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KR-102964646-B1 - Refining method of synthetic crude oil streams

KR102964646B1KR 102964646 B1KR102964646 B1KR 102964646B1KR-102964646-B1

Abstract

The present invention relates to a method for refining a synthetic crude oil stream comprising the following steps: - providing a synthetic crude oil stream; - washing the synthetic crude oil stream with a first aqueous washing solution at a first temperature to obtain a first refined synthetic crude oil stream; and - washing the first refined synthetic crude oil stream with a second aqueous washing solution at a second temperature to obtain a second refined synthetic crude oil stream, wherein the first aqueous washing solution is basic, the second aqueous washing solution is acidic, and the second temperature is lower than the first temperature. Furthermore, the present invention relates to a method for producing synthetic crude oil comprising the following steps: - producing a synthetic crude oil stream (1) preferably by depolymerization of a plastic material, in particular plastic waste; and - refining the synthetic crude oil stream (1) according to the method of the present invention.

Inventors

  • 마스탈리르, 마티아스

Assignees

  • 오엠브이 다운스트림 게엠베하

Dates

Publication Date
20260513
Application Date
20220916
Priority Date
20210917

Claims (15)

  1. As a method for refining synthetic crude oil stream (1), - Step of providing a synthetic crude oil stream (1); - A step of washing the synthetic crude oil stream (1) with a first aqueous washing solution (2) at a first temperature to obtain a first refined synthetic crude oil stream (3); and - A step of washing the first refined synthetic crude oil stream (3) with a second aqueous washing solution (4) at a second temperature to obtain a second refined synthetic crude oil stream (5). Includes, A method for purifying a synthetic crude oil stream (1), characterized in that the first aqueous washing solution (2) is basic, the second aqueous washing solution (4) is acidic, the second temperature is lower than the first temperature, and the first temperature is greater than 100°C.
  2. A method according to claim 1, characterized in that the first temperature is greater than 105℃.
  3. A method according to claim 1, characterized in that the step of washing the synthetic crude oil stream (1) with the first aqueous washing solution (2) is performed for an average washing period of at least 0.5 minutes, at least 1 minute, at least 2 minutes, at least 5 minutes, or at least 12 minutes.
  4. A method according to claim 1, characterized in that the step of washing the synthetic crude oil stream (1) with the first aqueous washing solution (2) is performed at a higher pressure than the step of washing the first refined synthetic crude oil stream (3) with the second aqueous washing solution (4).
  5. A method according to claim 1, characterized in that the pH value of the first aqueous washing solution (2) is greater than 8, greater than 9, greater than 10, greater than 11, greater than 12, or greater than 13.
  6. A method according to claim 1, characterized in that the pH value of the second aqueous washing solution (4) is less than 6, less than 5, less than 4, or less than 3.5.
  7. A method according to claim 1, characterized in that the volume mixing ratio between the synthetic crude oil stream (1) and the first aqueous washing solution (2) is 5:1 to 1:5, 2.5:1 to 1:2.5, or 1.5:1 to 1:1.5.
  8. A method according to claim 1, characterized in that no additional washing step is performed between the step of washing the synthetic crude oil stream (1) with the first aqueous washing solution (2) and the step of washing the first refined synthetic crude oil stream (3) with the second aqueous washing solution (4).
  9. A method according to claim 1, further comprising the following steps: - A step of washing the second refined synthetic crude oil stream (5) with a third aqueous washing solution (6) at a third temperature to obtain a third refined synthetic crude oil stream (7).
  10. A method according to claim 9, characterized in that the pH value of the third aqueous washing solution (6) is in the range of 3 to 13, 4 to 12, 5 to 11, 6 to 10, 6.5 to 9, or 7 to 8.
  11. A method according to claim 9, characterized in that the third temperature is lower than the first temperature.
  12. A method according to claim 9, characterized in that the step of washing the synthetic crude oil stream (1) with the first aqueous washing solution (2) is performed at a higher pressure than the step of washing the second refined synthetic crude oil stream (5) with the third aqueous washing solution (6).
  13. A method according to claim 9, characterized in that the volume mixing ratio between the second refined synthetic crude oil stream (5) and the third aqueous washing solution (6) is 10:1 to 1:5, 5:1 to 1:2.5, or 2.5:1 to 1:1.5.
  14. Synthetic crude oil production method including the following steps: - A step of producing a synthetic crude oil stream (1) by depolymerizing a plastic material, and - A step of refining a synthetic crude oil stream (1) according to a method according to any one of claims 1 to 13.
  15. A method according to claim 14, characterized in that the plastic material comprises at least one of polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyethylene terephthalate (PET), polyamide (PA), styrene-acrylonitrile (SAN), and acrylonitrile-butadiene-styrene (ABS).

