RU2496580C1 - Method of preparing hydroskimming catalyst - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a method of preparing a catalyst for hydroskimming organooxygen products of processing plant biomass. Described is a method of preparing a catalyst for hydroskimming organooxygen products of processing plant biomass, which is a composite containing nickel or a combination thereof with copper, which involves combined decomposition of transition metal compounds with a stabilising additive while heating to temperature of 300-350°C on air, followed by reduction with hydrogen, wherein the transition metal compounds used are nickel and copper carbonates, or hydroxides or a combination thereof, the stabilising additive used is ethyl silicate or powdered silicon dioxide SiO₂; after decomposition, a molybdenum and/or phosphorus compound is added to the composite.

EFFECT: catalysts obtained using said method have high stability in media with high acidity and high water content.

2 cl, 4 tbl, 4 ex

Description

The invention relates to the field of development of a method for preparing a catalyst for hydrofining of oxygen-organic products of plant biomass processing.

It is known that vegetable oils and animal fats (triglycerides of fatty acids) have recently been considered as a renewable partial substitute for traditional motor fuels (diesel and gasoline fuels). However, triglycerides are not directly used as components of motor fuels, but are transesterified with methanol in the presence of acids or alkalis, which act as catalysts, to obtain methyl esters of the corresponding fatty acids, the so-called biodiesel. Biodiesel can be used as an additive to standard diesel fuel no more than 15-20% weight. without loss of engine performance and its modernization. By its operational properties, biodiesel is inferior to diesel fractions due to the high oxygen content in its composition, which reduces its caloric content by 15-20%, stability and makes it twice as viscous than conventional diesel. In this regard, there is an urgent need for further processing in order to remove oxygen. The largest companies in Europe and the USA are intensively working in the direction of obtaining standard diesel fuel from biodiesel. The work is aimed at deoxygenation of biodiesel in the presence of standard sulfidized oil-refining catalysts based on Ni-Mo, Co-Mo supported on Al ₂ O ₃ [OI Senol, E.-M. Ryymin, T.-R. Vilijava, AOI Krause, Reaction of methyl heptanoate hydrodeoxygenation on sulphided catalysts, J. Mol. Cat. A: Chem., 268 (2007), 1-8; M. Ferrari, B. Delmon, P. Grange, Influence of the active phase loading in carbon supported molybdenum-cobalt catalysts for hydrodeoxygenation reactions, Micropor. Mesopor. Mat., 56 (2002), 279-290; E. Laurent, B. Delmon, Study of the hydrodeoxygenation of carbonyl, carboxylic and guaiacyl groups over sulfided CoMo / Al ₂ O ₃ and NiMo / Al ₂ O ₃ catalysts, Appl. Catal. A, 109 (1994), 777-96; OI Senol, T.-R. Vilijava, AOI Krause, Hydrodeoxygenation of methyl esters on sulphide CoMo / Al ₂ O ₃ and NiMo / Al ₂ O ₃ catalysts, Catalysis Today, 100 (2005), 331-335]. These catalysts have low activity and selectivity for the yield of diesel fractions and quickly deactivate when the sulfur content in the catalyst decreases, since unlike oil, the initial sulfur content in vegetable oils is minimal. To maintain the constant activity of sulfidated catalysts, it is necessary to constantly add H ₂ S or an organosulfur to the reaction zone. Under this condition and a hydrogen pressure of 1.5-2.0 MPa and 275-300 ° C, it is possible to achieve a degree of ether conversion of 100% and a degree of deoxygenation of 100%. In this case, saturated methyl heptanoate, diethyl decanodiate, ethyl decanoate, which have a higher reactivity in the hydrofining process than higher boiling derivatives of fatty acids - components of vegetable oils and animal fats - are mainly used as initial substrates.

