Method and system for producing refined hydrocarbons from waste plastic pyrolysis oil
Embodiments of the present disclosure relate to a method and system for producing refined hydrocarbons from waste plastic pyrolysis oil. The method and system for producing refined hydrocarbons from waste plastic pyrolysis oil according to the embodiments of the present disclosure may minimize formation of an ammonium salt (NH 4 Cl) and may prevent an adhesion phenomenon of impurity particles in a reactor in a refining process of waste plastic pyrolysis oil containing impurities including chlorine and nitrogen. In addition, the method and system for producing refined hydrocarbons according to the embodiments of the present disclosure may have excellent refining efficiency and may implement a long-term operation of a process because deactivation of a catalyst used in the process is prevented and may produce refined hydrocarbons having a low content of impurities and a high octane number from waste plastic pyrolysis oil.
1. A method for producing refined hydrocarbons from waste plastic pyrolysis oil, the method comprising:
a dehydration operation of applying a voltage to a first mixed solution obtained by mixing waste plastic pyrolysis oil, washing water, and a demulsifier to dehydrate the first mixed solution;
a hydrotreating operation of hydrotreating a second mixed solution obtained by mixing the dehydrated first mixed solution and a sulfur source to produce a refined oil from which impurities are removed; and
an alkylation operation of alkylating a third mixed solution obtained by mixing the refined oil and olefins.
2. The method of claim 1 , wherein in the dehydration operation, the waste plastic pyrolysis oil is mixed in a greater volume than the washing water.
3. The method of claim 2 , wherein in the dehydration operation, the waste plastic pyrolysis oil and the washing water are mixed in the first mixed solution at a volume ratio of 1:0.001 to 1:0.5.
4. The method of claim 1 , wherein in the dehydration operation, the waste plastic pyrolysis oil and the demulsifier are mixed in the first mixed solution at a volume ratio of 1:0.000001 to 1:0.001.
5. The method of claim 1 , wherein the voltage is applied as an alternating current or a combination of an alternating current and a direct current.
6. The method of claim 1 , wherein the voltage is applied through at least one pair of vertical electrodes.
7. The method of claim 1 , further comprising, after the application of the voltage in the dehydration operation, removing a rag layer from the first mixed solution.
8. The method of claim 1 , wherein the dehydration operation is performed under a temperature condition of 20° C. to 300° C.
9. The method of claim 1 , wherein a ratio of a content of moisture in the waste plastic pyrolysis oil to a content of moisture in the dehydrated first mixed solution is 1:0.0001 to 1:0.9.
10. The method of claim 1 , wherein in the dehydration operation, the dehydrated first mixed solution is additionally dehydrated by condensation of moisture.
11. The method of claim 1 , wherein a weight ratio of nitrogen to chlorine in the second mixed solution is 1:1 to 1:10.
12. The method of claim 1 , wherein the sulfur source includes a sulfur-containing oil.
13. The method of claim 12 , wherein the sulfur-containing oil is included in an amount of less than 0.5 parts by weight with respect to 100 parts by weight of the dehydrated first mixed solution.
14. The method of claim 1 , wherein the sulfur source includes one or two or more sulfur-containing organic compounds selected from a disulfide-based compound, a sulfide-based compound, a sulfonate-based compound, and a sulfate-based compound.
15. The method of claim 1 , wherein the hydrotreating is performed in the presence of a molybdenum-based hydrotreating catalyst.
16. The method of claim 15 , wherein the molybdenum-based hydrotreating catalyst is a catalyst in which a molybdenum-based metal, or a metal including one or two or more selected from nickel, cobalt, and tungsten, and a molybdenum-based metal are supported on a support.
17. The method of claim 1 , wherein the hydrotreating is performed under a pressure condition of 50 bar to 150 bar.
18. The method of claim 1 , further comprising, after the hydrotreating operation, subjecting a stream including the refined oil to gas-liquid separation to obtain a refined oil gas fraction and then washing the refined oil gas fraction with water.
19. The method of claim 1 , wherein the third mixed solution is obtained by further mixing petroleum hydrocarbons.
20. A method for producing a refined alkylated hydrocarbon from waste plastic pyrolysis oil, the method comprising:
a dehydration operation of applying a voltage to a first mixed solution obtained by mixing waste plastic pyrolysis oil, washing water, and a demulsifier to dehydrate the first mixed solution;
a hydrotreating operation of hydrotreating a second mixed solution obtained by mixing the dehydrated first mixed solution and a sulfur source to produce a refined oil from which impurities are removed;
distilling the refined oil to obtain a distilled refined oil fraction,
preparing a third mixed solution by mixing the distilled refined oil fraction with olefins, and
alkylating the third mixed solution.