阅读说明：本技术 作为急冷水系统的新型破乳剂的聚乙烯亚胺 (Polyethyleneimine as novel demulsifier for chilled water systems ) 是由 法布里斯·库科克 史蒂文·利恩 于 2018-12-12 设计创作，主要内容包括：在乙烯生产急冷水系统中通过抑制乳液形成或通过分解乳液来提高烃流裂解的效率和生产能力的方法。方法包括使非烷氧基化的带支链的或直链的聚乙烯亚胺(PEI)与来自急冷水系统的急冷水组合物在适于防止乳液形成或适于将急冷水组合物分解成两个不混溶相的条件下接触。(A method of increasing the efficiency and productivity of hydrocarbon stream cracking in an ethylene production quench water system by inhibiting emulsion formation or by breaking down the emulsion. The method comprises contacting a non-alkoxylated branched or linear Polyethyleneimine (PEI) with a quench water composition from a quench water system under conditions suitable to prevent formation of an emulsion or to decompose the quench water composition into two immiscible phases.)

1. A method of inhibiting emulsion formation or breaking down in an ethylene production chilled water system, the method comprising contacting a non-alkoxylated branched or linear Polyethyleneimine (PEI) with a chilled water composition from the chilled water system under conditions suitable to prevent emulsion formation or to break down the chilled water composition into two immiscible phases.

2. The method of claim 1, wherein the molecular weight of the PEI is from 100g/mol to 800000g/mol, 100g/mol to 750000g/mol, 100g/mol to 1300g/mol, or 100g/mol to 800 g/mol.

3. The method of claim 1, wherein the quenching water composition comprises 0.01ppm to 30ppm, preferably 0.01ppm to 10ppm, PEI.

4. The method of claim 1, wherein the PEI is:

wherein:

R₁to R₅Selected from hydrogen (H), CH₂CH₂NH₂、CH₂CH₂NHCH₂CH₂NH₂、CH₂CH₂N(CH₂CH₂NH₂)₂、CH₂CH₂NHCH₂CH₂NH(CH₂CH₂NH₂)、CH₂CH₂NHCH₂CH₂N(CH₂CH₂NH₂)₂、CH₂CH₂N(CH₂CH₂NH₂)(CH₂CH₂NHCH₂CH₂NH₂)、CH₂CH₂N(CH₂CH₂NH₂)(CH₂CH₂N(CH₂CH₂NH₂)₂)、CH₂CH₂N(CH₂CH₂NHCH₂CH₂NH₂)(CH₂CH₂N(CH₂CH₂NH₂)₂)、CH₂CH₂N(CH₂CH₂NHCH₂CH₂NH₂)₂And CH₂CH₂N(CH₂CH₂N(CH₂CH₂NH₂)₂)₂(ii) a And n is at least 1.

5. The method of claim 1, wherein the PEI is:

wherein:

o is at least 1, and

p is at least 1.

6. The process of claim 1, wherein the quench water system further comprises one or more than one Quench Water Tower (QWT), Quench Water Loop (QWL) or Quench Water Settler (QWS).

7. The process of claim 6, wherein the process comprises adding PEI to a feed of QWT, a feed of QWL, a feed of QWS, or any combination thereof.

8. A process according to claim 6, wherein the QWT temperature is from 25 ℃ to 150 ℃, preferably from 50 ℃ to 90 ℃.

9. The method of claim 1, wherein the quench water composition comprises a gasoline hydrocarbon.

10. The method of claim 1, wherein one of the two immiscible phases is an aqueous phase.

11. The method of claim 10, further comprising providing the aqueous phase to a Process Water Stripper (PWS).

12. The method of claim 10, further comprising providing the aqueous phase to a dilution steam generator preheater and/or a dilution steam generator.

13. The method of claim 10, further comprising inhibiting fouling of the PWS, dilution steam generator preheater, dilution steam generator, or any combination thereof.

14. The method of claim 10, wherein the residual turbidity level of the aqueous phase is less than 60%, preferably less than 20%, after 30ppm of PEI is added to the quench water composition.

