| 摘要 |
1,148,111. Purifying formic esters. RUHRCHEMIE A.G. 5 Oct., 1966 [16 Oct., 1965], No. 44544/66. Heading C2C. Removing a formic ester of an aliphatic alcohol from a mixture of the ester and the said alcohol by heating the mixture with an aqueous solution of an alkali metal salt of a strong organic acid at a temperature in the range 200- 260‹ C. The alkali metal salt is preferably a formate, acetate or oxalate and may be present in the aqueous solution in a concentration between 1 and 40% by weight. Under the conditions of the process the formic acid component of the esters is converted into gaseous products such as carbon dioxide, carbon monoxide and hydrogen. The process may be carried out in a continuous manner by introducing the mixture to be treated from a container and the aqueous alkali metal salt solution, e.g. from a container or recycled from phase separator, into the bottom of a stationary vertical heated tube, the major part of the tube, preferably 75% of its volume, being filled with the aqueous solution. The organic mixture ascends the heated tube and is passed through a cooler into a separator where gaseous products are removed from the liquid product which is then separated into organic and aqueous phases in a separating vessel, the aqueous phase being re-cycled. Although any mixture containing formic esters together with alcohols and other organic compounds which are inert under the reaction conditions may be used the preferred starting materials are ester/alcohol mixtures obtained by the hydroformylation of an olefin particularly those obtained as residue in the distillation of raw aldehydes formed in the hydroformylation. The treatment of mixtures containing iso- and normal-butyl formic ester and the corresponding alcohol and ether with aqueous sodium acetate, formate or oxalate; of 1, 3-propanediol difoamate and of an oxosynthesis product containing isooctyl formate with aqueous sodium formate is described. |
