Additive compositions for mercury removal from liquid hydrocarbons

Abstract

The present application relates generally to processes, systems, and compositions for removing mercury from liquid hydrocarbons. In one embodiment, the application pertains to a method for removing mercury from hydrocarbons. The method comprises reacting a mercury species within the hydrocarbons with an additive composition to produce a reaction product. The reaction product typically comprises a different speciation for mercury than the original mercury species. The reaction product is then removed from the hydrocarbons. The additive composition employed comprises a sulfur or heteroatom donating substance and a phase transfer agent wherein the heteroatom is nitrogen, sulfur, oxygen, or a mixture thereof.

Description

ADDITIVE COMPOSITIONS FOR MERCURY REMOVAL FROM LIQUID HYDROCARBONS CROSS REFERENCE TO RELATED APPLICATION(S)

[0001] This application relates to U.S. Provisional Patent Application Serial Nos.63 / 650,501, filed on May 22, 2024, the entire disclosures of which are incorporated herein by reference. FIELD OF THE INVENTION

[0002] The present invention relates generally to processes, systems, and compositions for removing mercury from liquid hydrocarbons. BACKGROUND AND SUMMARY

[0003] What is needed are improved processes, systems, and compositions for reducing, i.e., decreasing, or removing one or more mercury species in liquid hydrocarbons such as crudes, condensates, slop oil, and / or distillates. Ideally, such improved processes, systems, and compositions would be cost-efficient and energy efficient. Advantageously, the instant application meets one or more of the aforementioned needs.

[0004] In one embodiment, the application pertains to a method for removing mercury from hydrocarbons. The method comprises reacting a mercury species within the hydrocarbons with an additive composition to produce a reaction product. The reaction product typically comprises a different speciation for mercury than the original mercury species. The reaction product is then removed from the hydrocarbons. The additive composition employed comprises a heteroatom donating substance and a phase transfer agent wherein the heteroatom is sulfur, nitrogen, oxygen, or a combination thereof.

[0005] In another embodiment, the application pertains to a composition comprising water; from about 1 to about 500 ppm of a heteroatom donating substance wherein the heteroatom is sulfur, nitrogen, oxygen, or a combination thereof; and from about 10 to about 1000 ppm of a phase transfer agent. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] So that the way the above recited features, advantages, and objects of the present invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings only illustrate preferred embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments that vary only in detail. In the drawings:

[0007] Figure 1 illustrates kinetic studies of hydrocarbon condensate.

[0008] Figure 2 illustrates kinetic studies of hydrocarbon condensate.

[0009] Figure 3 illustrates kinetic studies of hydrocarbon condensate.

[0010] Figure 4 illustrates a GC-ICP-MS analysis of condensate.

[0011] Figure 5 illustrates a GC-ICP-MS analysis of condensate.

[0012] Figure 6 illustrates a GC-ICP-MS analysis of condensate.

[0013] Figure 7 illustrates a GC-ICP-MS analysis of condensate.

[0014] Figure 8 illustrates a GC-ICP-MS analysis of second condensate.

[0015] Figure 9 illustrates a GC-ICP-MS analysis of second condensate.

[0016] Figure 10 illustrates a GC-ICP-MS analysis of second condensate.

[0017] Figure 11 shows steps of representative processes.

[0018] Figure 12 shows steps of representative processes.

[0019] Figure 13 shows steps of representative processes.

[0020] Figure 14 shows steps of representative processes.

[0021] Figure 15 shows steps of representative processes.

[0022] Figure 16 shows steps of representative processes.

[0023] Figure 17 shows steps of representative processes.

[0024] Figure 18 shows steps of representative processes.

[0025] Figure 19 shows steps of representative processes. DETAILED DESCRIPTION

[0026] Certain terms are used throughout the following description and claims to refer to particular system components. As one skilled in the art will appreciate, different companies may refer to a component by different names.Definitions

[0027] The terms "comprise" (as well as forms, derivatives, or variations thereof, such as "comprising" and "comprises") and "include" (as well as forms, derivatives, or variations thereof, such as "including" and "includes") are inclusive (i.e., open-ended) and do not exclude additional elements or steps. For example, the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Accordingly, these terms are intended to not only cover the recited element(s) or step(s) but may also include other elements or steps not expressly recited. Furthermore, as used herein, the use of the terms "a" or "an" when used in conjunction with an element may mean "one," but it is also consistent with the meaning of "one or more," "at least one," and "one or more than one." Therefore, an element preceded by "a" or "an" does not, without more constraints, preclude the existence of additional identical elements.

[0028] The use of the term "about" applies to all numeric values, whether or not explicitly indicated. This term generally refers to a range of numbers that one of ordinary skill in the art would consider as a reasonable amount of deviation to the recited numeric values (i.e., having the equivalent function or result). For example, this term can be construed as including a deviation of ±10 percent of the given numeric value provided such a deviation does not alter the end function or result of the value. Therefore, a value of about 1% can be construed to be a range from 0.9% to 1.1%. Furthermore, a range may be construed to include the start and the end of the range. For example, a range of 10% to 20% (i.e., range of 10%-20%) includes 10% and also includes 20%, and includes percentages in between 10% and 20%, unless explicitly stated otherwiseherein. Similarly, a range of between 10% and 20% (i.e., range between 10% - 20%) includes 10% and also includes 20%, and includes percentages in between 10% and 20%, unless explicitly stated otherwise herein.

[0029] The term "if" may be construed to mean "when" or "upon" or "in response to determining" or "in accordance with a determination" or "in response to detecting," that a stated condition precedent is true, depending on the context. Similarly, the phrase "if it is determined [that a stated condition precedent is true]" or "if [a stated condition precedent is true]" or "when [a stated condition precedent is true]" may be construed to mean "upon determining" or "in response to determining" or "in accordance with a determination" or "upon detecting" or "in response to detecting" that the stated condition precedent is true, depending on the context.