15. The method of claim 10, wherein the aqueous phase comprises organic material.

16. The method of claim 15, wherein the organic material comprises indene and/or styrene derivatives.

17. The process of claim 15, wherein organic matter in the aqueous phase is reduced by 30% to 90%.

18. The method of claim 10, further comprising providing a portion of the aqueous phase to a quench water system.

19. The method of claim 1, wherein one of the two immiscible phases is an organic phase, and the method further comprises fractionating the organic phase.

20. A quenching water composition comprising non-alkoxylated branched or linear Polyethylenimine (PEI) and water.

Background

A. Field of the invention

The present invention relates generally to a method for increasing the efficiency of breaking emulsions. In particular, the present invention relates to the use of the novel demulsifiers for hydrocarbon/water systems to inhibit emulsion formation and hydrocarbon contaminants remaining in the water system (e.g., Dilution Steam Systems (DSS), oil fields, etc.).

B. Description of the related Art

During the normal operation of steam cracking systems in the petroleum industry, large amounts of hydrocarbons and other contaminants are concentrated in the process water. These contaminants must be removed or controlled to minimize problems throughout the process water system. If left uncontrolled, the increased contamination can lead to fouling, foaming, corrosion and product quality problems. This is particularly prevalent in olefin production where the process water system may include a Quench Water Tower (QWT), a process water stripper to remove hydrocarbons (PWS), a waste heat recovery system, or a combination thereof. The steam from the latter is fed to the pyrolysis furnace and recovered as water in the quench tower. This complex water circuit can experience various problems due to contamination. For example, emulsions formed in QWT and/or Quench Water Settlers (QWS) during gasoline/water separation can result in large amounts of hydrocarbons entering the PWS along with the water. This can lead not only to fouling of the stripper bottoms, but also to fouling at the Dilution Steam Generator (DSG) preheater, which can affect production efficiency and, worse, lead to plant shutdowns.

To improve the gasoline/water separation in the QWT or QWS, a demulsifier may be used to improve the water quality entering the Dilution Steam System (DSS). The petrochemical industry typically uses two types of demulsifiers: 1) a non-ionic demulsifier that alters the particle wettability of the stable emulsion, and 2) a high molecular weight cationic demulsifier that enhances phase separation by bridging flocculation. Exemplary nonionic and mixed ion demulsifiers include those found in U.S. patent No. 5846453 to Mohr et al and U.S. patent No. 5445765 to Elfers et al. Other methods of inhibiting emulsion formation include inhibiting polymerization in Process Water Strippers (PWS) using Stable Free Radical (SFR) type inhibitors.

Although various methods exist to reduce scale in process water systems, there is still a need to further reduce emulsion formation to improve water quality into DSS and to extend the life and efficiency of flow petroleum cracking systems.

Disclosure of Invention

A solution to the efficiency related deficiencies of steam cracking systems has been discovered. This discovery is premised on a method of inhibiting emulsion formation or breaking down an emulsion in ethylene production quench water systems using a demulsifier comprising non-alkoxylated branched or linear Polyethylenimine (PEI). In particular, the method helps to suppress emulsion formation and thus the residual of reactive monomers, thereby improving the water quality entering the DSS. For example, after 30ppm or less than 30ppm PEI has been added, the aqueous phase of the quench water system can include a residual haze level of less than 60%, preferably less than 20%, with a 30% to 90% reduction in organic matter. Thus, the reduction of fouling accumulation not only improves the energy efficiency of the system, but also prevents the reduction of plant capacity caused by fouling in DSS.

Embodiments of the present invention describe methods of inhibiting emulsion formation or breaking down an emulsion in an ethylene production quench water system. The method can include contacting a non-alkoxylated branched or linear Polyethyleneimine (PEI) with a quench water composition from a quench water system under conditions suitable to prevent formation of an emulsion or to decompose the quench water composition into two immiscible phases. In one aspect, the molecular weight of the PEI can be from 100g/mol to 800000g/mol, from 100g/mol to 750000g/mol, from 100g/mol to 8000g/mol, or from 800g/mol to 1300 g/mol. In other aspects, the quench water composition can comprise 0.01ppm to 30ppm, preferably 0.01ppm to 10ppm PEI. The PEI may be:

