EA021350B1 - Method of catalytic hydrogenation of hydroxycarboxylic acid esters to glycols - Google Patents

Abstract

The invention relates to processes for the low-cost production of glycols from esters of hydroxycarboxylic acids. The esters of hydroxycarboxylic acids and hydrogen in gas phase are contacted with the catalyst which contains hydroxysilicate of copper or reduced hydroxysilicate of copper. The reduced hydrosilicate of copper contains metallic copper nanoparticles decorated by amorphous oxyhydroxide of silicon. Such decorated copper nanoparticles have advantageous activity and selectivity in catalytic hydrogenation of hydroxycarboxylic acid esters to glycols.

Description

The present invention relates to processes for the production of diols with high yield and selectivity by hydrogenation of hydroxycarboxylic acid esters in the gas phase using catalysts containing copper. In particular, the present invention relates to a process for the production of ethylene and propylene glycols.

State of the art

Ethylene and propylene glycols are widely used, for example, as monomers in polyester resins, in antifreeze and anti-icing fluids, in the production of food products, pharmaceuticals and cosmetic products, as well as in washing liquids. Currently, the industrial production of glycols is oil-based and includes the hydrolysis of alkylene oxides under high pressure and at high temperature.

Since ethylene and propylene are used in this process, the price of the obtained 1,2-diols depends on the price of oil and another hydrocarbon. A new process is needed to produce glycols from renewable resources such as plants.

It is well known that plants produce carbohydrates from atmospheric carbon dioxide and sunlight during photosynthesis. Moreover, since carbon dioxide is a greenhouse gas, any additional gas removal from the atmosphere helps to compensate for the increase in the amount of this gas from industrial emissions. A method based on hydroxycarboxylic acids obtained by fermentation of raw biomass is a promising method for the production of glycols (\ UO 2000/030744, υδ 6455742, υδ 6479713).

It is known that liquid-phase hydrogenation of carboxyl groups occurs under high hydrogen pressure. To carry out the hydrogenation process under milder conditions, carboxylic acids are usually converted to more readily reduced esters. Various patents and articles disclose the reduction of hydroxycarboxylic acid esters. For example, the hydrogenation of organic esters to alcohols and glycols in the liquid phase was reported by Adkins and colleagues, who were able to achieve 80% yield of propylene glycol from methyl lactate through copper / chromium oxide and Raney nickel catalysts at temperatures from 150 to 250 ° C and ultrahigh hydrogen pressures from 20 to 30 MPa (Vo ^ beb aib Abkshk, 1. Ateg. Syet. §Os. 56: 689 (1934); Abktk aib Vyyea, 1. Ateg., Syet. 8os. 70: 3118 (1948); Abktk apb Vyysa , 1. Ateg., Siet. 70: 3121 (1948)).

In addition to high pressure, high catalyst loading is necessary to achieve these relatively high yields. Woah! e1 a1. (1. Ogd. Set. 24: 1847 (1959)) was able to obtain propylene glycol from ethyl lactate through black rhenium catalysts with a yield of up to 80% at a temperature of 150 ° C, but at a very high hydrogen pressure of approximately 25 MPa.

The hydrogenation of organic esters to glycols in the liquid phase was reported by Luo and colleagues, who achieved 83% yield of propylene glycol from ethyl lactate through Ki-8p / y-A1 ₂ Oz at a temperature of 150 ° C and a pressure of 5.5 MPa (Bio S. Wap, δ., Οίηί, M., 2yapd, 1., Rap, K. Arr1. Ca1a1. A. 275: 95 (2004)).

A major drawback of all of the aforementioned hydrogenation processes in the liquid phase is the need to use a high hydrogen pressure.

