PROCESS FOR THE PRODUCTION OF OLEFINIC COMPOUNDS AND A HYDROCARBON FUEL OR A FRACTION THEREOF

Abstract

The present invention relates to a process for the production of olefinic compounds that can be used for the production of detergents, additives, lubricants and/or plastic materials, or components which can be used in the field of oil explorations and productions, and a hydrocarbon fuel or a fraction thereof, which comprises subjecting a mixture of glycerides having at least one unsaturated hydrocarbon chain, to metathesis reaction and, after separating the olefinic mixture obtained, effecting a hydrodeoxygenation and subsequently hydroisomerization process, so as to obtain the hydrocarbon fuel or a fraction thereof.

Claims

1-18. (canceled)

19. A process for producing olefinic compounds and a hydrocarbon fuel or a fraction thereof, the process comprising: (a) subjecting to metathesis reaction a mixture of glycerides having at least one unsaturated hydrocarbon chain with at least one C.sub.2-C.sub.6 monoolefin in the presence of a metathesis catalyst, to obtain a mixture of glycerides having at least one unsaturated hydrocarbon chain with a carbon length less than an initial carbon length, and a mixture of C.sub.6-C.sub.18 olefins; (b) separating the mixture of C.sub.6-C.sub.18 olefins from the mixture of glycerides obtained by step (a); (c) subjecting the mixture of glycerides obtained by step (b) to a transesterification reaction with an alcohol selected from the group consisting of methanol, ethanol and mixtures thereof, to obtain a mixture of methyl esters, ethyl esters, or both, and glycerol; (c′) separating the glycerol from the mixture of methyl esters, ethyl esters, or both; and then (c″) separating a stream consisting essentially of methyl esters, ethyl esters, or both, having an unsaturated hydrocarbon chain from methyl esters, ethyl esters, or both, having a saturated hydrocarbon chain in the mixture; and (d) hydrodeoxygenating the stream of the methyl esters, ethyl esters, or both, having a saturated hydrocarbon chain, obtained by step (c″) to produce an effluent and then hydroisomerizing the effluent to obtain the hydrocarbon fuel or a fraction thereof.

20. The process of claim 19, wherein the hydrocarbon fuel is selected from the group consisting of a diesel fuel, a naphtha fuel, an aviation petrol, and mixtures thereof.

22. The process of claim 19, wherein the glycerides having at least one unsaturated hydrocarbon chain in the mixture in step (a) are glycerides of vegetable or animal origin or of microbial origin.

23. The process of claim 22, wherein the glycerides of vegetable or animal origin or of microbial origin are mono or polyunsaturated glycerides of fatty acids having at least one C.sub.12-C.sub.24 hydrocarbon chain.

24. The process of claim 22, wherein the glycerides are in the form of a vegetable oil, a recycled oil from a food industry, a recycled fat from a food industry, a lipid from a seaweed, an animal oil, an animal or mixtures thereof.

25. The process of claim 19, wherein the at least one C.sub.2-C.sub.6 monoolefin is selected from the group consisting of ethylene, propene, 1-butene, but-2-ene, 2-methyl-propene, and mixtures thereof.

26. The process of claim 19, wherein, in step (a), a molar ratio of double bonds of the mixture of glycerides having at least one unsaturated hydrocarbon chain and double bonds of the at least one C.sub.2-C.sub.6 monoolefin ranges from 1:0.1 to 1:20.

27. The process of claim 19, wherein step (a) occurs at a temperature from 20 to 120° C., for a period of time from 0.5 to 6 hours.

28. The process of claim 19, wherein step (a) occurs at a pressure of between 1 and 30 bars.

29. The process of claim 19, wherein the metathesis catalyst is a carbene complex of a transition metal of Group 8.

30. The process of claim 19, wherein separation in step (b) occurs by distillation.

31. The process of claim 19, wherein said hydrodeoxygenating in step (d) occurs with hydrogen in the presence of a hydrodeoxygenation catalyst.