wherein: r₁To R₅Can be selected from hydrogen (H), CH₂CH₂NH₂、CH₂CH₂NHCH₂CH₂NH₂、CH₂CH₂N(CH₂CH₂NH₂)₂、CH₂CH₂NHCH₂CH₂NH(CH₂CH₂NH₂)、CH₂CH₂NHCH₂CH₂N(CH₂CH₂NH₂)₂、CH₂CH₂N(CH₂CH₂NH₂)(CH₂CH₂NHCH₂CH₂NH₂)、CH₂CH₂N(CH₂CH₂NH₂)(CH₂CH₂N(CH₂CH₂NH₂)₂)、CH₂CH₂N(CH₂CH₂NHCH₂CH₂NH₂)(CH₂CH₂N(CH₂CH₂NH₂)₂)、CH₂CH₂N(CH₂CH₂NHCH₂CH₂NH₂)₂And CH₂CH₂N(CH₂CH₂N(CH₂CH₂NH₂)₂)₂(ii) a And n may be 1 to 500. In particular cases, PEI is:

wherein o is at least 1 and p is at least 1. In some embodiments, o is 1 to 20. In another embodiment, p is 1 to 30. In some aspects, the quench water system of the inventive process may further comprise one or more than one Quench Water Tower (QWT), Quench Water Loop (QWL), or Quench Water Settler (QWS), and PEI may be added to the feed of the QWT, the feed of the QWL, the feed of the QWS, or any combination thereof. When the quench water system includes QWT, the temperature of the QWT can be 25 ℃ to 150 ℃, preferably 50 ℃ to 90 ℃.

Other embodiments of the method incorporate the quench water composition of the present invention. In one aspect, the quench water composition can comprise a gasoline hydrocarbon. In other aspects, one of the two immiscible phases may be an aqueous phase. The other phase may be an organic phase. The method may further include providing the aqueous phase to a Process Water Stripper (PWS), a dilution steam generator preheater, and/or a dilution steam generator. Without being bound by theory, advantages of the present invention include inhibiting fouling of the PWS, dilution steam generator preheater, dilution steam generator, or any combination thereof. Specifically, the residual turbidity level of the aqueous phase of the quench water composition after the addition of 30ppm or less than 30ppm PEI can be less than 60%, preferably less than 20%. Typically, the aqueous phase of the quench water composition may comprise organic material. In some cases, the organic species may include reactive monomers and/or oligomers, such as indene and/or styrene derivatives. The process of the present invention can reduce such organic materials in the aqueous phase by 30% to 90%. Other aspects include providing a portion of the aqueous phase to a quench water system and fractionating the organic phase. In a particular embodiment, the present invention comprises a quench water composition for use in the process of the present invention for increasing the efficiency and capacity of a hydrocarbon steam cracking system.

In the context of the present invention, 20 embodiments are described. Embodiment 1 is a method of inhibiting emulsion formation or breaking down an emulsion in an ethylene production chilled water system comprising contacting a non-alkoxylated branched or linear Polyethyleneimine (PEI) with a chilled water composition from the chilled water system under conditions suitable to prevent emulsion formation or to break down the chilled water composition into two immiscible phases. Embodiment 2 is the method of embodiment 1 wherein the molecular weight of the PEI ranges from 100g/mol to 800000g/mol, 100g/mol to 750000g/mol, 800g/mol to 1300 g/mol. Embodiment 3 is the method of any one of embodiments 1 to 2 wherein the quench water composition comprises 0.01ppm to 30ppm, preferably 0.01ppm to 10ppm, PEI. Embodiment 4 is the method of any one of embodiments 1 to 3, wherein the PEI is:

wherein: r₁To R₅Selected from hydrogen (H), CH₂CH₂NH₂、CH₂CH₂NHCH₂CH₂NH₂、CH₂CH₂N(CH₂CH₂NH₂)₂、CH₂CH₂NHCH₂CH₂NH(CH₂CH₂NH₂)、CH₂CH₂NHCH₂CH₂N(CH₂CH₂NH₂)₂、CH₂CH₂N(CH₂CH₂NH₂)(CH₂CH₂NHCH₂CH₂NH₂)、CH₂CH₂N(CH₂CH₂NH₂)(CH₂CH₂N(CH₂CH₂NH₂)₂)、CH₂CH₂N(CH₂CH₂NHCH₂CH₂NH₂)(CH₂CH₂N(CH₂CH₂NH₂)₂)、CH₂CH₂N(CH₂CH₂NHCH₂CH₂NH₂)₂And CH₂CH₂N(CH₂CH₂N(CH₂CH₂NH₂)₂)₂(ii) a And n is at least 1. Embodiment 5 is the method of any one of embodiments 1 to 4, wherein the PEI is:

