

The effluentis heat exchanged with the diene saturated pyrolysis oil streamin heat exchanger. The cooled effluent streamis heat exchanged with the combined streamin heat exchanger.

A dilute caustic solutionis injected at a location in the reactor section before water can condense and/or before a chloride or sulfide salt can deposit. In one embodiment, the injection location is before the reactor effluent air cooler. In another embodiment, the injection location may be located upstream or between the feed-reactor effluent exchangersand. The injection of a dilute caustic solutionprevents the corrosion of the metal downstream of the injection point when the HCl is potentially dissolved in an aqueous media due to presence of water formed from hydrodeoxygenation. The dilute caustic will substantially neutralize the hydrogen chloride.

The cooled reactor effluentwith the spent caustic is separated in a separatorthat produces a spent caustic stream, a dechlorinated pyrolysis oil stream, and a hydrogen-rich gas stream.