METHOD FOR PRODUCING A HYDROCARBON PRODUCT

Abstract

A method for producing a hydrocarbon product from a hydrocarbon mixture containing at least 1 ppm of organically bound halogen includes providing the hydrocarbon mixture containing at least 1 ppm of organically bound halogen, heating the hydrocarbon mixture in order to obtain a gaseous hydrocarbon stream, bringing the gaseous hydrocarbon stream into contact with a composition containing at least one nitrogen compound in order to obtain a gaseous mixture, as a result of which organically bound halogen is converted into halide ions, and separating the halide ions in order to obtain the hydrocarbon product.

Claims

1-15. (canceled)

16. A method for producing a hydrocarbon product from a hydrocarbon mixture containing at least 1 ppm of organically bound halogen, the method comprising: providing the hydrocarbon mixture containing at least 1 ppm of organically bound halogen; heating the hydrocarbon mixture in order to obtain a gaseous hydrocarbon stream; bringing the gaseous hydrocarbon stream into contact with a composition containing at least one nucleophilic nitrogen compound in order to obtain a gaseous mixture, as a result of which organically bound halogen is converted into halide ions, wherein a mass ratio between the gaseous hydrocarbon stream and the composition containing the at least one nucleophilic nitrogen compound is at least 5:1, wherein a temperature of the gaseous hydrocarbon stream when brought into contact is at least 150 C. and wherein a temperature of the obtained gaseous mixture is at least 150 C.; and separating the halide ions in order to obtain the hydrocarbon product.

17. The method according to claim 16, wherein the at least one nucleophilic nitrogen compound is selected from the group consisting of primary amines, secondary amines, tertiary amines, ammonia and hydrazine.

18. The method according to claim 16, wherein the hydrocarbon mixture contains at least 0.2% wt % of polyvinyl chloride (PVC).

19. The method according to claim 16, wherein the hydrocarbon mixture contains bromine-containing flame retardants, preferably polybrominated diphenyl ethers and/or polybrominated biphenyls, more preferably decabromodiphenyl ether (DecaBDE), tetrabromobisphenol A (TBBPA) and/or hexabromocyclododecane (HBCD).

20. The method according to claim 16, wherein the hydrocarbon mixture is a hydrocarbon mixture obtained from plastic material, in particular waste plastic.

21. The method according to claim 16, wherein the hydrocarbon mixture is a crude oil, preferably a synthetic crude oil, in particular a pyrolysis oil.

22. The method according to claim 16, wherein the heating of the hydrocarbon mixture takes place in the course of a pyrolysis process, a hydrogenation process, or a distillation process.

23. The method according to claim 16, wherein the temperature of the gaseous hydrocarbon stream when brought into contact with the composition containing the at least one nucleophilic nitrogen compound is at least 200 C.

24. The method according to claim 16, wherein the composition containing the at least one nucleophilic nitrogen compound is an aqueous composition.

25. The method according to claim 16, wherein a concentration of nucleophilic nitrogen compounds in the composition is between 10 and 50 wt %.

26. The method according to claim 16, wherein the mass ratio between the gaseous hydrocarbon stream and the composition containing the at least one nucleophilic nitrogen compound is between 15:1 and 50:1.

27. The method according to claim 16, wherein the at least one nucleophilic nitrogen compound is a secondary amine having a boiling point of less than 200 C.

28. The method according to claim 16, wherein the at least one nucleophilic nitrogen compound is selected from the group consisting of ammonia, ethanolamine, 3-methoxypropylamine, dimethylamine, diethylamine, dibutylamine, morpholine, diethanolamine, and/or triethylamine; preferably dimethylamine, diethylamine, dibutylamine, and/or morpholine.

29. The method according to claim 16, wherein separating the halide ions takes place by washing with an aqueous washing solution, preferably wherein the aqueous washing solution is basic.

30. The method according to claim 16, wherein separating the halide ions takes place by distillation.

31. The method according to claim 16, wherein the hydrocarbon product contains less than 200 mg/kg of organically bound halogen.

Description

[0038] The present invention is illustrated by the following FIGURE and the following examples, to which, of course, it is not limited.

[0039] FIG. 1 shows a method flow diagram of a preferred embodiment of the method according to the invention.

[0040] In the embodiment shown in FIG. 1, the hydrocarbon mixture 1 is a melt obtained from plastic material, preferably containing 0.1 to 5 wt % of PVC. The plastic material is compacted, degassed and melted in an extruder 7. The plastic melt exiting the extruder 7 is mixed in a static mixer 8 with an external solvent 9, preferably heavy fuel oil, and/or with already pyrolised plastic material, which is recirculated as recycling stream 10, in order to reduce the viscosity of the plastic melt. The hydrocarbon mixture 1 thus obtained is heated in a depolymerisation reactor 11, preferably to a temperature between 400 C. and 440 C., resulting in depolymerisation of the plastic material. A gaseous hydrocarbon stream 2 containing pyrolysed plastic material is then obtained as the top product of a column 12. The gaseous hydrocarbon stream 2 is subsequently brought into contact with a composition 3 containing at least one nitrogen compound in order to obtain a gaseous mixture 4. The temperature of the gaseous hydrocarbon stream 2 when brought into contact with the composition 3 is preferably at least 300 C. The composition 3 can be metered in liquid form into the hot hydrocarbon stream 2, wherein the composition 3 evaporates rapidly, which enables good mixing with the hydrocarbon stream 2, in particular if the composition 3 is an aqueous composition. In the gaseous mixture 4 thus obtained, nucleophilic substitution reactions take place in which the nitrogen compounds contained in composition 3 nucleophilically attack the organic chlorine compounds originating from the PVC and thus the organically bound chlorine is converted into chloride ions. In the embodiment shown, a gas stream 13 can be segregated from the gaseous mixture 4 in a further column 14. In the embodiment shown, the material stream 15 obtained therefrom is mixed with an aqueous washing solution 6 in a mixing zone of a mixer-settler 16, wherein chloride ions pass into the aqueous phase. Subsequently, the purified oil phase is segregated from the aqueous phase in a settling zone of the mixer-settler 16. The aqueous phase is removed as wastewater stream 17 and the oil phase is obtained as hydrocarbon product 5.