wherein: o is at least 1 and p is at least 1. Embodiment 6 is the method of any one of embodiments 1 to 5, wherein the quench water system further comprises one or more than one Quench Water Tower (QWT), Quench Water Loop (QWL), or Quench Water Settler (QWS). Embodiment 7 is the method of embodiment 6, wherein the method comprises adding PEI to a feed of the QWT, a feed of the QWL, a feed of the QWS, or any combination thereof. Embodiment 8 is the method of any one of embodiments 6 to 7, wherein the QWT comprises a temperature of 25 ℃ to 150 ℃, preferably 50 ℃ to 90 ℃. Embodiment 9 is the method of any one of embodiments 1 to 8, wherein the quench water composition comprises a gasoline hydrocarbon. Embodiment 10 is the method of any one of embodiments 1 to 9, wherein one of the two immiscible phases is an aqueous phase. Embodiment 11 is the method of any one of embodiments 10, further comprising providing the aqueous phase to a Process Water Stripper (PWS). Embodiment 12 is the method of any one of embodiments 10 to 11, further comprising providing the aqueous phase to a dilution steam generator preheater and/or a dilution steam generator. Embodiment 13 is the method of any one of embodiments 10 to 12, further comprising inhibiting fouling of the PWS, the dilution steam generator preheater, the dilution steam generator, or any combination thereof. Embodiment 14 is the method of any one of embodiments 10 to 13, wherein the residual turbidity level of the aqueous phase after adding 30ppm or less than 30ppm of PEI to the quench water composition is less than 60%, preferably less than 20%. Embodiment 15 is the method of any one of embodiments 10 to 14, wherein the aqueous phase comprises organic matter. Embodiment 16 is the method of embodiment 15, wherein the organic material comprises indene and/or styrene derivatives. Embodiment 17 is the method of embodiment 15, wherein the organic matter in the aqueous phase is reduced by 30% to 90%. Embodiment 18 is the method of any one of embodiments 10 to 17, further comprising providing a portion of the aqueous phase to a quench water system. Embodiment 19 is the method of any one of embodiments 1 to 18, wherein one of the two immiscible phases is an organic phase, and the method further comprises fractionating the organic phase. Embodiment 20 is a quenching water composition comprising non-alkoxylated branched or linear Polyethylenimine (PEI) and water.

The following includes definitions of various terms and phrases used in the specification.

The term "cracking" refers to breaking the carbon-carbon bonds of a hydrocarbon molecule to produce hydrocarbons having a fewer number of carbon atoms than the starting hydrocarbon molecule.

The term "gasoline hydrocarbon" refers to a hydrocarbon stream containing hydrocarbons having 12 carbons suitable for making gasoline. E.g. C₅+ gasoline hydrocarbon means having C₅To C₁₂A hydrocarbon stream of hydrocarbons. Trace amounts of higher hydrocarbons may be present.

The term "about" or "approximately" is defined as being close as understood by one of ordinary skill in the art. In one non-limiting embodiment, the term is defined to be within 10%, preferably within 5%, more preferably within 1% and most preferably within 0.5%.

The terms "weight%", "volume%" or "mole%" refer to the weight, volume or mole percent of an ingredient, respectively, based on the total weight, volume or moles of the substance in which the ingredient is included. In one non-limiting example, 10 grams of an ingredient in 100 grams of a substance is 10% by weight of the ingredient.

The term "substantially" and variations thereof are defined as including ranges within 10%, within 5%, within 1%, or within 0.5%.

The terms "inhibit" or "reduce" or "prevent" or "avoid" when used in the claims and/or the specification includes any measurable reduction or complete inhibition that achieves the desired result.

