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KR-20260065853-A - Method for treating a silicon-containing hydrocarbon stream

KR20260065853AKR 20260065853 AKR20260065853 AKR 20260065853AKR-20260065853-A

Abstract

The present invention relates to a method for treating a silicon (Si)-containing hydrocarbon stream (1), the method comprising the following steps: - A step of providing the above hydrocarbon stream (1); - A step of separating a Si-rich fraction (24) from the above hydrocarbon stream (1), wherein the Si-rich fraction (24) has a boiling range with a lower limit of at least 120°C and a Si content of at least 10 ppm; - A step of processing the Si-rich fraction (24) in a fluid catalytic decomposition (FCC) unit (20).

Inventors

  • 마스탈리르, 마티아스

Assignees

  • 오엠브이 다운스트림 게엠베하

Dates

Publication Date
20260511
Application Date
20240906
Priority Date
20230906

Claims (15)

  1. A method for processing a silicon (Si)-containing hydrocarbon stream (1), wherein the method comprises: - A step of providing the above hydrocarbon stream (1); - A step of separating a Si-rich fraction (24) from the above hydrocarbon stream (1), wherein the Si-rich fraction (24) has a boiling range with a bottom of at least 120°C and a Si content of at least 10 ppm; - A step of processing the Si-rich fraction (24) in a Fluid Catalytic Cracking (FCC) unit (20). A method including
  2. In claim 1, the method wherein the Si-rich fraction (24) has a boiling range with an upper maximum of 280°C.
  3. A method according to claim 1 or 2, wherein in addition to the Si-rich fraction (24), a naphtha fraction (23) is separated from the hydrocarbon stream (1), preferably the naphtha fraction (23) has a boiling range with an upper limit of 200°C.
  4. A method according to any one of claims 1 to 3, wherein the Si-rich fraction (24) is washed with at least one aqueous washing solution (25) before being processed in the FCC unit (20).
  5. In paragraph 4, the washing with at least one aqueous washing solution (25) is performed at a temperature of at least 40°C.
  6. A method according to claim 4 or 5, wherein the pH of the aqueous washing solution (25) is less than 8.
  7. In any one of claims 1 to 6, the hydrocarbon stream (1) is a silicon (Si)- and phosphorus (P)-containing hydrocarbon stream (1), and Here, in addition to the Si-rich fraction (24), a P-rich fraction (9) is separated from the hydrocarbon stream (1), and the P-rich fraction (9) has a boiling range with a bottom of at least 350°C and a P content of at least 10 ppm, The above Si-rich fraction (24) and the above P-rich fraction (9) are processed in the above FCC unit (20), in a method.
  8. In claim 7, the method of undergoing solid reduction before the P-concentrated fraction (9) is processed in the FCC unit (20).
  9. In paragraph 8, the above-mentioned solid reduction method comprises the following steps: - A step of adding a solvent (13) to the P-concentrated fraction (9) to form a mixture (14); - A step of separating solids (16) from the above mixture (14).
  10. In claim 9, the solvent (13) comprises at least 20 weight percent of an aliphatic hydrocarbon based on the total weight of the solvent (13).
  11. In claim 9 or 10, the method wherein the mixture (14) has a temperature of at least 80°C.
  12. A method according to any one of claims 9 to 11, wherein after separating the solid (16) from the mixture (14), at least a portion of the solvent (13) is separated from the mixture (14).
  13. In paragraph 12, a method in which at least a portion of the separated solvent (18) is reused for the reduction of the solids.
  14. A method according to any one of claims 1 to 13, wherein the FCC unit (20) comprises a catalyst including a zeolite.
  15. A method according to any one of claims 1 to 14, wherein the hydrocarbon stream (1) is produced by the depolymerization of plastic materials, particularly plastic waste.