For the selective hydrogenation of fats and vegetable oils, a different type of catalyst is used in non-sulfidated form. Fat hydrogenation products are widely used in the food and chemical industries. Mainly used supported Ni-containing catalysts. So, for example, in [US 3896053, B01J 11/22, 07/22/1975] Ni, Co, Cu - Al ₂ O ₃ catalysts prepared by the coprecipitation of the corresponding transition metal carbonates and aluminum hydroxide are used. After calcination, the catalysts were reduced in a hydrogen atmosphere and were used in the selective hydrogenation of fats and vegetable oils at 100-140 ° C and atmospheric pressure of hydrogen. After 1 h of hydrogenation, it is possible to obtain a mixture of products with an iodine number of 37-40.

A known method of hydrogenation of oil in the presence of a Ni-Cu catalyst deposited by coprecipitation on various carriers: SiO ₂ , Al ₂ O ₃ , TiO ₂ , MgO, Cr ₂ O ₃ [US 3743662, C11C 3/12, 07/03/1973]. The catalyst recovered at 600 ° C at a content of 1 wt.% In oil shows the maximum activity in the hydrogenation of double bonds of triglycerides of fatty acids at 200 ° C and 0.5 MPa H ₂ .

A known method of selective hydrogenation of free fatty C ₁₂ -C ₂₀ acids in the presence of Ni-Cu-Cr catalyst at 0.25-0.7 MPa and 180-260 ° C [US 4133822, C11C 3/12, 01/09/1979]. The iodine number of the resulting hydrogenation product reaches 40 after 3 hours of hydrogenation.

The above hydrogenation catalysts selectively hydrogenate unsaturated hydrocarbon radicals of fats and vegetable oils without reducing oxygen-containing ether groups and especially without hydrocracking triglycerides with the formation of saturated alkanes.

Impregnation catalysts 15-25% Ni / Al ₂ O ₃ or 15-25% Co / Al ₂ O ₃ and Cu-Cr-Ni catalyst H14279 Degussa are known, which allow hydrogenation of a mixture of aldehydes, esters (for example, isotridecanyl formate) of carboxylic acids to alcohols at 2-3 MPa H ₂ and 160-190 ° C in the liquid phase [US 7524997, B01J 23/44, C07C 29/14, 04/28/2009]. Hydrogenation of the mixture goes only to alcohols without the formation of the corresponding alkanes.

Known methods for hydrofining oxygen-containing raw materials using phosphide catalysts [Oyama, ST, Wang, X., Lee, Y.-K., Chun, W.-J. Active phase of Ni ₂ P / SiO ₂ in hydroprocessing reactions // J. Catal. - 2004. - V.221. - P.263-273; Zhao, HY, Li, D., Bui, P., Oyama, ST Hydrodeoxygenation of guaiacol as model compound for pyrolysis oil on transition metal phosphide hydroprocessing catalysts // Appl. Catal. A. - 2011 .-- V.391. - P.305-310; Li, K., Wang, R., Chen, J. Hydrodeoxygenation of Anisole over Silica-Supported Ni ₂ P, MoP, and NiMoP Catalysts // Energy Fuels. - 2011 .-- V.25. - P.854-863; Whiffen, VML, Smith, KJ Hydrodeoxygenation of 4-Methylphenol over Unsupported MoP, MoS ₂ , and MoO _x Catalysts // Energy Fuels. - 2010 .-- V.24. - P.4728-4737]. For example, in [Zhao, HY, Li, D., Bui, P., Oyama, ST Hydrodeoxygenation of guaiacol as model compound for pyrolysis oil on transition metal phosphide hydroprocessing catalysts // Appl. Catal. A. - 2011 .-- V.391. - P.305-310] on a series of phosphide catalysts with transition metals Ni, Fe, Mo, Co, and W supported on silica, guaiacol was hydrotreated. At a temperature of 200-300 ° C and a contact time of 20.2 min, the highest conversion value of 93% is achieved using a Ni ₂ P catalyst, the smallest and equal to 50% is observed on a MoP catalyst. However, with decreasing temperature, the conversion of guaiacol to all tested samples decreases. In [Li, K., Wang, R., Chen, J. Hydrodeoxygenation of Anisole over Silica-Supported Ni ₂ P, MoP, and NiMoP Catalysts // Energy Fuels. - 2011 .-- V.25. - P.854-863] investigates the activity of phosphides Ni ₂ P, MoP and NiMoP deposited on silicon oxide SiO ₂ in the hydrofining of a model compound of bio-oil anisole. The process is carried out in a flow reactor at a temperature of 300 ° C and a pressure of H ₂ 1.5 MPa using a 4 wt.% Solution of anisole in n-octane. During the hydroprocessing of anisole on such catalysts for 10 h, a gradual decrease in their activity is observed, which is reflected in a decrease in the conversion of anisole, the degree of hydrodeoxygenation, and selectivity of cyclohexane formation. In this regard, the development of catalysts for hydrofining of oxygen-organic products of plant biomass processing is relevant.