The term "effective," when used in the specification and/or claims, means sufficient to achieve a desired, expected, or expected result.

The use of discrete quantities in the claims or the specification when used in conjunction with any of the terms "comprising," including, "" containing, "or" having "may mean" one, "but also conform to the meaning of" one or more, "" at least one, "" one, or more than one.

The term "comprising" any, "having" any, "including" any, or "containing" any is inclusive or open-ended and does not exclude additional, unrecited elements or method steps.

The methods of the present invention can "comprise," consist essentially of, "or" consist of the particular ingredients, components, compositions, etc. disclosed throughout the specification. With respect to the transitional phrase "consisting essentially of," in one non-limiting aspect, a basic and novel feature of the non-alkoxylated branched or linear PEI demulsifiers of the present invention is their ability to prevent the formation of emulsions or the breakdown of the quenched water composition into two immiscible phases.

Other objects, features and advantages of the present invention will become apparent from the following drawings, detailed description and examples. It should be understood, however, that the drawings, detailed description, and examples, while indicating specific embodiments of the present invention, are given by way of illustration only and are not intended to be limiting. Further, it is contemplated that changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. In other embodiments, features from specific embodiments may be combined with features from other embodiments. For example, features from one embodiment may be combined with features from any of the other embodiments. In other embodiments, additional features may be added to the specific embodiments described herein.

Drawings

Advantages of the present invention will become apparent to those skilled in the art from the following detailed description, taken in conjunction with the accompanying drawings.

FIG. 1 shows the haze generated by the jar test method for the PEI demulsifier of the present invention and the comparative demulsifier.

FIG. 2 shows the turbidity resulting from demulsification tests of the branched PEI demulsifiers of the present invention and two comparative demulsifiers.

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

Detailed Description

A method has been found to use a demulsifier comprising non-alkoxylated branched or linear Polyethylenimine (PEI) to inhibit emulsion formation or break down emulsions in ethylene production quench water systems. The process not only improves the overall energy efficiency of the cracking system, but also increases plant capacity by improving process water quality, thereby reducing equipment fouling.

These and other non-limiting aspects of the invention will be discussed in further detail in the following sections.

A. Demulsifier

The petroleum demulsifier is not only effective in breaking water-in-oil emulsions, but also provides separated water with minimal residual oil content. The demulsifiers of the present invention comprise non-alkoxylated branched or linear Polyethyleneimines (PEI). PEI, or polyethylenimine as it is sometimes called, is a polymer with repeating amine groups bound by ethylene spacers, usually prepared by ring-opening polymerization of aziridine. Alkoxylated PEI includes PEI further modified with oxyalkylated groups, typically prepared by alkoxylating PEI with an oxygenate. The PEI of the present invention is not alkoxylated (i.e., non-alkoxylated). PEI is generally used in a wide range of applications (e.g., detergents, adhesives, water treatment agents, cosmetics, etc.). The linear PEI may contain secondary amines and the branched PEI may contain primary, secondary, and/or tertiary amino groups. The degree of branching can be controlled by the reaction conditions employed (e.g., temperature, concentration, duration), and further functionalization can be achieved by post-chemical modifications (e.g., amine alkylation, acylation, condensation, sulfonylation, etc.). The PEI can have a molecular weight of 100g/mol to 800000g/mol, 100g/mol to 750000g/mol, 100g/mol to 8000g/mol, or 800 to 1300g/mol and all values and ranges therebetween (e.g., 100g/mol, 200g/mol, 300g/mol, 400g/mol, 500g/mol, 600g/mol, 700g/mol, 800g/mol, 900g/mol, 1000g/mol, 1100g/mol, 1200g/mol, 1300g/mol, 1400g/mol, 1500g/mol, 2000g/mol, 2500g/mol, 3000g/mol, 3500g/mol, 4000g/mol, 4500g/mol, 5000g/mol, 5500g/mol, 6000g/mol, 6500g/mol, 7000g/mol, 7500g/mol, 800000g/mol, 100g/mol, 7500g/mol, and/mol, 8000g/mol, 9000g/mol, 10000g/mol, 20000g/mol, 30000g/mol, 40000g/mol, 50000g/mol, 60000g/mol, 70000g/mol, 80000g/mol, 90000g/mol, 100000g/mol, 110000g/mol, 120000g/mol, 130000g/mol, 140000g/mol, 150000g/mol, 200000g/mol, 300000g/mol, 400000g/mol, 500000g/mol, 600000g/mol, 700000g/mol, and 800000 g/mol). PEI can have the following structure:

wherein: r₁To R₅May be hydrogen (H), an alkyl group or a substituted alkyl group; and n may be at least 1, or 1 to 1000, or at least any one of the following values, equal to any one of the following values, or between any two of the following values: 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 is understood that n is a number sufficient to produce PEI having the desired molecular weight, e.g., 100g/mol to 800000 g/mol.The alkyl group may comprise a saturated monovalent unbranched or branched hydrocarbon chain. Exemplary alkyl groups having 1 to 20 carbon atoms can include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, 1-pentyl, 2-pentyl, 3-methyl-1-butyl, 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, 1,3, 3-tetramethylbutyl, 2-methyl-ethyl, 2-hexyl, 3-pentyl, 3-hexyl, 3-heptyl, 4-octyl, 1-octyl, 3-tetramethylbutyl, 2-ethylbutyl, and the like, Nonyl, decyl, dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, cyclohexyl, cyclopentyl, benzyl, and the like. Substituted alkyl groups can include any of the above alkyl groups additionally substituted with one or more heteroatoms such as halogens (e.g., F, Cl, Br, I), boron, oxygen, nitrogen, sulfur, silicon, and the like. The substituted alkyl group of the present invention may include, but is not limited to, alkylamine, which may refer to straight or branched alkylamine having 1 to 10 carbon atoms, for example, CH₂NH₂、CH₂CH₂NH₂、CH₂CH₂CH₂NH₂、CH₂CH(NH₂)CH₃、CH₂CH₂CH₂CH₂NH₂、CH₂CH₂CH(NH₂)CH₃、CH₂CH(NH₂)CH₂CH₃、CH₂CH₂CH₂CH₂CH₂NH₂、CH₂CH₂CH₂CH(NH₂)CH₃、CH₂CH₂CH₂CH(NH₂)CH₃、CH₂CH₂CH(NH₂)CH₂CH₃、CH₂CH(NH₂)CH₂CH₂CH₂CH₃、CH₂CH₂CH₂CH₂CH₂CH₂NH₂、CH₂CH₂CH₂CH₂CH(NH₂)CH₃、CH₂CH₂CH₂CH₂CH(NH₂)CH₃、CH₂CH₂CH₂CH(NH₂)CH₂CH₃、CH₂CH₂CH(NH₂)CH₂CH₂CH₂CH₃、CH₂CH(NH₂)CH₂CH₂CH₂CH₂CH₃And the like. The alkyl amines may also include mono-or di-substituted alkyl groups as described above and/or substituted alkyl chains attached to the nitrogen atom of the amine. Preferably, the substituted alkyl group may be a cumulative reactive derivative of a ring opening polymerization of an aziridine reaction, including CH₂CH₂NH₂、CH₂CH₂NHCH₂CH₂NH₂、CH₂CH₂N(CH₂CH₂NH₂)₂、CH₂CH₂NHCH₂CH₂NH(CH₂CH₂NH₂)、CH₂CH₂NHCH₂CH₂N(CH₂CH₂NH₂)₂、CH₂CH₂N(CH₂CH₂NH₂)(CH₂CH₂NHCH₂CH₂NH₂)、CH₂CH₂N(CH₂CH₂NH₂)(CH₂CH₂N(CH₂CH₂NH₂)₂)、CH₂CH₂N(CH₂CH₂NHCH₂CH₂NH₂)(CH₂CH₂N(CH₂CH₂NH₂)₂)、CH₂CH₂N(CH₂CH₂NHCH₂CH₂NH₂)₂And CH₂CH₂N(CH₂CH₂N(CH₂CH₂NH₂)₂)₂. Without being bound by theory, the PEI polymer may include aziridine end groups. Exemplary PEI's for use as demulsifiers in the present invention can include:

wherein o can be at least or 1 to 1000 and all values and ranges therebetween (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 1000 and all values and ranges therebetween (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 is understood that o and/or p are numbers sufficient to produce PEI having the desired molecular weight, e.g., 100g/mol to 800000 g/mol. In some embodiments, o is 1 to 20 and/or p is 1 to 30. Linear and branched PEI's are commercially available from commercial manufacturers, such as Sigma-USA。