The process of hydrogenation in the vapor phase allows you to lower the pressure of hydrogen. For example, Bradley and the Bradley reported on the hydrogenation of organic esters to alcohols and glycols in the vapor phase through a reduced mixture of copper and zinc oxides at a temperature of 234 ° C, a pressure of 1.6 MPa and a fluid hourly space velocity of ΟδΥ'Ι = 1.06 h ^-1 colleagues (\ UO 8203854, 1982 by Eau Mskey Ub.), who achieved 97.7% selectivity for propylene glycol and 34.7% conversion of ethyl lactate. The yield of propylene glycol is 0.038 g of propylene glycol / (ml of catalyst). A similar approach was claimed in patent [CB 2150860, 1983 Eauu MsKey Uy.]. The reduced mixture of CuO and 2pO oxides was used to hydrogenate carboxylic acid esters. Carbon dioxide is added to the gas mixture in the latter invention.

Copper-containing catalysts need more effort to carry out the production process of 1,2-propanediol from a biomass derived substance. ΡΌ. S.'oPddyG M. δаηсееζ-Са5ΐШо, EA. OiteChs w [Arryeb Sa1a1u515 In: EpuyopteShak 39 (2002) 353-359] reported that the high selectivity and activity of the Cu catalyst impregnated Yu ^ _2, which comprises a nitrate of copper over the surface of silica. The authors achieved 88% selectivity for 1,2-propanediol at a pressure of 7 bar and 100% conversion of lactic acid.

In the claims [US Pat. No. 4,628,129; according to Ishop Sagyba Sogrogaiop, 1986] it is stated that catalysts on a Cu ^ U ₂ substrate (prepared by means of an impregnation method, as follows from the text) are suitable for the conversion of alkyl oxalates and alkyl glycolates to ethylene glycol.

Despite these efforts, the need for new methods for the production of glycols, which can be carried out under relatively mild conditions and which lead to a high conversion of esters, in terms of glycol selectivity and glycol yield, remains.

- 1 021350

SUMMARY OF THE INVENTION

The present invention relates to processes for the low-cost production of glycols from esters of hydroxycarboxylic acids under relatively mild conditions with high conversion of esters, high selectivity for glycols and glycol yield. In particular, the present invention provides a catalyst for the conversion of hydroxycarboxylic acid esters to 1,2-propanediol, which contains a copper hydroxysilicate phase with a chrysocoll structure or reduced copper hydroxysilicate. The present invention also provides a process for the production of glycols, which comprises the step of contacting a mixture of esters of hydroxycarboxylic acid and hydrogen in the gas phase with a catalyst that contains copper hydroxysilicate or reduced copper hydroxysilicate.

Said copper hydroxysilicate (CuH) ₄ 81 ₄ O1 ₀ (OH) ₈ pN ₂ O can be prepared by a precipitation method using precipitated silica, water soluble copper salt and urea as a raw material. Mentioned copper hydroxysilicate can also be obtained from natural deposits of chrysocolla mineral, however, in this case, mineral impurities can impair catalyst selectivity and / or activity. Said copper hydroxysilicate can also be prepared by hydrothermal treatment. The structure of chrysocolla is distinguished from other oxides containing copper or oxyhydroxides by the method of infrared spectroscopy with Fourier transform (ΡΤΙΚ), showing four bands in the ranges of about 470, 670, 1040 and 3620 cm ^-1 , which are the only characteristic of this hydroxysilicate [T. M. Yuryev, G.N. Kustova, T.P. Minyukova, E.K. Poels, A. Blick, M.P. Demeshkina, L.M. Plyasova, T.A. Krieger, V.I. Zaykovsky. Innovative testing of materials, 5 (1) (2001), 3-11].

