JP5747325B2 - Method for producing oxygen-containing compound having 3 or more carbon atoms - Google Patents

Description

  The present invention relates to a method for producing an oxygen-containing compound having 3 or more carbon atoms from ethanol and water in the presence of a catalyst.

A method of reacting ethanol with a catalyst to convert it into an oxygen-containing compound having 3 or more carbon atoms, particularly acetone, has been well known for a long time.
Acetone is manufactured in the modern chemical industry mainly from propylene produced by thermal decomposition of naphtha, etc., but as a measure to suppress the depletion of petroleum resources or the release of carbon dioxide originating from fossil raw materials to the atmosphere, Manufacturing methods from biomass raw materials are being reviewed.
Since ethanol can be easily produced by fermentation of biomass or the like, acetone synthesis from ethanol is useful as an ethanol conversion reaction.

  Here, Non-Patent Document 1 describes that when ethanol is reacted using an oxide catalyst made of iron and an alkaline earth metal, acetone is obtained in a yield of about 70%. Is described as short.

  Non-Patent Document 2 and Non-Patent Document 3 describe an acetone synthesis reaction from ethanol using an oxide catalyst composed of zinc and an alkaline earth metal (Ca), and the molar ratio of the alkaline earth metal to zinc. Is 0.1, the highest acetone yield (91%) is obtained, but when the alkaline earth metal molar ratio is increased from 0.1, the acetone yield decreases rapidly. It is shown. However, the reaction results in these documents are the results for 30 minutes after the start of the reaction, and there is no detailed description regarding the catalyst life. Moreover, although the catalyst which added the alkali metal (Na, K) is described, the acetone yield is low.

  Non-Patent Document 4 investigates the reaction of ethanol using iron and an oxide catalyst made of various metals. When iron and zinc are combined, the highest acetone yield is obtained, but with the addition of alkaline earth metals (Ca, Ba) and alkali metals (Na, K), the acetone yield is low. . Moreover, although the continuous reaction using the catalyst which consists of iron and zinc is performed, the acetone yield has fallen from 86% to 57% in about 24 hours.

  In addition, a copper catalyst (Non-patent Document 5), an iron-zirconium catalyst (Patent Document 1), and the like have been reported, but none of them are insufficient in activity or have been studied for long-term deterioration. A method for stably producing an oxygen-containing compound having 3 or more carbon atoms, particularly acetone, from ethanol in a high yield has not yet been established.

JP 2009-209059 A

Journal of the Indian Chemical Society, Industrial and News Edition, Vol. 16, pp. 109-113 (1953) Journal of the Chemical Society, Chemical Communications, 1987, pp. 394-395 (1987) Applied Catalysis, 52, 237-248 (1989) Journal of Materials Chemistry, Vol. 4, pp. 853-858 (1994) Applied Catalysis A: General, 172, 117-129 (1998)

As described above, a method for producing ethanol with a high yield of an oxygen-containing compound having 3 or more carbon atoms, particularly acetone, by reacting ethanol stably for a long time has not been established.
Accordingly, the present invention provides a method for producing an oxygen-containing compound having 3 or more carbon atoms, particularly an acetone-containing oxygen compound having 3 or more carbon atoms, in which ethanol is reacted stably over a long period of time to produce acetone in a high yield. With the goal.

  As a result of diligent research to solve the above problems, the present inventors have found that ethanol can be stably reacted over a long period of time by using a catalyst having a specific composition, and the present invention has been completed. That is, the present invention is as follows.

[1] A method for producing acetone and 2-pentanone from ethanol and water in the presence of a catalyst,
The catalyst contains iron, zinc, alkali metal and / or alkaline earth metal, and the molar ratio of alkali metal and / or alkaline earth metal to zinc is 0.2 to 2. A process for producing acetone and 2-pentanone .
[2] The method for producing acetone and 2-pentanone according to [1], wherein the molar ratio of zinc to iron is 0.01 to 10.
[ 3 ] The method for producing acetone and 2-pentanone according to [1] or [2] , wherein the ethanol and water are derived from hydrous ethanol.