[0030] It is understood that when combinations, subsets, groups, etc. of elements are disclosed (e.g., combinations of components in a composition, or combinations of steps in a method), that while specific reference of each of the various individual and collective combinations and permutations of these elements may not be explicitly disclosed, each is specifically contemplated and described herein. By way of example, if an item is described herein as including a component of type A, a component of type B, a component of type C, or any combination thereof, it is understood that this phrase describes all of the various individual and collective combinations and permutations of these components. For example, in some embodiments, the item described by this phrase could include only a component of type A. In some embodiments, the item described by this phrase could include only a component of type B. In some embodiments, the item described by this phrase could include only a component of type C. In some embodiments, the item described by this phrase could include a component oftype A and a component of type B. In some embodiments, the item described by this phrase could include a component of type A and a component of type C. In some embodiments, the item described by this phrase could include a component of type B and a component of type C. In some embodiments, the item described by this phrase could include a component of type A, a component of type B, and a component of type C. In some embodiments, the item described by this phrase could include two or more components of type A (e.g., A1 and A2). In some embodiments, the item described by this phrase could include two or more components of type B (e.g., B1 and B2). In some embodiments, the item described by this phrase could include two or more components of type C (e.g., C1 and C2). In some embodiments, the item described by this phrase could include two or more of a first component (e.g., two or more components of type A (A1 and A2)), optionally one or more of a second component (e.g., optionally one or more components of type B), and optionally one or more of a third component (e.g., optionally one or more components of type C). In some embodiments, the item described by this phrase could include two or more of a first component (e.g., two or more components of type B (B1 and B2)), optionally one or more of a second component (e.g., optionally one or more components of type A), and optionally one or more of a third component (e.g., optionally one or more components of type C). In some embodiments, the item described by this phrase could include two or more of a first component (e.g., two or more components of type C (C1 and C2)), optionally one or more of a second component (e.g., optionally one or more components of type A), and optionally one or more of a third component (e.g., optionally one or more components of type B).

[0031] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to make and use the invention. The patentable scope is defined by the claims, and may include other examples that occur to thoseskilled in the art. Such other examples are intended to be within the scope of the claims if they have elements that do not differ from the literal language of the claims, or if they include equivalent elements with insubstantial differences from the literal language of the claims.

[0032] Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of skill in the art to which the disclosed invention belongs. All citations referred herein are expressly incorporated by reference. General Process

[0033] In one embodiment the application pertains to methods for removing mercury from hydrocarbons. The specific hydrocarbons that may benefit from the instant process are not particularly limited and generally include liquid hydrocarbons that comprise one or more mercury species to be reduced or eliminated. Suitable hydrocarbons may comprise crude, condensate, a slop oil, distillate, or any combination thereof.

[0034] The processes described herein remove many different types of mercury species with representative mercury species including, for example, any mercury species that may form a reaction product in the process that comprises a different speciation for mercury than the original mercury species in the hydrocarbon. In particular, the processes described herein are effective for those original mercury species that are dissolved or otherwise suspended in hydrocarbons that tend form a precipitate or other solid when subjected to the steps described herein.

[0035] In general, the processes comprise reacting a mercury species within the hydrocarbons with an additive composition to produce a reaction product. The reaction product usually comprises a different speciation for mercury than the mercury species. At least a portion of thereaction product is then removed from the hydrocarbons. The additive composition may comprise a heteroatom donating substance and a phase transfer agent. Reacting

[0036] The mercury species within the hydrocarbons are reacted with an additive composition to produce a reaction product. The reaction conditions are not particularly critical so long as the desired reaction product or products are formed which can be at least partially removed from the mixture. The specific reaction conditions may differ depending upon, for example, the hydrocarbon composition, the mercury species in the hydrocarbon composition, the desired reaction product, the equipment employed, and the desired results.

[0037] Typically, the reacting may occur in any convenient manner. For example, in some embodiments the additive composition may be a component of a wash water solution that is mixed with the hydrocarbons in a mixing vessel. In other embodiments the additive composition may be added to a feed of the hydrocarbons before the hydrocarbons are introduced into a reactor. If a reactor is employed, then the hydrocarbons and the additive composition may be introduced into a reactor on a continuous basis, a batch basis, or a combination thereof.

[0038] The reacting of the mercury species comprising the hydrocarbons with the additive composition may be performed in any convenient vessel which may vary depending upon, for example, the origin of the hydrocarbons. In some embodiments, the reacting of the mercury species comprising the hydrocarbons with the additive composition may be performed in a dedicated reactor. In other embodiments the reacting may occur in, for example, a mixing tank, a storage tank, or in a pipe with a static mixer, or in a pipe with equipment or bends for mixing and / or residence time, and / or any combination thereof.Removing

[0039] The reacting step generally produces a reaction product that comprises a different speciation for mercury than the mercury species. At least a portion up to all of the reaction product formed is then removed from the hydrocarbons. The specific manner of removing is not particularly critical and may depend upon, for example, the original hydrocarbon composition, the mercury species in the original hydrocarbon composition, the amount and type of the reaction product, the equipment employed, and the desired amount of removal.

[0040] In situations where the reaction product is a precipitate and / or other solid suitable removing steps may comprise, for example, a solid-liquid separation process. The specific solid- liquid separation process is not particularly limited and may comprise filtration, centrifugation, sedimentation, flotation, or any combination thereof. In other embodiments, the removing may additionally, or alternatively comprise, for example, an extraction process. Such extraction processes may comprise steps such as, for example, desalting, water washing, sulfidic extraction, pH adjustment, or any combination thereof. Additive Compositions

[0041] The additive compositions useful herein vary depending upon, for example, such factors as the original hydrocarbon composition, the type and amount of mercury species in the original hydrocarbon composition, the amount and type of the reaction product desired, the equipment employed, the desired amount of removal of mercury, and / or the other steps employed.

