Patent Application
20140275433
The disclosed subject matter relates to additives to reduce fouling of crude hydrocarbon refinery components, and methods and systems using the same.
This application relates to U.S. Provisional Application Nos. 61/704,939, filed on Sep. 24, 2012, and U.S. Provisional Application No. 61/704,639, filed Sep. 24, 2012, the disclosure of each of which is incorporated by reference in its entirety herein.
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 may be found in 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 can precipitate from the crude oil process stream, thermally degrade to form a coke and adhere to the hot surfaces. Further, the high ΔT found in heat transfer operations 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.
There is a need to reduce precipitation/adherence of particulates and asphaltenes from the heated surface to prevent fouling, particularly before the asphaltenes are thermally degraded or coked. Such reduction 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.
Antifoulant additives have been described in a number of commonly-owned applications, including U.S. Patent Application Publication Nos. 20110147275 and 20100170829, the disclosure of each of which is incorporated herein by reference in its entirety. However, there remains a need for alternative antifoulant additives capable of reducing precipitation and/or adherence of particulates and asphaltenes.
In accordance with one aspect of the disclosed subject matter, a compound is provided. The compound being represented by
wherein R1 is a branched or straight-chained C10-C800 alkyl or alkenyl group;
m is an integer between 0 and 10 inclusive;
R2 is represented by
or —CH2—CH2—CH2—CH2—*, wherein the asterisk (*) indicates a connecting point of R2 with the nitrogen that connects with R3;
R3 is a C1-C4 branched or straight chained alkylene group;
R31 is hydrogen or —R8—R9, wherein R8 is defined the same as R2 above, and R9 is branched or straight-chained C10-C800 alkyl or alkenyl group, or R8 and R9 together are a C1-C4 branched or straight chained alkyl group optionally substituted with one or more amine groups;
and further wherein the —N(R31)—R3— repeat unit is optionally interrupted in one or more places by a nitrogen-containing heterocyclic cycloalkyl group; and
R4 and R5 are each independently selected from (a) hydrogen, (b) —R6—R7, wherein R6 is defined the same as R2 above, and R7 is a C10-C800 branched or straight chained alkyl or alkenyl group, or (c) a bond connected to R31 in the m-th —N(R31)—R3— repeat unit.
According to another aspect of the disclosed subject matter, a method for preparing a compound is provided. The method includes:
(a) converting a polymer base unit R11 which is a branched or straight-chained C10-C800 alkyl or alkenyl group having a vinyl terminal group, to a polymer having an aldehyde terminal group;
(b) reacting the polymer having the aldehyde terminal group obtained in (a) with a polyamine represented by
to generate an imine (C═N) intermediate, wherein R12 is hydrogen or a C1-C4 branched or straight chained alkyl optionally substituted with one or more amine groups, R13 is a C1-C4 branched or straight chained alkylene group, and x is an integer between 1 and 10, and further wherein the —N(R12)—R13— unit is optionally interrupted in one or more places by a nitrogen-containing heterocyclic group, and wherein when the x-th —N(R12)—R13— unit along with the terminal nitrogen atom forms a heterocyclic cycloalkyl group, the terminal —NH2 is replaced by a —NH— group for valency, and
(c) reducing the imine intermediate to form a product with a saturated C—N bond.
According to a further aspect of the disclosed subject matter, a compound prepared by the above method is provided.
According to yet another aspect of the disclosed subject matter, a method for reducing fouling in a hydrocarbon refining process is provided. The method includes providing a crude hydrocarbon for a refining process; and adding an additive to the crude hydrocarbon, the additive being represented by:
wherein R1 is a branched or straight-chained C10-C800 alkyl or alkenyl group;
m is an integer between 0 and 10 inclusive;
R2 is represented by
or —CH2—CH2—CH2—CH2—*, wherein the asterisk (*) indicates a connecting point of R2 with the nitrogen that connects with R3;
R3 is a C1-C4 branched or straight chained alkylene group;
R31 is hydrogen or —R8—R9, wherein R8 is defined the same as R2 above, and R9 is branched or straight-chained C10-C800 alkyl or alkenyl group, or R8 and R9 together are a C1-C4 branched or straight chained alkyl group optionally substituted with one or more amine groups;
and further wherein the —N(R31)—R3— repeat unit is optionally interrupted in one or more places by a nitrogen-containing heterocyclic cycloalkyl group; and
R4 and R5 are each independently selected from (a) hydrogen, (b) —R6—R7, wherein R6 is defined the same as R2 above, and R7 is a C10-C800 branched or straight chained alkyl or alkenyl group, or (c) a bond connected to R31 in the m-th —N(R31)—R3— repeat unit.
In addition, the disclosed subject matter provides the additives as described in the above methods, antifouling compositions comprising such additives, and systems for refining hydrocarbons containing such additives and compositions.
The disclosed subject matter 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, particularly processing equipment in a hydrocarbon refining process.
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, 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 can 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 can 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.