The closest to the claimed technical essence and the achieved effect is a catalyst for hydrodeoxygenation of fatty acids, their esters and triglycerides [RU 2356629, B01J 32/00, C07C 1/00, 05/27/2009]. The above compounds are oxygen-containing products of the processing of plant biomass. The process of hydrodeoxygenation is carried out at 250-350 ° C and a hydrogen pressure of 1.0-3.0 MPa with a space velocity (LHSV) of an oxygen-organic liquid (CL) equal to 0.3-2.0 ml CL / ml cat / h. The catalyst is a composite composite containing a noble metal in an amount of not more than 1 wt.%, Or nickel, or copper, or iron, or a combination thereof in reduced form in an amount of not more than 40 wt.%, Transition metals in an oxide form in an amount of not more than 40 wt.% And the carrier. The preparation of the hydrodeoxygenation catalyst is carried out in three ways: either by the method of simultaneous (sequential) impregnation of the water capacity with water-soluble salts of transition metals with further drying at 100-120 ° C and calcination at 400-550 ° C (in this case, the noble metal salt is applied last) either by the method of sequential or simultaneous precipitation of transition metal hydroxides or carbonates in the presence or absence of a carrier, followed by aging of the precipitate at a temperature of 20-90 ° C for 10-48 hours in a mat solution and drying and calcining at 500-550 ° C (the noble metal is applied by impregnation by moisture capacity to the previously formed composite), or by the method of joint fusion / decomposition of transition metal nitrates with stabilizing additives such as zirconium nitride, cerium, aluminum or aluminum hydroxide to melting point of the mixture.

The catalysts prepared according to each of the three variants of the method described above are activated before the target process by heating in a stream of hydrogen-containing gas to the process temperature and keeping at the final temperature for 2 hours.

A disadvantage of the known hydrofining catalysts is that catalysts that do not contain a noble metal do not have sufficient activity and stability in environments with high acidity (pH 2-3) and high water content. Such media include biooil, a mixture of carboxylic acids, and more.

The invention solves the problem of developing a method for preparing a catalyst for hydrofining of oxygen-organic products of plant biomass processing, stably working in environments with high acidity (pH = 2-3) and high water content.

The problem is solved by the method of preparation of a catalyst for hydrofining of oxygen-organic products of plant biomass processing, which is a complex composite containing nickel or its combination with copper, obtained together with the decomposition of transition metal compounds together with a stabilizing additive when heated to a temperature of 300-350 ° C in air, followed by hydrogen reduction , nickel and copper carbonates, or hydroxides, or a combination thereof, are used as transition metal compounds, as tabiliziruyuschey additives used ethyl silicate powder or silica SiO _2, after expansion in composite administered compound of molybdenum and / or phosphorus.

After decomposition, the composite is impregnated with a solution of ammonium molybdate and / or phosphoric acid solution, followed by drying and heating at a temperature of 400-500 ° C, subsequent reduction with hydrogen is carried out at a temperature of 500-600 ° C.

At this stage, the introduction of molybdenum and phosphorus into the composite after decomposition is carried out sequentially.

