RU2775227C1 - Method for producing furfuryl alcohol using a magnetically separable catalyst - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to a method for producing furfuryl alcohol by means of selective hydrogenation of furfural in the presence of a catalyst, wherein a magnetically separable 3% Ru-Fe₃O₄/SPSMN270 catalyst is applied as said catalyst. Hydrogenation is therein performed in a batch reactor at a temperature of 120°C, a hydrogen pressure of 6.0 MPa, for 90 minutes, with a mixing speed of 1,000 rpm, in the presence of isopropyl alcohol as a solvent, and the weightof the catalyst is 0.1 g.

EFFECT: production of furfuryl alcohol with an output above 93% with selective hydrogenation of furfural with a conversion above 96%.

1 cl, 2 dwg, 1 tbl, 5 ex

Description

The invention relates to the development of a method for producing furfuryl alcohol by hydrogenation of furfural.

Furfuryl alcohol is used in the manufacture of adhesives, various resins, solvents, anti-corrosion and water-repellent varnishes, rubber, pesticides, and is also used in the rocket and space industry in the production of a special type of fuel, parts for rockets and aircraft.

A known method for the hydrogenation of furfural (US 4302397, B01J 23/86, C07D 307/44, publ. 11/24/1981) in the presence of a catalyst based on copper chromite, promoted CaO, allowing to obtain a yield of furfuryl alcohol up to 98% at a reduced hydrogen pressure of 3.0 MPa.

However, the disadvantage of such catalysts is the toxicity of chromium compounds and relatively low stability. One of the main reasons for the deactivation of copper-based catalysts during the hydrogenation of furfural is the formation of coke deposits, strong adsorption of reaction products on the catalyst surface, a change in the degree of oxidation of active sites, and sintering of metal particles.

A.J., Aw M.S.,

J., Huband S., Sloan J., Paniwnyk L., Rebrov E.V, Active site isolation in bismuth-poisoned Pd/SiO₂ catalysts for selective hydrogenation of furfural, Applied Catalysis A: General, 57 (2019), 183-191), основанный на гидрировании фурфурола в воде с 5 мас. % катализаторами Pd/SiO₂ и Pd-Bi/SiO₂ в реакторе периодического действия при различных температурах и давлениях реакции. Из-за различных условий проведения реакции гидрирования образуются различные количества, как основных, так и побочных продуктов.There is also a method for producing furfuryl alcohol (Cherkasov N.,

AJ, Aw MS,

J., Huband S., Sloan J., Paniwnyk L., Rebrov EV, Active site isolation in bismuth-poisoned Pd/SiO ₂ catalysts for selective hydrogenation of furfural, Applied Catalysis A: General, 57 (2019), 183-191 ), based on the hydrogenation of furfural in water with 5 wt. % Pd/SiO ₂ and Pd-Bi/SiO ₂ catalysts in a batch reactor at various reaction temperatures and pressures. Due to the different conditions of the hydrogenation reaction, different amounts of both main and by-products are formed.

However, the error of this invention is that with an increase in hydrogen pressure above 3.0 MPa (30 bar) it has little effect on the kinetics of hydrogenation, while the reaction temperature affects the distribution of the product. Also, this method is characterized by the poisoning of the Pd-Bi/SiO ₂ catalyst with bismuth, which reduces the number of available active centers, but has little effect on the turnover frequencies, most likely due to the absence of electronic effects of Bi on Pd nanoparticles.

Another method for producing furfuryl alcohol is known (Ghashghaee M., Sadjadi S., Shirvani S., Farzaneh V. A Novel, Consecutive Approach for the Preparation of Cu-MgO Catalysts with High Activity for Hydrogenation of Furfural to Furfuryl Alcohol, Catalysis Letters, 147 (2017), 318-327), which is carried out using a copper-magnesium catalyst containing CuO and MgO. The use of such a catalyst makes it possible to achieve stable conversion of furfural (91%) and high selectivity (99%) for furfuryl alcohol.

However, a direct relationship between the catalytic activity and the structural features of the catalysts in this method has not been established, which may affect the further use of the catalyst.

The closest in technical essence is a method for producing furfuryl alcohol (RU 2680799; C07D 307/44, B01J 21/04; publ. 27.02.2019) by selective hydrogenation of furfural in the presence of a catalyst containing oxides of copper and iron, in which the catalyst is taken in the composition 5.0-40.0 wt. % CuO, the carrier is the rest, while the carrier contains a spinel with the structure of Fe ₃ O ₄ , consisting of 40.0-85.0 wt. % Fe ₂ O ₃ and 10.0-20.0 wt. % Al ₂ O ₃ , and hydrogenation is carried out in a batch plant at a temperature of 100°C, a hydrogen pressure of 6.0 MPa in the presence of a solvent with a furfural/isopropanol volume ratio of 0.1 or in a flow-type plant in the absence of a solvent at a temperature of 120-160 °C, hydrogen pressure 4.0-6.0 MPa, raw material feed rate 2-4 ml/h and hydrogen space velocity 100-300 ml/min. A yield of furfuryl alcohol of more than 95% is achieved by selective hydrogenation of furfural with a conversion of more than 98%.