As used herein, reference to a group being a particular polymer (e.g., polypropylene or poly(ethylene-co-propylene) encompasses polymers that contain primarily the respective monomer along with negligible amounts of other substitutions and/or interruptions along polymer chain. In other words, reference to a group being a polypropylene group does not require that the group consist of 100% propylene monomers without any linking groups, substitutions, impurities or other substituents (e.g., alkylene or alkenylene substituents). Such impurities or other substituents can be present in relatively minor amounts so long as they do not affect the industrial performance of the additive, as compared to the same additive containing the respective polymer substituent with 100% purity.
For the purposes of the present application, when a polymer is referred to as comprising an olefin, the olefin present in the polymer is the polymerized form of the olefin.
As used herein, a copolymer is a polymer comprising at least two different monomer units (such as propylene and ethylene). A homo-polymer is a polymer comprising units of the same monomer (such as propylene). A propylene polymer is a polymer having at least 50 mole % of propylene.
The term “vinyl termination”, also referred to as “allyl chain end(s)” or “vinyl content” is defined to be a polymer having at least one terminus represented by:
where the “” represents the polymer chain.
In a preferred embodiment the allyl chain end is represented by:
The amount of allyl chain ends (also called % vinyl termination) is determined using 1H NMR at 120° C. using deuterated tetrachloroethane as the solvent on a 500 MHz machine and in selected cases confirmed by 13C NMR. Resconi has reported proton and carbon assignments (neat perdeuterated tetrachloroethane used for proton spectra while a 50:50 mixture of normal and perdeuterated tetrachloroethane was used for carbon spectra; all spectra were recorded at 100° C. on a Bruker AM 300 spectrometer operating at 300 MHz for proton and 75.43 MHz for carbon) for vinyl terminated propylene polymers in J American Chemical Soc 114 1992, 1025-1032, hereby incorporated by reference in its entirety, that are useful herein.
“Isobutyl chain end” is defined to be a polymer having at least one terminus represented by:
where M represents the polymer chain. In an example embodiment, the isobutyl chain end is represented by one of the following formulae:
where M represents the polymer chain.
The “isobutyl chain end to allylic vinyl group ratio” is defined to be the ratio of the percentage of isobutyl chain ends to the percentage of allylic vinyl groups.
As used herein, the term “polymer” refers to a chain of monomers having a Mn of 100 g/mol and above.
Reference will now be made to various aspects of the disclosed subject matter in view of the definitions above.
In one aspect, the additives of the disclosed subject matter can interact with the materials in crude oils in a refinery or the like that are prone to cause fouling, e.g., particulate impurities/contaminants and asphaltenes. The interaction can be physical or chemical such as absorption, association, or chemical bonding. The fouling materials can be rendered more soluble in the crude oils as a result of interaction with the antifouling additives, therefore the fouling on the exchanger metal surfaces can be reduced or eliminated.
In accordance with one aspect of the disclosed subject matter, a compound (additive) is provided, represented by
wherein R1 is a branched or straight-chained C10-C800 alkyl or alkenyl group;
m is an integer between 0 and 10 inclusive;
R2 is represented by
or —CH2—CH2—CH2—CH2—*, wherein the asterisk (*) indicates a connecting point of R2 with the nitrogen that connects with R3;
R3 is a C1-C4 branched or straight chained alkylene group;
R31 is hydrogen or —R8—R9, wherein R8 is defined the same as R2 above, and R9 is branched or straight-chained C10-C800 alkyl or alkenyl group, or R8 and R9 together are a C1-C4 branched or straight chained alkyl group optionally substituted with one or more amine groups;
and further wherein the —N(R31)—R3— repeat unit is optionally interrupted in one or more places by a nitrogen-containing heterocyclic cycloalkyl group; and
R4 and R5 are each independently selected from (a) hydrogen, (b) —R6—R7, wherein R6 is defined the same as R2 above, and R7 is a C10-C800 branched or straight chained alkyl or alkenyl group, or (c) a bond connected to R31 in the m-th —N(R31)—R3— repeat unit.
In certain embodiments, at least one of R1, R7, and R9 of the compound of Formula I shown above comprises polypropylene (PP), which can be atactic polypropylene or isotactic polypropylene. The polypropylene can be amorphous, and can include isotactic or syndiotactic crystallizable units. In some embodiments, the polypropylene includes meso diads constituting from about 30% to about 99.5% of the total diads of the polypropylene. In alternative embodiments, at least one of R1, R7, and R9 of the compound of Formula I comprises polyethylene (PE).
In a further embodiment, at least one of R1, R7, and R9 of the additive of Formula I comprises poly(ethylene-co-propylene) (EP). The mole percentage of the ethylene units and propylene units in the poly(ethylene-co-propylene) can vary. For example, in some embodiments, the poly(ethylene-co-propylene) can contain about 1 to about 90 mole % of ethylene units and about 99 to about 10 mole % propylene units. In other embodiments, the poly(ethylene-co-propylene) can contain about 10 to about 90 mole % of ethylene units and about 90 to about 10 mole % propylene units. In certain embodiments, the poly(ethylene-co-propylene) contains about 20 to about 50 mole % of ethylene units.
