Ethylene copoylmers for hydrocarbon applications

Abstract

Embodiments of the present disclosure are directed towards a composition that includes a hydrocarbon mixture and at least an ethylene acrylic ester copolymer having about 10 to about 50 weight % of alkyl acrylate based on the total weight of the ethylene acrylic ester copolymer, where the ethylene acrylic ester copolymer is formed from (A) a first monomer of ethylene, (B) a second monomer selected from the group consisting of vinyl acetate, alkyl acrylic esters, alkyl (meth)acrylic esters and combinations thereof, and (C) a third monomer of carbon monoxide. The ethylene acrylic ester copolymer can optionally also include (D) propylene.

Description

ETHYLENE COPOYLMERS FOR HYDROCARBON APPLICATIONSField of DisclosureEmbodiments of the present disclosure are directed towards ethylene copolymers and in particular ethylene copolymers for hydrocarbon applications.BackgroundPetroleum and refined petroleum products (e.g., crude oils, condensates fuel oil, middle distillates, diesel fuel, and heavy fuel oil) are complex mixtures of various compounds including paraffinic, olefinic, and aromatic hydrocarbons, as well as resins and asphaltenes. The composition of these mixtures can have a strong effect on their flow characteristics, especially at low temperatures. For example, paraffin wax molecules can precipitate at room temperature or at low temperatures, depending on the petroleum or the refined petroleum product composition. Once precipitated, the paraffin wax can cause an increase in the viscosity of the petroleum and / or paraffin deposition leading to clogged pipelines, pumps, engine filters, etc. making transport, storage and use of these fluids challenging. Thus, paraffin wax precipitation and deposition can lead to production downtime resulting in reduced output in petroleum and refined petroleum product production.One petroleum source used in producing fuels that suffers from high paraffin wax content is the so-called "opportunistic heavy crude oil." For example, fuels refined from this opportunistic heavy crude oil can include up to 30% paraffin wax. In addition to opportunistic heavy crude oil, there are other petroleum and / or refined petroleum products that can contain high levels of paraffin wax. When present, upon cooling the paraffin wax in these materials (e.g., petroleum and / or refined petroleum products) tends to crystalize as an interlocking network of fine sheets that can cause a variety of problems. For example, the interlocking network of fine sheets of paraffin wax can clog engine filters, where the paraffin wax if cooled enough can trap the remaining fuel in cage-like structures that entirely stops the flow of the fuel.The temperature at which this paraffin wax precipitation can occur depends upon the composition of the petroleum or refined petroleum products and their respective pour point temperature. The pour point (PP) of a petroleum or refined petroleum product is the lowest temperature at which the petroleum or refined petroleum product will pour or flow when it iscooled, without stirring, under standard cooling conditions. The PP represents the lowest temperature at which petroleum or refmed petroleum product is capable of flowing under gravity. Paraffin precipitation can cause an increase in the viscosity of petroleum and flow restrictions and / or clogs in petroleum pipelines, storage tanks or other installations. Thus, paraffin precipitation and deposition leads to production downtime resulting in reduced output in oil and gas production and reduced usability of refined petroleum products.Three strategies have been used to manage paraffin wax crystal formation in petroleum and / or refined petroleum products: (1) blending the refined petroleum product (e.g., diesel fuel) with lighter fuels such as kerosene; however, such blending reduces the energy value of the refined petroleum product; (2) heating the petroleum and / or refmed petroleum product during storage and transportation ; however, many customers and regions may not readily have access to heated utilities; and (3) add a chemical reagent to the petroleum and / or refmed petroleum products, such as a pour point depressant (PPD).Chemical treatments based on using PPDs are commonly used to ensure flow to increase the petroleum and refined petroleum product transportation and productivity. PPDs are additives used to change the rheology of