Patent GB-757308-A (GB)
Title: Improvements in or relating to production of high alcohols by improved oxo process
Inventor: CERVENY WILLIAM J
IPC: C07C45/50
Filed: 1952-02-05
Abstract: Alcohols are made by reacting aliphatic olefines containing 3-17 carbon atoms per molecule with CO and H2 in a mol. ratio of about 1:1 in the presence of a cobalt catalyst so that a substantial portion, but not all of the olefines are converted to aldehydes and material boiling higher than the desired alcohols, a part but not all of the aldehydes being hydrogenated prior to a final hydrogenation stage, all of the cobalt catalyst being removed from the aldehydric product by scrubbing with acid and th liquid products thus obtained are fractionated, prior to the final hydrogenation, so as to remove all of the said higher boiling material.  As a modification in which some hydrogenation occurring in the carbonylation stage takes the place of the initial hydrogenation, the olefines are reacted with CO and H2 in a mol. ratio of about 1:1 in the presence of a cobalt catalyst so that about 40-60 per cent of the olefine is converted chiefly to aldehydes and alcohols whilst a minor amount is converted to higher boiling materials, cobalt is removed from the products by washing with sulphuric acid, the acid is removed from the acid-washed liquid which is then flash distilled and steam stripped at reduced pressure to remove material boiling higher than the required alcohol the product stream, containing some low boiling material, being finally hydrogenated with excess hydrogen containing less than 3 per cent of CO at about 350-550 DEG  F. and about 500 p.s.i.g. in the presence of a hydrogenation catalyst and at a space velocity of about 0.01-1 the final products being fractionated to obtain a substantially pure alcohol.  In this modification, the final hydrogenation is preferably effected at 3,000 p.s.i.  The CO and the feed is obtained by reacting normally gaseous hydrocarbons with steam in a multiple reformer system, the products of the first reformer being passed through a converter with additional steam to yield CO2 and H2, the former gas being separated and reacted with hydrocarbons and steam to yield CO and H2 in a ratio of about 1:1 and CO2 which is recycled.  The hydrogen from the first reformer may be used in the hydrogenation stage.  Carbonylation may be effected at 240-400 DEG  F., e.g. about 330 DEG  F. and about 3,000 p.s.i.g. with liquid space velocities of about 0.15-1.5, e.g. about 0.5 using about 0.01-0.2, e.g. about 0.1 weight per cent of catalyst as cobalt and about 20-50 or more, e.g. about 25-40 cu. ft. of fresh H2-CO feed per gallon of olefine charged.  These conditions give aldehyde to alcohol ratios of about 3:1 (1:1 to 5:1), an aldehyde-plus-alcohol to bottoms ratio of about 3:1 (2:1 to 17:1) and a low olefine saturation (0 to 10 per cent). The liquid products from the carbonylation stage may be first hydrogenated by trickling over supported cobalt catalyst, preferably about 3-15 per cent cobalt in pumice, at about 350-600 DEG  F. and about 850 p.s.i.g. in the presence of hydrogen from the final hydrogenation.  A substantial part of the hydrogenated product may be recycled to the hydrogenator.  The final hydrogenation of the fractionated product may be effected over cobalt on pumice at about 300-500 DEG  F. and about 900 p.s.i.g. with a large excess of hydrogen obtained from the reformer.  The alcohols obtained, e.g. nonyl alcohol, are substantially free from colour.  The cobalt sulphate obtained by the acid washing may be converted into catalyst for re-use in the process by e.g. treatment with an alkali metal hydroxide in the presence of an oil-soluble fatty acid and olefine feed.  Production of high boiling materials in the carbonylation stage is inhibited by the addition of 1 to 10 per cent of copper based on the cobalt metal in the catalyst used.  Suitable apparatus lay-outs are provided for each modification.  In the first octenes are converted to nonanols, the preferred carbonylation catalyst being cobalt naphthenate and in the second heptenes to octanols.  The alcohols may be converted to their esters, dioctyl and dimonyl phthalates being described.  Specification 647,363 is referred to.