In some embodiments of the above method, at least one of R1, R7, and R9 of the additive of Formula I has a number-averaged molecular weight of from about 300 to about 30,000 g/mol (assuming one olefin unsaturation per chain, as measured by 1H NMR). Alternatively, at least one of R1, R7, and R9 of the additive of Formula I has a number-averaged molecular weight of from about 500 to 5,000 g/mol. In one embodiment, the PP or EP included in the R1, R7 or R9 of the additive Formula I, individually, has a molecular weight from about 300 to about 30,000 g/mol, or from about 500 to about 5000 g/mol. In one embodiment, the PP or EP groups have a molecular weight, individually, ranging from about 500 to about 2500 g/mol, or a molecular of from about 500 to about 650 g/mol, or a molecular weight of from about 800 to about 1000 g/mol, or a molecular weight of from about 2000 to about 2500 g/mol.
In other embodiments of the compound, at least one of R1, R7, and R9 comprises poly(higher alpha-olefin) or polypropylene-co-higher alpha-olefin), the higher alpha-olefin including two or more carbon atoms on each side chain. For example, suitable higher alpha-olefins can include, but are not limited to, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-hexadecene, 1-octadecene and the like.
In certain embodiments of the above compound, the nitrogen content in the compound of Formula I is about 1 wt % to about 10 wt % based on the total weight of the compound.
In certain embodiments, R3 is —CH2—CH2—, and R31 is hydrogen. In these embodiments, the —N(R31)—R3— repeat unit can be interrupted in one or more places by a 1,4-diethylenediamine.
In accordance with another aspect of the subject matter disclosed herein, a method is provided for preparing a compound (or additive), such as the compound described above. The method includes:
(a) converting a polymer base unit R11 which is a branched or straight-chained C10-C800 alkyl or alkenyl group having a vinyl terminal group, to a polymer having an aldehyde terminal group (The aldehyde terminal group is primarily formed at the first position (1-CO(H)), but it may also be formed at the second position (2-CO(H) based upon the selected catalyst);
(b) reacting the polymer having the aldehyde terminal group obtained in (a) with a polyamine represented by
to obtain an imine (C═N) intermediate, wherein R12 is hydrogen or a C1-C4 branched or straight chained alkyl optionally substituted with one or more amine groups, R13 is a C1-C4 branched or straight chained alkylene group, and x is an integer between 1 and 10, and further wherein the —N(R12)—R13— unit is optionally interrupted in one or more places by a nitrogen-containing heterocyclic group, and wherein when the x-th —N(R12)—R13— unit along with the terminal nitrogen atom forms a heterocyclic cycloalkyl group, the terminal —NH2 is replaced by a —NH— group for valency, and
(c) reducing the imine intermediate to form a product with a saturated C—N bond.
In certain embodiments of the above method, the polymer base unit R11 has a number-averaged molecular weight of 300 to 30,000 g/mol (assuming one olefin unsaturation per chain, as measured by 1H NMR), and alternatively, about 500 to 5,000 g/mol.
In some embodiments of the above method, the polymer base unit R11 comprises polypropylene. The polypropylene can be either atactic polypropylene or isotactic polypropylene. The polypropylene can be amorphous, and can include isotactic or syndiotactic crystallizable units. In some embodiments, the polypropylene includes meso diads constituting from about 30% to about 99.5% of the total diads of the polypropylene. The polymer base unit R11 can also comprise polyethylene.
In alternative embodiments, the polymer base unit R11 comprises poly(ethylene-co-propylene). The poly(ethylene-co-propylene) can contain from about 1 or 10 mole % to about 90 or 99 mole % of ethylene units and from about 99 or 90 mole % to about 10 or 1 mole % propylene units. In one embodiment, the poly(ethylene-co-propylene) polymer contains from about 2 or 20 mole % to about 50 mole % ethylene units.
In one embodiment, the PP or EP included in the R11 of the additive Formula I, individually, have a number-averaged molecular weight (Mn) molecular weight from about 300 to about 30,000 g/mol, or from about 500 to about 5000 g/mol (assuming one olefin unsaturation per chain, as measured by 1H NMR). In one embodiment, the PP or EP groups have a molecular weight, individually, ranging from about 500 to about 2500 g/mol, or a molecular of from about 500 to about 650 g/mol, or a molecular weight of from about 800 to about 1000 g/mol, or a molecular weight of from about 2000 to about 2500 g/mol.
In embodiments where the polymer base unit R11 include polypropylene or poly(ethylene-co-propylene), such groups can be prepared, for example, by metallocene-catalyzed polymerization of propylene or a mixture of ethylene and propylene, which are then terminated with a high vinyl group content in the chain end. The number-averaged molecular weight (Mn) of the PP or EP can be from about 300 to about 30,000 g/mol, as determined by 1H NMR spectroscopy. The vinyl-terminated atactic or isotactic polypropylenes (v-PP) or vinyl-terminated poly(ethylene-co-propylene) (v-EP) suitable for further chemical functionalization can have a molecular weight (Mn) approximately from about 300 to about 30,000 g/mol, and preferably about 500 to 5,000 g/mol. The terminal olefin group can be a vinylidene group or an allylic vinyl group (both covered in Formula I). In certain embodiments, the terminal olefin group is an allylic vinyl group. In this regard, the terminal allylic vinyl group rich PP or EP as disclosed in U.S. Pat. No. 8,372,930 and co-pending application, U.S. Patent Application Publication No. 20090318646, can be used, each of which is hereby incorporated by reference in its entirety. Some of the vinyl terminated EP or PP according to these co-pending applications contains more than 90% of allylic terminal vinyl group.