According to the present invention, there is provided a method for stably producing an oxygen-containing compound having 3 or more carbon atoms, particularly acetone, in a high yield for a long time by reacting with ethanol.
This makes it possible to produce useful chemicals by effectively using biomass, and to contribute to the suppression of fossil resource consumption and the suppression of the release of carbon dioxide originating from fossil raw materials into the atmosphere.

The method for producing an oxygen-containing compound having 3 or more carbon atoms of the present invention produces an oxygen-containing compound having 3 or more carbon atoms from ethanol and water in the presence of a specific catalyst.
The catalyst contains iron, zinc, and an alkali metal and / or alkaline earth metal. The molar ratio of the alkali metal and / or alkaline earth metal to zinc (hereinafter referred to as “M / Zn” ( M: alkali metal and / or alkaline earth metal) is 0.2 to 2.

  According to the conventional knowledge in this reaction (Non-Patent Document 2 and Non-Patent Document 3), the activity decreases when an alkali metal is introduced, and the activity is increased when the molar ratio of alkaline earth metal to zinc is increased from 0.1.・ It is known that selectivity decreases rapidly.

  From these findings, it can be said that the range of M / Zn of the present invention is unique. In the catalyst of the present invention, when M / Zn is less than 0.2 and when the molar ratio is larger than 2, the activity and selectivity are lowered, so that the efficiency is deteriorated. The M / Zn is preferably 0.2-1.

  Further, the molar ratio of zinc to iron in the catalyst is preferably 0.01 to 10, more preferably 0.02 to 5, and further preferably 0.05 to 1. By the said molar ratio being 0.01-10, a side reaction can be suppressed and acetone selectivity can be improved.

The catalyst according to the present invention can be prepared by any method as long as it has a composition within the above-mentioned component ratio range.
For example, a method in which a base such as aqueous ammonia is dropped into an aqueous solution in which a salt of iron, zinc, alkali metal and / or alkaline earth metal prepared to the above component ratio is dissolved, and a method of firing after filtration, The powder may be prepared by impregnating a commercially available iron oxide powder with an aqueous solution of a zinc salt, an alkali metal salt and / or an alkaline earth metal salt, followed by firing.

  The catalyst powder thus prepared becomes a molded catalyst that can be used in a fixed bed reactor by kneading and molding with a general binder (silica, alumina, silicate, etc.).

  As ethanol used for the reaction in the present invention, general ethanol produced by various methods such as fermentation can be used, and it may contain impurities such as water and acetaldehyde.

When the ratio of ethanol and water contains water, acetone selectivity is improved. Therefore, the molar ratio of water to ethanol is preferably 0.1 to 10, and preferably 0.5 to 5. More preferably, it is more preferably 1 to 3.
When ethanol having a purity higher than these ratios is used, it is preferable to dilute ethanol with water or supply water separately to the reactor so that the above ratio is obtained.

  The reaction according to the present invention can be carried out in any form such as a fixed bed, moving bed, fluidized bed, etc., but is carried out in a fixed bed flow system in which a molded catalyst is filled into a tubular reactor and ethanol and water are supplied. It is preferred that

The space velocity in the reaction, it is more preferable that it is a preferred 400～4000H ^-1 to 400~6500h ^-1.

The reaction temperature is preferably 250 to 600 ° C, more preferably 300 to 550 ° C, and further preferably 350 to 550 ° C.
The reaction pressure can be any of reduced pressure, normal pressure, and increased pressure, but it is preferably performed in an atmosphere of normal pressure to slightly increased pressure.
This reaction can also be carried out in the presence of nitrogen, hydrogen, hydrocarbon gas or the like.

Example 1
(1) Catalyst preparation Zinc nitrate hexahydrate (manufactured by Wako Pure Chemical Industries, Zn (NO ₃ ) ₂ .6H ₂ O, purity 99.0% or more) 3.74 g, strontium nitrate (manufactured by Wako Pure Chemical Industries, Sr (NO ₃ ) ₂ , purity 98.0% or more) 1.09 g was dissolved in 4.00 g of ion-exchanged water to prepare an aqueous solution containing zinc and strontium.

  An aqueous solution containing zinc and strontium prepared in advance to 10.03 g of iron oxide hydroxide (manufactured by Kanto Chemical Co., FeO (OH), purity 95.0% or more) dried at 120 ° C. for 18 hours or more in a constant temperature dryer It was added to form a slurry, and kneaded for 5 minutes in this state to prepare a slurry-like substance.

