Patent Application
20100038290
The present invention relates to additives to reduce fouling of crude hydrocarbon refinery components, and methods and systems using the same.
Petroleum refineries incur additional energy costs, perhaps billions per year, due to fouling and the resulting attendant inefficiencies caused by the fouling. More particularly, thermal processing of crude oils, blends and fractions in heat transfer equipment, such as heat exchangers, is hampered by the deposition of insoluble asphaltenes and other contaminants (i.e., particulates, salts, etc.) that are inherent in most crude oils. Further, the asphaltenes and other organics are known to thermally degrade to coke when exposed to high heater tube surface temperatures.
Fouling in heat exchangers receiving petroleum-type process streams can result from a number of mechanisms including chemical reactions, corrosion, deposit of existing insoluble impurities in the stream, and deposit of materials rendered insoluble by the temperature difference (ΔT) between the process stream and the heat exchanger wall. For example, naturally-occurring asphaltenes may precipitate from the crude oil process stream, thermally degrade to form a coke and adhere to the hot surfaces. Further, the high ΔT inherent in a heat transfer operation result in high surface or skin temperatures when the process stream is introduced to the heater tube surfaces, which contributes to the precipitation of insoluble particulates. Another common cause of fouling is attributable to the presence of salts, particulates and impurities (e.g. inorganic contaminants) found in the crude oil stream. For example, iron oxide/sulfide, calcium carbonate, silica, sodium chloride and calcium chloride have all been found to attach directly to the surface of a fouled heater rod and throughout the coke deposit. These solids promote and/or enable additional fouling of crude oils.
The buildup of insoluble deposits in heat transfer equipment creates an unwanted insulating effect and reduces the heat transfer efficiency. Fouling also reduces the cross-sectional area of process equipment, which decreases flow rates and desired pressure differentials to provide less than optimal operation. To overcome these disadvantages, heat transfer equipment are ordinarily taken offline and cleaned mechanically or chemically cleaned, resulting in lost production time.
Accordingly, there is a need to reduce precipitation/adherence of particulates and asphaltenes from the heated surface to prevent fouling, and before the asphaltenes are thermally degraded or coked. This will improve the performance of the heat transfer equipment, decrease or eliminate scheduled outages for fouling mitigation efforts, and reduce energy costs associated with the processing activity.
One aspect of the present application provides a method for reducing fouling in a hydrocarbon refining process. The method includes providing a crude hydrocarbon for a refining process; and adding to the crude hydrocarbon one or more additives selected from:
wherein R1 is a branched or straight-chained C10-C80 alkyl or alkenyl group;
n is an integer from 1 to 10;
R2 and R3 are independently a C1-C10 branched or straight chained alkylene group;
R5 and R6 are H or R5 and R6 together along with the N atom bound thereto form the group:
wherein R7 is a branched or straight-chained C10-C80 alkyl or alkenyl group;
wherein the N atom bound to the R2 and R3 groups above may optionally be substituted in one or more places with the group:
—R8—R9
wherein R8 is a C1-C10 branched or straight chained alkylene group; and R9 is NH2 or
wherein R10 is a branched or straight-chained C10-C80 alkyl or alkenyl group; and wherein the R2—NH—R3 group may optionally be interrupted in one or more places by a heterocyclic or homocyclic cycloalkyl group. In one particular embodiment, the fouling is particulate-induced fouling.
Another aspect of the present application is directed to a system for refining hydrocarbons. The system includes at least one crude hydrocarbon refinery component and crude hydrocarbon in fluid communication with the at least one crude hydrocarbon refinery component, wherein the crude hydrocarbon includes at least one of the above-mentioned additives. In one particular embodiment, the system is particularly adept at reducing and/or preventing particulate-induced fouling.
Another aspect of the present invention provides a composition for reducing fouling (e.g. particulate-induced fouling) that includes at least one of the above-described additives, and a boronating agent complexed or in association with one of the above-mentioned additives.
The application will now be described in conjunction with the accompanying drawings in which:
The following definitions are provided for purpose of illustration and not limitation.
As used herein, the term “fouling” generally refers to the accumulation of unwanted materials on the surfaces of processing equipment or the like.