In some embodiments of the above method, R11 can comprise propylene and less than 0.5 wt % comonomer, preferably 0 wt % comonomer, wherein the R11 has:
In some embodiments of the above method, R11 can comprise a propylene copolymer having an Mn of 300 to 30,000 g/mol as measured by 1H NMR and assuming one olefin unsaturation per chain (preferably 400 to 20,000, preferably 500 to 15,000, preferably 600 to 12,000, preferably 800 to 10,000, preferably 900 to 8,000, preferably 900 to 7,000 g/mol), comprising 10 to 90 mol % propylene (preferably 15 to 85 mol %, preferably 20 to 80 mol %, preferably 30 to 75 mol %, preferably 50 to 90 mol %) and 10 to 90 mol % (preferably 85 to 15 mol %, preferably 20 to 80 mol %, preferably 25 to 70 mol %, preferably 10 to 50 mol %) of one or more alpha-olefin comonomers (preferably ethylene, butene, hexene, or octene, or decene, preferably ethylene), wherein the polymer has at least X % allyl chain ends (relative to total unsaturations), where X is 80% or more, preferably 85% or more, preferably 90% or more, preferably 95% or more. Alternatively, R11 can have at least 80% isobutyl chain ends (based upon the sum of isobutyl and n-propyl saturated chain ends), preferably at least 85% isobutyl chain ends, preferably at least 90% isobutyl chain ends. Alternately, R11 can have an isobutyl chain end to allylic vinyl group ratio of 0.8:1 to 1.35:1.0, preferably 0.9:1 to 1.20:1.0, preferably 0.9:1.0 to 1.1:1.0.
In other embodiments, R11 can comprise a polypropylene copolymer having more than 90 mol % propylene (preferably 95 to 99 mol %, preferably 98 to 9 mol %) and less than 10 mol % ethylene (preferably 1 to 4 mol %, preferably 1 to 2 mol %), wherein the copolymer has:
at least 93% allyl chain ends (preferably at least 95%, preferably at least 97%, preferably at least 98%);
a number average molecular weight (Mn) of about 400 to about 30,000 g/mol, as measured by 1H NMR and assuming one olefin unsaturation per chain (preferably 500 to 20,000, preferably 600 to 15,000, preferably 700 to 10,000 g/mol, preferably 800 to 9,000, preferably 900 to 8,000, preferably 1000 to 6,000);
an isobutyl chain end to allylic vinyl group ratio of 0.8:1 to 1.35:1.0, and
less than 1400 ppm aluminum, (preferably less than 1200 ppm, preferably less than 1000 ppm, preferably less than 500 ppm, preferably less than 100 ppm).
In alternative embodiments, R11 can comprise a polypropylene copolymer comprising:
at least 50 (preferably 60 to 90, preferably 70 to 90) mol % propylene and from 10 to 50 (preferably 10 to 40, preferably 10 to 30) mol % ethylene, wherein the polymer has:
at least 90% allyl chain ends (preferably at least 91%, preferably at least 93%, preferably at least 95%, preferably at least 98%);
an Mn of about 150 to about 20,000 g/mol, as measured by 1H NMR and assuming one olefin unsaturation per chain (preferably 200 to 15,000, preferably 250 to 15,000, preferably 300 to 10,000, preferably 400 to 9,500, preferably 500 to 9,000, preferably 750 to 9,000); and
an isobutyl chain end to allylic vinyl group ratio of 0.8:1 to 1.3:1.0, wherein monomers having four or more carbon atoms are present at from 0 to 3 mol % (preferably at less than 1 mol %, preferably less than 0.5 mol %, preferably at 0 mol %).
In further embodiments, R11 can comprise a polypropylene copolymer comprising:
at least 50 (preferably at least 60, preferably 70 to 99.5, preferably 80 to 99, preferably 90 to 98.5) mol % propylene, from 0.1 to 45 (preferably at least 35, preferably 0.5 to 30, preferably 1 to 20, preferably 1.5 to 10) mol % ethylene, and from 0.1 to 5 (preferably 0.5 to 3, preferably 0.5 to 1) mol % C4 to C12 olefin (such as butene, hexene or octene, or decene, preferably butene), wherein the polymer has:
at least 90% allyl chain ends (preferably at least 91%, preferably at least 93%, preferably at least 95%, preferably at least 98%);
a number average molecular weight (Mn) of about 150 to about 15,000 g/mol, as measured by 1H NMR and assuming one olefin unsaturation per chain (preferably 200 to 12,000, preferably 250 to 10,000, preferably 300 to 10,000, preferably 400 to 9500, preferably 500 to 9,000, preferably 750 to 9,000); and
an isobutyl chain end to allylic vinyl group ratio of 0.8:1 to 1.35:1.0.
