DE2525296C2 - Process for the production of acetic acid - Google Patents

Description

gear gas described, dj. 28 percent by volume of water ^ ^^ J «^^ ^u _then ⁸ dry and contains steam (DT-AS 1643824), column 6, line around 'calcine. The vanadium contain-

of the catalysts there can be gradual differences in the test results with regard to activity, seiectivity and service life can be achieved. However, it will also come with a very simple system such as the Oxygen compounds containing vanadium on a carrier such as silicon dioxide are excellent Get results.

The reaction of acetone with oxygen to form acetic acid can be given by the reaction equation

Acetone + 2.0 O ₂ - »acetic acid + CO ₂ + H ₂ O

to be discribed. The direct oxidation of acetone to CO ₂ according to the reaction equation can be a side reaction

Acetone + 4 O ₂ - »3 CO ₂ + 3 H ₂ O ^iS

appear. Another side reaction can be carbon oxide according to the equation

Acetone + 2.5 O ₂ - »3 CO + 3 H ₂ O

form.

The acetic acid formed in the inventive gas-phase oxidation can be separated from the reaction gas by various methods, for example by cooling the Reaktionsga- ² S ses or by a water wash. By cooling to temperatures of 20 to 70 ° C., for example, it is achieved, for example, that all or some of the acetic acid formed during the reaction condenses out. The remaining gas, consisting essentially of oxygen, nitrogen or carbon dioxide, water vapor and unconverted organic starting material, can be returned to the oxidation. The organic starting compound contained therein can be separated off by distillation from the condensate, which essentially consists of water and acetic acid, and can likewise be returned to the reaction. The acetic acid can be obtained in pure form from the remaining acetic acid / water mixture by distillation. Some of the water obtained is fed back into the reaction or discharged from the reaction in the form of clean waste water.

A technical implementation of the process can be seen using the example of the gas phase oxidation of acetone Acetic acid described on the basis of the figure:

A cycle gas consisting of acetone, water, oxygen and CO _{2 is introduced into the reactor 1.} The conversion of the acetone with oxygen to acetic acid, CO ₂ and water takes place at about 300 ° C and a pressure of about 6 bar. The reaction gas 12 is cooled to about 70 ° C. in the cooler 2 and fed into the separator 3 via line 13. The gas phase obtained here is returned to the reactor via 14 after compression in 4. The liquid phase, which consists of acetic acid, water and acetone, reaches the distillation column 6 via 15. The top product consisting of acetone is removed via 16 and returned to the oxidation. The bottom product of the column 6 is fed via 17 into the distillation column 7, in which water is distilled off as the top product 18. The bottom product is fed via 21 into the column 8, in which the acetic acid 22 is obtained as the end product by redistillation and is removed from small amounts of higher boilers 23. A partial flow of the circulating gas 14 is taken off via 25 and freed from acetone in the water scrubber 5, so that the carbon dioxide formed in the reaction is removed via 27. The water of reaction formed during the reaction is removed over a 20-cycle period. The remainder of the water stream 18 is partly returned directly to the oxidation via 19, partly first introduced into the scrubber 5 via line 24 and then returned to the oxidation via 26 as acetone-containing water. The oxygen required to carry out the oxidation is introduced as pure oxygen via 28. Acetone 9 and oxygen 28 are converted into acetic acid 22, waste water 20 and carbon dioxide 27 via the overall process.

example

A vanadium-containing catalyst is prepared in the following manner. A silica support in the form of 5 mm spheres with an internal surface area of 160 m ² / g (BET) is impregnated with an aqueous solution of vanadyl oxalate. After drying, a catalyst is obtained which contains vanadyl oxalate on silica. The amount of vanadium corresponds to a concentration of 10 percent by weight, calculated as vanadium pentoxide.

1.0 1 of the catalyst obtained in this way is placed in a reaction tube 3 m long and 30 mm clear width installed. The catalyst is at 6 bar and 300 ° C per hour 5000 Nl gas of the following composition (in mol percent):

acetone 2 water 5 oxygen 8th Carbon dioxide 85

The reaction gas is cooled to room temperature under the reaction pressure. It becomes a liquid Phase consisting of water, acetone and acetic acid obtained. From the amount and composition of the liquid Phase is calculated that 130 g per hour of acetic acid are formed per liter of catalyst. on 1 mol of converted acetone gives 0.85 mol of acetic acid.