petroleum and / or refined petroleum products to improve their flowability at low temperatures. The efficiency of the additive used as a PPD is attributed to their ability to modify the wax crystals' size and shape and to disperse the paraffin wax. Most PPDs are polymers designed to include nonpolar crystalline segments that are similar to the paraffin chains and segments that include polar moieties. The nonpolar paraffin-like segments interact with wax molecules, whereas the polar moieties are responsible for providing electrostatic repulsion to wax crystals and disorganizing the crystallization process of the wax. However, the effectiveness of PPDs are highly dependent on the composition of the petroleum or refmed petroleum product. Thus, a PPD proven to be effective for petroleum from one location may not be effective for petroleum from another location, even from within the same well and / or from wells within the same field. Similarly, varied refining processes result in disparate wax distributions across refined petroleum products. Developing a specific type of PPD that is universally applicable for diverse fields and finished fuels remains a challenge, which emphasizes the need to have a wide range of polymers for different compositions of petroleum and refined petroleum products.SummaryThe present disclosure provides for a composition that is less dependent on the makeup of the petroleum or refined petroleum product to be an effective pour point depressant (PPD). Specifically, the composition of the present disclosure is more universally applicable to a wide range of petroleum and / or refined petroleum products due to the diversity of functionality in the ethylene acrylic ester copolymer of the present disclosure. This diversity of functionality in the ethylene acrylic ester copolymer, as discussed herein, makes this compound more universally effective as a PPD with petroleum or refined petroleum products. The composition of the present disclosure can interact with the petroleum and / or refined petroleum product via, e.g., interactions such as covalent bonds or other interactions such as ionic bonds, van der Waals forces, and / or hydrogen bonding and thereby better act as a universal PPD.For the various embodiments, the composition of the present disclosure includes (1) a hydrocarbon mixture that include a paraffin wax; and (2) an ethylene acrylic ester copolymer. The ethylene acrylic ester copolymer can include about 10 to about 50 weight % of alkyl acrylate based on the total weight of the ethylene acrylic ester copolymer. For the various embodiments, the ethylene acrylic ester copolymer (e.g., a random or block copolymer of monomers A / B / C) is formed from (A) a first monomer of ethylene, (B) a second monomer selected from the group consisting of vinyl acetate, alkyl acrylic esters, alkyl (meth)acrylic esters and combinations thereof, and (C) a third monomer of carbon monoxide. For the various embodiments, the alkyl acrylate can be selected from the group consisting of methyl acrylate, ethyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate, and combinations thereof. In additional embodiments, the ethylene acrylic ester copolymer can have about 10 to about 35 weight % of alkyl acrylate, where the wt.% is based on the total weight of the ethylene acrylic ester copolymer.For the various embodiments, the ethylene acrylic ester copolymer can be formed from (A), (B), (C) and 0.1 to 5 wt.% of (D) a monomer of propylene, where the wt.% is based on the total weight of the ethylene acrylic ester copolymer. In an additional embodiment, the ethylene acrylic ester copolymer is formed from 15 to 40 wt.% of (B), 5 to 20 wt.% of (C) with the remainder being (A), where the wt.% is based on the total weight of the ethylene acrylic ester copolymer. In a further embodiment, the ethylene acrylic ester copolymer is formed from 15 to 40 wt.% of (B), 5 to 20 wt.% of (C), 0.1 to 5 wt.% of (D) with the remainder being (A) where the wt.% is based on the total weight of the ethylene acrylic ester copolymer. For the variousembodiments, the ethylene acrylic ester copolymer can be a random copolymer. For the various embodiments, the ethylene acrylic ester copolymer can have a polydispersity index of about 5 to about 11.5.For the various embodiments, the composition can have 10 to 1000 parts per million (ppm) of the ethylene acrylic ester copolymer based on actives for the hydrocarbon mixture.