[0042] Typically, useful additive compositions herein may comprise a sulfur or heteroatom donating substance and a phase transfer agent. The heteroatom donating substance may comprise one or more heteroatoms selected from oxygen, nitrogen, sulfur, or a combination thereof. Asolvent such as water and / or other useful solvent or solvents may be employed if desired. In some cases, the additive composition comprising a heteroatom donating substance, a phase transfer agent, and / or other components is in an aqueous solution.

[0043] The specific sulfur or heteroatom donating substance and amount may vary depending upon, for example, the type and amount of mercury species in the original hydrocarbon composition, the amount and type of the reaction product desired, and the amount and type of phase transfer agent and other components. Taking as an example to illustrate the processes pertaining to this application, the sulfur donating substance may comprise a sulfide, a thiolate functionalized solid, a thiol, a dithiol, a dithiocarbamate, or any combination thereof. In some embodiments, the sulfur or heteroatom donating substance may further comprise a polymer such as, for example, a NALMET™ compound from Nalco and / or a METCLEAR™ compound available from GE / Suez.

[0044] Representative sulfides in the additive compositions may include, for example, those compositions wherein the sulfide is Na2S, (NH4)2S, a polysulfide having the formula MSx wherein M is selected from Na2, K2, or Ca, or any combination thereof. Representative thiolate functionalized solids in the additive compositions may include, for example, self-assembled monolayers on mesoporous supports (SAMMS), a functionalized silica gel (SiliaMetS), or any combination thereof. Representative dithiols may comprise 1,3,4-thiadiazole-2,5-dithiol (TDT).

[0045] As described above, the amount of sulfur or heteroatom donating substance in the additive composition may vary. Typically, the amount employed depends upon how much mercury is to be removed and the specific sulfur or heteroatom donating substance. In many applications the amount of sulfur or heteroatom donating substance is at least about 1, or at least about 5, or at leastabout 10, or at least about 25 ppm in the aqueous additive composition. On the other hand, the amount of sulfur or heteroatom donating substance in the aqueous additive composition may be present in an amount of up to about 400, or up to about 400, or up to about 200, or up to about 100, or up to about 50 ppm.

[0046] The amount and type of phase transfer agent is not particularly limited so long as the phase transfer agent facilitates phase transfer and thereby may increase the reaction kinetics and / or the extent of reaction between mercury and the sulfur or heteroatom donating substance. Suitable phase transfer agents are those that are at least partially soluble to near fully soluble in the aqueous phase and oil phase.

[0047] In some embodiments, the phase transfer agent comprises a quaternary ammonium salt, a quaternary phosphonium salt, an imidazolium salt, or any combination thereof. The specific quaternary ammonium salt is not particularly limited and may comprise an alkyl ammonium salt, an aryl ammonium salt, or any combination thereof. Particularly preferable alkyl ammonium salts include those with an alkyl group of 1 to 6 carbons, preferably 1 to 3 carbons. In some embodiments, the quaternary ammonium salt comprises tetrabutylammonium chloride (TBAC).

[0048] The amount of the phase transfer agent in the additive composition may vary depending upon the nature of the phase transfer agent and hydrocarbons in which it will be employed. Generally, an amount is employed that is useful to control the desired reaction kinetics and / or the extent of reaction. In some embodiments, the amount of the phase transfer agent is at least about 1, or at least about 10, or at least about 50, or at least about 250, or at least about 500 ppm in the aqueous additive composition. On the other hand, the amount of phase transfer agentin the aqueous additive composition may be present in an amount of up to about 1000, or up to about 900, or up to about 750, or up to about 600, or up to about 500 ppm

[0049] The additive composition is generally an aqueous composition, but other solvents may be employed so long as they do not substantially interfere with the desired reaction. Similarly, additional optional ingredients for the aqueous additive composition may be added so long as they do not substantially interfere with the desired mercury removal.

[0050] The above description is also applicable to certain additives that comprise sulfur and / or nitrogen in the chemical structure such as, for example, functionalized silica gel (SiliaMetS) with cysteine, diamine on the chemical structure. Examples Example 1 - Tetrabutyl Ammonium chloride addition with Na2S

[0051] Figure 1 shows kinetic studies of hydrocarbon condensate with 10 ppm Na2S (1 wt%) at 250 rpm with or without phase transfer agent (500 ppm, tetrabutylammonium chloride, TBAC).

[0052] As shown in Figure 1, the kinetics reaction and extent of reaction increases at low mixing(250 rpm, 3.7 kW / m3) increaseswhen tetrabutylammonium chloride (TBAC) is also present.TBAC is an oil soluble salt may be employed as a phase transfer catalyst.

[0053] Higher mixing intensities (250 vs 750 rpm, 3.7 vs 99 W / m3) show no difference in thereaction kineticsand extent of reaction between Na2S and Na2S with TBAC. It is possible that themass transfer limitationsare minimized at 750 rpm (99 W / m3) mixing intensity. This couldexplain the lack of effect of TBAC at higher mixing intensities. Example 2 - Tetrabutyl Ammonium chloride addition with Na2S

[0054] Figure 2 shows kinetic studies of hydrocarbon condensate with various additives in 125 ml Parr reactor at ambient temperature and pressure. Higher concentrations (10 vs 1000 ppm) of the main mercury reactive compound, Na2S, increases the reaction rate modestly. The addition of a phase transfer agent, 1000 ppm tetrabutylammonium chloride (TBAC), increases the reaction rate and extent of rate more significantly especially at higher sulfide concentrations.