32. The process of claim 31, wherein the hydrodeoxygenation catalyst comprises at least one metal of group VIII or of group VIB.

33. The process of claim 31, wherein the hydrodeoxygenation catalyst is supported on at least one metallic oxide.

34. The process of claim 19, wherein the said hydroisomerizing in step (d) occurs with hydrogen in the presence of a hydroisomerization catalyst.

35. The process of claim 34, wherein the hydroisomerization catalyst comprises at least one metal of group VIII and an acid-containing support.

36. The process of claim 19, wherein the glycerides are triglycerides.

37. The process of claim 19, wherein the at least one C.sub.2-C.sub.6 monoolefin is a C.sub.2-C.sub.4 monoolefin.

38. The process of claim 19, wherein the glycerides are in the form of a vegetable oil and said vegetable oil is selected from the group consisting of sunflower, rapeseed, canola, palm, soya bean, hemp, olive, linseed, mustard, peanut, castor, coconut and tall oil.

39. The process of claim 19, wherein the glycerides are in the form of a fat and said fat is selected from the group consisting of lard, lard cream, tallow, and milk fat.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0050] FIG. 1: the passages of the process of the invention according to a preferred embodiment, are exemplified in a block scheme (scheme 1): effecting the metathesis step, followed by separation of the olefins with less than 18 carbon atoms, hydrolysis of the fraction comprising triglycerides by the addition of C.sub.1-C.sub.2 alcohols, separation of the glycerine produced and unsaturated and saturated esters formed, wherein only the latter fraction is initiated to the Ecofining process for the formation of Green diesel, jet-fuel and naphtha.

[0051] FIG. 2: the passages of the process of the invention according to another preferred embodiment, are exemplified in a block scheme (scheme 2): effecting the metathesis step, followed by separation of the olefins with less than 18 carbon atoms, Ecofining process for the formation of Green diesel, naphtha and jet-fuel.

DETAILED DESCRIPTION OF THE FIGURES

[0052] FIG. 1

[0053] As indicated in the scheme of FIG. 1, in a preferred embodiment of the process of the invention, the metathesis reaction can be effected on the mixture of triglycerides which form the starting oil with C.sub.2-C.sub.6, preferably C.sub.2-C.sub.4 olefins. The olefins having a number of carbon atoms lower than C.sub.18 (i.e. C.sub.6-C.sub.18), formed after the metathesis reaction, which can be used as intermediates for the production of detergents, additives, lubricants and/or plastic materials or components that can be used in the field of oil explorations and productions, are easily separated by distillation from the rest of the reaction mixture which, after separation, is still composed of triglycerides of saturated fatty acids and unsaturated fatty acids which are formed as a result of the metathesis reaction. The latter are characterized in that they have an unsaturated hydrocarbon chain having a length which is less than the starting length. A transesterification reaction is then effected on these triglycerides, thus obtaining unsaturated esters of medium-chain acids (for example, C.sub.10 if the metathesis has been effected with ethylene or ester of 9-decenoic acid, C.sub.10-C.sub.13 if, on the other hand, the metathesis has been effected with 1-butene, etc.) and esters of saturated fatty acids, mainly C.sub.16 and C.sub.18, initially present in the oil and which have remained unaltered through the metathesis reaction. Again, the difference in the boiling points allows an easy separation of the unsaturated esters from the saturated esters. The latter are sent to the hydrotreating process, or to the Ecofining process described above as a two-step process, wherein the first step consists of a hydrogenation/deoxygenation reaction (hydrodeoxygenation), whereas the second step is a hydroisomerization/cracking step.

[0054] The treatment of a composition of C.sub.16 and C.sub.18 methyl esters with respect to the treatment of lipids or glycerides (i.e. glycerine esters) minimizes the undesired formation of propane (mainly deriving from the direct hydrogenation of glycerine), obtaining a narrower distribution of the products with greater applicative advantages.