As used herein, the term “particulate-induced fouling” generally refers to fouling caused primarily by the presence of variable amounts of organic or inorganic particulates. Organic particulates (such as precipitated asphaltenes and coke particles) include, but are not limited to, insoluble matter precipitated out of solution upon changes in process conditions (e.g. temperature, pressure, or concentration changes) or a change in the composition of the feed stream (e.g. changes due to the occurrence of a chemical reaction). Inorganic particulates include, but are not limited to, silica, iron oxide, iron sulfide, alkaline earth metal oxide, sodium chloride, calcium chloride and other inorganic salts. One major source of these particulates results from incomplete solids removal during desalting and/or other particulate removing processes. Solids promote the fouling of crude oils and blends due to physical effects by modifying the surface area of heat transfer equipment, allowing for longer holdup times at wall temperatures and causing coke formation from asphaltenes and/or crude oil(s).
As used herein, the term “alkyl” refers to a monovalent hydrocarbon group containing no double or triple bonds and arranged in a branched or straight chain.
As used herein, the term “alkylene” refers to a divalent hydrocarbon group containing no double or triple bonds and arranged in a branched or straight chain.
As used herein, the term “alkenyl” refers to a monovalent hydrocarbon group containing one or more double bonds and arranged in a branched or straight chain.
As used herein, the abbreviation “PIB” refers to polyisobutylene and includes both normal polyisobutylene and highly reactive polyisobutylene.
As used herein, a “boronating agent” include compounds encompassed by the formula:
(R1—O)(R2—O)(R3—O)B and (R4—O)2—B—O—B—(O—R5)(O—R6); and
wherein R1, R2, R3, R4, R5, R6, R7 and R8 are independently C3 to C20 hydrocarbyl groups. Examples of these materials include Mobilad C-700 and Mobilad C-701, currently under new trade names.
As used herein, a “boronating agent” also includes compounds disclosed in International Published Application No. 1996/13618, applied for by Mobil Oil Corporation and hereby incorporated by reference in its entirety. Accordingly, boric acid can be used as a boronating agent; organic borates, particularly ortho-borates, meta-borates, trialkyl borates may also be used in additive-containing compositions of the present application. Suitable metaborates include but are not limited to trimethyl metaborate (trimethoxyboroxine), triethyl metaborate, tributyl metaborate. Suitable trialkyl borates include, without limitation, trimethyl borate, triethylborate, triisopropyl borate (triisopropoxyborane), tributyl borate (tributoxyborane) and tri-t-butyl borate.
As used herein, a “hydrocarbyl” group refers to any univalent radical that is derived from a hydrocarbon, including univalent alkyl, aryl and cycloalkyl groups.
As used herein, the term “crude hydrocarbon refinery component” generally refers to an apparatus or instrumentality of a process to refine crude hydrocarbons, such as an oil refinery process, which is, or may be, susceptible to fouling. Crude hydrocarbon refinery components include, but are not limited to, heat transfer components such as a heat exchanger, a furnace, a crude preheater, a coker preheater, or any other heaters, a FCC slurry bottom, a debutanizer exchanger/tower, other feed/effluent exchangers and furnace air preheaters in refinery facilities, flare compressor components in refinery facilities and steam cracker/reformer tubes in petrochemical facilities. Crude hydrocarbon refinery components can also include other instrumentalities in which heat transfer may take place, such as a fractionation or distillation column, a scrubber, a reactor, a liquid-jacketed tank, a pipestill, a coker and a visbreaker. It is understood that “crude hydrocarbon refinery components,” as used herein, encompasses tubes, piping, baffles and other process transport mechanisms that are internal to, at least partially constitute, and/or are in direct fluid communication with, any one of the above-mentioned crude hydrocarbon refinery components.
As used herein, a reduction (or “reducing”) particulate-induced fouling is generally achieved when the ability of particulates to adhere to heated equipment surfaces is reduced, thereby mitigating their impact on the promotion of the fouling of crude oil(s), blends, and other refinery process streams.
Reference will now be made to various aspects of the present application in view of the definitions above.