[0011] For the various embodiments, the hydrocarbon mixture can be selected from the group consisting of petroleum and refined petroleum products, as provided herein. For the various embodiments, the hydrocarbon mixture that includes paraffin wax is a petroleum or a petroleum product, as provided herein.The present disclosure also includes a method of treating a hydrocarbon mixture that includes paraffin wax. The method includes providing the ethylene acrylic ester copolymer as provided herein and mixing the ethylene acrylic ester copolymer with the hydrocarbon mixture that includes paraffin wax.Brief Description of the DrawingsFIG. 1 is a temperature versus viscosity profile of 5 wt.% solutions of Examples of the polymers of the present disclosure and Comparative Examples in Aromatic 150.

[0014] FIG. 2 is an enlarged view of the temperature versus viscosity profile of 5 wt.% solutions of Examples of the polymers of the present disclosure and Comparative Examples in Aromatic 150.Detailed DescriptionThe present disclosure provides for a composition that is less dependent on the makeup of the petroleum or refined petroleum product to be an effective pour point depressant (PPD). Specifically, the composition of the present disclosure is more universally applicable to a wide range of petroleum and / or refined petroleum products due to the nature of the composition towards the petroleum and / or refined petroleum products. Through moieties present on the petroleum and / or refined petroleum product, the composition of the present disclosure can interact with the petroleum and / or refined petroleum product and thereby better act as a universal PPD.As used herein, the term "petroleum" includes unprocessed crude oil, synthetic crude oil, sour crude oil and other mixtures of liquids and solids of alkanes, naphthenes, aromatics and asphaltenes.As used herein, the term "refined petroleum products" include processed crude oil, including refined crude oil products that can include solid petroleum, solid petroleum products, petroleum and petroleum products such as diesel fuel, fuel oil, kerosene, gasoline, heavy fuel oils, marine fuels, and bunker fuels.As used herein, the term "hydrocarbon mixture" can be selected from the group consisting of petroleum or refined petroleum products, as provided herein, where each such hydrocarbon mixture includes paraffin wax. For the various embodiments, the hydrocarbon mixture that includes paraffin wax can be a petroleum or a petroleum product, as provided herein. As appreciated by one skilled in the art, the petroleum or the petroleum product can be a liquid petroleum or a liquid petroleum product, where at least a portion of the petroleum could also be solid or partially solid at room temperature (e.g., 23 °C).As used herein, the term "paraffin wax" includes a mixture of hydrocarbons containing from about 10 to about 40 carbon atoms, where the majority of the paraffin wax consists of straight chain saturated hydrocarbons and the remainder as branched paraffins, cycloparaffins, and aromatic paraffins.For the various embodiments, the composition of the present disclosure includes the hydrocarbon mixture, as provided herein, that includes paraffin wax as discussed herein. For the various embodiments, the amount of paraffm wax present in the hydrocarbon mixture, as provided herein, can be up to about 35 percent by total weight of the hydrocarbon mixture.

[0021] The composition of the present disclosure further includes an ethylene acrylic ester copolymer. For the various embodiments, the ethylene acrylic ester copolymer can include about 10 to about 50 weight % of alkyl acrylate (based on the total weight of the ethylene acrylic ester copolymer) as discussed herein. In some embodiments, the ethylene acrylic ester copolymer can include about 15 to about 40 weight % of alkyl acrylate, based on the total weight of the ethylene acrylic ester copolymer. In additional embodiments, the ethylene acrylic ester copolymer has about 10 to about 35 weight % of alkyl acrylate, where the wt.% are based on the total weight of the ethylene acrylic ester copolymer. For the various embodiments, the alkyl acrylate can be selected from the group consisting of methyl acrylate, ethyl acrylate, n-butyl acrylate, iso-butyl acrylate, tert-butyl acrylate and combinations thereof.