[0055] The output of the metathesis section, in fact, becomes richer in the C.sub.16 saturated component. The typical characteristics of the second Ecofining step (hydroisomerization, cracking), nevertheless, broadens the range of products leading to the formation of jet-fuel (prevalent), naphtha and diesel having improved engine performances.

[0056] FIG. 2

[0057] Analogously to what is described for FIG. 1, in a preferred embodiment of the process of the invention, the metathesis reaction can be carried out on the mixture of triglycerides forming the starting oil with C.sub.2-C.sub.6, preferably C.sub.2-C.sub.4 olefins. The olefins having a number of carbon atoms lower than C.sub.18 (i.e. C.sub.6-C.sub.18), formed after the metathesis reaction, which can be used as intermediates for the renewable production of detergents, additives, lubricants and/or plastic materials or components that can be used in the field of oil explorations and productions, are easily separated by distillation from the rest of the reaction mixture which, after separation, is still composed of triglycerides of saturated fatty acids and unsaturated fatty acids which are formed as a result of the metathesis reaction. The latter are characterized in that they have an unsaturated hydrocarbon chain having a length which is less than the starting length.

[0058] This mixture can be sent directly to hydrocracking, or to the Ecofining process described above as a two-step process, wherein the first step consists of a hydrogenation/deoxygenation reaction (hydrodeoxygenation), whereas the second step is a hydroisomerization/cracking step which, due to the presence of acids having a C.sub.10-C.sub.13 chain, again produces not only a diesel cut but also naphtha and jet-fuel.

[0059] In view of what is described above, the process of the present invention has the following advantages: [0060] a complete upgrading of the starting renewable biomass, with a specific production of renewable products to be used in the field of both intermediates and fine chemistry, and also in refining; [0061] lower costs (OPEX—Operating Expenditure) in the Ecofining section, thanks to a reduction in the hydrogen consumption due to a decrease/absence of instaurations on the chain of the esters sent to said process; [0062] improvement in the same hydrotreating section (Ecofining) as the feedstock is already pretreated and purified in the metathesis section, with a consequent reduction in investments (CAPEX—Capital Expenditure) and OPEX; [0063] lower production of propane in the ecofining section due to the absence of glycerine derivatives in the feedstock; [0064] maximization of the range of products to be used in the field of biofuels as they are component products useful in the field of naphtha, jet-fuel and diesel.

[0065] Some embodiment examples of the present invention are provided hereunder for illustrative but non-limiting purposes.

EXAMPLES

Example 1 (According to the Scheme of FIG. 1)

[0066] 1 ton of palm oil, consisting of about 49% of myristic, palmitic and stearic derivatives (saturated components) and 41% of oleic acid, 10% of linoleic acid, is sent to a metathesis section with ethylene in excess at a pressure of 10 bar (stoichiometric consumption of 41 kg of ethylene). The reaction is carried out at 60° C. for about 1-1.5 hours in the presence of 100 ppm of metathesis catalyst based on ruthenium. After separation of the catalyst, the reaction mixture is distilled according to the known techniques, so as to separate about 200 kg of 1-decene and 32 kg of 1-heptene. The bottom mixture is sent to a hydrolysis section with methanol (60° C., about 2 hours of residence time, catalyst NaOMe 1% in MeOH) obtaining about 108 kg of glycerine, 330 kg of methyl ester of 9-decenoic acid, and about 470 kg of methyl esters of saturated acids C.sub.16-C.sub.18 (85% of C.sub.16 ester). The 470 kg of saturated esters are separated by distillation and sent to an Ecofining section, obtaining about 375 kg of components suitable for being used in the field of biofuels of the jet-fuel type, diesel and naphtha. The components 1-decene, 1-heptene and methyl ester of 9-decenoic acid are used in the field of the production of bio-chemicals (intermediates which can be used for the production of detergents, additives, lubricants and/or plastic materials or components which can be used in the field of oil explorations and productions).