In accordance with one aspect of the present application, a method is provided for reducing fouling in which one or more additives are selected from:
wherein R1 is a branched or straight-chained C10-C80 alkyl or alkenyl group;
n is an integer from 1 to 10;
R2 and R3 are independently a C1-C10 branched or straight chained alkylene group;
R5 and R6 are H or R5 and R6 together along with the N atom bound thereto form the group:
wherein R7 is a branched or straight-chained C10-C80 alkyl or alkenyl group;
wherein the N atom bound to the R2 and R3 groups above may optionally be substituted in one or more places with the group:
—R8—R9
wherein R8 is a C1-C10 branched or straight chained alkylene group; and R9 is NH2 or
wherein R10 is a branched or straight-chained C10-C80 alkyl or alkenyl group; and wherein the R2—NH—R3 group may optionally be interrupted in one or more places by a heterocyclic or homocyclic cycloalkyl group. The additive can be added to a crude hydrocarbon process stream in a variety of locations and manners as described in order to reduce various types of fouling. For example, the fouling can be particulate-induced fouling.
In one embodiment of the present application, at least one of R1, R7 and R10, as defined above is polyisobutylene. In a further embodiment, R2 and R3, as defined above, are independently a C1-C10 straight chained alklyene group. In another embodiment at least one of R2, R3 and R5, as defined above, is an unsubstituted ethylene group. In one embodiment, a piperazine group may interrupt the R2—NH—R3 chain.
In one embodiment, the additive is selected from
In one embodiment, any one of the above-described additives are associated or complexed with a boronating agent. In one embodiment, the boronating agent is selected from boric acid, an ortho-borate, or a meta-borate, for example, boric acid, trimethyl metaborate (trimethoxyboroxine), triethyl metaborate, tributyl metaborate, trimethyl borate, triethylborate, triisopropyl borate (triisopropoxyborane), tributyl borate (tributoxyborane) and tri-t-butyl borate.
Another aspect of the present invention provides a system for refining hydrocarbons that include at least one crude hydrocarbon refinery component, in which the crude hydrocarbon refinery component includes an additive selected from any one of the above-described additives. The crude hydrocarbon refining component may be selected from a heat exchanger, a furnace, a crude preheater, a coker preheater, a FCC slurry bottom, a debutanizer exchanger, a debutanizer tower, a feed/effluent exchanger, a furnace air preheater, a flare compressor component, a steam cracker, a steam reformer, a distillation column, a fractionation column, a scrubber, a reactor, a liquid-jacketed tank, a pipestill, a coker, and a visbreaker. In one preferred embodiment, the crude hydrocarbon refining component is a heat exchanger (e.g. a crude pre-heat train heat exchanger).
Another aspect of the present invention provides a composition for reducing fouling that includes at least one of any of the above-described additives, and a boronating agent. The boronating agent is selected from boric acid, an ortho-borate, or a meta-borate, for example, boric acid, trimethyl metaborate (trimethoxyboroxine), triethyl metaborate, tributyl metaborate, trimethyl borate, triethylborate, triisopropyl borate (triisopropoxyborane), tributyl borate (tributoxyborane) and tri-t-butyl borate.
Exemplary further embodiments of the present application are provided below for illustrative purposes, and not for purposes of limitation.
The additives of the present application are generally soluble in a typical hydrocarbon refinery stream and can thus be added directly to the process stream, alone or in combination with other additives that contribute to either reduce fouling or improve some other process parameter in order to optimize the refining process.
The additives can be introduced, for example, upstream from the particular crude hydrocarbon refinery component(s) (e.g. a heat exchanger) in which it is desired to prevent fouling (e.g. particulate induced fouling). Alternatively, the additive can be added to the crude oil prior to being introduced to the refining process, or at the very beginning of the refining process.
It is noted that water may have a negative impact on boron-containing additives. Accordingly, it is advisable to add boron-containing additives at process locations that have a minimal amount of water.
While not limited thereto, the additives of the present application are particularly suitable in reducing or preventing particulate-induced fouling. Thus one aspect of the present application provides a method of reducing and/or preventing, in particular, particulate-induced fouling that includes adding at least one additive of the present application to a process stream that is known, or believed to contribute to particulate-induced fouling. To facilitate determination of proper injection points, measurements can be taken to ascertain the particulate level in the process stream.
In one embodiment of the present application, a method to reduce fouling is provided comprising adding any one of the above-mentioned additives to a crude hydrocarbon refinery component that is in fluid communication with a process stream that contains, at least 50 wppm of particulates, including organic and inorganic particulates. In another embodiment of the present application, a method to reduce fouling is provided comprising adding any one of the above-mentioned additives to a crude hydrocarbon refinery component that is in fluid communication with a process stream that contains at least 250 wppm (or 1000 wppm, or 10,000 wppm) of particulates, including organic and inorganic particulates, as defined above.