Description

Method for treating a silicon-containing hydrocarbon stream The present invention relates to a method for processing silicon (Si)-containing hydrocarbon streams. In oil refining processes, material flows of different origins are used, and these can be contaminated with various impurities. Silicon (Si) and phosphorus (P) play important roles here. For example, material flows can be contaminated by silicone oil, which is used as a lubricant and sealant in oil refining systems. Silicone oil is also sometimes used as a process additive or anti-foaming agent, for example, in cokers or Thermal Gasoil Units (TGUs). P compounds are also often used as additives, for example, as corrosion inhibitors, which can appear as P-containing impurities. These impurities are particularly important in relation to synthetic crude oil. Synthetic crude oil, sometimes also called syncrude, can be obtained from various processes. For example, synthetic crude oil can be shale oil obtained by pyrolysis from oil shale. Another source is hydrocarbons obtained from oil sands, particularly bitumen, from which synthetic crude oil can be obtained through upgrading. Additionally, synthetic crude oil can be produced by cracking plastic materials, for example, plastic waste. Other sources of synthetic crude oil are biomass, wood, and other biological raw materials, which may already contain organic P compounds from natural sources (e.g., phospholipids and nucleic acids), to which Si and P compounds are often added in the form of impregnation and surface treatments (e.g., flame retardants, surface improvement with silicone, silicone adhesives, etc.). Synthetic crude oil typically contains various impurities, which can negatively impact refining processes and refinery systems or render the crude oil completely unsuitable for specific refining processes. The types and content of impurities can vary significantly depending on the source and method used to obtain the synthetic crude oil. However, Si and P play important roles. Si and P can cause problems in relation to various processes in oil refining systems. For example, Si and P compounds can be detrimental to catalysts in hydrogenation systems and can lead to vitrification. Therefore, Si and P must typically be removed before these processes. Separation is usually achieved by sophisticated guard beds. However, guard beds incur operating costs and require periodic replacement, which consequently necessitates system shutdown. When large volumes of hydrocarbon streams are used, guard beds can quickly become overloaded even at low Si or P content and must be replaced frequently. FIG. 1 shows a process flow diagram of a preferred embodiment of the method according to the present invention. Until now, conventional technology has generally assumed that impurities must be removed from hydrocarbon streams prior to refining processes such as FCC. For example, WO 2021/201932 A1 describes a method for the pyrolysis of plastic waste, in which the entire liquid fraction from the pyrolysis is fed to an FCC unit. It is explicitly noted that impurities (including P compounds and silica, among many others) must be removed from the plastic waste as much as possible to less than 5 ppm (WO 2021/201932 A1, [0036]). If this is not achieved, a separate guard bed must be provided to remove impurities (WO 2021/201932 A1, [0037]). Additionally, a pretreatment unit may be provided prior to the FCC unit to remove sulfur, nitrogen, phosphorus, silica, dienes, and metals (WO 2021/201932 A1, [0014]). In the course of the present invention, it has now been surprisingly discovered that, in the case of Si and P compounds, there is no need to remove them prior to the FCC process. Furthermore, surprisingly, the FCC unit can even be specifically used to remove such compounds. This is convincingly demonstrated by the examples included herein, in which a hydrocarbon stream with excess silicone oil or organic P compounds could still be processed without issue in the FCC unit even at a concentration of 1 wt% (i.e., 10,000 ppm). Si and P were efficiently removed even at such high concentrations. Without being bound by theory, the inventor explains this by the fact that during the FCC process, any organic component of the Si and P compounds is cleaved to formally form SiO2 or PO43- groups . In contrast to hydrogenation systems where the best catalyst layer can be vitrified, SiO2 or PO43- groups do not harm the FCC process. Instead, they can even extend the backbone of the FCC catalyst. In the FCC process, zeolites composed of a silicate backbone and capable of being modified into phosphate groups at the active center are regularly used as catalysts. According to the inventor, the SiO2 or PO43- groups formed during the process can accumulate on the existing catalyst and, consequently, may act as catalysts themselves or at least not negatively affect catalytic activity. This effect is particularly advantageous when the zeolite is already