[0055] As shown in Figure 2,increased reaction kinetics and extent were observed with increasingNa2S concentration withtetrabutylammonium chloride (1000 ppm) at low mixing intensities (250rpm, 3.7 kW / m3). Example 3 - Tetrabutyl Ammonium chloride addition with Na2S

[0056] Figure 3 shows kinetic studies of hydrocarbon condensate with different mercury reactive additives with 1000 ppm of additive in 125 ml Parr reactor at ambient temperature and pressure with 250 rpm mixing (3.7 W / m3). The reaction rate of (NH4)2S is faster than Na2S. Higher oil solubility of (NH4)2S may contribute to a faster reaction rate. Addition of a phase transfer agent, tetrabutylammonium chloride (TBAC), to Na2S increases the reaction rate.

[0057] Condensate Reactivity: Summary of the reactivity of mercury in condensate with various additives. Additives were reacted for 1 hr. before filtration with 0.45 μm filter. The initialconcentration of mercury in condensate before filtration is 2,300 ppb. Functional speciation studies indicate condensate is >95% elemental mercury.

[0058] Summary of condensate reactivity. The table below is a summary of the reactivity of mercury condensed with various additives. Additives were reacted for 1 hr. before filtration with 0.45 μm filter. The initial concentration of mercury in condensate before filtration is 2,300 ppb. Functional speciation studies indicate condensate is >95% elemental mercury.

[0059] Table 1 for Condensate Additive Elemental (17-21 s) Hg (SR)2and / or HgSHg after filtration NP(800-1200 s)(ppb) Baseline Peak Peak (1000 s) 900 ppb Na2S Complete removal Sharping of peak (970 s) 600TBAC No removal Partially removed 700 Na2S + TBAC Complete removal Mostly removed 100Na2SxComplete removal Sharping of peak (1100600 s) (NH4)2S Complete removal Partially removed 100SiliaMetS thiol No removal Sharping, shift of peak 600 (1100 s) TDT Complete removal Large decrease 100

[0060] Na2S + TBAC, (NH4)2S, and TDT quantitatively reacted elemental mercury (Hg0) and most of the other mercury species to form species that can be removed by filtration (HgS)

[0061] Na2S, and Na2Sxquantitatively reacted with Hg0 to mercury that can be removed byfiltration (HgS). It also formed new species of mercury, possibly HgS NP, as shown by the sharping of a peak in 800-1200 s.

[0062] Condensate is a dark liquid that comprises some waxes / semi-solids. It contains 2,300 ppb total mercury. Functional speciation of condensate shows that it contains 15% volatile mercury, 65% filterable mercury, and 20% non-filterable and non-volatile mercury. Aging has had minimal effect on its composition. Example 4 - Tetrabutyl Ammonium chloride addition with Na2S

[0063] Figure 4 shows GC-ICP-MS analysis of condensate with and without 10 ppm Na2S addition followed by 0.45 μm filtration. The mercury concentration after filtration and no chemical addition is 900 ppb. The additive decreases the concentration to 600 ppb. The Hg0 peak at 17-21 s decreases while a new peak at 970 s forms. The results suggest that Na2S is converting Hg0to a less volatile species such as HgS NP.

[0064] Figure 5 shows a repeat of examining the reactivity of Na2S with condensate. The results are like previous results except the appearance of a new peak occurs at 900 s as opposed to 970 s.

[0065] Tetrabutylammonium chloride (TBAC) reacted with some non-volatile mercury in condensate. Condensate was dosed with 1,000 ppm TBAC, allowed to react, and filtered before GC- ICP-MS analysis. The addition of TBAC reduced mercury from 900 ppb to 700 ppb after filtration. The addition of TBAC does not react with Hg0 as shown by the unchanged peak at 17-21 s. It partially reacted with the non- volatile mercury (800-1200 s) which may contain Hg(SR)2 and / or HgS NP based on its high removal rate and the small reduction of the peak area. No additional peaks were formed suggesting that the combination of TBAC reacts with mercury species to form HgS particles larger than 0.45 μm. It is hypothesized that TBAC may be causing HgS NP to agglomerate into filterable HgS particles.

[0066] Figure 6 shows a GC-ICP-MS analysis of condensate with and without 1000 ppm tetrabutylammonium chloride (TBAC) addition followed by 0.45 μm filtration. The mercury concentration after filtration and no chemical addition is 900 ppb. The additive decreases the concentration to 700 ppb. The Hg0 peak at 17-21 s is unchanged while non-volatile mercury peak (800-1200 s) is slightly reduced. No new peaks are formed. The results suggest that TBAC is converting non-volatile mercury, such as HgS NP, to filterable HgS particles.

[0067] A combination of 10 ppm Na2S and 1,000 ppm tetrabutylammonium chloride (TBAC) reacted with Hg0 and non-volatile mercury in condensate. Condensate was dosed with 10 ppm Na2S and 1000 ppm TBAC, allowed to react, and filtered before GC-ICP-MS analysis. The addition of Na2S and TBAC reduced mercury from 900 ppb to 100 ppb after filtration. The combination quantitatively reacts with Hg0 as shown by the disappearance of the peak at 17-21 s. It partially reacted with the non-volatile mercury (800-1200 s) based on its high removal rate and the reduction of the peak area. No additional peaks were formed suggesting that the combination of Na2S and TBAC reacts with mercury species such as Hg(SR)2 and / or HgS NP to form HgS particles larger than 0.45 μm.