1 sheet of drawings

Claims (3)

of carbon dioxide. By using increased pressure and patent claims: It is the presence of only small amounts of water - • - Hamof in the process according to the invention 1. Process for the production of acetic acid ^ ⁰ P _{iQ economically} advantageous way to obtain _{acetic acid concentrated} by the reaction of acetone, isobutyraldehyde, 5 mg. Methyl ethyl ketone or sec-butanol in the uas- «. reaction of the invention can, for example, in phase with oxygen in the presence of vanadium corresponds ^ ^ _preferably from 5 to 6 carried out bar werhaltender catalysts and in the use of <j "Especially suitable concentrations of what-water vapor, characterized geke nnzeichnet.daB ° e _rdamD f jm input gas are 2 to 8, preferably 4 to the reaction at pressures of 3 to 10 bar serf _water . Suitable for the reaction and with a water vapor content of 1 to 10 ° Moipr ^ ^ _{4 {) () O c is 250 bJs} mole percent water, optionally in the presence of lempei "J ^ j _te residence times are 0.1 to 100, be of carbon dioxide , takes 1 to 10 seconds, the oxygen content 2. The method according to claim 1, characterized ge '"^« _{gas can vary within} wide limits works that at pressures of 4 to 8 * 5 ™ ^m "f. ° 1 _{1 bcisp} i _e i ise _swe 1 to 20, preferably 5 to bar and a water vapor content of 2 to 8 shows the .a ^^^ _{g to 10 M} olprozent. The conversion mole percent water works. _Zun e can in the presence of other gases, such as. B. Stick 3. The method according to claim 1 and 2, thereby tongue can | _{ndioxid be carried} out. It is characterized by the fact that at pressures from 5 to 6 mole percent isobutyraldehyde, methyl ethylke-6 bar and a water vapor content of 4 to 4 to 4 _{mole percent water in the} inlet gas can be used. Boundaries fluctuate. It is expedient to work in such a way that the contents of the compounds mentioned are outside the range in which explosive a5 sive gas mixtures can form. In addition, the gas phase oxidation according to the invention in different ,,,, ^ "" ". R WpUp can be carried out. One can go to The present invention relates to a method of _{Gasstronv containing We ed C ff} for the production of acetic acid by catalytic nemSt «tetonu ^ ^ oxidizing organic Gas phase oxidation of alcoholic or ketone eg_in r ^ explosive limit common oxidation products of butene, such as ace- 3o ^ν «" ^^ ^Β ^ _{8 gas mixture} then via the clay, isobutyraldehyde, methyl ethyl ketone, sec.-buta- JjJ «^ ^ _{n fefner m a gasför} . ^nO! From the DT-AS 1643824 a method for ^^^^ ^T ^^^^! ^ Production of concentrated acetic acid by ka- Menger £ a £ «killing ^ _atalysa ^B _tor direct. Man Analytical gas phase oxidation of butenes or the 35 "" ^d _n ^dl _h ^e _e ^S f _d ^ _r ^em ; ^S _hnic performing the procedure alcoholic or ketomian obtainable from it can be tader ¹ ^ ™ ^ _{5εηίΗςηεη} | _us nitrogen Oadation products beierhighter tempera ur inGereia audi ™ ^ ^ιηε ™ _{d existing} rice gas work- presence of water vapor containing vanoium oxide ^{and /} ° ^the _s ^er _d ™ ^e oxidizing organic compound, tendency heavy metal catalysts known that da- ^, Jte the ω contains water vapor. The content of is characterized by the fact that the butene or 4 ° Saü.rstott to ^. ₇ ^ _{to 9 ()} percent by volume its alcoholic or ketonic oxidation pro-carbon dioxide Can products of a series of consecutive wear. _{ate kata} i _yt ic gas phase single reactor in portions zufuhrt, wah The .l ^r ™ f ^ _{est angeord} ^ _th catalysts rend one required for the total sales ^Ο1 ^ ™™ Λ ³ ^ Katllysatoren in a fluidized bed air flow and water vapor bereUs the er 45 ^ ™ ^ ™ Ζ ™ ^ the most diverse reactor enters. The process of the DT-Ab ^ Hd ™ for the production of the vanadium contained-