JP5273724B2 - Catalyst for hydrogenolysis of triglycerides - Google Patents

Description

  The present invention relates to a novel catalyst used in hydrocracking triglycerides to produce a hydrocarbon mixture corresponding to light oil having 15 to 18 carbon atoms.

  The triglyceride structure is an oil or fat composed of 3 molecules of carboxylic acid having 18 carbon atoms and 1 molecule of glycerol. Specifically, rapeseed oil and non-edible Jatropha oil are not suitable for use as light oil because of their viscosity and boiling point, so they can be converted to monoester-structured biodiesel by methanolysis and used as an alternative to light oil. Is normal. However, since biodiesel has an unsaturated bond or a carboxylic acid structure in its molecular structure, oxidation stability has become a practical problem. In recent years, attempts have been made to directly hydrocrack triglycerides to obtain a hydrocarbon mixture having 15 to 18 carbon atoms. In this case, the product does not have an unsaturated bond or a carboxylic acid structure, so that the oxidation stability is high. It is expected as a blend base material with petroleum-based light oil.

  A platinum / zeolite system is known as a catalyst for direct hydrogenolysis of triglycerides (Non-Patent Document 1), but the weight ratio of triglyceride / catalyst needs to be about 1, and reduction of the catalyst amount is indispensable. It was.

“Hydrocarbonsformation from renewable oxygenates such as glycerol and vegetable oil overModified H-ZSM-5 Catalysts”, K. Murata et al., PI-46-17, 14ICC in Korea, 2008.

  The present invention provides a novel catalyst system capable of producing a hydrocarbon mixture having 15 to 18 carbon atoms in sufficient yield by directly hydrocracking / deoxygenating a raw triglyceride even when the triglyceride / catalyst ratio is about 10. The purpose is to provide.

As a result of intensive studies on various catalyst groups in order to solve the above problems, the present inventors have completed the present invention.
That is, according to this application, the following invention is provided.
<1> Hydrogenation of a triglyceride comprising a porous solid oxide modified with a metal belonging to Group 10 of the Periodic Table or a compound containing the same and rhenium or a compound containing the same, to obtain a carbon number A hydrocracking catalyst used in producing a hydrocarbon corresponding to 15 to 18 diesel oil.
<2> The hydrocracking catalyst according to <1>, wherein the porous solid oxide is a zeolite compound.
<3> The hydrocracking catalyst according to <1> or <2>, wherein the triglyceride is an oil or fat such as edible oil or jatropha oil.

  When the novel catalyst of the present invention is used, even if the triglyceride / catalyst ratio is about 10, the raw material triglyceride is directly hydrocracked / deoxygenated to produce a hydrocarbon mixture having 15-18 carbon atoms in a sufficient yield. be able to.

  The hydrocracking catalyst used in the production of a hydrocarbon mixture having 15 to 18 carbon atoms by directly hydrocracking / deoxygenating the triglyceride of the present invention contains a metal belonging to Group 10 of the periodic table or a metal containing this. It contains a compound and a porous solid oxide modified with a metal belonging to Group 6 or 7 of the periodic table or a compound containing the same.

  As the porous solid oxide, a group 10 metal of the periodic table or a compound containing the same, and a metal belonging to the group 6 or 7 of the periodic table or a compound containing the same, or a compound such as a metal on the surface thereof are used. Any oxide can be used as long as it can be supported, but a metal oxide (which may be non-porous or porous) or a porous oxide generally known as a catalyst support may be used. preferable.

Examples of such porous solid oxides include zeolite compounds.
Examples of the zeolite compound include Y-type, L-type, mordenite, ferrierite, beta-type, and H-ZSM-5.
Examples of the porous oxide other than the zeolite compound include crystalline metallosilicates such as TS-1, MCM-41, MCM-22, MCM-48, and gallosilicate, and large-diameter silica compounds.

  In addition, these porous oxides include those containing elements such as titanium, aluminum, vanadium, niobium, tantalum, boron, zirconium, and amorphous porous silica compounds.

  Examples of other porous solid oxides include oxides obtained by surface modification of commonly used metal oxides such as silica, alumina, zirconia, titania and ceria with sulfate radicals, tungstic acid and the like. It is also possible to use an oxide obtained by modifying a composite oxide such as silica-alumina with sulfate radical or tungstic acid. In this case, it can be obtained by supporting a sulfate group or a water-soluble tungsten compound on an ordinary metal oxide such as zirconia by an impregnation method, drying at 100 ° C., and further firing. The firing temperature at this time is 300-1500 ° C, preferably 500-900 ° C.

  The porous solid oxide particularly preferably used in the present invention is capable of adsorbing triglycerides on the surface, and has a high-pressure hydrogen due to the cooperative effect of a metal belonging to Group 10 or 7 of the Periodic Table. Zeolite compounds with a low silica / alumina ratio (especially H-ZSM5) and solid superacidic acids that can be activated to convert unsaturated bonds of triglycerides and carboxylic acids to hydrogenated / deoxygenated and converted to saturated hydrocarbons Examples thereof include sulfate radicals or zirconia tungstate.

