JPH0789945B2 - Method for producing 3,3,3-trifluoropropene oxide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to 3,3,3-trifluoropropene (hereinafter referred to as “TFP”).
Abbreviated as “)” by microbial oxidation to industrially produce 3,3,3-trifluoropropene oxide (hereinafter abbreviated as “TFPO”).

[Prior Art] TFPO can be widely used as a raw material intermediate for the production of various organic chemical products such as synthetic resins, surfactant drugs or agricultural chemicals.

As a method for producing these, the present inventor has proposed a method in which TFP is oxidized by a microorganism to be epoxidized (Japanese Patent Publication Sho 61).
-14798 and 63-50996). In these methods, TFP was allowed to react with microorganisms, the mixed gas after the reaction was introduced into a trap tube cooled with dry ice-methanol, and condensed to separate and purify TFPO.

However, this method is too costly and not preferable for mass production.

[Problems to be Solved by the Invention]

The present inventor, in order to solve the above problems, as a result of diligent studies, while continuously introducing TFP in a gas state into a reaction medium containing microorganisms, withdrawing the reaction product in a gas state,
It was found that by absorbing with an organic solvent, it is possible to stably and continuously separate and purify.

The present invention has been made based on such findings, and an object of the present invention is to provide a method for producing TFPO in large quantities at low cost.

[Means for Solving the Problems]

In the present invention, TFP is brought into contact with bacteria in a gas state under aerobic conditions, converted TFPO is taken out together with other exhaust gas in a gas state, and the exhaust gas is an organic substance that preferentially dissolves the TFPO. It consists of contacting with a solvent to absorb the TFPO into the organic solvent, heating the absorbing solution to remove and recover the TFPO, and further absorbs and removes TFPO with the organic solvent. The exhaust gas is brought into contact with an alkaline solution to absorb and remove carbon dioxide gas in the exhaust gas, and then the exhaust gas is supplemented with TFP and oxygen consumed in the reaction, and again contacted with and reacted with bacterial cells. Is taken.

The above-mentioned bacterial cells of the present invention include Nocardia, Micrococcus, and Astrobacter (A).
rthrobacter), Corynebacteri
um), Mycobacterium, Rhodococcus, Brevibacterium
It is preferable to use a microorganism having an epoxide-producing ability selected from bacterium) and the like, and the characteristics of these cells are described in JP-B-61-14798 or JP-B-63.
It is described in detail in Japanese Patent Publication No. 50996.

In the present invention, the above-mentioned bacterial cells are contacted with TFP in a gas state under aerobic conditions to be converted into TFPO. That is, a gaseous TFP is supplied together with an oxygen-containing gas such as air to a culture solution containing the above-mentioned microbial cells, and brought into contact with the microbial cells to be converted into TFPO. In this case, the concentration of the bacterial cells in the culture solution is preferably 5 to 100 g / l in terms of dry bacterial cell weight. When the cell concentration is 5 g / l or less, the conversion efficiency of TFP to TFPO is poor, and the production of epoxide is low. Conversely, when it is 100 g / l or more, agitation is required to maintain aerobic conditions. It is not preferable because it costs too much and leads to an increase in cost. This conversion reaction is carried out in the range of pH 5-9, preferably 6-8, at 20-50
C., preferably 25 to 45.degree. C.

Also, when using an oxygen-containing gas with an oxygen concentration of about 20%, such as air, the TFP supply should be 0.5-4.5% or 20% or more of that gas, and not within the explosion limit range. It is preferable from the safety point of view that the concentration of TFP is as described above. In this case, it is advisable to adjust the supply amount so that the contact time between TFP and bacteria is 0.1 to 10 minutes. Further, this reaction may be carried out under normal pressure, but also under reduced pressure or under pressure.
There is no problem in the pressure range of 1 to 10 kg / cm ² .

In this reaction, it is preferable to use a liquid in which components such as a carbon source, a nitrogen source and other salts are appropriately added as the culture liquid because the reaction activity of the bacterial cells can be maintained for a long time and the activity can be further enhanced. In this case, as the carbon source, sugars such as glucose, sucrose, molasses, starch hydrolyzate or cellulose hydrolyzate, hydrocarbons such as propane, butane, dodecane, tetradecane and acetic acid can be preferably used. . As the nitrogen source, ammonium chloride, ammonium sulfate, ammonium phosphate, ammonium nitrate, urea, aqueous ammonia, amino acids and other assimilable organic nitrogen compounds and the like, potassium phosphate, sodium phosphate as other salts, Magnesium sulfate, manganese sulfate, ferrous sulfate, ferrous chloride,
Calcium chloride, magnesium chloride and the like are preferable. Further, substances such as vitamins, yeast extract and corn steep liquor that promote the growth of bacterial cells may be added to the culture solution, if necessary.