[0022] In more specific embodiments, the ethylene acrylic ester copolymer (e.g., a random or block copolymer of monomers A / B / C) is formed from (A) a first monomer of ethylene, (B) a second monomer selected from the groupconsisting of vinyl acetate, alkyl acrylic esters, alkyl (meth)acrylic esters and combinations thereof, and (C) a third monomer of carbon monoxide. A particularly preferred ethylene acrylic ester copolymers is formed from (A) monomers of ethylene, (B) vinyl acetate and (C) carbon monoxide. Another particularly preferred ethylene acrylic ester copolymer is formed from (A) monomers of ethylene, (B) n-butyl acrylate and (C) carbon monoxide.For the various embodiments, the term "alkyl acrylic esters" refers to, for example, methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, n-pentyl acrylate, neopenty 1 acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate, neooctyl acrylate, 2-ethyl hexyl acrylate, nonyl acrylate, neononyl acrylate, decyl acrylate, neodecyl acrylate, lauryl acrylate, palmity 1 acrylate and stearyl acrylate.For the various embodiments, the term "alkyl (meth)acrylic esters" refers to, for example, methyl (meth)acrylate, ethyl (meth)acrylate and butyl (meth)acrylate, propyl (meth)acrylate), isopropyl (meth)acrylate, n-butyl (meth)acrylate, s-butyl (meth)acrylate, i- butyl (meth)acrylate, t-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate and decyl (meth)acrylate.For the various embodiments, the ethylene acrylic ester copolymer can be formed from 15 to 40 wt.% of (B), 5 to 20 wt.% of (C) with the remainder being (A), where the wt.% are based on the total weight of the ethylene acrylic ester copolymer. In additional embodiment, the ethylene acrylic ester copolymer can be formed from 20 to 35 wt.% of (B), 5 to 15 wt.% of (C) with the remainder being (A), where the wt.% are based on the total weight of the ethylene acrylic ester copolymer. In additional embodiment, the ethylene acrylic ester copolymer can be formed from 25 to 35 wt.% of (B), 7.5 to 12.5 wt.% of (C) with the remainder being (A), where the wt.% are based on the total weight of the ethylene acrylic ester copolymer. For the various embodiments provided herein, (B) is n-butyl acrylate.For the various embodiments, the ethylene acrylic ester copolymer can also be formed from (A), (B), (C), as provided herein, and 0.1 to 5 wt.% of (D) a monomer of propylene, where the wt.% is based on the total weight of the ethylene acrylic ester copolymer. In a preferred embodiment, the ethylene acrylic ester copolymer can be formed from 15 to 40 wt.% of (B), 5 to 20 wt.% of (C), 0.1 to 5 wt.% of (D) with the remainder being (A), where the wt.% are basedon the total weight of the ethylene acrylic ester copolymer. In additional embodiment, the ethylene acrylic ester copolymer can be formed from 20 to 35 wt.% of (B), 5 to 15 wt.% of (C), 0.1 to 5 wt.% of (D) with the remainder being (A), where the wt.% are based on the total weight of the ethylene acrylic ester copolymer. In additional embodiment, the ethylene acrylic ester copolymer can be formed from 25 to 35 wt.% of (B), 7.5 to 12.5 wt.% of (C), 1 to 3 wt.% of (D) with the remainder being (A), where the wt.% are based on the total weight of the ethylene acrylic ester copolymer. For the various embodiments provided herein, (B) is preferably n-butyl acrylate.For the various embodiments provided herein, the ethylene acrylic ester copolymer can be a random copolymer.The ethylene acrylic ester copolymer of the present disclosure can have a melt index as measured according to ASTM D-1238 at 190 °C and at 2.16 kg from 5 to 150 g / 10 minutes, more preferably from 10 to 100 g / 10 minutes and most preferably from 25 to 75 g / 10 minutes. In addition, for the various embodiments the ethylene acrylic ester copolymer can have a poly dispersity index of about 5 to about 11.5.The ethylene acrylic ester copolymer formed from monomers A, B, C and, optionally, (D), as provided herein, can be prepared by known methods; for example, as described in WO 2005 / 087868 Al, U.S. Pat. No. 5,700,890, U.S. Pat. No. 4,351,931, U.S. Pat. No. 2,897,183 and / or U.S. Pat. No. 3,350,372, among others. Generally, the ethylene acrylic ester copolymer of A / B / C and optionally D can be prepared by direct, free-radical, high-pressure copolymerization of the unsaturated