POLYETHYLENIMINE AS A NEW EMULSION BREAKER FOR QUENCH WATER SYSTEMS

Abstract

Methods to increase the efficiency and throughput of hydrocarbon stream cracking by inhibiting the formation of, or resolving an emulsion, in an ethylene production quench water system. The method includes contacting a non-alkoxylated branched or linear polyethylenimine (PEI) with a quench water composition from the quench water system under conditions suitable to prevent the formation of an emulsion or to resolve the quench water composition into two immiscible phases.

Claims

1. A quench water composition, comprising: a non-alkoxylated branched or linear polyethylenimine (PEI) and water, wherein the PEI is selected from the group consisting of ##STR00007## and any combination thereof, wherein o is at least 1; R.sub.3 is H; R.sub.1, R.sub.2, R.sub.4, and R.sub.5 are selected from the group consisting of hydrogen (H), CH.sub.2CH.sub.2NH.sub.2, CH.sub.2CH.sub.2NHCH.sub.2CH.sub.2NH.sub.2, CH.sub.2CH.sub.2N(CH.sub.2CH.sub.2NH.sub.2).sub.2, CH.sub.2CH.sub.2NHCH.sub.2CH.sub.2NH(CH.sub.2CH.sub.2NH.sub.2), CH.sub.2CH.sub.2NHCH.sub.2CH.sub.2N(CH.sub.2CH.sub.2NH.sub.2).sub.2, CH.sub.2CH.sub.2N(CH.sub.2CH.sub.2NH.sub.2)(CH.sub.2CH.sub.2NHCH.sub.2CH.sub.2NH.sub.2), CH.sub.2CH.sub.2N(CH.sub.2CH.sub.2NH.sub.2)(CH.sub.2CH.sub.2N(CH.sub.2CH.sub.2NH.sub.2).sub.2), CH.sub.2CH.sub.2N(CH.sub.2CH.sub.2NHCH.sub.2CH.sub.2NH.sub.2)(CH.sub.2CH.sub.2N(CH.sub.2CH.sub.2NH.sub.2).sub.2), CH.sub.2CH.sub.2N(CH.sub.2CH.sub.2NHCH.sub.2CH.sub.2NH.sub.2).sub.2 and CH.sub.2CH.sub.2N(CH.sub.2CH.sub.2N(CH.sub.2CH.sub.2NH.sub.2).sub.2).sub.2; and n is at least 1.

2. The composition of claim 1, wherein the water comprises ethylene production quench water.

3. The composition of claim 1, further comprising a hydrocarbon.

4. The composition of claim 3, wherein the hydrocarbon comprises a C2 to a C12 hydrocarbon.

5. The composition of claim 1, wherein the PEI comprises a molecular weight of about 100 to about 800,000 g/mol.

6. The composition of claim 1, further comprising from about 0.01 ppm to about 30 ppm of the PEI.

7. The composition of claim 1, wherein the PEI comprises: ##STR00008## wherein p is at least 1.

8. The composition of claim 1, further comprising a feed of a quench water tower (QWT), a feed of a quench water loop (QWL), and/or a feed of a quench water settler (QWS).

9. The composition of claim 8, wherein the feed of the QWT comprises a temperature of about 25 C. to about 150 C.

10. The composition of claim 1, further comprising a first phase and a second phase, which are immiscible.

11. The composition of claim 10, wherein the first phase comprises an aqueous phase.

12. The composition of claim 11, wherein the aqueous phase comprises an organic material.

13. The composition of claim 12, wherein the organic material comprises an indene derivative and/or a styrene derivative.

14. The composition of claim 10, wherein the second phase comprises an organic phase.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Advantages of the present invention may become apparent to those skilled in the art with the benefit of the following detailed description and upon reference to the accompanying drawings.

[0024] FIG. 1 shows the turbidity results from bottle tests of the PEI emulsion breakers of the present invention and a comparative emulsion breaker.