[0068] Figure 7 shows GC-ICP-MS analysis of condensate with and without a combination of 10 ppm Na2S and 1000 ppm tetrabutylammonium chloride (TBAC) addition followed by 0.45 μmfiltration. The mercury concentration after filtration and no chemical addition is 900 ppb. The additive decreases the concentration to 100 ppb. The Hg0 peak at 17-21 s and non-volatile mercury peak (800-1200 s) is significantly reduced. No new peaks are formed. The results suggest that TBAC is converting Hg0 and non-volatile mercury, such as Hg(SR)2 and HgS NP, to filterable HgS particles.

[0069] Comparison of the reaction products of mercury in condensate with Na2S, TBAC, and Na2S + TBAC show a complicated reaction pathway. TBAC reacts with mercury in the 800-1200 s range to form filterable mercury (HgS). Na2S reacts with Hg0to form some non-filterable mercury in the 800-1200 s range. It is possible that it is reacting with mercury species to form HgS NP that are too small to be filtered. The combination of Na2S and TBAC increase overall mercury removal. It is possible that the TBAC additive is allowing HgS NP formed by the reaction with Na2S to agglomerate or to grow larger. One possible mechanism is that TBAC is increasing the ionic strength of the solution thereby shielding charge-charge repulsions between HgS NP. This may give them the opportunity to agglomerate and grow into large particles.

[0070] Summary of a second condensate reactivity. Table 2: Summary of the reactivity of mercury in a second condensate which is different than the condensate above with various additives. Additives were reacted for 1 hr. before filtration with 0.45 μm filter. The initial concentration of mercury in the second condensate is 500 ppb. Functional speciation studies indicate the second condensate is >95% non-volatile and non-filterable mercury. It is suspected it is a mercury thiolate (Hg(SR)2) or mercury sulfide nanoparticles (HgS NP) species.Additive Elementa Hg(SR) 2 and / or HgS Hg after filtration 1(17-21 s) NP (8—1200 s) (ppb) Baseline No peak Peak (centered at 1000 s) 500 ppb Na2SComplete removal <10TBAC Sharpen, shifted peak500 (920 s) Na2S +Complete removal <10TBACNa2Sx Complete removal <10(NH4)2SComplete removal <10SiliaMetSComplete removal <10thiol TDT

[0071] Na2S, Na2Sx, (NH4)2S, and SiliaMetS thiol quantitatively reacted with mercury species in second condensate at 800-1200 s (potentially Hg(SR)2 and / or HgS NP) to form mercury that can be removed by filtration (HgS).

[0072] Tetrabutylammonium chloride (TBAC) incompletely reacted with mercury species at 800- 1200 s (potentially Hg(SR)2 and / or HgS NP) as shown by the sharping of a peak at 920 s. The newly formed species is non-filterable suggesting it is not bulky HgS.

[0073] TBAC in combination with Na2S quantitatively reacted to mercury species at 800-1200 s (potentially Hg(SR)2 and / or HgS NP) to form mercury that can be removed by filtration (HgS).

[0074] The second condensate used in this study is aged. It contains almost no Hg0 (<5%) and is mostly non- volatile and non-filterable mercury (>95%). It is suspected that the main constituent is a Hg(SR)2. Fresh condensate from the same origin is known to have Hg0 (>90%, 300-700 ppb). It is suspected that the mercaptans (3 ppm) may react with Hg0 to form the non-volatile and non-filterable Hg(SR)2species. This allows for an examination on the reactivity and reaction products of unspecified Hg(SR)2 species with different additives in a condensate matrix.

[0075] Sodium sulfide (Na2S) reacted with mercury in second condensate to form filterable HgS. The second condensate was dosed with 10 ppm Na2S, allowed to react, and filtered before GC- ICP-MS analysis. The addition of Na2S reduced mercury from 500 ppb to <10 ppb after filtration (>98% removal). It is suspected that Na2S quantitatively reacts with Hg(SR)2as shown by the disappearance of the peak at 800-1200 s. This suggests that Hg(SR)2 compounds can be precipitated by Na2S.

[0076] Figure 8 shows GC-ICP-MS analysis of second condensate with and without 10 ppm Na2S addition followed by 0.45 μm filtration. The mercury concentration after filtration and no chemical addition is 500 ppb. The additive decreases the concentration to <10 ppb. It is suspected that Na2S quantitatively reacts with Hg(SR)2 to form filterable HgS as shown by the disappearance of the peak at 800-1200 s.

[0077] Tetrabutylammonium chloride (TBAC) reacted with mercury in second condensate to form filterable HgS. Second condensate was dosed with 1,000 ppm TBAC, allowed to react, and filtered before GC-ICP-MS analysis. The addition of TBAC did not change the concentration after filtration (<5% removal). The GC-ICP-MS data suggests some reaction occurred. The broad peak of the unreacted sample at 800-1200 s sharpens to a distinct peak at 900 s with a range of 800-950s after reaction with TBAC. The reaction of TBAC with Hg(SR)2 compounds is not obvious. Thedata suggests TBAC reacts with a significant amount of the Hg(SR)2to either another Hg(SR)2species or HgS NP.

[0078] Figure 9 shows a GC-ICP-MS analysis of second condensate with and without 1000 ppm tetrabutylammonium chloride (TBAC) addition followed by 0.45 μm filtration. The mercury concentration after filtration is unchanged with chemical addition. However, a reaction is suggested. The broad peak of the unreacted sample at 800-1200 s sharpens to a distinct peak at 900 s with a range of 800-950 s after reaction with TBAC.

[0079] A combination of sodium sulfide (Na2S) and tetrabutylammonium chloride (TBAC)reacted withmercury in second condensate to form filterable HgS. The second condensate wasdosed with 10ppm Na2S and 1,000 ppm TBAC, allowed to react, and filtered before GC-ICP-MSanalysis. Thecombination of additives decrease mercury from 500 ppb to <10 ppb after filtration(>98% removal). It issuspected that the combination quantitatively reacts with Hg(SR)2compounds as shown by the disappearance of the peak at 800-1200 s. This suggests that Hg(SR)2compounds can be precipitated by a combination of Na2S and TBAC.