Reduced copper hydroxysilicate can be prepared by treating copper hydroxysilicate with a gas that contains hydrogen, CO, or another reducing substance at elevated temperatures from 100 to 500 ° C. The reduced copper hydroxysilicate contains metallic copper nanoparticles decorated with amorphous oxyhydroxide silicon clusters. This system is very different from the system of metallic copper particles on a silicon substrate in its physical, spectral, catalytic and adsorption properties (including its catalytic activity and selectivity in the hydrogenation of hydroxycarboxylic acid esters). The decoration of metallic copper particles can be unambiguously controlled by spectroscopy in the ultraviolet and visible spectral regions (IU-U18), since the decorated metallic copper particles have lower surface plasmon resonance energy (below the range of 16500 cm ^-1 , while the ranges of 17000-18000 cm ^-1 are observed for a Cu / 8Yu ₂ substrate without decoration of the substrate [see, for example, E. SaIagi // A.S. Vabadbn, R. SapUnp, Τ. Ρίηοΐΐο, apb S. 8aba, Maisgr δοί apb Udp. 26 (5-7) (2006), 1092-1096]. Decrease in the surface plasmon re the zonation energy is caused by changes in the surface properties of metallic copper nanoparticles due to the decoration of these particles with a silicon oxyhydroxide shell having a high dielectric constant. Examples of the effect of decoration of Cu nanoparticles with an oxide shell on their optical properties are given in the literature (see, for example, information on the Cu-ΖπΟ system [ A.A. Hassin, S.F. Ruzhankin, V.F. Anufrienko, A.A. Altynnikov, T.V. Larina, J.S. van den Hewell, T.M. Yuryev and V.N. Parmon. Reports on Physical Chemistry 409 (1) (2006), 193-197], and on the Cu-Cu ₂ O [Τ. Godselah, M.A. Vesagi and A. Shafiehani, Journal of Physics, D: Applied Physics, 42 (2009), 015308]).

The reduction of copper hydroxysilicate in the catalyst can be carried out after loading the catalyst into the reactor by contacting the catalyst with hydrogen of a gas mixture containing hydrogen at elevated temperatures, including contacting the catalyst with a mixture of hydrogen and hydroxycarboxylic esters.

The catalyst may contain other components that improve its rheological properties, pore structure or mechanical strength, such as graphite, zinc oxide, etc. Preferably, the copper content of the catalyst should be more than 10% by weight. It is also preferred that the catalyst does not contain other oxyhydroxide or oxide components containing copper, with the exception of copper hydroxysilicate, as they may impair the selectivity of the catalyst. However, minor impurities of such oxides may be present in the composition of the catalyst and do not significantly affect the catalytic properties.

The catalytic properties of the catalyst in the hydrogenation of esters of hydroxycarboxylic acids possess considerable advantages in relation to known catalysts on the substrate Si / occupies 8 ₂ or with respect to catalysts obtained by reduction of oxide mixtures containing copper (e.g., a mixture of CuO and ΖηΟ), both illustrated by the following examples.

To illustrate the method, esters of aliphatic alcohols and lactic and glycolic acids were used as esters of hydroxycarboxylic acids, leading to the formation of propylene and ethylene glycols, respectively.

- 2 021350

Examples

Three catalysts were prepared: two in accordance with the present invention and one in accordance with [Κ.Ό. Soitdy, Μ. δ; · ιηο1ιοζ-ί '. ’; · ΐ5ΐί11ο. ΐ.Ά. Iitezu Arrieb Sa1a1u818 B .: Epuegopteia1, 39 (2002), 353359] as a comparison. Information on these samples is given in table. one.

Example 1

The catalyst was prepared by reductive thermal treatment of copper hydroxysilicate with Cu: §1 in a stoichiometric ratio of 1: 2 atomic mass with a chrysocoll structure at a hydrogen stream and a temperature of 300 ° C for 1 h. The structure of the chrysocolla of the catalyst before reduction is confirmed by the presence of bands at 480, 670 , 1035 and 3624 cm ^-1 , the catalyst does not contain phases of Cu nitrate, CuO, Cu ₂ O phases, as confirmed by X-ray diffraction analysis (ΧΚΌ). After recovery, the catalyst is characterized by resonant absorption of light in the range of 14600 cm ^-1 , which shows a high degree of decoration of particles of metallic copper.

Liquid butyl lactate (flow rate 0.5 ml / min) was evaporated and mixed with a stream of hydrogen (flow rate 300 ml / min). A gas mixture of hydrogen and butyl lactate was fed into a tubular quartz reactor packed with 5 g of catalyst (Table 1, catalyst number 1). The temperature in the reactor was maintained at about 190 ± 2 ° C, pressure - 10 bar. The process was carried out for 24 hours. The molar ratio of butyl lactate: hydrogen is 1: 3.97.