However, this method uses a large amount of catalyst, which can further affect the quality of the reaction mixture and the contamination of the catalyst itself. The alumina (Al ₂ O ₃ ) contained in the catalyst carrier exhibits strong acidity on the surface, which can also affect the quality of the reaction mixture and the yield of the reaction product.

The technical problem to be solved by the invention is the development of a method for producing furfuryl alcohol in a batch reactor by selective hydrogenation of furfural, which makes it possible to achieve high values of furfural conversion and selectivity for furfuryl alcohol.

The technical result is the production of furfuryl alcohol with a yield of over 93% by selective hydrogenation of furfural with a conversion of over 96%.

The technical problem is solved and the technical result is achieved by selective hydrogenation of furfural in the presence of a catalyst, and a magnetically separated catalyst 3% Ru-Fe ₃ O ₄ /SPSMN270 is used as a catalyst, hydrogenation is carried out in a batch reactor at a temperature of 120 ° C, a hydrogen pressure of 6.0 MPa, for 90 min, with a stirring speed of 1000 rpm in the presence of isopropyl alcohol as a solvent, while the mass of the catalyst is 0.1 g.

The hydrogenation process of the present invention was carried out in a batch reactor (Series 5000 (USA) Multiple Reactor System (MRS) at a temperature of 120°C, a hydrogen pressure of 6.0 MPa, a stirring speed of 1000 rpm, a reaction time of 90 minutes in the presence of isopropyl alcohol as a solvent and a catalyst weight of 0.1 g.

The invention is illustrated by the following graphics: FIG. 1 shows the chromatogram of the peaks of the reaction products of the hydrogenation of furfural using catalysts: (1) 3%Pd-3%Cu-Fe ₃ O ₄ /MN270; (2) 3%Cu-Fe ₃ O ₄ /MN270; (3) 3% Ru-Fe ₃ O ₄ /SPSMN270; (4) 3%Pd-Fe ₃ O ₄ /MN270, in FIG. 2 shows a bar chart of furfural and furfuryl alcohol values for these catalysts.

The use of an improved magnetically detachable catalyst containing ruthenium in the process of selective hydrogenation of furfural provides high activity and yield of furfuryl alcohol in batch mode. The method uses a ready-made catalyst 3% Ru-Fe ₃ O ₄ /SPSMN270 (Manaenkov O.V. et al. Magnetically detachable polymer catalyst for the hydrogenolysis of cellulose, Izv. Vuzov. Chemistry and chemical technology, 2020, Vol. 63. Issue 2 , pp. 59-63). The composition of the 3%Ru-Fe ₃ O ₄ /SPSMN270 catalyst used in the selective hydrogenation of furfural contains Fe ₃ O ₄ (magnetite), which can be easily separated from the reaction mixture with a magnet. Also, the composition of the magnetically detachable catalyst 3% Ru-Fe ₃ O ₄ /SPSMN270 includes hypercross-linked polystyrene with microcavities in the polymer matrix, in which the active components - iron and ruthenium compounds - are evenly distributed. In addition, due to the cross-linking of the polymer matrix, hypercross-linked polystyrene has a strong structure, the ability to swell in a liquid medium, and a large internal surface.

To select the magnetically detachable catalyst with ruthenium nanoparticles as the most preferred, it was compared with other magnetically detachable catalysts containing nanoparticles of other metals such as copper, palladium and palladium-copper. These catalysts were compared experimentally using furfural hydrogenation in a batch reactor (Series 5000 (USA) Multiple Reactor System (MRS)) at a temperature of 120°C, a pressure of 6.0 MPa, a stirring speed of 1000 rpm, a reaction time of 90 min , in the presence of a solvent (isopropyl alcohol) and a catalyst mass of 0.1 g. Analysis of the reaction mass after the process was carried out on a gas chromatograph "Crystallux-4000M" in the programming mode: column temperature -50°C, detector 200°C, evaporator 120° FROM. The chromatograms were processed using the NetChrom program. Chromatogram of peak hydrogenation products of catalysts 3%Cu-Fe ₃ O ₄ /SPSMN270, 3%Ru-Fe ₃ O ₄ /SPSMN270, 3%Pd-Fe ₃ O ₄ /SPSMN270, 3%Pd-3%Cu-Fe ₃ O ₄ /SPSMN270 shown in Fig 1. Were identified: the original substance - furfural, and the main product - furfuryl alcohol. A column chart of furfural and furfuryl alcohol values for each catalyst was plotted as shown in FIG. 2, which amounted to: 89.4 mol. % and 83.5 mol. % for 3% Pd-3% Cu-Fe ₃ O ₄ /MN270, 80.2 mol. % and 76.7 mol. % for 3% Cu-Fe ₃ O ₄ /MN270, 96.3 mol. % and 93.8 mol. % for 3% Ru-Fe ₃ O ₄ /SPSMN270, 94.9 mol. % and 90.1 mol. % for 3% d-Fe ₃ O ₄ /MN270.