[0080] Figure 10 shows GC-ICP-MS analysis of second condensate with and without 10 ppm Na2S and 1000 ppm tetrabutylammonium chloride (TBAC) addition followed by 0.45 μm filtration. The mercury concentration after filtration and no chemical addition is 500 ppb. The additive decreases the concentration to <10 ppb. It is suspected that the combination quantitativelyreacts with Hg(SR)2compounds to form filterable HgS as shown by the disappearance of the peak at 800-1200 s.

[0081] The mercury in second condensate appears to have reactivity with TBAC. It forms a different dissolved species of mercury. No filterable HgS is formed. It converts the range of mercury species at >900 s to a more specific mercury species at 900 s. Representative Example

[0082] The table below shows the effect of various additives and doses on mercury removal. The reactions were conducted at ambient conditions with 1 hr reaction time. Removal by filtration was conducted using syringe filters of 0.45 um and 40 um rating. Removal by water washing (WW) was conducted by mixing reacted sample with equal volumes of D.I. water for 15 min followed by separation for 1 hr. While sulfur donating compounds are shown to be effective, compounds with other heteroatoms are also effective. For example, the following were effective: 1, 3, 4, thiadiazole-2,5 dithiol ; 2, 4, 6,-trimercaptotriazine (Surface functionality of SiliaMetS DMT, a silica adsorbent); Cysteine (Surface functionality of SiliaMetS Cysteine, a silica adsorbent); and 2,3-dimercapto propanol. Phase Initial Hg H Hg ansfer agent Add g removal Additive || Phase tr itve transfer Hg removal removal (ppm) agent conc 0.45 um 40 um filte WW 1h (ppm) (ppb) filter (%) r (%) (%) Sodium polysulfide 1317 2453 63% -2% 72%Sodium polysulfide 1261 2490 67% 2% 72%Calcium polysulfide 1287 2340 77% 7% 76%Calcium polysulfide 1289 2453 78% 14% 77%Nalmet 1295 2593 75% 13% 92%Nalmet 1253 2490 77% 14% 90%SiliaMetS thiol 1010 2500 72% 18% 67%SiliaMetS thiol 966 2417 71% 16% 68%2,3 dimercaptosuccinic acid 986 2357 68% -1% 47%2,3 dimercaptosuccinic acid 966 2393 70% 2% 49%2,3 dimercapto propanol 958 2447 78% -2% 93%1,3, 4 Thiadiazole-2,5 dithiol 986 2730 90% 2% 74%No additive 0 2680 61% 2%Na2S || Decyl methyl imidizolium Cl 1000 100 2806 77% -13% 35%

[0083] Additive composition + Filtration: As shown in FIG. 11, the process may include the following steps: 1) Additive composition is dosed into hydrocarbon feed, 2) Additive composition and hydrocarbon feed react in a continuous stirred tank reactor (CSTR) or other type of reactor where mercury species are precipitated, 3a) Reacted hydrocarbon feed is then filtered; or 3b) Alternatively, other solid-liquid processes may be used in place of filtration includingsedimentation, flotation, centrifugation, electrostatic separation, etc. Some embodiments may use combinations of solid-liquid separations.4) The process results in a low mercury product.

[0084] Additive composition + water wash or sulfidic extraction: The example process of FIG.12 includes the following steps: 1) Additive composition is dosed into hydrocarbon feed, 2) Additive composition and hydrocarbon feed react in a CSTR or other type of reactor where mercury species are precipitated, 3) Reacted hydrocarbon feed is then mixed with water or an additive composition such as described herein , 4) Results in a low mercury product, 5) Spent wash water or sulfidic solution is treated or disposed.

[0085] Water wash or sulfidic extraction: The example process of FIG.13 includes the following steps: 1) Feed is mixed with a wash water with additive composition or sulfidic solution, 2) The spent wash water or sulfidic solution is separated from the feed, 3) Results in a low mercury product, 4) Spent wash water or sulfidic solution is treated or disposed.

[0086] Water wash or sulfidic extraction with recycling: The process of FIG. 14 is the same as FIG.13, except with a recycle loop on the water wash / sulfidic extraction solution. A fraction of fresh wash water or sulfidic extraction solution is added with an equal volume being discharged for treatment or disposal. This will reduce the amount of water / sulfidic solution needed.

[0087] Process options: Several options exist for implementation of the disclosed processes. Non- limiting examples of process options are provided below.

[0088] Overall: The overall process may be batch or continuous.

[0089] Additive compositions are as described above. Those additive compositions may be used alone or in combination with each other and / or other glycols or acids, such as (ethylene glycol(MEG), triethylene glycol (TEG)) or terephthalic acid (or similar) may also increase removal.

[0090] Reactor: The reactor used in the disclosed process may be a continuous stirred tank reactor (CSTR), or any other dedicated reactor. By way of non-limiting example, the reactor may include an existing tank with mixer or recirculation pump (e.g., a floating storage and offloading (FSO) storage tank, a D / S storage tank, a U / S oil treatment tank). By way of another non-limiting example, the reactor may include a pipe and static mixer (e.g., a desalter). By way of further non- limiting example, the reactor may include a pipe with equipment or bends for mixing and residence time (e.g., a wellhead chemical injection, injection before a heat exchanger, a separator with baffles).

[0091] Solid-liquid separation: Solid-liquid separation as used in the disclosed process may be performed using a variety of techniques. By way of non-limiting example, such separation techniques may include filtration, centrifugation, sedimentation (e.g., in a cargo hold, in an oil storage tank), or flotation.