In certain embodiments, R11 can comprise a polypropylene copolymer comprising:
at least 50 (preferably at least 60, preferably 70 to 99.5, preferably 80 to 99, preferably 90 to 98.5) mol % propylene, from 0.1 to 45 (preferably at least 35, preferably 0.5 to 30, preferably 1 to 20, preferably 1.5 to 10) mol % ethylene, and from 0.1 to 5 (preferably 0.5 to 3, preferably 0.5 to 1) mol % diene (such as C4 to C12 alpha-omega dienes (such as butadiene, hexadiene, octadiene), norbornene, ethylidene norbornene, vinylnorbornene, norbornadiene, and dicyclopentadiene), wherein the polymer has:
at least 90% allyl chain ends (preferably at least 91%, preferably at least 93%, preferably at least 95%, preferably at least 98%);
a number average molecular weight (Mn) of about 150 to about 20,000 g/mol, as measured by 1H NMR and assuming one olefin unsaturation per chain (preferably 200 to 15,000, preferably 250 to 12,000, preferably 300 to 10,000, preferably 400 to 9,500, preferably 500 to 9,000, preferably 750 to 9,000); and an isobutyl chain end to allylic vinyl group ratio of 0.7:1 to 1.35:1.0.
In other embodiments of the method, R11 can comprises poly(higher alpha-olefin) or poly(propylene-co-higher alpha-olefin), the higher alpha-olefin including two or more carbon atoms on each side chain. For example, suitable higher alpha-olefins can include, but are not limited to, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 1-tridecene, 1-tetradecene, 1-hexadecene, 1-octadecene and the like.
In certain embodiments, R11 includes those vinyl terminated macromonomers disclosed in U.S. Patent Application Publication Nos. 20120245312, 20120245310, 20120245311, 20120245313, and U.S. Provisional Application No. 61/704,604, the disclosure of each of which is incorporated by reference in its entirety herein.
In the above method of preparation, for the reaction of converting a polymer base unit R11 having a terminal vinyl functionality, a reaction called hydroformylation can be employed. Hydroformylation is a method for introducing an aldehyde functionality while saturating the double bond. A mixture of the normal- and iso-aldehydes can often be co-produced. As a general example, the hydroformylation of a vinyl-terminated polypropylene (PP), ethylene-propylene (EP), or propylene-higher alpha-olefin copolymer is illustrated in Scheme 1 below.
The general conditions and operating parameters of the hydroformylation reaction have been described in U.S. Provisional Application No. 61/704,606, filed Sep. 24, 2012, the disclosure of which is incorporated by reference in its entirety herein.
As previously noted, the method of preparing the compound can include reacting the polymer obtained above with a polyamine (PAM). The reaction is commonly known as hydroamination or reductive amination. When an amine is added to an aldehyde, an imine intermediate and water (a by-product that can be removed) can form. The imine intermediate may be isolated if desired but can also be conveniently reduced to the more stable C—N single bond by a reducing agent (such as a hydride source). The hydride source can be an organometallic metal hydride, hydrogen with catalyst, sodium borohydride, sodium cyanoborohydride, sodium triacetoxyborohydride, lithium aluminum hydride, borane-pryidine complex, trialkylsilanes, or any other hydrogen donor that can reduce an imine (C═N) bond. Alternatively, the imine intermediate can be reduced via catalytic hydrogenation by providing H2 at pressure in the presence of a suitable hydrogenation catalyst, such as platinum oxide, palladium on solid support, Raney nickel, rhodium complexes, ruthenium complexes or other transition metal compounds.
The reactants for the hydroamination can be combined in a reaction vessel at a temperature of −50° C. to 300° C. (e.g., 25° C., or 150° C.). Likewise, the reactants can be combined at a pressure of 0 to 1000 MPa (e.g., 0.5 to 500 MPa, or 1 to 250 MPa) for a residence time of 0.5 seconds to 10 hours (preferably 1 second to 5 hours, preferably 1 minute to 1 hour).
In certain embodiments, the reaction of the amine and aldehyde compounds is performed in an inert solvent at a temperature between room temperature and 140 C under reflux conditions. Suitable cosolvents include alcohol, ethers, benzene, toluene, and xylene.
Other conditions and operating parameters of the hydroamination reaction include those disclosed in U.S. Provisional Application No. 61/704,939, the disclosure of which is incorporated by reference in its entirety herein.
The polyamine for the hydroamination reaction can include linear, branched or cyclic isomers of an oligomer of ethyleneamine, or mixtures thereof, wherein each two neighboring nitrogens in the oligomer of ethyleneamine are bridged by one or two ethyleneamine groups. For example, the polyamine can be selected from polyethyleneamines with general molecular formula H2N(CH2CH2NH)xH (where x=1, 2, 3, . . . ) such as ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, and mixtures thereof. In some embodiments, the polyamine can comprise a heavy polyamine, such as polyethyleneamine heavy bottoms available from Dow Chemical as “Heavy Polyamine X” or HPA-X which has about 6.5 nitrogen atoms per molecule on average.