In one embodiment of the present application, the additives of the present application are added to selected crude oil process streams known to contain, or possibly contain, problematic amounts of organic or inorganic particulate matter (e.g. 1-10,000 wppm), such as inorganic salts. Accordingly, the additives of the present application can be introduced far upstream, where the stream is relatively unrefined (e.g. the refinery crude pre-heat train). The additives can be also added, for example, after the desalter to counteract the effects of incomplete salt removal or to the bottoms exit stream from the fractionation column to counteract the high temperatures that are conducive to fouling.
The additives of the present application may be added in a solid (e.g. powder or granules) or liquid form directly to the process stream. As mentioned above, the additives may be added alone, or combined with other components to form a composition for reducing fouling (e.g. particulate-induced fouling). Any suitable technique can be used for adding the additive to the process stream, as known by a person of ordinary skill in the art in view of the process to which it is employed. As a non-limiting example, the additives may be introduced via injection that allows for sufficient mixing of the additive and the process stream.
The (non-borate) additives of the present application may be obtained from commercial sources. For example, additives of the present application may also be obtained from Chevron Oronite Company LLC (San Ramon, Calif.), including Oronite™ OLOA 11000. These products are described as useful as additives for gasoline and natural gas engines as well as additives for gear oils and hydraulic fluids. Additive of the present application can also be obtained from Infineum Co. (Oxfordshire, UK and Linden, N.J.), including Infineum™ C-9230.
A preferred alkyl group on the additives of the present application is polyisobutylene (R1, R7, and/or R10 as defined above). The polyisobutylene (PIB) can be normal PIB and/or Highly Reactive PIB (HRPIB). HRPIB is generally characterized has having a vinylidene double bond content from about 1% to about 100%.
Boronating Agents for use in the present application can be obtained by persons of ordinary skill in the art from commercial vendors. Non-limiting examples of vendors include products available from ExxonMobil Chemical Co. (Houston, Tex.) under the “Mobilad”™ brand, particularly Mobilad™ C-700 and Mobilad™ C-701.
Boronating agents of the present application may also be synthesized by persons of ordinary skill in the art, in view of, for example, the exemplary reaction schemes disclosed in U.S. Pat. Nos. 5,804,667, 5,936,041, 5,026,495, 5,788,722 and 6,030,930, each of which is hereby incorporated by reference in their entirety.
The boron-modified additives of the present application, i.e. an additive complexed or in association with a boronating agent, can be prepared by introducing (e.g. mixing) a non-borate additive with a boronating agent. Preferably, the mixture is heated (e.g. heated up to about 80° C.) for about 1-2 hours to obtain the boron-complexed additive.
Alternatively boron-modified additives of the present application may be directly purchased from commercial vendors. For example, various boron-containing succinic acid ester additives are available from the Infineum Co. (Oxfordshire, UK and Linden, N.J.), including Infineum™ C-9230. Boron-containing additives may also be obtained from Afton Chemical Co. (Richmond, Va.) such as Afton Hitec™ 643D.
An example of a boron-modified additive of the present application, shown solely for illustrative purposes, and not for purposes of limitation, is shown below:
One embodiment of the present application provides boron-modified additives with a particularly high boron content (e.g. above 1 wt %, 2 wt % or 5 wt % boron). To achieve these relatively high amounts of boron, it is possible to introduce a commercially available boron-containing additive with a boronating agent to further increase the boron content of the additive.
While not being bound by any particular theory, it is believed that the polyamine group and the borate group complex together to form a strong polar network that significantly contributes to the further increase the anti-fouling effects, as compared to the additive without the borate group.
In one embodiment of the present application, the boron-modified additive contains at least 1 wt %, or at least 2 wt %, or at least 5 wt % boron. Weight ratios of nitrogen:boron may range from about 1:5 to about 5:1, more preferably from about 1:2 to 2:1.
The additives of the present application can be used in compositions that prevent fouling, including particulate-induced fouling. In addition to the additives of the present application, the compositions may optionally further contain a hydrophobic oil solubilizer for the additive and/or a dispersant for the additive.