monomers. The ethylene acrylic ester copolymer can be prepared in a stirred high-pressure autoclave, a high-pressure tubular reactor or in a high- pressure stirred reactor or combinations of the two. Suitable pressure conditions for the polymerization are from 100 to 300 MPa, preferably from 150 to 200 MPa. The reaction temperatures are, for example, in the range from 160 to 320 °C, preferably in the range from 200 to 280 °C. Initiators for the free-radical polymerization can also be used, where examples include organic peroxides, oxygen, azo compounds and mixtures thereof. Examples of useful free-radical initiators include, for example, one or more peroxides selected from the following commercially obtainable substances: lauroyl peroxide, didecanoyl peroxide, 2,5-dimethyl-2,5- di(2-ethylhexanoylperoxy)hexane, tert-amyl peroxy-2-ethylhexanoate, dibenzoyl peroxide, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxydiethyl acetate, tert-butyl peroxydiethylisobutyrate, l ,4-di(tert-butylperoxycarbo)cyclohexane as an isomer mixture, tert-butyl pcrisononanoatc, 1 , 1 -di(tcrt-butylpcroxy)-3,3,5-trimcthylcyclo-hcxanc, 1 , 1 -di(tcrt- butylperoxy)cyclohexane, methyl isobutyl ketone peroxide, tert-butyl peroxyisopropyl carbonate, 2,2-di-tert-butylperoxy)butane or tert-butyl peroxyacetate; tert-butyl peroxybenzoate, di-tert-amyl peroxide, dicumyl peroxide, the isomeric di(tert- butylperoxyisopropyl)benzenes, 2,5-dimethyl-2,5-di-tert-butylperoxyhexane, tert-butyl cumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hex-3-yne, di-tert-butyl peroxide, 1,3- diisopropyl monohydroperoxide, cumene hydroperoxide or tert-butyl hydroperoxide. Particularly suitable peroxides are di-tert-butyl peroxide, tert-butyl peroxypivalate, tert-butyl peroxyisononanoate or dibenzoyl peroxide or mixtures thereof. An example of an azo compound is azobisisobutyronitrile (AIBN). The free-radical initiators are used in amounts customary for polymerizations.The rate of addition of (A), (B), (C) and, optionally (D), monomers to the reactor will depend on variables such as the polymerization temperature, reactor pressure, the combination along with the concentration of the (A), (B), (C) and, optionally, (D) monomers needed to achieve the target composition of the ethylene acrylic ester copolymer. For the various embodiments, the ethylene acrylic ester copolymer can be continuously removed from the reactor (e.g., the autoclave) and then separated from the unreacted monomers and solvent (if solvent was used) by conventional means, e.g., vaporizing the non-polymerized materials and solvent under reduced pressure and / or at an elevated temperature.The present disclosure also includes a method of treating a hydrocarbon mixture, as provided herein, which includes paraffin wax. The ethylene acrylic ester copolymer of the present disclosure can be added to, for example, petroleum and / or refined petroleum products, as defined herein, individually or as a mixture of such ethylene acrylic ester copolymer and optionally in combination with other additives known per se. The method includes providing the ethylene acrylic ester copolymer, as provided herein, and mixing the ethylene acrylic ester copolymer with the hydrocarbon mixture that includes paraffin wax. For the various embodiments, mixing the ethylene acrylic ester copolymer of the present disclosure with the hydrocarbon mixture having the paraffin wax can occur at a temperature of 20 °C to 60 °C and at a pressure of 50 to 150 kPa.For the various embodiments, the mixture of the ethylene acrylic ester copolymer and the hydrocarbon mixture can have 10 to 1000 parts per million (ppm) of the ethylene acrylic ester copolymer based on actives for the hydrocarbon mixture. All individual values and subranges from 10 to 1000 ppm of the ethylene acrylic ester copolymer based on actives for the hydrocarbon mixture are included herein; for example, the mixture of the ethylene acrylic ester copolymer and the hydrocarbon mixture can have a ppm of the ethylene acrylic ester copolymer in the mixture based on actives for the hydrocarbon mixture from a lower limit of 10, 20, 50, 100 or 250 to an upper limit of 1000, 900, 800 or 500 ppm of the ethylene acrylic ester copolymer based on actives for the hydrocarbon mixture. Modifications to this method are of course possible and can be