The produced slurry-like substance was placed in a muffle furnace at 200 cm ³ / min. In an air stream, dried at 120 ° C. (heated at 5 ° C./min.) For 6 hours, and further fired at 600 ° C. (heated at 5 ° C./min.) For 3 hours to obtain iron, zinc and strontium. A reddish brown solid (SrO / ZnO / Fe ₂ O ₃ catalyst) was obtained.

(2) Analysis method Elemental composition analysis in the obtained catalyst was performed by ICP (inductively coupled plasma) emission spectroscopy. The composition analysis by ICP emission spectroscopic analysis was performed with an ICPE-9000 type ICP emission spectroscopic analyzer manufactured by Shimadzu. As a measurement sample, an acid solution was prepared by dissolving the catalyst to be analyzed with a mixed acid of hydrofluoric acid and hydrochloric acid.
From the measurement results, the molar ratio of strontium to zinc in the catalyst was 0.39, and the molar ratio of zinc to iron in the catalyst was 0.12.

(3) Production of oxygen-containing compound having 3 or more carbon atoms The reaction tube used for the production has a double structure, the outside is a tube made of SUS316 (φ27.2 × t5.5 mm), and the inside is made of quartz. It is an electric melting tube (φ15 × t2.0 mm), and has a quartz thermocouple insertion tube (φ3.5 × t1.0 mm) inside thereof.

  After pulverizing the catalyst and classifying it to 300 to 600 μm, 2.00 g of this catalyst (pulverized product) was filled in a reaction tube, and quartz wool was filled above and below the catalyst layer to hold the catalyst. The height of the catalyst layer was 3.0 cm.

Into the reaction tube filled with the catalyst, nitrogen was supplied at 18.2 cm ³ / min. The temperature of the catalyst layer was raised to 400 ° C. by external heating while flowing at 25 ° C., converted to 1 atm (the same applies hereinafter), and held there for 1 hour.
Thereafter, the reaction was carried out by continuously supplying ethanol, water, and nitrogen at a normal pressure from the reaction tube inlet side so as to have a molar ratio of 33:50:17 (inlet side total gas flow rate: 18.3 cm). ³ / min.).

  One hour after the start of the reaction, the reaction tube outlet gas was analyzed with an on-line gas chromatograph. As a result, the conversion rate of ethanol was 100%, and the yield of oxygen-containing compounds with 3 or more carbon atoms including pentanones One hour after the start, the yield was 88% and the acetone yield was 84%.

  Thereafter, the supply of the raw material was continued for 100 hours while maintaining the temperature of the catalyst layer at 400 ° C., and the reaction tube outlet gas was similarly analyzed. Even after 100 hours from the start of the reaction, the ethanol conversion was 100%, the yield of oxygen-containing compounds having 3 or more carbon atoms including pentanones was 90% after 100 hours, and the acetone yield was 84%.

  Here, the ethanol conversion rate, the acetone yield, and the yield of the oxygen-containing compound having 3 or more carbon atoms including pentanones were calculated according to the formulas (1) to (5) (calculated by molar amount).

Ethanol conversion rate = 100 × (reactor inlet ethanol amount−reactor outlet ethanol amount) / reactor inlet ethanol amount (1)

Acetone yield = 100 × reactor outlet acetone amount / (reactor inlet ethanol amount / 2) Formula (2)

The above formula is based on the following reaction formula.
2C ₂ H ₅ OH + H ₂ O → CH ₃ COCH ₃ + 4H ₂ + CO ₂ Formula (3)
That is, when the conversion is 100% and the selectivity is 100%, 1 mol of acetone is produced from 2 mol of ethanol.

2-pentanone yield = 100 × reactor outlet 2-pentanone amount / (reactor inlet ethanol amount / 3) Formula (4)

The above formula is based on the following reaction formula.
3C ₂ H ₅ OH → CH ₃ CO (CH ₂ ) ₂ CH ₃ + 4H ₂ + CO ₂ Formula (5)

  The yield of the oxygen-containing compound having 3 or more carbon atoms was calculated by the sum of the yields obtained from the formulas (2) and (4).