[0025] FIG. 2 shows the turbidity results from de-emulsification tests of a branched PEI emulsion breaker of the present invention and two comparative emulsion breakers.

[0026] While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings. The drawings may not be to scale.

DETAILED DESCRIPTION OF THE INVENTION

[0027] A method of inhibiting the formation of, or resolving, an emulsion in an ethylene production quench water system using an emulsion breaker including a non-alkoxylated branched or linear polyethylenimine (PEI) has been discovered. The method not only improves the overall energy efficiency of cracking systems, but can also increase plant throughput by increasing process water quality, which decreases equipment fouling.

[0028] These and other non-limiting aspects of the present invention are discussed in further detail in the following sections.

A. Emulsion Breaker

[0029] The petroleum emulsion breakers provide not only efficiently break water-in-oil emulsions, but also result in the separated water having a minimum remaining oil content. The emulsion breaker of the current invention includes a non-alkoxylated branched or linear polyethylenimine (PEI). PEI or sometimes known as a polyaziridine is a polymer with repeating amine groups tethered by ethylene spacers typically prepared by the ring opening polymerization of aziridine. Alkoxylated PEI includes PEI that is further modified with oxygenated alkyl groups typically prepared by alkoxylation of PEI with oxygenates. The PEI of the current invention is not alkoxylated (i.e., non-alkoxylated). PEI can typically be used in a wide range of applications (e.g., detergents, adhesives, water treatment agents, cosmetics, etc.). Linear PEis can contain secondary amines and branched PEis can contain primary, secondary, and/or tertiary amino groups. The degree of branching can be controlled by the reactions condition employed (e.g., temperature, concentration, duration) and further functionalization can be achieved through chemical post-modification (e.g., amine alkylation, acylation, condensation, sulfonylation, etc.). The PEI can have a molecular weight of 100 to 800,000 g/mol, 100 to 750,000, 100 to 8000 g/mol, or 800 to 1300 g/mol, and all values and ranges there between (e.g., 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 2000, 2500, 3000, 3500, 4000, 4500, 5000, 5500, 6000, 6500, 7000, 7500, 8000, 9000, 10000, 20000, 30000, 40000, 50000, 60000, 70000, 80000, 90000, 100000, 110000, 120000, 130000, 140000, 150000, 200000, 300000, 400000, 500000, 600000, 70000, and 800000 g/mol). The PEI can have the structure:

##STR00005##

wherein: R.sub.1-R.sub.5 can be hydrogen (H), an alkyl group, or a substituted alkyl group; and n can be at least 1, or 1 to 1,000, or at least any one of, equal to any one of, or between any two of 1, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 110, 150, 200, 250, 300, 350, 400, 450 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, and 1000. It should be understood than n is a number sufficient to produce a PEI having a desired molecular weight for example, between 100 and 800,000 g/mol. An alkyl group can include a saturated, monovalent unbranched or branched hydrocarbon chain. Exemplary alkyl groups having 1 to 20 carbon atoms can includes, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 1-pentyl, 2-pentyl, 3-pentyl, 3-methyl-1-butyl, 2-methyl-1-butyl, 2,2-dimethyl-1-propyl, 3-methyl-2-butyl, 2-methyl-2-butyl, 1-hexyl, 2-hexyl, 3-hexyl, 1-heptyl, 2-heptyl, 3-heptyl, 4-heptyl, 1-octyl, 2-octyl, 3-octyl, 4-octyl, 2-ethylhexyl, 1,1,3,3-tetramethylbutyl, nonyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, cyclohexyl, cyclopentyl, benzyl, etc. A substituted alkyl group can include any of the aforementioned alkyl groups that are additionally substituted with one or more heteroatoms, such as a halogen (e.g., F, Cl, Br, I), boron, oxygen, nitrogen, sulfur, silicon, etc. Without limitation, the substituted alkyl group of the present invention can include an alkylamine, which can refer to a straight or branched chain alkylamine having 1 to 10 carbon atoms, for example, CH.sub.2NH.sub.2, CH.sub.2CH.sub.2NH.sub.2, CH.sub.2CH.sub.2CH.sub.2NH.sub.2, CH.sub.2CH(NH.sub.2) CH.sub.3, CH.sub.2CH.sub.2CH.sub.2CH.sub.2NH.sub.2, CH.sub.2CH.sub.2CH(NH.sub.2) CH.sub.3, CH.sub.2CH.sub.2CH.sub.2CH(NH.sub.2) CH.sub.3, CH.sub.2CH.sub.2CH.sub.2CH.sub.2CH.sub.2NH.sub.2, CH.sub.2CH.sub.2CH.sub.2CH(NH.sub.2) HC.sub.3, CH.sub.2CH.sub.2CH(NH.sub.2) CH.sub.2CH.sub.3, CH.sub.2CH(NH.sub.2) CH.sub.2CH.sub.2CH.sub.2CH.sub.3, CH.sub.2CH.sub.2CH.sub.2CH.sub.2CH.sub.2CH.sub.2NH.sub.2, CH.sub.2CH.sub.2CH.sub.2CH.sub.2CH(NH.sub.2) CH.sub.3, CH.sub.2CH.sub.2CH.sub.2CH.sub.2CH(NH.sub.2) CH.sub.3, CH.sub.2CH.sub.2CH.sub.2CH(NH.sub.2) CH.sub.2CH.sub.3, CH.sub.2CH.sub.2CH(NH.sub.2) CH.sub.2CH.sub.2CH.sub.2CH.sub.3, CH.sub.2CH(NH.sub.2) CH.sub.2CH.sub.2CH.sub.2CH.sub.2CH.sub.3, etc. The alkylamine can further include mono- or di-substituted alkyl and/or substituted alkyl chains mentioned above attached to the nitrogen atom of the amine. Preferably, the substituted alkyl group can be a cumulative reaction derivative of the ring opening polymerization of aziridine reaction that includes CH.sub.2CH.sub.2NH.sub.2, CH.sub.2CH.sub.2NHCH.sub.2CH.sub.2NH.sub.2, CH.sub.2CH.sub.2N(CH.sub.2CH.sub.2NH.sub.2).sub.2, CH.sub.2CH.sub.2NHCH.sub.2CH.sub.2NH(CH.sub.2CH.sub.2NH.sub.2), CH.sub.2CH.sub.2NHCH.sub.2CH.sub.2N(CH.sub.2CH.sub.2NH.sub.2).sub.2, CH.sub.2CH.sub.2N(CH.sub.2CH.sub.2NH.sub.2)(CH.sub.2CH.sub.2NHCH.sub.2CH.sub.2NH.sub.2), CH.sub.2CH.sub.2N(CH.sub.2CH.sub.2NH.sub.2)(CH.sub.2CH.sub.2N(CH.sub.2CH.sub.2NH.sub.2).sub.2), CH.sub.2CH.sub.2N(CH.sub.2CH.sub.2NHCH.sub.2CH.sub.2NH.sub.2)(CH.sub.2CH.sub.2N(CH.sub.2CH.sub.2NH.sub.2).sub.2), CH.sub.2CH.sub.2N(CH.sub.2CH.sub.2NHCH.sub.2CH.sub.2NH.sub.2).sub.2 and CH.sub.2CH.sub.2N(CH.sub.2CH.sub.2N(CH.sub.2CH.sub.2NH.sub.2).sub.2).sub.2. Without being limited by theory, the PEI polymer can include aziridine end groups. Exemplary PEI for used as an emulsion breaker of the present invention can include:

##STR00006##

wherein o can be at least or 1 to 1,000 and all values and ranges there between (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 50, 100, 150, 200, 250, 300, 400, 500, 600, 700, 800, 900, 1000), and p can be at least 1, or 1 to 1,000 and all values and ranges there between (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950 and 1000). It should be understood than o and/or pare numbers sufficient to produce a PEI having a desired molecular weight for example, between 100 and 800,000 g/mol. In some embodiments, o is 1 to 20 and/or p is 1 to 30. Linear and branched PEis can be purchased from commercial manufactures such as Sigma-Aldrich, USA

