US-12618017-B2 - Application of surfmers to mitigate fouling in olefins plants

Abstract

A method for reducing fouling in an aqueous system of an olefin production plant is disclosed. The method includes adding an effective amount of a surfmer to the aqueous system, wherein the surfmer forms a water soluble adduct by covalently bonding to one or more fouling precursor compounds formed during olefin production.

Inventors

• Fabrice Cuoq
• Martijn FRISSEN
• Sharankumar G. Shetty

Assignees

• SABIC GLOBAL TECHNOLOGIES B.V.

Dates

Publication Date

20260505

Application Date

20210927

Claims (18)

1. 1 . A method for reducing fouling in an aqueous system of an olefin production plant, the method comprising: adding an effective amount of a polyethylene glycol (PEG) functionalized maleamide to the aqueous system, wherein the PEG functionalized maleamide forms a water soluble adduct by covalently bonding to one or more fouling precursor compound(s) formed during olefin production, and wherein the PEG functionalized maleamide has a chemical structure of formula I or formula II, wherein n, k and l are independently 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 or 10.
2. 2 . The method of claim 1 , wherein the olefin production plant produces olefin by steam cracking of a hydrocarbon feed.
3. 3 . The method of claim 2 , wherein the hydrocarbon feed is naphtha, liquid petroleum gas, ethane, butane, or any combination thereof.
4. 4 . The method of claim 2 , wherein the hydrocarbon feed is liquid petroleum gas, ethane, propane, butane, or any combination thereof.
5. 5 . The method of claim 2 , wherein the hydrocarbon feed is naphtha, liquid petroleum gas, propane, butane, or any combination thereof.
6. 6 . The method of claim 2 , wherein the hydrocarbon feed is naphtha, ethane, propane, butane, or any combination thereof.
7. 7 . The method of claim 2 , wherein the hydrocarbon feed is naphtha, liquid petroleum gas, ethane, propane, or any combination thereof.
8. 8 . The method of claim 1 , wherein the aqueous system is a dilution steam system.
9. 9 . The method of claim 1 , wherein the PEG functionalized maleamide is added to a process water stripper unit of the dilution steam system.
10. 10 . The method of claim 9 , wherein the PEG functionalized maleamide is added to a bottom portion of the process water stripper unit.
11. 11 . The method of claim 1 , wherein the water soluble adduct is a water soluble polymer.
12. 12 . The method of claim 1 , wherein the one or more fouling precursor compounds are styrene, indene, divinylbenzene, methyl styrene, or cyclopentadiene, or any combination thereof.
13. 13 . The method of claim 1 , further comprising removing the water soluble adduct from the aqueous system.
14. 14 . The method of claim 13 , wherein the aqueous system is a dilution steam system and the water soluble adduct is removed from a process water of the dilution steam system by a blow down process.
15. 15 . The method of claim 1 , further comprising: determining amount of the fouling precursor compound present in the aqueous system; and adding the PEG functionalized maleamide to the aqueous system such that weight ratio of the added PEG functionalized maleamide to the fouling precursor compound is 0.25:1 to 1.2:1.
16. 16 . The method of claim 15 , wherein the fouling precursor compound is styrene.
17. 17 . The method of claim 16 , wherein weight ratio of the added PEG functionalized maleamide to styrene is 0.25:1 to 1:1, and wherein the aqueous system is a dilution steam system.
18. 18 . The method of claim 1 , wherein the PEG functionalized maleamide is dosed continuously.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a national phase under 35 U.S.C. § 371 of International Application No. PCT/IB2021/058808, filed Sep. 27, 2021, which claims the benefit of priority to U.S. Provisional Patent Application No. 63/085,980, filed Sep. 30, 2020, the entire contents of each of which are hereby incorporated by reference in their entirety. FIELD OF INVENTION The invention generally concerns reducing fouling in an olefin production plant. In particular, the invention can include using a surfmer to reduce fouling in an aqueous system of an olefin production plant. BACKGROUND OF THE INVENTION Olefins are common building blocks for a variety of petrochemicals. One way of producing olefins is to steam crack hydrocarbon feedstocks such as naphtha, liquid petroleum gas (LPG), ethane, propane and/or butane. In the steam cracking (pyrolysis) process, the hydrocarbons are superheated in a reactor to temperatures as high as 750-950° C. For the cracking process, a dilution steam generator (DSG) supplies dilution steam to the reactor to reduce the partial pressure of the hydrocarbons. The heated hydrocarbons are then rapidly cooled (quenched) to stop the reactions after a certain point to optimize cracking product yield. The quenching of the heated gas in many processes is carried out using water in a quench water tower (QWT). The heated cracked gas (including olefins) is flowed into the bottom of the quench water tower and, at the same time, water is sprayed into the top of the quench water tower. As the water in the quench water tower falls, it makes contact with the upwardly flowing heated cracked gas and, in that way, cools the heated cracked gas (that includes olefins) and dilution steam. Because of the direct contact between the heated cracked gas in the quench water tower and the condensation of the dilution steam, the water flowing from the quench water tower is mixed with condensed hydrocarbons (e.g., pyrolysis gasoline). In the quench water tower, the pyrolysis gasoline and water mixes and can form an emulsion. Thus, the quench water tower effluent stream flowing from the bottom of the quench water tower may include an emulsion having a hydrocarbon phase dispersed in a continuous water phase. Hydrocarbon in water emulsions are particularly difficult to break. In other words, the emulsion is stable because, once the emulsion is formed, the water does not easily separate from the pyrolysis gasoline. To facilitate the separation of the water from the pyrolysis gasoline, the quench water tower effluent stream is flowed from the quench water tower to a quench water settler (QWS). At the quench water settler, the quench water effluent stream (including the emulsion) is settled and water is drawn off from the quench water settler. Then, the water from the quench water settler is sent to a process water stripper (PWS). The process water stripper strips the water of acid gases and dissolved hydrocarbons. After being stripped in the process water stripper, the water is routed to the dilution steam generator (mentioned above). The water that is used to generate dilution steam for the cracking furnaces, and subsequently condensed in the quench water tower, then circulated to the quench water settler, then to the process water stripper, and finally back to the dilution steam generator can be oftentimes be referred to as process water, which circulates in a quench water tower loop. The quench water tower, quench water settler, process water stripper, and dilution steam generator can be collectively referred to as a dilution steam system (DSS). Because the emulsion in the quench water tower tends to be stable, the attempt to separate pyrolysis gasoline and various other contaminants formed as a result of the pyrolysis from water in the quench water tower and/or quench water tower settler is often ineffective and can be time consuming and costly. Consequently, the process water may carry a large amount of fouling precursors, for example reactive monomeric species, to the process water stripper, which causes fouling of the process water stripper. The dilution steam generator can also get fouled because of hydrocarbons carry-over and subsequent polymerization. The conditions at which the dilution steam is generated is effective for continued reactions between the fouling precursors. Further, process water that flows from the bottom of the quench water tower and the quench water settler can contain traces of fouling precursors such as styrene as well as oligomers of styrene that form in the water as a result of the long residence time of the water recycle in the quench water tower loop. These oligomers can grow further at process water stripper conditions and can cause fouling in the dilution steam system. Fouling at the dilution steam system, such as at a bottom of the process water stripper and in the dilution steam generator preheaters, can lead to poor energy efficiency and, in a worst cas