B. Application method

In quench water systems, the emulsification problem can be exacerbated by the following reasons: 1) the pH value fluctuation of the quenching water is lower than 4.0 and higher than 8.0; 2) liquid feedstocks and heavy Liquefied Petroleum Gas (LPG) feedstocks, such as butane; 3) high yield and increased turbulence; and 4) furnace operating cycles (e.g., during decoking). The present invention provides a method for demulsifying a petroleum emulsion wherein the emulsion may be treated with a demulsifier that inhibits emulsion formation or breaks down the 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 a quench water system under conditions suitable to prevent the formation of an emulsion or to decompose the quench water composition into two immiscible phases. Preferably, the hydrocarbon production quench water system is used to produce olefins (e.g., ethylene, propylene, butylene, etc.) from gasoline hydrocarbons. The gasoline hydrocarbon may include 4 to 12 carbons (C) per molecule₄-C₁₂) A mixture of hydrocarbons of (a). Exemplary gasoline hydrocarbons include paraffins (alkanes), naphthenes (naphthalenes), and alkenes (alkenes). Although a chilled water system has been described in detail,it should be understood that the demulsifier may be used in other hydrocarbon/water systems. For example, hydrocarbon/water systems from hydrocarbon production generated underground may be treated.

The quench water system may include any components used in hydrocarbon cracking processes that will be apparent to those skilled in the art. In some embodiments, the quench water system may include one or more than one Quench Water Tower (QWT), Quench Water Loop (QWL), or Quench Water Settler (QWS), and the non-alkoxylated PEI may be added to the feed of the QWT, the feed of the QWL, the feed of the QWS, or any combination thereof. The quench water composition may be any aqueous petrochemical composition suitable for use in steam cracking systems known to those skilled in the art that employ quench water systems. In a preferred aspect, the quench water composition comprises an organic phase and an aqueous phase that are immiscible with each other, wherein a non-alkoxylated linear or branched PEI demulsifier promotes the persistence of such immiscible phases during continuous cracking operations. The demulsifier can be added to the feed stream to the quench water module, directly into the module, or both. The organic phase may include gasoline hydrocarbons and the aqueous phase may be transferred to a Process Water Stripper (PWS), a dilution steam generator preheater, and/or a dilution steam generator. Advantages of the present invention include inhibiting fouling of the PWS, dilution steam generator preheater, dilution steam generator, or any combination thereof.

The quench water composition of the process of the present invention can be used to increase the efficiency and capacity of a hydrocarbon steam cracking system. The non-alkoxylated branched or linear PEI demulsifiers employed in the present invention may be more effective than other known treatments using, for example, heavy amine treatments. Furthermore, the process of the present invention may be more efficient than adding inhibitors in a Process Water Stripper (PWS) because the temperature within the PWS may be high and complete inhibition of polymerization may not be achieved. In such a case, it would be beneficial to reduce the amount of contamination entering the PWS. In other cases where the non-alkoxylated branched or linear PEI demulsifier of the present invention was used, similar efficiencies to the addition of acid in the QWT could be achieved. The use of an acid may lower the pH in the QWT, which may also improve the gasoline/water separation. However, the large amount of acid required to normalize QWT pH and subsequent downstream neutralization increases overall operating costs.

