Method of production of high-value hydrocarbon products from waste plastics and apparatus for method of production of high-value hydrocarbon products from waste plastics
View Patent ↗A method and apparatus for producing high value hydrocarbon products from waste plastic is accomplished in an inert atmosphere wherein waste plastics are fed to an extruded and melted, the melted plastics is then depolymerized in a thermolysis reactor, the vapors from depolymerization are separated into hydrocarbon fractions which are then hydro refined and subjected to secondary separation and finishing operations to produce desired high value hydrocarbon products.
1. A method of obtaining high-value hydrocarbon products from plastic waste in an inert gas atmosphere comprising:
continuously feeding plastic waste into an extruder;
melting the plastic waste in the extruder to obtain a melt;
depolymerizing the melt in a thermolysis reactor;
conducting depolymerization product vapors into a preliminary separation unit;
separating the vapors into fractions in the preliminary separation unit by an introductory separation;
hydrorefining the obtained fractions; and
conducting the hydrorefined fractions to a secondary separation unit and to a finishing operations unit.
2. The method according to claim 1 , wherein all product fractions obtained in the preliminary separation unit are hydrorefined one by one in charges in the same system.
3. The method according to claim 1 , wherein product fractions are catalytically hydrogenated then catalytically hydrodesulphurized and then secondly separated.
4. The method according to claim 3 , wherein the hydrogenated and desulphurized product fractions are catalytically dewaxed and then conducted to the secondary separation unit.
5. The method according to claim 1 , wherein depolymerization product vapors are separated in the preliminary separation unit in two steps.
6. The method according to claim 1 , wherein the plastic waste is melted and mixed with powder additives in a feedstock feeding unit.
7. The method according to claim 6 , wherein the powder additives are selected from the group consisiting of carbonates, bicarbonates, aluminosilicates, oxides of iron, aluminum, zinc, magnesium, calcium, and sodium.
8. The method according to claim 1 , wherein the separating in the preliminary separation unit results in condensed vapors, which are separated into a light fraction and a heavy fraction, wherein the light fraction consists of hydrocarbons of up to 15 carbon atoms in chain and the heavy fraction consists of hydrocarbons with more than 15 carbon atoms in chain.
9. The method according to claim 8 , further comprising separating the heavy fraction, using a vacuum evaporator, into a heavy oil fraction consisting of hydrocarbons with up to 24 carbon atoms in chain and a waxy fraction consisting of hydrocarbons with more than 24 carbon atoms in chain.
10. The method according to claim 8 , wherein the light fraction and the heavy fraction are decolorized in an adsorber using bleaching clay.
11. The method according to claim 8 , wherein waxes are blended with the heavy fraction.
12. An apparatus for continuously obtaining high-value hydrocarbon products from plastic waste, the apparatus comprising a feedstock feeding unit, a depolymerization reactor, a preliminary separation unit, a hydrorefining system, a secondary separation unit, and a finishing operations unit, wherein the hydrorefining system is situated after the preliminary separation unit, the secondary separation unit is situated after the hydrorefining system, and the finishing operations unit is situated after the secondary separation unit.
13. The apparatus according to claim 12 , wherein the hydrorefining system consists of a catalytic hydrogenation reactor and a catalytic hydrodesulphurization reactor.
14. The apparatus according to claim 12 , wherein the hydrorefining system consists of a catalytic hydrogenation reactor, a catalytic hydrodesulphurization reactor, and a catalytic dewaxing reactor.
15. The apparatus according to claim 13 , wherein the catalytic hydrogenation reactor is situated after the preliminary separation unit and the catalytic hydrodesulphurization reactor is situated after the catalytic hydrogenation reactor.
16. The apparatus according to claim 13 , wherein the catalytic hydrogenation reactor and the catalytic hydrodesulphurization reactor each consist of two elementary flow tubular reactors connected in series.
17. The apparatus according to claim 16 , wherein the catalytic hydrogenation reactors and the catalytic hydrodesulphurization reactors diameter to length ratio is at least 1:30.
18. The apparatus according to claim 14 , wherein the catalytic dewaxing reactors diameter to length ratio is at least 1:30.
19. The apparatus according to claim 14 , wherein the secondary separation unit is connected to the hydrodesulphurization reactor and the catalytic dewaxing reactor.
20. The apparatus according to claim 12 , wherein the finishing operations unit comprises at least one adsorber.