EXAMPLE 1: PRODUCTION OF SYNTHETIC CRUDE OIL WITH REDUCED CONTENT OF ORGANICALLY BOUND HALOGEN

[0041] In order to test the reduction of organically bound chlorine and bromine with the method according to the invention, test runs for producing synthetic crude oil were carried out essentially as shown in FIG. 1. The starting material used was plastic mixtures to which 0.5 wt % or 1 wt % of PVC had been added and which contained between 5 and 250 ppm of bromine.

[0042] The plastic mixtures were extruded as described in FIG. 1 and cracked at a temperature between 400 C. and 440 C. A gaseous hydrocarbon stream was segregated as the top product of a column downstream of the depolymerisation reactor. Immediately after the column, an amine composition was metered into the hydrocarbon stream. The temperature of the hydrocarbon stream during metering in was 370 C. A solution of 10 wt % ethanolamine in water was used as the amine composition. The amount metered in of the amine composition was 3 kg/h at a feed rate of 80 kg/h. The product obtained was washed and the content of organically bound chlorine and bromine in the organic phase was determined.

[0043] The following concentrations of organically bound chlorine and bromine were obtained in the product: [0044] 0.5 wt % PVC in the feed: 16 ppm organically bound chlorine, 0 ppm organically bound bromine; [0045] 1 wt % PVC in the feed: 58 ppm organically bound chlorine, 0 ppm organically bound bromine; [0046] Comparative experiments without dosing in the amine composition: 200-2,000 ppm organically bound chlorine; up to 250 ppm organically bound bromine.

[0047] In summary, the metering in of nitrogen compounds provided according to the invention thus led to a considerable reduction in the content of organically bound halogen in the product.

EXAMPLE 2: COMPARATIVE EXPERIMENTS WITH DIFFERENT NITROGEN COMPOUNDS

[0048] In order to investigate the influence of the choice of nitrogen compound, comparative experiments were carried out with different nitrogen compounds. As a feedstock, a synthetic crude oil contaminated with halocarbons and with an organochlorine content of 58 ppm was used. The feedstock was placed in a pressure vessel with the respective amine (2 wt %) at room temperature and heated to 130 C. for 30 min. After cooling, the organic phase was washed with water and analysed.

[0049] The following results were achieved with the respective nitrogen compounds:

TABLE-US-00001 Nitrogen Degree of Boiling Result (organically compound substitution point bound chlorine [ppm]) Ammonia 33 C. 52.0 Ethanolamine primary 170 C. 32.1 Dimethylamine secondary 7 C. 22.0 Diethylamine secondary 56 C. 27.4 Dibutylamine secondary 159 C. 28.3 Morpholine secondary 129 C. 24.6 Diethanolamine secondary 269 C. 43.0 Triethylamine tertiary 89 C. 54.0

[0050] As can be seen from the table above, the best results were achieved with secondary amines with a boiling point of less than 200 C. (dimethylamine, diethylamine, dibutylamine, morpholine; all below 30 ppm of organically bound chlorine in the product). These nitrogen compounds proved to be advantageous both over primary (ethanolamine) and tertiary (triethylamine) amines as well as ammonia, and over secondary amines with a higher boiling point (diethanolamine).

EXAMPLE 3: COMPARATIVE EXPERIMENTS WITH DIFFERENT NITROGEN COMPOUNDS AT HIGHER TEMPERATURES

[0051] In order to investigate the effect of the different nitrogen compounds at higher temperatures, the experiments described in example 2 were carried out at a higher temperature. As a feedstock, in turn, a synthetic crude oil contaminated with halocarbons and with an organochlorine content of 58 ppm was used. The feedstock was placed in a pressure vessel with the respective amine (2 wt %) at room temperature and heated to 300 C. for 10 min. After cooling, the organic phase was washed with water and analysed.

TABLE-US-00002 Nitrogen Degree of Boiling Result (organically compound substitution point bound chlorine [ppm]) Ethanolamine primary 170 C. 15 Dimethylamine secondary 7 C. 2 Morpholine secondary 129 C. 4 Diethanolamine secondary 269 C. 8

[0052] As can be seen from the table above, the higher temperature led to an even more significantly increased reduction of organically bound chlorine. Again, the use of secondary amines with a boiling point of less than 200 C. (dimethylamine, morpholine) proved to be advantageous both over a primary amine (ethanolamine) and over a secondary amine with a higher boiling point (diethanolamine).