(Example 2)
In Example 1, in place of strontium nitrate, calcium nitrate tetrahydrate (manufactured by Wako Pure Chemical Industries, Ca (NO ₃ ) ₂ .4H ₂ O, purity 99.9% or more) was used in the same manner. Thus, a catalyst (CaO / ZnO / Fe ₂ O ₃ catalyst) containing iron, zinc and calcium was obtained. The molar ratio of calcium to zinc in the catalyst was 0.45, and the molar ratio of zinc to iron was 0.12.

In the same manner as in Example 1, 2.00 g of this catalyst was charged into a reaction tube, the temperature of the catalyst layer was maintained at 400 ° C., and ethanol, water, and nitrogen were continuously added so that the molar ratio was 33:50:17. And the reaction was carried out (total gas flow rate on the inlet side: 19.3 cm ³ / min.).

  One hour after the start of the reaction, the reaction outlet gas was analyzed. As a result, the conversion rate of ethanol was 98%, the yield of oxygen-containing compounds having 3 or more carbon atoms including pentanones was 91%, and the acetone yield was 85%. It was.

(Example 3)
In Example 1, instead of strontium nitrate, barium nitrate (manufactured by Wako Pure Chemical Industries, Ba (NO ₃ ) ₂ , purity 99.0% or more) was used, and iron, zinc and barium were contained in the same manner. Catalyst (BaO / ZnO / Fe ₂ O ₃ catalyst) was obtained.
The molar ratio of barium to zinc in the catalyst was 0.38, and the molar ratio of zinc to iron was 0.12.

2.11 g of this catalyst was charged into a reaction tube in the same manner as in Example 1, the temperature of the catalyst layer was maintained at 400 ° C., and ethanol, water, and nitrogen were continuously added so that the molar ratio was 33:50:17. And the reaction was carried out (total gas flow rate on the inlet side: 37.1 cm ³ / min).

  One hour after the start of the reaction, the reaction outlet gas was analyzed. As a result, the conversion rate of ethanol was 99%, the yield of oxygen-containing compounds having 3 or more carbon atoms including pentanones was 90%, and the acetone yield was 86%. It was.

Example 4
In Example 1, a catalyst containing iron, zinc, and lithium (LiO / ZnO /) was used in the same manner except that lithium nitrate (made by Aldrich, LiNO ₃ , purity 99.99% or more) was used instead of strontium nitrate. Fe ₂ O ₃ catalyst) was obtained.
The molar ratio of lithium to zinc in the catalyst was 0.43, and the molar ratio of zinc to iron was 0.11.

0.353 g of this catalyst was charged into a reaction tube in the same manner as in Example 1, the temperature of the catalyst layer was maintained at 450 ° C., and ethanol, water, and nitrogen were continuously added so that the molar ratio was 33:50:17. And the reaction was carried out (total gas flow rate on the inlet side: 18.3 cm ³ / min.).

  One hour after the start of the reaction, the reaction outlet gas was analyzed. As a result, the conversion rate of ethanol was 97%, the yield of oxygen-containing compounds having 3 or more carbon atoms including pentanones was 91%, and the acetone yield was 89%. It was.

(Example 5)
In Example 1, instead of strontium nitrate, sodium nitrate (manufactured by Aldrich, NaNO ₃ , purity: 99.995% or more) was used in the same manner to obtain a catalyst (NaO / ZnO / Fe ₂ O ₃ catalyst) was obtained.
The molar ratio of sodium to zinc in the catalyst was 0.40, and the molar ratio of zinc to iron was 0.11.

0.356 g of this catalyst was charged into a reaction tube in the same manner as in Example 1, the temperature of the catalyst layer was maintained at 500 ° C., and ethanol, water, and nitrogen were continuously added so that the molar ratio was 33:50:17. And the reaction was carried out (total gas flow rate on the inlet side: 18.3 cm ³ / min.).

  One hour after the start of the reaction, the reaction outlet gas was analyzed. As a result, the conversion rate of ethanol was 98%, the yield of oxygen-containing compounds containing 3 or more carbon atoms including pentanones was 91%, and the acetone yield was 89%. It was.

(Comparative Example 1)
To 10.03 g of the same iron oxide hydroxide as used in Example 1, 4.00 g of ion-exchanged water was added to form a slurry, and kneaded for 5 minutes to prepare a slurry-like substance.