The vapor mixture leaving the reactor passed through a water-cooled condenser, and then through a second cooled condenser, through which a cooling liquid passed at a temperature of 0 ° C. The resulting condensate was analyzed. The condensate has the following composition, wt.%: Butyl lactate - 28.5; propylene glycol - 33.9; butanol - 34.9; 1-hydroxy-2-propanone - 1.9; unidentified by-products - 0.8. The conversion of butyl lactate was 71.5% of the molecular weight, the propylene glycol selectivity was 91.3% of the molecular weight. The yield of propylene glycol (g glycol / g catalyst / h) was 2.01.

Examples 2-12.

The hydrogenation processes were repeated analogously to example 1, but under different conditions.

The conditions and results of hydrogenation of butyl lactate are given in table. 2.

Examples 13-15.

Hydrogenation processes were carried out analogously to example 1, but methyl lactate was used as an ester of hydroxycarboxylic acid.

The conditions and results of hydrogenation of methyl lactate under different conditions are given in table. 2.

Examples 16-18.

Hydrogenation processes were carried out analogously to example 1, but ethyl lactate was used as an ester of hydroxycarboxylic acid.

The conditions and results of hydrogenation of ethyl lactate under different conditions are given in table. 2.

Examples 19, 20.

Hydrogenation processes were carried out analogously to example 1, but methyl glycolate was used as an ester of hydroxycarboxylic acid.

The conditions and results of hydrogenation of methyl glycolate to ethylene glycol under different conditions are given in table. 2.

Examples 21, 22 (low copper content).

The catalyst was prepared analogously to example 1, but the atomic ratio Cu: §1 in the catalyst was 1: 8. The catalyst before reduction contains a hydroxysilicate with a chrysocoll structure, which is confirmed by the presence of bands in the ranges 470, 668, 1040 and 3620 cm ^-1 , the catalyst does not contain a Cu, CuO nitrate phase, Cu ₂ O phase, as confirmed by X-ray diffraction analysis ((), a certain amount poorly crystallizing §YU ₂ present in the sample, as follows from the data of X-ray diffraction analysis (ΧΚΌ) and infrared spectroscopy Fourier transform (ΡΤ-ΙΚ). After recovery, the catalyst is characterized by resonant absorption of light in the range of 14300 cm ^-1 , which shows a high degree of decoration of particles of metallic copper.

Hydrogenation processes were carried out analogously to examples 7 and 9, but with a lower copper content in the catalyst, as described above.

Examples 23, 24 (comparative).

The catalyst was prepared by impregnation of the finely divided silica (aerosol A-180) with copper nitrate by the moisture capacity, as suggested by по.Ό. Soyshdy, Μ. δαη ^ ζ ^ αδίίΐΐο, TA. Iitevu ίη [Arrieb Sa1a1u818 V .: Epuegopteia1, 39 (2002), 353-359], R.D. Cortwright, M. Sanchez Castillo, J.A. Dumesik in [Catalysis Used B: Natural, 39 (2002), 353-359]. After reduction treatment the catalyst contains 10 wt.% Of metallic copper and §YU _2. The surface plasmon resonance absorption by the reduced catalyst is recorded in the range of 17200 cm ⁻¹ , which shows metallic copper deposited in the usual way over silicon with a low degree of copper decoration. Hydrogenation processes were carried out analogously to examples 7 and 9.

The conditions and results of hydrogenation of methyl glycolate to ethylene glycol under different conditions are given in table. 2. From the data it can be seen that the catalyst proposed in this invention hydro- 3 021 350 ksisilikata copper has the advantage with respect to the catalyst on the substrate C / ₂ occupies 8 having no metallic copper decoration.