The resulting catalyst is a composite containing nickel or nickel and copper in an amount of at least 40 wt.%, Molybdenum in a reduced form, or phosphorus in the form of phosphides, or a combination thereof in an amount of not more than 20 wt.%, And a stabilizing additive is silicon dioxide SiO ₂ .

The composite catalyst in the activated state contains nickel or nickel and copper phosphides, which provide catalytic activity, impart mechanical strength similar to ceramics, and molybdenum, which increases the corrosion resistance of the catalyst in the process. The stabilizing additives ethyl silicate and SiO ₂ as a whole are non-acidic in nature to stabilize the active component and preserve the porosity and high specific surface area of the catalyst in the target process.

The technical result consists in high activity and stability to coking and the degree of leaching of the catalysts obtained by the method proposed above for the hydrofining of oxygen-organic products of plant biomass processing in comparison with the catalysts obtained by known methods.

The invention is illustrated by the following examples and tables.

Example 1

20 g of nickel carbonate (or hydroxide) and 2 g of copper carbonate (or hydroxide) (for nickel-copper catalysts) (table 1), 40 ml of distilled water, 10 ml of ammonia solution (25 wt.%) And 10 ml of ethyl silicate are intensively mixed on a stirrer for 2 hours. Then add 15 g of a solution of ammonium molybdate, dry at 120 ° C, calcine at 400 ° C and / or after the introduction of molybdenum add 10 g of phosphoric acid solution (85 wt.%), filter the resulting mixture, dry at 120 ° C and calcined at 400-500 ° C. The composition of the obtained composites is given in table 1. The obtained composites are reduced in a stream of hydrogen at 500-600 ° C for 2 hours. Nickel and copper carbonates are taken as salts for the preparation of catalysts 1 and 4, and the reduction is carried out at 500 ° C; nickel and copper hydroxides are taken for catalysts 2, 3, 6 and 7, samples 2 and 6 are calcined at 400 ° C, and 3 and 7 at 500 ° C, all samples are reduced at 550 ° C; for catalysts 5 and 8, nickel carbonate and copper hydroxide are used, samples are calcined at 450 ° C, and the resulting catalysts are reduced at 600 ° C.

The catalysts are tested in an autoclave at a hydrogen pressure of 17.0 MPa, a temperature of 320 ° C, m (guaiacol): m (catalyst) = 33: 1 during the hydrofining of guaiacol. The activity of the catalysts and the degree of deoxygenation of guaiacol are shown in table 1.

Table 1 No. Catalyst Active component, wt.% Guaiacol conversion,% The degree of deoxygenation,% The degree of carbonization of the catalyst, wt.% Ni Cu Mo P one Ni / SiO ₂ 58 98 99 14.7 2 NiMo / SiO ₂ 55 9 91 95 4.7 3 NiP / SiO ₂ 54 6 85 92 0.6 four NiCu / SiO ₂ 52 5 91 95 3,1 5 NiMoP / SiO ₂ 49 12 8 76 91 0 6 NiCuMo / SiO ₂ 48 5 8 89 93 1,2 7 NiCuP / SiO ₂ 48 5 four 85 93 0.4 8 NiCuMoP / SiO ₂ 36 four 10 5 67 90 0

Example 2

It differs from example 1 in that the catalysts, the composition of which are shown in table 2, are tested in an autoclave under the following conditions: 150 ° C at a hydrogen pressure of 12.0 MPa for 1 h, then 320 ° C at a hydrogen pressure of 18.0 MPa in for 3 hours in the process of hydrofining of bio-oil (elemental composition, wt.%: C - 36.5; O - 51.1; H - 8.0; N - 0.4). The oxygen content as an indicator of the activity and degree of leaching and carburization as indicators of the stability of the catalysts in the process of hydrotreating bio-oil are shown in table 2.

table 2 No. Catalyst Active component, wt.% Content
oxygen *, wt.% The degree of leaching **, wt.% The degree of carbonization, wt.% Ni Cu Mo P one Ni / SiO ₂ 58 22 0.9 4,5 2 NiCu / SiO ₂ 52 5 21 0.8 3.4 3 NiMoP / SiO ₂ 49 12 8 eighteen 0.02 0.3 four NiCuMo / SiO ₂ 48 5 8 eighteen 0.08 0.65 5 NiCuP / SiO ₂ 48 5 four eighteen 0.05 0.5 6 NiCuMoP / SiO ₂ 36 four 10 5 19 0,03 0.3 * (The oxygen content in the original bio-oil is 51 wt.%
** (The proportion of the active component of the catalyst dissolved in the product (in the aqueous phase).