undertaken by those skilled in the art without unreasonable effort.For the various embodiments, to facilitate mixing with the hydrocarbon mixture the ethylene acrylic ester copolymer can first be dissolved, for example, in a C4 to C15 solvent, where the solvent can be aromatic, aliphatic or mixtures thereof. Examples of suitable aromatic and aliphatic hydrocarbons and alkoxy alkanols commonly used in the industry, include heptane, hexane, Aromatic 100, Aromatic 150, Aromatic 200, toluene, xylene, or diluent from crude oil processing, such as kerosene, naphtha or brightstock, and combinations thereof. Dissolving the ethylene acrylic ester terpolymer in the C4 to C15 solvent with stirring over 1 to 3 hours. The use of other solvents is also possible.As seen and discussed in the Examples section, below, test results demonstrate the surprisingly good performance of the polymeric additives used in accordance with the disclosure as pour point depressants in conventional crude oil and diesel fuel compositions. Viscosity measurement, as defined below in the Examples section, indicate the polymers used in accordance with the disclosure also enable better and more convenient handling, since they can be mixed in at low temperatures and also have a lower viscosity and a lower pour point than conventional additives. As a result, they do not have to be warmed up or have to be warmed up to a lesser extent before they are mixed into the fuel oil. For example, viscosity measurements from data collected from compositions that include 5 wt. % of the hydrocarbon mixture based on the total weight of the composition demonstrated compositions have a viscosity of 10 to 40 cP in a temperature range of -10 to 10 °C. This 5 wt.% compositions that include 5 wt. % of thehydrocarbon mixture based on the total weight of the composition would be highly beneficial to customers in cold regions.EXAMPLESThe examples below are provided to be illustrative only and are not intended to define or limit the embodiments in any way.In the Examples (EX) and CE Examples (CE), various terms and designations for materials are used including, for instance, the following:Table 1 — MaterialsEthylene Acrylic Ester Copolymer EX 1 — EX 5; and CE A and CE BThe ethylene acrylic ester copolymer of EX 1 through EX 5; and CE A and CE B from Table 2 were prepared as follows. EX have an "A / B / C" or an "A / B / C / D" copolymer structure, while the CE have an "A / B" structure, where A is derived from ethylene, B is derived from n- butyl acrylate and C is derived from carbon monoxide, and D is derived from propylene.An autoclave was charged with a mixture of ethylene (E), n-butyl acrylate (nBA), carbon monoxide (CO), and propylene (PP) in the amounts as seen in Table 2. Organic peroxide (t-butyl peroctoate) as a 1 wt.% to 3 wt.% solution in odorless mineral spirits was added as a polymerization initiator to the mixture, which was subjected to a set pressure of approximately 27,000 psi (1,898 kg / cm2). The reactor temperature was set to a target temperature of 205 °C. Under the polymerization conditions shown in Table 3, the copolymer was continuously synthesized and subsequently converted into pellet forms by melt extrusion. The conditions listed in Table 3 arc averages over the time span that the Examples were collected. The "autoclave-made" experimental reactor copolymer thus formed was found to have the characteristics set forth in Table 4. The weight percent of nBA, CO, and P are based on the total weight of the Example or CE respectively.Table 2 — EX and CE CompositionsTable 3. Polymerization conditions of EX 1 — EX 5; and CE A and CE B.The properties of EX 1 — EX 5 and CE A and CE B are provided in Table 4 below.The melt index was measured according to ASTM D-1238 at 190°C and at 2.16 kg.Table 4 - EX and CE Physical PropertiesPreparation of Solvent-Based EX and CE Samples:A five (5) weight percent (wt.