[0092] Extraction: The extraction used in the disclosed process may be performed using a variety of techniques and associated equipment. Non-limiting examples include using a desalter. As another non-limiting example, the extraction may include washing using an existing tank with a mixer, recirculation pumps, and spray nozzles. As another non- limiting example, the extraction may include sulfidic extraction. Extraction may include water washing, which may or may not include performing pH adjustments and / or the use of a further additive or additives. Extraction may further include recycling of wash water and / or the sulfidic extraction solution.

[0093] Wash water / additive solutions source: The water source of the wash water and / or sulfidic solution may include, by way of non-limiting example, fresh water, fresh process water,recycle / spent water, or a non-freshwater source. Non-limiting examples of recycle / spent water include cooling tower blowdown, stripped sour water, and desalter brine water. Non-limiting examples of non-freshwater sources include seawater and produced water.

[0094] Spent wash water / sulfidic additive solution disposal: Disposal of the spent wash water and / or sulfidic solutions used in the disclosed process may include treatment and / or direct disposal in a disposal well. Disposal may include disposal in an injection well alone or after a combination of other injection streams such as produced water and / or refinery wastewater. Treatment of the spent wash water and / or sulfidic additive solution for eventual disposal may be performed using an existing treatment system or using a dedicated aqueous treatment system. Existing treatment systems may include treatment systems used for produced water (e.g., gravity separators, gas flotation, media filtration / adsorption, chemical treatment) or refinery effluent systems (e.g., gravity separators, flotation, chemical flocculation / coagulation, bioreactors, media filtration / adsorption). A dedicated treatment system for spent wash water and / or sulfidic solutions ay include a system dedicated to mercury and / other heavy metal removal.

[0095] Emulsion removal and disposal: The emulsion phase, which may be withdrawn with the spent wash water / additive solution may contain significant concentrations of mercury. Separation and treatment of this stream may be a beneficial part of the process. The oil / hydrocarbon and aqueous phase may be separated from the emulsion by gravity separation, flotation, centrifugation, or other processes. The aqueous phase can be disposed of or recycled in the process. The oil / hydrocarbon phase may be disposed or treated further by filtration, centrifugation, or othermethods and combined with the low mercury produced. The solids removed by the separation process may contain higher mercury and may require disposal.

[0096] Chemical injection upstream of desalter. In this example embodiment, the reaction between mercury and the additive composition occurs in pipes and at a desalter mixing valve. Mercury partitions from the crude oil to the desalter brine water and emulsion phase. The desalter brine water and optionally the emulsion phase is withdrawn to the effluent treatment plant. Mercury is removed in the process units in the effluent treatment plant including any one or a combination of the following: sedimentation, activated carbon or other adsorbents, gravity separators (API separators), flotation, and / or a bioreactor.

[0097] Chemical injection upstream of oil treatment process in upstream. In this example embodiment, additive compositions are injected near the wellhead or before oil / water separation tanks. Turbulence and long pipe run allow enough residence time for the additive composition to react with mercury. Mercury is separated out in the oil / water separation processes (tanks with baffles) or other solid-liquid separations units (filters, centrifuges).

[0098] Water washing / extraction in FSO cargo tanks, or other oil storage tanks. Feed with an initial concentration of mercury is placed in a holding tank. Water is pumped into a tank to a volume large enough to allow recirculation of water. Additive compositions are added to either the oil phase, aqueous phase, or both. The water and / or emulsion phase is pumped into the oil phase directly or with nozzles to allow for mixing of the water and oil phases. This continues for several volumes or until mercury concentrations decrease in the oil phase. The pumps are turned off to allow the water and oil phases to separate. The water and / or emulsion phase is removed to result in a lower mercury concentration in oil. In certain embodiments, this process may also be used forsulfidic extraction. In another embodiment, the pump may withdraw from both the oil and water phase to a static mixer before returning to the tank for enhanced mixing. In another embodiment, in a continuous process oil and water can be pumped to a static mixer before the tank. Water and oil would then be continuously withdrawn from the tank. In the water washing / extraction process, the spent wash water / sulfidic solution may be disposed in an injection well alone or with other aqueous streams (e.g., produced water, refinery wastewater).

[0099] Example Visualization: The figures described below provide example visualizations for embodiments of the water washing / extraction in vessels, such as FSO cargo tanks, or other oil storage tanks. In the depicted embodiments below, the hydrocarbon phase will generally have a reduced mercury concentration relative to its source.

[0100] FIG.15 depicts a multi-tank system (e.g., a two-tank system) that utilizes water / oil circulation to maximize mixing between the aqueous and oil phases. One of the tanks, such as a storage tank, may be outfitted with crude oil wash (COW) nozzles. The nozzles rotate to allow for distribution and mixing. In this example, pump 1 and the COW nozzles are used for an initial transfer of water (e.g., an aqueous solution with additive compositions) from tank 2 to tank 1 with metal-containing hydrocarbons. Pump 2 is then utilized, along with a series of valves and the COW nozzles, to recirculate the mixture to enhance mixing. This allows the additive compositions in the aqueous phase to interact with the metals (e.g., mercury) in the hydrocarbons.

[0101] Alternative embodiments for the disclosed process used with water washing / extraction in FSO cargo tanks, or other oil storage tanks are depicted below. In particular, FIGS.16-18 depict embodiments where the aqueous and oil phases are mixed using recirculation, and optionally additional features.

[0102] FIG. 16 depicts an embodiment where the aqueous phase is recirculated via introduction above the oil phase. The aqueous phase is withdrawn from a level of the tank corresponding to the aqueous phase and reintroduced to the tank into the oil phase. This may be considered a batch process.