Example 3

It differs from Example 2 in that, at the preparation stage, SiO ₂ powder is used as a stabilizing additive. The catalysts, the composition of which is shown in table 3, are tested in an autoclave under the following conditions: 150 ° C at a hydrogen pressure of 12.0 MPa for 1 h, then 320 ° C at a hydrogen pressure of 18.0 MPa for 3 h in the process of hydrotreating bio-oil (elemental composition, wt.%: C - 36.5; O - 51.1; H - 8.0; N - 0.4). The oxygen content as an indicator of the activity and degree of leaching and carbonization as indicators of the stability of the catalysts in the process of hydrotreating bio-oil are shown in table 3.

Table 3 No. Catalyst Active component, wt.% Content
oxygen
wt.% The degree of leaching, wt.% The degree of carbonization, wt.% Ni Cu Mo P one Ni / SiO ₂ 56 25 1,2 5.3 2 NiCu / SiO ₂ 54 6 24 1,2 4.8 3 NiMoP / SiO ₂ 56 10 8 23 0.2 0.8 four NiCuMo / SiO ₂ 49 6 9 23 0.3 1,2 5 NiCuP / SiO ₂ 52 5 6 23 0.25 0.9 6 NiCuMoP / SiO ₂ 55 6 19 5 23 0.15 0.8

Example 4

It differs from example 1 in that the catalysts, the composition of which is shown in table 4, in an amount of 5 ml are tested in a flow reactor at a hydrogen pressure of 8.0 MPa, a temperature of 360 ° C, a flow of H _{2 of} 20 l / h and Ar 3 l / h in the process of hydrofining triglycerides of rapeseed oil fatty acids, which are supplied with a space velocity of 1 h ^-1 . The conversion values and the degree of deoxygenation of rapeseed oil fatty acid triglycerides are presented in Table 4.

Table 4 No. Catalyst Active component, wt.% Conversion% The degree of deoxygenation,% Ni Cu Mo P one NiCu / SiO ₂ 52 5 96 92 2 NiMoP / SiO ₂ 49 12 8 92 88 3 NiCuMo / SiO ₂ 48 5 8 93 96 four NiCuP / SiO ₂ 48 5 four 95 95 5 NiCuMoP / SiO ₂ 38 2 10 5 97 97

As can be seen from the above examples, the catalysts prepared by the proposed method are highly active in the processes of hydrofining of oxygen-organic products of plant biomass processing. Also, the inventive catalytic systems have sufficient stability in environments with high acidity and high content, which can improve the quality of the process of hydrofining.

Claims (2)

1. The method of preparation of the catalyst for hydrofining of oxygen-organic products of plant biomass processing, which is a composite composite containing nickel or its combination with copper, obtained jointly by decomposition of transition metal compounds together with a stabilizing additive when heated to a temperature of 300-350 ° C in air with subsequent reduction with hydrogen at a temperature of 500-600 ° C, characterized in that nickel and copper carbonates, or hydroxides, sludge are used as transition metal compounds combination thereof, as a stabilizing additive used ethyl silicate powder or silica SiO _2, after expansion in composite administered compound of molybdenum and / or phosphorus. 2. The method according to claim 1, characterized in that the composite after decomposition is impregnated with a solution of ammonium molybdate and / or phosphoric acid solution, the stages of introducing molybdenum and phosphorus into the composite are carried out sequentially, followed by drying and heating at a temperature of 400-500 ° C.