%) solution of each of the EX and CE was prepared in a four- neck round bottom flask equipped with a mechanical stirrer, thermocouple, and condenser as follows. The copolymer was added to A150 and the copolymer / A150 mixture was heated under a nitrogen blanket to 80 °C for 120 minutes with stirring at 300 rpm. The solvent-based EX and CE samples were cooled to room temperature after complete dissolution of the copolymer pellets. Test MethodsMelt index, MI, is measured in accordance with ASTM D-1238 at 190 °C and at 2.16 kg, where values are reported in g / 10 min.Dynamic viscosity of the solvent-based EX and CE samples was determined using a TA Instruments-Waters LLC Discovery HR-1 with a temperature sweep from 60 °C to -10 °C with a cooling rate of 1 °C / min, shear rate of 30 s'1, using a concentric cylinder DIN geometry. The viscosity measurements are presented in FIGS. 1 and 2 from data collected from the 5 wt.% solutions of the EX copolymers in the A150. With respect to the results, the viscosity of the EX terpolymers is an aspect of their handling when they are mixed in at low temperatures. As the results of FIGS. 1 and 2 illustrate, the ethylene acrylic ester terpolymer of EX 1-4 used in accordance with the disclosure in the 5 wt.% solution have distinctly lower viscosity at low temperatures, which is required for use by customers in cold regions.Pour Point DepressionThe evaluation of the EX and CE as pour point depressant was studied through preparation of diesel samples and a hard-to-treat conventional crude oil sample dosed with different concentrations from each EX and CE (100 and 250 parts per million (ppm) based on actives for diesel and 500 ppm for crude oil). To measure the pour point in this application, the Scientifique de Laboratoire MPP 5Gs Pour Point Analyzer was used, which has high repeatability and reproducibility with a 0.1 °C resolution (ASTM D97). The EX and CE were dosed directly intothe diesel fuel samples, which were stirred 1 hour to ensure sample homogeneity before analyzing. The untreated crude oil was first heated to 60 °C in a water bath and shaken well to ensure a homogeneous mixture. A 10 mL sample of the untreated crude oil was added to a 20 mL sample vial with SEPTA cap for formulation and digestion. The appropriate amount of the polymeric additive formulation was added to the 10 mL crude oil sample and shaken well. The vial containing the treated crude oil was then placed in the water bath at 60 °C for one hour. After digestion, the 20 mL sample vial was again shaken well. Empty PPD vials were placed into an aluminum block, which had been previously heated to 60 °C. A 0.5 pl., sample of the formulation was then dispensed into the pour point vials and capped for pour point measurements. The dosed samples were compared to a blank. For each dosage level, samples were prepared in duplicate. The average of the two points were reported.The performance testing for each solvated EX and CE in A 150 was measured at various additive concentrations (based on actives) in a diesel fuel (Tables 5 and 6) and in a conventional crude oil from Nigeria (Table 7) using pour point analyses. The diesel fuel has a pour point of 15.0 °C (without additive). The Nigeria crude oil has a pour point of 12.0 °C (without additive).Table 5 - Diesel Fuel at 250 ppm, Pour Point of -15.0 °CEX 1 through EX 4 depressed the pour point by 15.0 °C at 250 ppm and EX 5 depressed the pour point by 16.5 °C at 250 ppm whereas CE A only lowered the pour point by 7.5 °C.Table 6 -Diesel Fuel at 100 ppm, Pour Point ofEX 1 depressed the pour point the most, by 12.0 °C at 100 ppm. EX 4 depressed the pour point by 9 °C whereas CE A only lowered the pour point by 7.5 °C. Table 7 - Conventional Crude Oil from Nigeria 500 ppmAs the above results show, the EX 4 and EX 5 depressed the pour point by 1.5 and 3.0 °C at 500 ppm, respectively, whereas the addition of CE B resulted in an increase of the pour point by 6 °C. The observed increase in pour point observed with CE B indicates CE B promotes the precipitation of wax in the conventional crude oil sample instead of inhibiting the precipitation of wax.The test results compiled in Tables 5 through Table 7 demonstrate surprisingly good performance of the EX polymeric additives used in accordance with the disclosure as pour point depressants in conventional crude oil and diesel fuel compositions. Viscosity measurement indicate, the polymers used in accordance with the disclosure also enable better and more convenient handling, since they can be mixed in at low temperatures and also have a lower viscosity and a lower pour point than conventional additives, so that they do not have to be warmed up or have to be warmed up to a lesser extent, before they are mixed into the fuel oil.