The reaction temperature of 120°C is due to the analysis of literature data, in which the hydrogenation reactions carried out below or above this temperature caused a decrease in the yield of the product.

At temperatures below 120°C, the product yield is 90.1 mol. %, at temperatures above 120°C - 91.5 mol. %.

The hydrogen pressure of 6.0 MPa is due to the fact that when the pressure decreases to 4.0 MPa, the yield of the product and the conversion of the starting substance decrease, with an increase to 8.0 MPa, the same situation occurs.

The reaction time of 90 minutes is optimal, since by varying the time during the hydrogenation process, the conversion of furfural and the yield of furfuryl alcohol vary.

The stirring speed of 1000 rpm is due to the fact that when stirring at 500 rpm, there is an insufficient yield of the product, and when stirring at 1500 rpm, there is a decrease, or the same product yield as at 1000 rpm.

The choice of isopropyl alcohol as a solvent is due to the fact that with other solvents, for example, water or hexane, a small amount of the finished product is hydrogenated, which is unacceptable in this case.

The catalyst weight of 0.1 g was chosen as such, since with an excess of catalyst, the values of the conversion of furfural and the yield of the hydrogenation reaction product do not change, and with a deficiency, these values decrease.

The essence of the proposed technical solution is illustrated by the following examples.

Example 1

Hydrogenation of furfural was carried out in a 5000 Series Multiple Reactor System steel batch reactor (Parr Instruments). The magnetically detachable catalyst 3% Ru-Fe ₃ O ₄ /SPSMN270 weighing 0.1 g, furfural with a volume of 4 ml and isopropyl alcohol with a volume of 48 ml were introduced into the reactor. The reactor was purged with nitrogen and heated to a temperature of 120°C. After the reactor was heated to operating temperature, hydrogen was supplied. The hydrogen pressure was 6.0 MPa. The hydrogenation process was carried out with continuous stirring (stirring speed 1000 rpm). During the reaction, samples of the reaction medium were taken for analysis. The time of one experiment was 90 min. The results of the furfural hydrogenation process are shown in Table 1.

Example 2

Hydrogenation of furfural with a magnetically detachable catalyst is carried out analogously to example 1, at a temperature of 100°C. The results of the furfural hydrogenation process are shown in Table 1.

Example 3

Hydrogenation of furfural with a magnetically separated catalyst is carried out analogously to example 1, at a temperature of 140°C. The results of the furfural hydrogenation process are shown in Table 1.

Example 4

Hydrogenation of furfural with a magnetically detachable catalyst is carried out analogously to example 1, at a hydrogen pressure of 4.0 MPa. The results of the furfural hydrogenation process are shown in Table 1.

Example 5

Hydrogenation of furfural with a magnetically separated catalyst is carried out analogously to example 1, at a hydrogen pressure of 8.0 MPa. The results of the furfural hydrogenation process are shown in Table 1.

Thus, as can be seen from the above examples, the proposed method for producing furfuryl alcohol using a magnetically separated catalyst 3% Ru-Fe ₃ O ₄ /SPSMN270 by selective hydrogenation of furfural with isopropyl alcohol as a solvent allows for high conversion (more than 96 mol.%) of furfural obtain the target product in high yield (at least 93 mol. %) at a temperature of 120°C and a pressure of 6 MPa.

Claims (1)

A method for producing furfuryl alcohol by selective hydrogenation of furfural in the presence of a catalyst, characterized in that a magnetically separated catalyst 3% Ru-Fe ₃ O ₄ /SPSMN270 is used as a catalyst, hydrogenation is carried out in a batch reactor at a temperature of 120 ° C, a hydrogen pressure of 6.0 MPa, for 90 min, with a stirring speed of 1000 rpm in the presence of isopropyl alcohol as a solvent, while the mass of the catalyst is 0.1 g.

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