The prepared slurry was dried and fired in the same manner as in Example 1 to obtain a reddish brown solid (Fe ₂ O ₃ catalyst).

The obtained reddish brown solid was pulverized and classified to 300 to 600 μm, 0.353 g of this catalyst (pulverized product) was charged into the reaction tube in the same manner as in Example 1, the temperature of the catalyst layer was maintained at 400 ° C., ethanol, Reaction was carried out by continuously supplying water and nitrogen at a molar ratio of 33:50:17 (inlet-side total gas flow rate: 19.3 cm ³ / min.).

  One hour after the start of the reaction, the reaction outlet gas was analyzed. As a result, the conversion rate of ethanol was 62%, the yield of oxygenated compounds containing 3 or more carbon atoms including pentanones was 66%, and the acetone yield was 44%. It was.

(Comparative Example 2)
A catalyst (ZnO / Fe ₂ O ₃ catalyst) containing iron and zinc was obtained in the same manner as in Example 1 except that iron oxide hydroxide and zinc nitrate hexahydrate were used and strontium nitrate was not used. It was.
The molar ratio of zinc to iron in the catalyst was 0.13.

0.354 g of this catalyst was charged into a reaction tube in the same manner as in Example 1, the temperature of the catalyst layer was maintained at 450 ° C., and ethanol, water, and nitrogen were continuously added so that the molar ratio was 33:50:17. (The inlet side total gas flow rate: 37.5 cm ³ / min.)

One hour after the start of the reaction, the reaction outlet gas was analyzed. As a result, the ethanol conversion was 99% and the acetone yield was 81%.
Thereafter, the feed of the raw material was continued for 19 hours while maintaining the temperature of the catalyst layer at 450 ° C., and the reaction tube outlet gas was similarly analyzed. As a result, the ethanol conversion was 73% and the acetone yield was 52%. It was falling. The yield of oxygen-containing compounds having 3 or more carbon atoms including pentanones was also reduced to 87% after 1 hour and 57% after 19 hours from the start of the reaction.

(Comparative Example 3)
Ammonium hydroxide solution (Aldrich, NH ₄ OH, 28.0 to 30.0%) was added dropwise to an aqueous solution containing zinc in which 10.03 g of zinc nitrate hexahydrate was dissolved in 50.12 g of ion-exchanged water. = 7.0 to obtain a white suspension. The solid substance obtained by suction filtration was dried at 120 ° C. for 24 hours in a constant temperature dryer to obtain white zinc hydroxide.

3.50 g of zinc hydroxide and 0.292 g of calcium hydroxide (manufactured by Wako Pure Chemical Industries, Ca (OH) ₂ , 99.9%) were mixed together while adding 1.00 g of ion-exchanged water. The obtained white solid was subjected to 200 cm ³ / min. In a muffle furnace. Under an air flow, dried at 80 ° C. (heated at 5 ° C./min.) For 6 hours, and further calcined at 500 ° C. (heated at 5 ° C./min.) For 3 hours to contain zinc and calcium. A white solid (CaO / ZnO catalyst) was obtained. The molar ratio of calcium to zinc in the catalyst was 0.10.

In the same manner as in Example 1, 0.400 g of this catalyst was charged into a reaction tube, the temperature of the catalyst layer was maintained at 500 ° C., and ethanol, water, and nitrogen were continuously added so that the molar ratio was 33:49:18. (The inlet side total gas flow rate: 37.5 cm ³ / min.)
One hour after the start of the reaction, when the reaction outlet gas was analyzed, the ethanol conversion was 55% and the acetone yield was 18%.

Claims (3)

A process for producing acetone and 2-pentanone from ethanol and water in the presence of a catalyst,
The catalyst contains iron, zinc, alkali metal and / or alkaline earth metal, and the molar ratio of alkali metal and / or alkaline earth metal to zinc is 0.2 to 2. A process for producing acetone and 2-pentanone . The method for producing acetone and 2-pentanone according to claim 1, wherein the molar ratio of zinc to iron is 0.01 to 10. The method for producing acetone and 2-pentanone according to claim 1 or 2 , wherein the ethanol and water are derived from hydrous ethanol.