For example and as embodied herein, the reaction can include reacting the polymer having a terminal aldehyde group (as illustrated by the product obtained from Scheme 1) with a polyamine (diethylenetriamine is used as an example) to provide compounds as depicted in Scheme 2 below.
In some embodiments, the charge molar ratio of the hydroformylated polymer with the PAM can be from 20:1 to 1:20, and in some embodiments, 5:1 to 1:1, depending on the product sought
As illustrated in the above example, the number of polymer chain attached to each polyamine molecule can vary from one to two to three or more. In addition, both primary and secondary amino groups on the polyamine can participate in the reaction with the aldehyde-functionalized polymer. Other commercially available lower or higher polyamines with linear, branched, cyclic or heterocyclic structures can also be used. It is well-known and understood by those skilled in the art that these polyamines can be mixtures of compounds comprised of molecules with a distribution of chain lengths, different level and type of amine (primary, secondary, and tertiary) functional groups, and varying degree of linear, branched and cyclic structures. For example, possible isomers for tetraethylenepentamine include the following:
As the molecular weight of polyamines increases, the number of possible isomers increases as well.
In another aspect of the disclosed subject matter, a compound (additive) is prepared by the method discussed above and various embodiments thereof.
In another aspect, a method for reducing fouling in a hydrocarbon refining process is provided, which comprises providing a crude hydrocarbon for a refining process, and adding to the crude hydrocarbon an additive of Formula I or various embodiments thereof as described above (e.g., at standard operation conditions).
Another aspect of the disclosed subject matter provides a system for refining hydrocarbons that includes at least one crude hydrocarbon refinery component, in which the crude hydrocarbon refinery component includes an additive selected from any one of the additives described herein. The crude hydrocarbon refining component can 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. For example, the crude hydrocarbon refining component can be a heat exchanger (e.g., a crude pre-heat train heat exchanger). Such methods and systems are described in greater details in the following sections and examples.
Another aspect of the disclosed subject matter 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 can be any one or more compounds 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. Other boronating agents can be used, such as those disclosed in co-pending applications US20100038290 and US20100170829, each incorporated by reference herein in its entirety.
The additives of the disclosed subject matter can be used in compositions that prevent fouling, including particulate-induced fouling. In addition to the additives of the disclosed subject matter, the compositions can further contain a hydrophobic oil solubilizer for the additive and/or a dispersant for the additive.
Suitable solubilizers can 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 in its entirety, surfactants that can be included in compositions of the disclosed subject matter can include, for example, 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 disclosed subject matter can further include, for example, viscosity index improvers, anti-foamants, antiwear agents, demulsifiers, anti-oxidants, and other corrosion inhibitors.
Furthermore, the additives of the disclosed subject matter can be added with other compatible components that address other problems that can present themselves in an oil refining process known to one of ordinary skill in the art.
The additives of the disclosed subject matter 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 either reduce fouling or improve some other process parameter.
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 can 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 disclosed subject matter are particularly suitable in reducing or preventing particulate-induced fouling. Thus one aspect of the disclosed subject matter provides a method of reducing and/or preventing, in particular, particulate-induced fouling that includes adding at least one additive of the disclosed subject matter 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. Thus, one embodiment of the disclosed subject matter includes identifying particular areas of a refining process that have relatively high particulate levels, and adding any one of the additives of the disclosed subject matter in close proximity to these areas (e.g., just upstream to the area identified as having high particulate levels).
In some embodiments of the disclosed subject matter, a method to reduce fouling is provided comprising adding any one of the above-mentioned additives or compositions 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 disclosed subject matter, a method to reduce fouling is provided comprising adding any one of the above-mentioned antifouling additives or compositions to a crude hydrocarbon refinery component that is in fluid communication with a process stream. In another embodiment of the disclosed subject matter, 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 some embodiments of the disclosed subject matter, the additives or compositions of the disclosed subject matter 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 disclosed subject matter 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.
In certain embodiments of the disclosed subject matter, the additive is dissolved in an inert carrier solvent by a mechanical blending process to reduce its material viscosity. Suitable carrier solvents include but are not limited to naphtha, mineral oil, hydrocarbon fluid, and paraffinic oil. For example, the additive is diluted with solvent until the viscosity of the resulting solution is acceptable for pumping and transfer of the additive blend to the crude oil stream at ambient conditions. As embodied herein, the additive is diluted until the resulting solution is acceptable for pumping and transfer of the additive blend to the crude oil stream at ambient conditions in refineries subject to cold climates.
The total amount of additive to be added to the process stream can be determined by a person of ordinary skill in the art. In one embodiment, up to about 1000 wppm of additive is added to the process stream. For example, the additive can be added such that its concentration, upon addition, is about 50 ppm, 250 ppm or 500 ppm. More or less additive can be added depending on, for example, the amount of particulate in the stream, the ΔT associated with the particular process and the degree of fouling reduction desired in view of the cost of the additive.
The additives or compositions of the disclosed subject matter can be added in a solid (e.g. powder or granules) or liquid form directly to the process stream. As mentioned above, the additives or compositions can 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 or compositions can be introduced via injection that allows for sufficient mixing of the additive and the process stream.