[0103] FIG. 17 depicts an embodiment where the aqueous phase is recirculated via introduction above the oil phase and a COW nozzle. The aqueous phase is withdrawn from a level of the tank corresponding to the aqueous phase and reintroduced to the tank into the oil phase. This may be considered a continuous process, but a batch approach is also contemplated.

[0104] Certain embodiments of this disclosure may utilize a static mixer situated outside (or, in other embodiments, inside) of the vessel. FIG. 18 depicts an embodiment where a batch process uses a storage tank and includes water inlet and outlet options for direct injection of the aqueous phase into the hydrocarbon phase, and / or withdrawal of both hydrocarbons and the aqueous phase at a position proximate their interface (e.g., as an emulsion phase). Both withdrawn streams may be mixed in a static mixer in a particular ratio and the resulting mixture may be reintroduced to the top of the hydrocarbon phase (away from the interface of both phases) to encourage diffusion / mixing. The ratio may be controlled by the rate of withdrawal of the phases.

[0105] FIG.19 depicts an embodiment of a continuous process that utilizes a static mixer upstream of a tank, such as an existing oil cleaning / storage tank. In this example embodiment,water and oil (e.g., an aqueous solution with an additive composition and the hydrocarbons, respectively) are introduced to a static mixer, which then introduces a mixture into the tank.

[0106] The downstream portion of the embodiment of FIG. 19 includes an oil outlet for the hydrocarbons, an outlet for an emulsion phase proximate the interface between the hydrocarbon and aqueous phases, and a water outlet. The rate of injection of water and oil may be balanced with the rate of withdrawal of the hydrocarbons, water, and emulsion phase.

[0107] It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplifications of example embodiments. For example, the functions described above and implemented as the best mode for operating the present invention are for illustration purposes only. Other arrangements and methods may be implemented by those skilled in the art without departing from the scope and spirit of this invention. Moreover, those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.

Claims

WHAT IS CLAIMED IS:

1. A method for removing mercury from hydrocarbons, comprising: reacting a mercury species within the hydrocarbons with an additive composition to produce a reaction product wherein the reaction product comprises a different speciation for mercury than the mercury species; and removing at least a portion of the reaction product from the hydrocarbons; wherein the additive composition comprises a sulfur or heteroatom donating substance and a phase transfer agent wherein the heteroatom is nitrogen, sulfur, oxygen, or a mixture thereof.

2. The method of claim 1, wherein the additive composition is in an aqueous solution.

3. The method of claim 1, wherein the sulfur or heteroatom donating substance comprises a sulfide, a thiolate functionalized solid, a thiol, a dithiol, a dithiocarbamate, or any combination thereof.

4. The method of claim 3, wherein the sulfur or heteroatom donating substance comprises the thiol, the dithiol, or the dithiocarbamate, or any combination thereof and wherein the sulfur or heteroatom donating substance further comprises a polymer.

5. The method of claim 3, wherein the sulfide isNa2S, (NH4)2S, a polysulfide having theformula MSxwherein M is selected from Na2, K2, or Ca, or any combination thereof.

6. The method of claim 3, wherein thethiolate functionalized solid comprises self-assembledmonolayers on mesoporous supports (SAMMS), a functionalized silica gel (SiliaMetS), or any combination thereof.

7. The method of claim 3, wherein the dithiol comprises 1,3,4-thiadiazole-2,5-dithiol (TDT).

8. The method of claim 1, wherein the phase transfer agent comprises an oil soluble cationsalt.

9. The method of claim 1, wherein the phase transfer agent comprises a quaternary ammonium salt, a quaternary phosphonium salt, an imidazolium salt, or any combination thereof.

10. The method of claim 9, wherein the quaternary ammonium salt comprises an alkyl ammonium salt, an aryl ammonium salt, or any combination thereof.

11. The method of claim 10, wherein the quaternary ammonium salt comprises tetrabutylammonium chloride (TBAC).

12. The method of claim 1, wherein the additive composition comprises from about 1 to about 500 ppm of the sulfur or heteroatom donating substance and from about 10 to about 1000 ppm of the phase transfer agent.

13. The method of claim 1, wherein the hydrocarbons comprise a crude, a condensate, a slop oil, a distillate, or any combination thereof.

14. The method of claim 1, wherein the additive composition is a component of a wash water solution that is mixed with the hydrocarbons in a mixing vessel 15. The method of claim 1, wherein the additive composition is added to a feed of the hydrocarbons before the hydrocarbons are introduced into a reactor.

16. The method of claim 1, wherein the hydrocarbons and the additive composition are introduced into a reactor on a continuous basis.

17. The method of claim 1, wherein the hydrocarbons and the additive composition are introduced into a reactor and are mixed in a batch process.

18. The method of claim 1, wherein the reaction of the mercury species with the hydrocarbons with the additive composition is performed in a dedicated reactor, in a mixing tank, in a pipe with a static mixer, in a pipe with equipment or bends for mixing and residence time, or any combinationthereof.

19. The method of claim 1, wherein the reaction product is a precipitate and wherein the removing comprises a solid-liquid separation process.

20. The method of claim 19, wherein the solid-liquid separation process comprises filtration, centrifugation, sedimentation, flotation, or any combination thereof.

21. The method of claim 1, wherein the removing comprises an extraction process comprising desalting, water washing, sulfidic extraction, pH adjustment, or any combination thereof.

22. A composition comprising: water; from about 1 to about 500 ppm of a heteroatom donating substance wherein the heteroatom is nitrogen, sulfur, oxygen, or a mixture thereof; and from about 10 to about 1000 ppm of a phase transfer agent.

23. The composition of claim 22 wherein the phase transfer agent comprises tetrabutylammonium chloride.

24. The composition of claim 23 which further comprises a hydrocarbon and one or more mercury compounds.

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