B. Methods of Use

[0030] In quench water systems, emulsion problems can be aggravated by: 1) fluctuation in the quench water pH below 4.0 and above 8.0; 2) liquid feedstocks and heavier liquefied turbulence; and 4) furnace operation cycling (e.g., during decoking). The present invention provides a method for the demulsification of petroleum emulsions in which the emulsion can be treated with an emulsion breaker that inhibits the formation of, or resolves an emulsion, in a hydrocarbon production quench water system. The method can include contacting a non-alkoxylated branched or linear polyethylenimine (PEI) with a quench water composition from the quench water system under conditions suitable to prevent the formation of an emulsion or to resolve the quench water composition into two immiscible phases. Preferably the hydrocarbon production quench water system is utilized for the production of alkenes (e.g., ethylene, propylene, butylenes, etc.) from gasoline hydrocarbons. Gasoline hydrocarbons can include mixtures of hydrocarbons with between 4 and 12 carbons (C4-C12) per molecule. Exemplary gasoline hydrocarbons include paraffins (alkanes), cycloalkanes (naphthalenes), and olefins (alkenes). While quench water systems are described, it should be understood that the emulsion breaker can be used in other hydrocarbon/water systems. By way of example, hydrocarbon/water systems from hydrocarbon production from a subsurface formation) can be treated.

[0031] The quench water system can include any of the components apparent to those having ordinary skill in the art for use during hydrocarbon cracking. In some embodiments, the quench water system can include one or more Quench Water Towers (QWT), Quench Water Loops (QWL), or Quench Water Settlers (QWS), and the non-alkoxylated PEI can be added to a feed of the QWT, a feed of the QWL, a feed of the QWS, or any combination thereof. The quench water composition can be any aqueous petrochemical composition applicable to steam cracking systems known to those having ordinary skill in the art that utilize a quench water system. In preferred aspects, the quench water composition includes an organic phase and an aqueous phase that are immiscible with each other wherein the non-alkoxylated linear or branched PEI emulsion breaker promotes the longevity of this immiscibility during continued cracking operation. The emulsion breaker can be added to a feed stream entering a quench water component, directly to the component, or both. The organic phase can include gasoline hydrocarbons and the aqueous phase can be transferred to a process water stripper (PWS), a dilution steam generator preheater and/or a dilution steam generator. The advantages of the present invention include inhibiting fouling of the PWS, dilution steam generator preheater, dilution steam generator, or any combination thereof.

[0032] The quench water compositions of the current methods can be used to increase the efficiency and throughput in hydrocarbon steam cracking systems. The currently employed non-alkoxylated branched or linear PEI emulsion breakers can be more efficient than using other known treatments, such as heavy amine treatment. Additionally, the current methods can be more efficient than dosing an inhibitor in the process water stripper (PWS) as temperatures within the PWS can be high and complete polymerization inhibition might not be reached. In this scenario, decreasing the amount of contamination going to the PWS could be beneficial. In another instance of using the current non-alkoxylated branched or linear PEI emulsion breakers, a similar efficiency compared to acid dosing in the QWT can be achieved. The use of acid can decrease the pH in the QWT which can also improve gasoline/water separation. However, the high amounts of acid required to normalize QWT pH and consequent downstream neutralization could increase overall operational costs.