Suitable solubilizers may include, for example, surfactants, carboxylic acid solubilizers, such as the nitrogen-containing phosphorous-free carboxylic solubilizers disclosed in U.S. Pat. No. 4,368,133, hereby incorporated by reference in its entirety.
Also as disclosed in U.S. Pat. No. 4,368,133, hereby incorporated by reference, surfactants that may be included in compositions of the present application may include, for example, any one of a cationic, anionic, nonionic or amphoteric type of surfactant. See, for example, McCutcheon's “Detergents and Emulsifiers”, 1978, North American Edition, published by McCutcheon's Division, MC Publishing Corporation, Glen Rock, N.J., U.S.A., including pages 17-33, which is hereby incorporated by reference in its entirety.
The compositions of the present application may further optionally include, for example, viscosity index improvers, anti-foamants, antiwear agents, demulsifiers, anti-oxidants, and other corrosion inhibitors.
Furthermore, the additives of the present application can be added with other compatible components that address other problems that may present themselves in an oil refining process known to one of ordinary skill in the art.
The present application is further described by means of the examples, presented below. The use of such examples is illustrative only and in no way limits the scope and meaning of the invention or of any exemplified term. Likewise, the invention is not limited to any particular preferred embodiments described herein. Indeed, many modifications and variations of the invention will be apparent to those skilled in the art upon reading this specification. The invention is therefore to be limited only by the terms of the appended claims along with the full scope of equivalents to which the claims are entitled.
Several commercially available PIBSA-PAM-Ester products or boron-containing PIBSA-PAM-Ester products made from either conventional PIB or Highly Reactive-PIB (HR-PIB) were blended with organic borates at elevated temperatures to form a series of new products with high boron content in the following manner:
37.5 grams of a commercial, boron-containing succinimide/succinic acid ester dispersant [Infineum C-9230 with 1.3 wt % boron and 1.2 wt % nitrogen commerically available from Infineum Co.] were mixed with 12.5 grams of an organic boron additive [Mobilad C-700, 5.6 wt % boron, commercially available from ExxonMobil Chemical Co. (Houston, Tex.)] and the viscous mixture was heated to 80° C. for about one hour. The resulting final adduct upon cooling is a light brownish liquid [elemental analysis, boron: 2.56 wt %, nitrogen: 0.83 wt %].
A commercial boron-free, succinimide/succinic acid ester dispersant, (Infineum 9268, 1.2 wt % nitrogen) was used as an anti-fouling agent.
37.5 grams of a commercial, boron-containing succinimide/succinic acid ester dispersant [Afton Hitec 643D with 0.8 wt % boron and 1.6 wt % nitrogen, commercially available from Afton Chemical Co. (Richmond, Va.)] were mixed with 12.5 grams of an organic boron additive [Mobilad C-700] and the viscous mixture was heated to 80° C. for about one hour. The resulting final adduct upon cooling is a light brownish liquid [elemental analysis, boron: 2.36 wt %, nitrogen: 1.1 wt %].
37.5 grams of a commercial succinimide/succinic acid ester dispersant [Oronite OLOA 11000 with 3.2 wt % nitrogen, commercially available from Chevron Oronite Corp. (San Ramon, Calif.)] were mixed with 12.5 grams of an organic boron additive [Mobilad C-700] and the viscous mixture was heated to 80° C. for about 1.5 hour. The resulting final adduct upon cooling is a dark brownish, very viscous liquid [elemental analysis, boron: 1.2 wt %].
25 grams of a commercial succinimide/succinic acid ester dispersant [Oronite OLOA 11000 with 3.2 wt % nitrogen] were mixed with 25 grams of an organic boron additive [Mobilad C-700] and the viscous mixture was heated to 80° C. for about 1.5 hour. The resulting final adduct upon cooling is a dark brownish, very viscous liquid [elemental analysis, boron: 3.5 wt %].
A commercial boron-free, succinimide/succinic acid ester dispersant, (Afton Hitec 638, 2.0 wt % nitrogen) was used as the anti-fouling agent.
25 grams of a commercial, boron-containing succinimide/succinic acid ester dispersant [Infineum C-9230 with 1.3 wt % boron and 1.2 wt % nitrogen] were mixed with 25 grams of an organic boron additive [Mobilad C-701, 2.9 wt % boron] and the viscous mixture was heated to 80° C. for about one hour. The resulting final adduct upon cooling is a dark brownish liquid [elemental analysis, boron: 2.3 wt %, nitrogen: 0.3 wt %].