Claims

ClaimsWhat is claimed is:

1. A composition, comprising: a hydrocarbon mixture that includes paraffin wax; and an ethylene acrylic ester copolymer having about 10 to about 50 weight % of alkyl acrylate based on the total weight of the ethylene acrylic ester copolymer, wherein the ethylene acrylic ester copolymer is formed from (A) a first monomer of ethylene, (B) a second monomer selected from the group consisting of vinyl acetate, alkyl acrylic esters, alkyl (meth)acrylic esters and combinations thereof, and (C) a third monomer of carbon monoxide.

2. The composition of claim 1, wherein the ethylene acrylic ester copolymer is formed from (A), (B), (C) and 0.1 to 5 wt.% of (D) a monomer of propylene, wherein the wt.% is based on the total weight of the ethylene acrylic ester copolymer.

3. The composition of any one of claims 1-2, wherein the ethylene acrylic ester copolymer has a polydispersity index of about 5 to about 11.5.

4. The composition of any one of claims 1-3, wherein the ethylene acrylic ester copolymer is formed from 15 to 40 wt.% of (B) with the remainder being (A) and (C), wherein the wt.% is based on the total weight of the ethylene acrylic ester copolymer.

5. The composition of any one of claims 1-4, wherein the ethylene acrylic ester copolymer is formed from 5 to 20 wt.% of (C) with the remainder being (A) and (B), wherein the wt.% is based on the total weight of the ethylene acrylic ester copolymer.

6. The composition of any one of claims 1-5, wherein the alkyl acrylate is selected from the group consisting of methyl acrylate, ethyl acrylate, n-butyl acrylate, iso-butyl acrylate, tertbutyl acrylate, and combinations thereof.

7. The composition of any one of claims 1-6, wherein the composition includes from 10 to 1000 parts per million of the ethylene acrylic ester copolymer based on actives for the hydrocarbon mixture.

8. The composition of any one of claims 1-7, wherein the ethylene acrylic ester copolymer is a random copolymer.

9. The composition of any one of claims 1-8, wherein the hydrocarbon mixture that includes paraffin wax is a petroleum or a petroleum product.

10. The composition of any one of claims 1-9, wherein the ethylene acrylic ester copolymer has about 10 to about 35 wt. % of alkyl acrylate, wherein the wt.% is based on the total weight of the ethylene acrylic ester copolymer.

11. The composition of any one of claims 1-10, wherein the composition includes 5 wt. % of the hydrocarbon mixture based on the total weight of the composition, and the compositionhas a viscosity of 10 to 40 cP in a temperature range of -10 to 10 °C.

12. A method of treating a hydrocarbon mixture that includes paraffm wax, comprising: providing an ethylene acrylic ester copolymer of any one of claims 1-11; and mixing the ethylene acrylic ester copolymer with the hydrocarbon mixture that includes paraffin wax.

Images