[0033] It is anticipated that the quench water composition can include a broad range of non-alkoxylated PEI with lower risk of overdosing. The resulting quench water composition that is contacted with non-alkoxylated branched or linear PEI emulsion breaker of the present invention to inhibit the formation of, or resolves an emulsion can include 0.01 to 30 ppm, preferably 0.01 to 10 ppm and all value or ranges there between (e.g., 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.15, 0.2, 0.3, 0.4, 0.5, 1, 2, 3, 4, 5, 6, 7, 8, or 9 ppm) of the non-alkoxylated PEI. In certain aspects, the quench water system includes a QWT and the QWT can include a temperature of 25 to 150 C., preferably to 50 to 90 C. and all values and ranges there between (e.g., 55, 60, 65, 70, 75, 80, 85, 90, or 95 C.).

[0034] The non-alkoxylated branched or linear PEI emulsion breakers of the current invention can be used to decrease the residual turbidity of the aqueous phase of the aqueous phase of the quench water composition. The residual turbidity level can be less than 60% after addition of 30 ppm or less of the non-alkoxylated branched or linear PEI, preferably less than 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, or 1%. Typically, the aqueous phase of the quench water composition can include an organic material. In certain instances, the organic material can include reactive monomers and/or oligomers, such as indene and/or styrene derivatives. The methods of the current invention can result in a reduction of such organic material in the aqueous phase by 30 to 90% and all values and ranges there between (e.g., 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or 95%). Further aspects can include providing a portion of the aqueous phase to the quench water system and fractionating of the organic phase.

EXAMPLES

[0035] The present invention will be described in greater detail by way of specific examples. The following examples are offered for illustrative purposes only, and are not intended to limit the invention in any manner. Those of skill in the art will readily recognize a variety of noncritical parameters which can be changed or modified to yield essentially the same results.

[0036] Branched PEI (average Mw800 by LS, average Mn600 by GPC), branched PEI (average Mn1,200, average Mw1300 by LS, 50 wt. % in H2O), and branched PEI (average Mn60,000 by GPC, average Mw750,000 by LS, 50 wt. % in H2O) were obtained from Sigma-Aldrich (U.S.A.). Reagents were used as obtained.

Example 1

(Bottle Tests)

[0037] Bottle tests were performed using process water and gasoline from the quench water tower (QWT) of a naphtha olefin cracker. Process water (10 mL) and gasoline (10 mL) were added to vials containing different concentrations of emulsion breaker (e.g., 0 to 50 ppm). The vials were hand-shaken at room temperature and the turbidity of the water was measured. Lower residual turbidity values were desired.

[0038] FIG. 1 shows the turbidity results from the bottle tests in Example 1. Branched PEI data points 10 (Mw800 g/mol), 12 (Mw1300 g/mol), 14 (Mw750,000 g/mol) of the present invention, and comparative sample 16 (commercial non-PEI emulsion breaker A) were tested at several ppm (e.g., 0 to 50 ppm). From the results it was determined that the non-alkoxylated branched or linear PEI emulsion breakers had a normalized residual turbidity that was lower than Commercial non-PEI emulsion breakers A Furthermore, the comparative same 16 contained polyepichlorhydrin and trimethylamine, which can also contribute to the corrosion potential of this additive.

Example 2

(Demulsification Tests)

[0039] Demulsification tests were performed using process water and gasoline from the quench water tower (QWT) of a naphtha olefin cracker. Process water (60 mL) and gasoline (60 mL) were added to multiple vessels and each vessel was heated at 80 C. for 30 min. After cooling the mixtures where then stirred at 1000 rpm for 5 min and then added different concentrations of emulsion breaker (e.g., 0, 1, 5, and 10 ppm) followed by stirring for an additional 15 min and then the stirring is stopped. After complete demulsification, the turbidity of each water phase was measured. The lower the residual turbidity, the better the demulsification.

[0040] FIG. 2 shows the turbidity results of branched PEI 20 (Mw 1300 g/mol) of the present invention, comparative sample 22 (commercial non-PEI emulsion breaker A), and comparative sample 24, (commercial non-PEI emulsion breaker B). The branched PEI 20 reached lower residual turbidity levels, which makes the material more suitable for treating process water systems suffering from emulsion issues with decreasing the risk of increasing emulsion by overdosing than the commercial product.