It is contemplated that the quench water composition may comprise a wide variety of non-alkoxylated PEI's with less risk of overdosing. The resulting chilled water composition contacted with the non-alkoxylated branched or linear PEI demulsifier of the present invention to inhibit the formation of or break down of an emulsion may comprise non-alkoxylated PEI in the following amounts: 0.01ppm to 30ppm, preferably 0.01ppm to 10ppm and all values or ranges therebetween (e.g., 0.02ppm, 0.03ppm, 0.04ppm, 0.05ppm, 0.06ppm, 0.07ppm, 0.08ppm, 0.09ppm, 0.1ppm, 0.15ppm, 0.2ppm, 0.3ppm, 0.4ppm, 0.5ppm, 1ppm, 2ppm, 3ppm, 4ppm, 5ppm, 6ppm, 7ppm, 8ppm or 9 ppm). In certain aspects, the quench water system includes a QWT, and the temperature of the QWT can be from 25 ℃ to 150 ℃, preferably from 50 ℃ to 90 ℃, and all values and ranges therebetween (e.g., 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃, or 95 ℃).

The non-alkoxylated branched or linear PEI demulsifiers of the present invention can be used to reduce the residual aqueous phase turbidity of the aqueous phase of a quench water composition. The residual haze level may be less than 60%, preferably less than 20%, 19%, 18%, 17%, 16%, 15%, 14%, 13%, 12%, 11%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2% or l% after addition of 30ppm or less than 30ppm of non-alkoxylated branched or linear PEI. Typically, the aqueous phase of the quench water composition may comprise organic material. In some cases, the organic species may include reactive monomers and/or oligomers, such as indene and/or styrene derivatives. The process of the invention can result in a 30% to 90% reduction in such organic material in the aqueous phase and all values and ranges therebetween (e.g., 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, or 95%). Other aspects may include providing a portion of the aqueous phase to a quench water system and fractionating the organic phase.

Examples

The present invention will be described in more detail by way of specific examples. The following examples are provided for illustrative purposes only and are not intended to limit the invention in any way. Those skilled in the art will readily recognize that various non-critical parameters may be changed or modified to achieve substantially the same results.

Branched PEI (average Mw of about 800, as measured by LS; average Mn of about 600, as measured by GPC), branched PEI (average Mn of about 1200, average Mw of about 1300, as measured by LS; 50 wt.% in H₂O) and branched PEI (average Mn about 60000, measured by GPC; average Mw of about 750000 as measured by LS; 50% by weight of a compound represented by formula (I) in the specification₂O) from Sigma-(U.S.A.). The reagents were used as received.

Example 1

(bottle test method)

The jar test method was performed using process water from the Quench Water Tower (QWT) of the naphtha olefins cracking unit and gasoline. Process water (10mL) and gasoline (10mL) were added to vials containing varying concentrations of demulsifier (e.g., 0ppm to 50 ppm). The vial was shaken by hand at room temperature and the turbidity of the water was measured. Lower residual haze values are required.

Figure 1 shows the turbidity results from the bottle test method in example 1. Branched PEI data points 10(Mw about 800g/mol), 12(Mw about 1300g/mol), 14(Mw about 750000g/mol) and comparative sample 16 (commercial non-PEI demulsifier A) of the present invention were tested at several ppm (e.g., 0ppm to 50 ppm). From the results, it was determined that the normalized residual haze of the non-alkoxylated branched or linear PEI demulsifiers was lower than that of the commercial non-PEI demulsifier A. Furthermore, comparative sample 16 contains polyepichlorohydrin and trimethylamine, which also contribute to the corrosion potential of the additive.

Example 2

(demulsification test)

The demulsification test was conducted using process water from the Quench Water Tower (QWT) of the naphtha olefin cracking unit and gasoline. Process water (60mL) and gasoline (60mL) were added to multiple vessels and each vessel was heated at 80 ℃ for 30 minutes. After cooling the mixture, it was then stirred at 1000rpm for 5 minutes, then different concentrations of demulsifier (e.g., 0ppm, 1ppm, 5ppm, and 10ppm) were added, then stirred for an additional 15 minutes, and then the stirring was stopped. After complete demulsification, the turbidity of each aqueous phase was measured. The lower the residual turbidity, the better the demulsification effect.

FIG. 2 shows the turbidity results for branched PEI 20 of the present invention (Mw about 1300g/mol), comparative sample 22 (commercial non-PEI demulsifier A), and comparative sample 24 (commercial non-PEI demulsifier B). Branched PEI 20 achieves lower residual turbidity levels, which makes the material more suitable for handling process water systems that suffer from emulsification problems, while reducing the risk of increased emulsification due to over-addition than commercial products.