The exhaust gas is then contacted with an organic solvent that preferentially dissolves TFPO. What is an organic solvent that preferentially dissolves TFPO?
Of the various components contained in the exhaust gas, those that have a better ability to dissolve TFPO than other components, such as diethylene glycol dimethyl ether (diglyme), triethylene glycol dimethyl ether (triglyme), tetraethylene glycol dimethyl ether. (Tetraglyme), isopropanol, ethylene glycol, n-butanol, triethylamine, n-hexane, n-heptane, dimethyl sulfoxide, N, N-dimethylformamide and the like can be exemplified, but in particular, diglyme, triglyme or tetra Glyme is preferred because of its high TFPO dissolution selectivity. In this exhaust gas, TF
In addition to PO, unreacted TFP, carbon dioxide and residual oxygen, water, etc. are contained, but TFPO is absorbed preferentially and TFP is also absorbed at the same time. This absorption is most efficiently performed at a temperature of −40 to 80 ° C., and the pressure is 0.1 to 10 kg / cm ²
It may be appropriately selected within the range. The amount of absorption liquid used is determined by considering the amount of exhaust gas and the amount of each component in the exhaust gas, but especially the flow rate (weight ratio) of 10 to 2000 times the production rate (flow rate) of TFPO. ) It is advisable to select as appropriate within the range.

The absorbing liquid thus absorbing TFPO can generally recover TFPO by heating it to the boiling point of the absorbing solvent used. In this case, TF absorbed at the same time
P can be easily separated and removed from TFPO by distillation.

Incidentally, in the above-mentioned absorption of TFPO, it is naturally possible to absorb almost all the amount of TFP together with TFPO by adjusting the absorption conditions. In this case, TFPO in the final step described above is absorbed.
Increasing the capacity of the distillation apparatus for separation of TFP and TFP can be addressed and, of course, such methods are also included in the present invention.

[Examples] Examples of the present invention will be described below with reference to the drawings. The figure shows the flow of the process implementing the invention.

This process includes a pre-culture apparatus 1 for growing inoculum, a main culture apparatus 2 for further growing the bacteria cultured in the pre-culture apparatus 1, and a centrifugal separation for concentrating the cells of the culture solution of the main culture apparatus 2. Vessel 3, reaction tank 4 for converting TFP to TFPO using the concentrated bacterial cell liquid, absorption tower 5 for collecting TFPO in the gas discharged from the reaction tank 4, TFPO in the absorption tower 5
Solvent recovery tower 6 for separating TFPO from the absorbing liquid that has absorbed
TFP recovery tower 7 for separating TFPO and TFP in the gas recovered in solvent recovery tower 6, carbon dioxide absorption tower 8 for recovering carbon dioxide in the TFPO recovery residual gas discharged from absorption tower 5, and solvent recovery, etc. It is composed of a device such as a solvent dehydration tower 9 for removing water from the solvent recovered in 6, and the processes after the reaction process are continuously performed, and the reaction exhaust gas system is a closed system. Using this process, reaction, recovery, etc. were performed under the following conditions.

KH ₂ PO ₄ , 43 parts by weight, Na ₂ HPO ₄
H ₂ O, 67 parts by _{weight, MgSO 4 · 7H 2 O,} 15 parts by _{weight, FeSO 4 · 7H 2 O,} 1
Salt consisting of parts by weight of 118g, corn steep liquor 50g, defoaming agent 10ml, tap water 10 sterilized, sterilized at 121 ℃ for 30 minutes, this, separately sterilized at 121 ℃ 20 minutes 50% glucose aqueous solution 800ml, Nocardia coralina B-27 cultured in a flask to which 200 ml of 20% urea aqueous solution was added
6 (Deposit No. FERM-P, Institute of Microbial Science and Technology, AIST)
-4094) inoculate 0.5, at a temperature of 30 ° C, air 5 /
Culture was performed for 24 hours while supplying min. This culture solution was prepared by dissolving 12.6 kg of the salt having the above composition, 5 kg of corn steep liquor and defoaming agent 1 in 800 tap water and sterilizing at 121 ° C. for 30 minutes, and adding 75 kg of glucose to 300 tap water and 7.5 urea.
Dissolve each kg in 100 tap water and sterilize at 140 ℃ for 2 minutes, then add and transfer to a 2m ² main culturing device 2 and incubate at a temperature of 30 ℃ and air aeration of 500 / min for 48 hours. went.
This culture solution was concentrated about 3 times in a centrifuge 3, and this concentrated solution was transferred to a 2 m ³ reaction tank 4 in which KH ₂ PO ₄ , 1.74 kg and MgSO ₄ .
₄ · 7H ₂ O, tap water having dissolved therein 1.5kg was added and 1000. While adding a 50% glucose solution at a rate of 2.7 kg / hr to this reaction tank 4, a raw material gas was aerated at a rate of 179.1 kg / hr, and the reaction was carried out at 35 ° C. The raw material gas supplied to the reaction tank 4 is the exhaust gas from the carbon dioxide absorption tower 8 and the TFP recovered from the TFP recovery tower 7, to which oxygen and TFP are added.