The disclosed subject matter 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 disclosed subject matter or of any exemplified term. Likewise, the disclosed subject matter is not limited to any particular preferred embodiments described herein. Indeed, many modifications and variations of the disclosed embodiments will be apparent to those skilled in the art upon reading this specification.
To ethylenediamine (1.0 g, 16.64 mmol) in a round-bottomed flask was added a solution of propylene/l-hexene copolymer aldehyde (2.1 g, 3.23 mmol) in benzene (60 ml) at room temperature. The solution turned cloudy immediately upon addition of the aldehyde, which indicated formation of water as a by-product. The reaction mixture was heated to reflux for 3 hours and water was removed by using a Dean-Stark trap. An aliquot analyzed by 1H NMR indicated the major product was the imidazolidine. The volatiles were removed and replaced with tetrahydrofuran (40 ml) and methanol (20 ml). Sodium borohydride (180 mg) was added in small portions to the reaction mixture. After 14 hours, the reaction was quenched with 40 ml of water and extracted with 40 ml of hexane. The organic layer was reduced to a colorless clear liquid product (2.1 g), which is characterized by GPC: Mw 1167, Mn 630, and by elemental analyses: C: 80.79%, H: 14.50%, N: 3.36%.
To triethylenetetramine (2.2 g, 15.04 mmol) in a round-bottomed flask was added a solution of atactic polypropylene aldehyde (33.4 g) in THF (80 ml) and the mixture was heated to reflux for 2 hours. The yellow reaction mixture was cooled to room temperature and methanol (20 ml) was added. Sodium borohydride (1.3 g) was added in small portions to the reaction mixture over a 40 minute interval. The reaction was stirred for an additional hour. Two layers were evident and an aliquot of the top layer showed that the reaction was complete. The reaction mixture was transferred into a separatory funnel, hexane (60 ml) added, and the bottom layer removed. The top layer was gently washed with H2O (3×30 ml) and the aqueous layers added to the original bottom layer. The original bottom layer and aqueous washings were extracted with hexane (60 ml) and this was added to the original top layer. The hexane solubles were reduced to an oil and dried in a vacuum oven at 70° C. for 12 hours. The product obtained was a colorless viscous oil (32.5 g), which was characterized by GPC: Mw 3243, Mn 1412, and by elemental analyses: C: 82.66%, H: 14.52%, N: 2.33%.
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
Additionally or alternately, the disclosed subject matter can include one or more of the following embodiments.
A compound represented by:
wherein R1 is a branched or straight-chained C10-C800 alkyl or alkenyl group; m is an integer between 0 and 10 inclusive;
R2 is represented by
or —CH2—CH2—CH2—CH2—*, wherein the asterisk (*) indicates a connecting point of R2 with the nitrogen that connects with R3; R3 is a C1-C4 branched or straight chained alkylene group; R31 is hydrogen or —R8—R9, wherein R8 is defined the same as R2 above, and R9 is branched or straight-chained C10-C800 alkyl or alkenyl group, or R8 and R9 together are a C1-C4 branched or straight chained alkyl group optionally substituted with one or more amine groups; and further wherein the —N(R31)—R3— repeat unit is optionally interrupted in one or more places by a nitrogen-containing heterocyclic cycloalkyl group; and R4 and R5 are each independently selected from (a) hydrogen, (b) —R6—R7, wherein R6 is defined the same as R2 above, and R7 is a C10-C800 branched or straight chained alkyl or alkenyl group, or (c) a bond connected to R31 in the m-th —N(R31)—R3— repeat unit.
The compound of Embodiment 1, wherein at least one of R1, R7, and R9 comprises polypropylene.
The compound of Embodiment 2, wherein the polypropylene is atactic polypropylene, isotactic polypropylene, or syndiotactic polypropylene.
The compound of Embodiment 2, wherein the polypropylene is amorphous.
The compound of Embodiment 2, wherein the polypropylene includes isotactic or syndiotactic crystallizable units.
The compound of Embodiment 2, wherein the polypropylene includes meso diads constituting from about 30% to about 99.5% of the total diads of the polypropylene.
The compound of Embodiment 2, wherein at least one of R1, R7, and R9 has a number-averaged molecular weight of from about 300 to about 30000 g/mol.
The compound of Embodiment 7, wherein at least one of R1, R7, and R9 has a number-averaged molecular weight of from about 500 to about 5000 g/mol.
The compound of Embodiment 1, wherein at least one of R1, R7, and R9 comprises polyethylene.
The compound of Embodiment 1, wherein at least one of R1, R7, and R9 comprises poly(ethylene-co-propylene).
The compound of Embodiment 10, wherein at least one of R1, R7, and R9 comprises from about 1 mole % to about 90 mole % of ethylene units and from about 99 mole % to about 10 mole % propylene units.
The compound of Embodiment 11, wherein at least one of R1, R7, and R9 comprises from about 10 mole % to about 50 mole % of ethylene units.
The compound of Embodiment 1, wherein at least one of R1, R7, and R9 comprises poly(higher alpha-olefin), the higher alpha-olefin including two or more carbon atoms on each side chain.
The compound of Embodiment 1, wherein at least one of R1, R7, and R9 comprises polypropylene-co-higher alpha-olefin), the higher alpha-olefin including two or more carbon atoms on each side chain.