Table 1

Catalyst Characteristics

Katali congestion No. The composition of the catalyst phase Atomic the attitude C: 3 | Maximum surface plasmon resonance band for reduced catalyst The composition of the phase of the reduced catalyst one Copper hydrosilicate (CuH) ₄ ZCO, o (OH) ₈ pN ₂ 0 one 14600 cm ’ Cu ⁰ , decorated with amorphous silicon hydroxide 2 Hydrosipicate of copper (CuH) 48cO, ₀ (OH) _in pN ₂ O and 5 _g 0.14 14300 cm * ’ Cu ⁰ , decorated with amorphous silicon hydroxide and amorphous silicon 3 Cu (SOS) ₂ and 5 _g 0.1 17200 cm ¹ C ° and zyu _g

Conditions and results for the hydrogenation of esters of hydroxycarboxylic acids

table 2

At- measures Katali congestion Complicated ether T R Flow difficult ether Flow hydrogen Attitude Simple ether Turning difficult ether Glycol Selectivity Glycol yield FROM bar ml / min ml / min mol / mol % % (g glycope / g rolled isator / h) one one Butyl lactate 190 10 0.50 300 3.97 71.5 91.3 2.01 2 one Butyl lactate 190 10 0.25 200 5.31 98.2 99.0 1.49 3 one Butyl lactate 195 fifteen 0.45 400 5.89 93.3 97.6 2,52 4 one Butyl lactate 195 6 0.17 167 6.54 97.2 93.2 0.95 5 one Butyl lactate 190 7 0.17 167 6.54 97.7 94.5 0.96 6 one Butyl lactate 190 nine 0.17 167 6.54 98.9 96.5 0.99 7 one Butyl lactate 190 10 0.17 167 6.54 99.1 98.3 1.01 8 one Butyl lactate 190 one 0.14 157 7.46 95.2 81.6 0.67 nine one Butyl lactate 190 one 0.30 200 4.42 64,2 72.9 0.86 10 one Butyl lactate 200 8 0.10 120 8.00 99.9 83.1 0.85 eleven one Butyl lactate 220 2 0.10 120 8.00 99.9 52,5 0.32 12 one Butyl lactate 215 12 0.60 800 8.84 97.2 82.1 2.94 thirteen one Methyl lactate 180 4 0.20 400 8.50 93.7 92.8 1,67 14 one Methyl lactate 190 fifteen 0.30 400 5.67 96.8 93.9 2.61 fifteen one Methyl lactate 160 nine 0.10 300 12.76 83,2 89.1 0.71 sixteen one Ethyl lactate 200 5 0.25 300 6.12 95.1 92.2 1.75 17 one Ethyl lactate 190 8 0.20 250 6.38 96.7 94.6 1.46 eighteen one Ethyl lactate 180 12 0.15 200 6.82 98.9 98.4 1.16 nineteen one Methyl glycolate 200 4 0.21 300 4.85 96.8 93.1 1.85 twenty one Methyl glycolate 180 10 0.13 300 7.83 97.7 98.3 1.22 21 g Butyl lactate 190 10 0.17 167 6.54 91.6 92.3 0.88 22 2 Butyl lactate 190 one 0.30 200 4.42 30.8 64.8 0.37 23 Compares. Butyl lactate 190 10 0.17 167 6.54 43.1 62.0 0.27 24 Compares. Butyl lactate 190 one 0.30 200 4.42 12,2 43,2 0.09

CLAIM

Claims (5)

1. A method for the catalytic hydrogenation of esters of hydroxycarboxylic acids in glycol, according to which the mixture containing the ester of hydroxycarboxylic acid and hydrogen in the gas phase is contacted with a catalyst containing reduced copper hydroxysilicate containing metal copper nanoparticles decorated with amorphous oxyhydroxide silicon clusters. 2. The method according to claim 1, in which the recovered copper hydroxysilicate contains 10-55 wt.% Copper. 3. The method according to any one of claims 1, 2, in which the process of catalytic hydrogenation of esters of hydroxycarboxylic acids into glycols is carried out in the gas or gas / liquid phases. 4. The method according to claim 3, in which the process is carried out under pressure from 1 to 15 bar and at a temperature in the range of 140-220 ° C. 5. The method according to claim 4, in which the process is carried out at a temperature in the range of 180-200 ° C.