The gas supplied to the reaction tank 4 was replaced with nitrogen 68.4 at the time when the equilibrium of the system was established (all values below are at this equilibrium).
Wt%, oxygen 20.8 wt%, carbon dioxide 0.0 wt%, TFP1
0.8 wt%, TFPO 0.0 wt%, composition in exhaust gas is nitrogen 68.1 wt%, oxygen 19.8 wt%, carbon dioxide 0.9 wt%, TFP 10.1 wt%, TFPO 0.6 wt%, moisture 0.4 wt% there were. This exhaust gas is introduced from the lower part of the absorption tower 5, and 274 kg / hr of triglyme is supplied from the upper part. The temperature of the absorbing solution in the absorption tower 5 was -20 ° C in the upper part and 5 ° C in the lower part. The composition of the exhaust gas from the upper part of this absorption tower 5 is nitrogen 6
9.5% by weight, oxygen 20.3% by weight, carbon dioxide 0.9% by weight, TF
The P content was 9.4% by weight and the TFPO content was 0.0% by weight. This exhaust gas is
It is supplied to a carbon dioxide absorption tower 8 filled with sodium hydroxide, absorbs and removes carbon dioxide, and then circulates in the reaction tank 4.

On the other hand, the liquid extracted from the lower part of the absorption tower 5 is heated and supplied to the solvent recovery tower 6. This solvent recovery tower 6
The tower top temperature was 170 ° C and the tower bottom temperature was 240 ° C. The collected triglyme is replenished with loss and circulated to the absorption tower.
Since this triglyme dissolves water, it is dehydrated in the solvent dehydration tower 9. The composition of the gas discharged from the upper part of the solvent recovery tower 6 is 3.3% by weight of nitrogen, 60.0% by weight of TFP, TF
It was PO36.7% by weight. This gas is cooled and supplied to the TFP recovery tower 7 to distill and separate TFPO and TFP. TFPO
It was produced at 1.1 kg / hr. The recovered TFP is circulated and reused as a raw material in the reaction tank 4.

[Effects of the Invention] The present invention as described above has an effect that TFPO can be stably and continuously produced in a large amount at low cost.

[Brief description of drawings]

The figure is a flow diagram of the process used in an embodiment of the present invention. In the figure, 4 is a reaction tank, 5 is an absorption tower, 6 is a solvent recovery tower, and 7
Is a TPF recovery tower, 8 is a carbon dioxide absorption tower, and 9 is a solvent dehydration tower.

Claims (2)

[Claims] 1. A converted 3,3,3-trifluoropropene is converted into a gas state by contacting and reacting with bacterial cells under aerobic conditions.
3,3-trifluoropropene oxide is taken out in a gas state together with other exhaust gas, and the exhaust gas is replaced with the above 3,3,
The 3,3,3-trifluoropropene oxide is contacted with an organic solvent that preferentially dissolves the 3,3,3-trifluoropropene oxide to be absorbed by the organic solvent, and the 3,3,3 from the organic solvent after the absorption. -Desorption and recovery of trifluoropropene oxide, and the exhaust gas from which the 3,3,3-trifluoropropene oxide is absorbed and removed with an organic solvent is contacted with an alkaline solution to absorb carbon dioxide gas in the exhaust gas. Then, the exhaust gas is supplemented with 3,3,3-trifluoropropene consumed in the reaction and oxygen, and the exhaust gas is again contacted with and reacted with the bacterial cells 3,3,
Process for producing 3-trifluoropropene oxide. 2. The organic solvent which preferentially dissolves 3,3,3-trifluoropropene oxide according to claim 1 is any one of diethylene glycol dimethyl ether, triethylene glycol dimethyl ether and tetraethylene glycol dimethyl ether, or two of these. A method for producing 3,3,3-trifluoropropene oxide, which is a mixture of at least one species.