The compound of Embodiment 1, wherein the nitrogen content in the additive is about 1 wt % to about 10 wt % based on the total weight of the additive.
The compound of Embodiment 1, wherein R3 is —CH2—CH2—, and R31 is hydrogen.
The compound of Embodiment 16, wherein the —N(R31)—R3— repeat unit is interrupted in one or more places by a 1,4-diethylenediamine ring.
A method for preparing compound, comprising: (a) converting a polymer base unit R11 which is a branched or straight-chained C10-C800 alkyl or alkenyl group having a vinyl terminal group, to a polymer having an aldehyde terminal group; (b) reacting the polymer having the aldehyde terminal group obtained in (a) with a polyamine represented by
to generate an imine intermediate, wherein R12 is hydrogen or a C1-C4 branched or straight chained alkyl optionally substituted with one or more amine groups, R13 is a C1-C4 branched or straight chained alkylene group, and x is an integer between 1 and 10, and further wherein the —N(R12)—R13— unit is optionally interrupted in one or more places by a nitrogen-containing heterocyclic group, and wherein when the x-th —N(R12)—R13— unit along with the terminal nitrogen atom forms a heterocyclic cycloalkyl group, the terminal —NH2 is replaced by a —NH— group for valency; and (c) reducing the imine intermediate to form a product with a saturated C—N bond.
The method of Embodiment 18, wherein R11 comprises polypropylene.
The method of Embodiment 19, wherein the polypropylene is atactic polypropylene, isotactic polypropylene, or syndiotactic polypropylene.
The method of Embodiment 19, wherein the polypropylene is amorphous.
The method of Embodiment 19, wherein the polypropylene includes isotactic or syndiotactic crystallizable units.
The method of Embodiment 19, wherein the polypropylene includes meso diads constituting from about 30% to about 99.5% of the total diads of the polypropylene.
The method of Embodiment 18, wherein the molar ratio of R11: polyamine is between about 5:1 and about 1:1.
The method of Embodiment 18, wherein R11 has a number-averaged molecular weight of from about 300 to about 30000 g/mol.
The method of Embodiment 25, wherein R11 has a number-averaged molecular weight of from about 500 to about 5000 g/mol.
The method of Embodiment 18, wherein R11 comprises polyethylene.
The method of Embodiment 18, wherein R11 comprises poly(ethylene-co-propylene).
The method of Embodiment 18, wherein R11 comprises from about 10 mole % to about 90 mole % of ethylene units and from about 90 mole % to about 10 mole % propylene units.
The method of Embodiment 29, wherein R11 comprises from about 20 mole % to about 50 mole % of ethylene units.
The method of Embodiment 18, wherein R11 comprises poly(higher alpha-olefin), the higher alpha-olefin including two or more carbon atoms on each side chain.
The method of Embodiment 18, wherein R11 comprises polypropylene-co-higher alpha-olefin), the higher alpha-olefin including two or more carbon atoms on each side chain.
The method of Embodiment 18, wherein R11 comprises poly(ethylene-co-higher alpha-olefin), the higher alpha-olefin including two or more carbon atoms on each side chain.
The method of Embodiment 18, wherein at least 50% of the terminal vinyl groups of R11 are an allylic vinyl group.
The method of Embodiment 18, wherein the polyamine comprises linear, branched or cyclic isomers of an oligomer of ethyleneamine, or mixtures thereof, wherein each two neighboring nitrogens in the oligomer of ethyleneamine are bridged by one or two ethyleneamine groups.
The method of Embodiment 35, wherein the polyamine is selected from ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, hexaethyleneheptamine, and mixtures thereof
The method of Embodiment 18, wherein the polyamine comprises a heavy polyamine
The method of Embodiment 18, wherein (a) comprises reacting the polymer having the terminal vinyl group with carbon monoxide and molecular hydrogen.
The method of Embodiment 38, wherein the reaction in (a) is performed under the catalysis of Rh(acac)(CO)2 with the addition of PPh3.
The method of Embodiment 18, wherein (c) comprises reacting the polymer having the aldehyde terminal group obtained in (a) with the polyamine using a reducing agent.
The method of Embodiment 40, wherein the reducing agent includes sodium borohydride.
A compound produced by the method of any of Embodiments 18-41.
A method for reducing fouling in a hydrocarbon refining process comprising providing a crude hydrocarbon for a refining process; adding an additive to the crude hydrocarbon, the additive being represented by the compound of any of Embodiments 1-17.
A method for reducing fouling in a hydrocarbon refining process comprising providing a crude hydrocarbon for a refining process; and adding an additive to the crude hydrocarbon, the additive being prepared by the method of any of Embodiments 18-41.
A system for refining hydrocarbons comprising: at least one crude hydrocarbon refinery component; and crude hydrocarbon in fluid communication with the at least one crude hydrocarbon refinery component, the crude hydrocarbon comprising an additive represented by the compound of any of Embodiments 1-17.
The system of claim 45, wherein the at least one crude hydrocarbon refinery component is 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.
The disclosed subject matter 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.