The porous solid oxide used in the present invention should be modified with a compound containing a metal belonging to Group 10 of the periodic table and a compound containing a metal belonging to Group 6 or 7 of the periodic table before use. Is essential.
Examples of the compound containing a metal belonging to Group 10 of the periodic table include a platinum compound and a palladium compound. Examples of the platinum compound include chloroplatinic acid, ammonium platinum chloride, sodium chloroplatinum chloride, and cyanide first. Examples include platinum potassium, dichlorotetraammine platinum, tetramine platinum nitrate, bis-acetylacetonato platinum, tetrakistriphenylphosphine platinum, and the like. Examples of the palladium compound include palladium acetate, bis-acetylacetonato palladium, palladium chloride, ammonium ammonium tetrachloride, sodium palladium hexachloride, palladium diaminonitrite, tetrakistriphenylphosphine palladium, palladium nitrate, and palladium sulfate.

As a method for incorporating a compound such as platinum into the porous solid oxide, a conventionally known method such as a physical mixing method, an impregnation method, a precipitation method, a kneading method, or an incipient wetness method can be employed.
For example, a compound such as platinum is usually supported on a solid oxide as an aqueous solution. Organic solvents such as acetone, isopropanol, and benzene are also used. The firing temperature of the zeolite oxide or the like containing a compound such as platinum is about 300 to 900 ° C, preferably about 500 to 700 ° C. The amount of platinum or the like supported is arbitrary, but it is 0.001 to 10 g, preferably 0.1 to 10 g as platinum metal per 100 g of the carrier oxide. These additives can be used alone or as a mixture of two or more.

In the present invention, the porous solid oxide modified with the compound containing a metal belonging to Group 10 of the Periodic Table is further modified with a compound element containing a metal belonging to Group 6 or 7 of the Periodic Table. is necessary.
That is, for example, the fired porous solid oxide (Pt / porous solid oxide) carrying a compound such as platinum is further modified with a compound containing a metal belonging to Group 6 or Group 7. Examples of the compound containing a metal belonging to Group 6 or 7 include compounds containing rhenium, molybdenum, and tungsten. Of these, rhenium compounds are particularly preferred.
Examples of the rhenium compounds include inorganic acid salts such as nitrates and sulfates, halides such as chlorides and bromides, rhenic acid compounds such as potassium hexachlororhenate, rhenates such as ammonium perrhenate, decacarbonyl dirhenium (0 ), Organometallic rhenium compounds such as pentacarbonylmethylrhenium, and the like.
The molybdenum compounds include halides such as molybdenum chloride, molybdenum complex compounds such as 2 molybdenum acetate, organometallic molybdenums such as hexacarbonylmolybdenum (0), sodium molybdate, 7- (6-) ammonium molybdate 4 Examples thereof include molybdate cationic compounds such as hydrates, dodecaboribdophosphoric acid (3-) 30 hydrate, dodecamolybdophosphoric acid compounds such as dodecamolybdophosphoric acid (3-) ammonium, and the like.
Examples of tungsten compounds include tungsten halides such as tungsten chloride, tungstic acid cation compounds such as 12-tungstic acid (10-) ammonium decahydrate, ammonium metatungstate, 12-tungstic acid (10-) potassium decahydrate, Tungstoheteroacid compounds such as dodecatungstophosphoric acid (3-) 14 hydrate, dodecatungstosilicate (4-) 26 hydrate, organometallic tungsten compounds such as hexacarbonyltungsten, hexamethyltungsten (VI), Etc.
These can be used alone or in combination.

  The hydrocracking catalyst of the present invention can be prepared by (i) a method in which a porous solid oxide such as zeolite as a support is impregnated with a solution containing all the modifying substances at once, and (b) the porosity described above. A method of dropping a modifier solution containing all components into a solid oxide (incipient wetness method), (c) A method of mixing the porous solid oxide with all modifier components, (d) Porous Examples thereof include (i) firing after supporting platinum or the like on a solid oxide, and (ii) a method of preparing by supporting a second metal such as rhenium. The firing temperature performed in any of the methods (a) to (d) is 300 to 1500 ° C., preferably 500 to 900 ° C.

  The triglyceride used in the present invention has a tricarboxylic acid structure of glycerol and is generally prominent as a neutral fat, but in the present invention, edible oil and non-edible oil are mainly targeted. Examples of edible oils include rapeseed oil, sunflower oil, corn oil, soybean oil, salad oil, palm oil, coconut oil, safflower oil, olive oil and the like, and non-edible oils include jatropha oil, oilseed oil, alga oil , Copaiba oil, jojoba oil, milk bush, and the like.

In the present invention, in order to synthesize C18 hydrocarbon, triglyceride and hydrogen may be reacted under high pressure in the presence of the above-described catalyst.
In this synthesis reaction, as shown in the following reaction formula, C18 hydrocarbon, propane and water are obtained as the main products, but in addition, carbonization of C15 to C17, in which carbon-carbon bonds are partially broken, is obtained. Hydrogen is also produced. C15-C18 hydrocarbon has characteristics equivalent to diesel oil.