Description

Refining method of synthetic crude oil streams The present invention relates to a method for refining a synthetic crude oil stream. Synthetic crude oil, sometimes referred to as syncrude, can be obtained through various processes. For example, synthetic crude oil can be shale oil obtained by pyrolysis of oil shale. Another source is hydrocarbons derived 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, such as plastic waste. Synthetic crude oil typically contains various impurities, which can negatively impact refining processes and facilities 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 process used to obtain the synthetic crude oil. WO 2020/020769 A1 describes a method for purifying a recyclable or renewable organic material, comprising heating the recyclable or renewable organic material in the presence of an aqueous alkali metal hydroxide solution and hydrotreating it in the presence of a hydrotreating catalyst to obtain a purified material with reduced chlorine content. WO 2021/105326 A1 describes a method for treating liquefied plastic waste, comprising a pretreatment step of liquefied plastic waste using an aqueous medium having a pH value of at least 7 at a temperature of at least 200°C, subsequent hydrogenation to obtain a steam cracker feed, and post-treatment. WO 2014/165859 A1 describes a method and apparatus for treating synthetic crude oil, wherein the synthetic crude oil is washed with an aqueous basic process solution to reduce the acidity level. This method may also include two or more washing steps. Additional methods for refining or processing oil are described in US 9 045 698 B2, US 2006/144761 A1 and GB 590 635 A. However, purification methods known from the latest technology are often complex and/or inadequate. In particular, impurities, such as neutral compounds (e.g., esters, aldehydes, ketones, organohalogen compounds, amides, nitriles) or polycyclic amines, are often insufficiently or not removed at all. This is a particular problem for complex starting materials where the impurity profile can vary significantly, for example, in the case of synthetic crude oil obtained from plastic waste. Insufficiently removed impurities can cause problems during the subsequent further processing of the purified crude oil. Another problem observed during many purification processes is the formation of precipitates in the equipment, which makes cleaning the equipment more difficult and hinders efficient operation. FIG. 1 shows a process flow diagram of a preferred embodiment of the method according to the present invention for producing synthetic crude oil. In the process of the present invention, performing the basic washing step at a higher temperature followed by the acidic washing step at a lower temperature yielded surprisingly advantageous results. Remarkable advantages arise from both the fact that the basic washing step is performed before the acidic washing step and the fact that the temperature of the basic washing step is higher than that of the acidic washing step. Regarding the order of washing steps, it was surprisingly found that performing a basic washing step before an acidic washing step not only resulted in superior phase separation but also significantly reduced precipitates. When the acidic washing step was performed without a prior basic washing step, the inventors observed the formation of precipitates, which were found to be primarily precipitated wax carboxylic acids. Wax carboxylic acids are long-chain carboxylic acids, consisting of carbon atoms with chain lengths ranging from 20 to 75, for example. In addition to paraffinic unbranched and branched chains, wax carboxylic acids may also possess aromatic, olefinic, and heteroatom functionalities. Wax carboxylic acids are present in many synthetic crude oils, particularly in pyrolysis oils (e.g., from the pyrolysis of plastics), because these compounds can be increasingly formed during the pyrolysis process, for example, through reactions with introduced oxygen or by pre-existing functional polymers or additives. In synthetic crude oils, wax carboxylic acids often exist in the form of salts. In the course of the present invention, it was found that treating an untreated synthetic crude oil stream with an acidic aqueous washing solution can protonate and release bound wax carboxylic acids. It was indicated that the wax carboxylic acids released in this manner can, on the one hand, precipitate to form unwanted precipitates, and on the other hand, act as surfactants to form a mixed phase or bind to unwanted compounds such as water, heavy metals, and nitrogen compounds in the oil phase. Unremoved wax carboxylic acids can also cause corrosion in the equipment and act as catalyti