A commercial dispersant modified organic borate additives, succinimide/succinic acid ester dispersant, (Infineum C9230, 1.24 wt % nitrogen, and 1.3 wt % boron) was used as an anti-fouling agent.
20 grams of a commercial succinimide/succinic acid ester dispersant [Oronite OLOA 11000 with 3.2 wt % nitrogen] were mixed with 30 grams of an organic boron additive [Mobilad C-700, 5.6 wt % boron] and the viscous mixture was heated to 80° C. for about 1.5 hour. The resulting final adduct upon cooling is a dark brownish, very viscous liquid [elemental analysis—pending].
30 grams of a commercial succinimide/succinic acid ester dispersant [Oronite OLOA 11000 with 3.2 wt % nitrogen] were mixed with 20 grams of an organic boron additive [Mobilad C-700, 5.6 wt % boron] and the viscous mixture was heated to 80° C. for about 1.5 hour. The resulting final adduct upon cooling is a dark brownish, very viscous liquid [elemental analysis—pending].
20 grams of a commercial succinimide/succinic acid ester dispersant [Oronite OLOA 11000 with 3.2 wt % nitrogen] were mixed with 10 grams technical grade xylene and 30 grams of an organic boron additive [Mobilad C-700, 5.6 wt % boron] and the viscous mixture was heated to 80° C. for about 1.5 hour. The resulting final adduct upon cooling is a dark brownish, very viscous liquid [elemental analysis—pending].
25 grams of a commercial, boron-containing succinimide/succinic acid ester dispersant [Infineum C-9230 with 1.3 wt % boron and 1.2 wt % nitrogen] were mixed with 25 grams of an organic boron additive [Mobilad C-700] and the viscous mixture was heated to 80° C. for about one hour. The resulting final adduct upon cooling is a light brownish liquid [elemental analysis, boron: 3.5 wt %, nitrogen: 0.4 wt %].
37.5 grams of a commercial, boron-containing succinimide/succinic acid ester dispersant [Mobilad C-200 with 1.8 wt % boron and 1.6 wt % nitrogen] were mixed with 12.5 grams of an organic boron additive [Mobilad C-700] and the viscous mixture was heated to 80° C. for about one hour. The resulting final adduct upon cooling is a dark brownish liquid [elemental analysis, boron: 3 wt %, nitrogen: 1.2 wt %].
25 grams of a commercial, boron-containing succinimide/succinic acid ester dispersant [Oronite OLOA 11000 with 3.2 wt % nitrogen] were mixed with 25 grams of an organic boron additive [Mobilad C-701, 2.9 wt % boron] and the viscous mixture was heated to 80° C. for about 1.5 hour. The resulting final adduct upon cooling is a dark brownish, very viscous liquid [elemental analysis, boron: 2.1 wt %, nitrogen: 2.2 wt %].
During the constant surface temperature testing, foulant deposits and builds up on the heated surface. The foulant deposits are thermally degraded to coke. The coke deposits cause an insulating effect that reduces the efficiency and/or ability of the surface to heat the oil passing over it. The resulting reduction in outlet bulk fluid temperature continues over time as fouling continues. This reduction in temperature is referred to as the outlet liquid ΔT or ΔT and can be dependent on the type of crude oil/blend, testing conditions and/or other effects, such as the presence of salts, sediment or other fouling promoting materials. A standard Alcor fouling test is carried out for 180 minutes. The total fouling, as measured by the total reduction in outlet liquid temperature over time, is plotted on the y-axis of
The present invention is not to be limited in scope by the specific embodiments described herein. Indeed, various modifications of the invention in addition to those described herein will become apparent to those skilled in the art from the foregoing description and the accompanying figures. Such modifications are intended to fall within the scope of the appended claims.
It is further to be understood that all values are approximate, and are provided for description.
Patents, patent applications, publications, product descriptions, and protocols are cited throughout this application, the disclosures of each of which is incorporated herein by reference in its entirety for all purposes.
The application relates to and claims priority to U.S. Provisional Patent Application No. 61/136,172, filed on Aug. 15, 2008.
| Number | Date | Country | |
|---|---|---|---|
| 61136172 | Aug 2008 | US |