  The formation mechanism of the hydrocarbon mixture is not clear at the present time, but is considered to be due to complex reactions such as hydrogenation of triglycerides, deoxygenation, and carbon-carbon bond cleavage.

The reaction for obtaining a C15-C18 hydrocarbon mixture using the hydrocracking catalyst of the present invention can be carried out in either a gas phase or a liquid phase. preferable. In this case, the reaction temperature is 50 to 600 ° C., preferably 200 to 350 ° C., and the reaction pressure is arbitrary, but pressurization is preferable, 0.01 MPa to 100 MPa, preferably 0.5 MPa to 10 MPa. .
An inert gas or hydrogen is used as the atmospheric gas, and argon, helium, nitrogen, or the like can be used as the inert gas. However, since hydrogenation is included as a reaction, hydrogen pressure is more preferably used. The proportion of hydrogen used is 0.05 to 1000 mol, preferably 10 to 300 mol, per mol of triglyceride. Hydrogen can be diluted with an inert gas such as nitrogen, helium, or argon gas.

In the present invention, a solvent can be allowed to coexist, and a normal organic solvent can be arbitrarily used as the solvent, but an inorganic solvent such as water or CO ₂ is particularly preferable. The ratio of water and CO ₂ used in this case is 1 to 2000 mol, preferably 10 to 600 mol, per mol of triglyceride. The compatibility of triglyceride with water and other solvents is not good, but it has no effect on the progress of the reaction.

  Next, the present invention will be described in more detail with reference to examples.

Example 1
[Preparation of Re-modified 1wt% Pt / H-ZSM5 catalyst]
Zeolyst H-ZSM-5 (Si / Al2 ratio = 23) was impregnated with dichlorotetraammineplatinum (1 wt% in terms of platinum) and ammonium perrhenate (1 wt% in terms of rhenium) at the same time, and dried at 333 K overnight. Further, after drying at 373 K for 3 hours, air baking was performed at 813 K for 6 hours.
[Hydrocracking reaction of Jatropha oil]
1% Re-1% Pt / H-ZSM-5 (0.1 g) thus obtained was placed in a 100 ml autoclave, pressurized with 4 MPa of hydrogen, and subjected to hydrogen reduction at 200 ° C. for 5 hours. After cooling to room temperature, the inside of the autoclave was replaced with argon gas, the autoclave was opened, 1 g of jatropha oil (1.12 mmol, jatropha oil / catalyst weight ratio = 10) and 9 g of water (500 mmol) were added, and hydrogen and nitrogen were added. A mixed gas (volume ratio (hydrogen / nitrogen = 84.3 / 15.7)) was introduced at a total pressure of 6.5 MPa and reacted at 543 K for 12 hours. When the product after the reaction was analyzed by gas chromatography, the conversion to hydrocarbon was 13.6% and the C15-C18 selectivity was 48.0%. As by-products, methane, C2-C13 and C19 + hydrocarbons, and CO ₂ were detected.

The conversion to hydrocarbons and C15-C18 selectivity were calculated as follows for convenience.
(1) Conversion to hydrocarbon = [(total C atoms in the generated hydrocarbon) / (total carbon introduced)] * 100
(2) Carbon selectivity = (Hydrocarbon mole x Number of carbons in the hydrocarbon) / (Number of carbons in all hydrocarbons) * 100.
Here, * represents a product. Other hydrocarbon selectivity was calculated similarly.

Comparative Example 1
Hydrolysis of jatropha oil was performed in the same manner as in Example 1 except that Re was not used. As a result, the conversion to hydrocarbons was 14.2%, but the C15-C18 selectivity was 16.0%, which was extremely low.

Example 2-4
The reaction was carried out in the same manner as in Example 1 except that the supported amounts of Re were 10%, 20% and 25%, respectively. As shown in Table 1, the conversion rates to hydrocarbons were 46.9, 79.1, 25.5, The C15-C18 selectivity was 88.6, 86.1, and 75.2%, respectively. The catalyst performance was improved, and even with an oil / catalyst weight ratio of 10, the catalyst performance was sufficiently high. This is extremely useful in practice in that the amount of catalyst used can be reduced.

Example 5
Catalyst preparation and reaction were carried out in the same manner as in Example 1 except that 1 wt% of palladium was used instead of platinum. As a result, the conversion to hydrocarbon was 67.0%, and the C15-C18 selectivity was 91.2%. The conversion rate and C15-C18 selectivity were comparable to platinum.

Claims (3)

15 to 18 carbon atoms obtained by hydrocracking triglycerides containing a porous solid oxide modified with a metal belonging to Group 10 of the periodic table or a compound containing the same and rhenium or a compound containing the same. Hydrocracking catalyst used when producing hydrocarbons equivalent to diesel oil.   The hydrocracking catalyst according to claim 1 or 2, wherein the porous solid oxide is a zeolite compound.   The hydrocracking catalyst according to claim 1 or 2, wherein the triglyceride is an oil or fat such as edible oil or jatropha oil.