Patent GB-428450-A (GB)
Title: Improvements in or relating to the catalytic production of acetic acid
IPC: C07C51/12
Filed: 1933-10-02
Abstract: In the production of acetic acid from carbon monoxide and methanol in presence of hydrated tungsten oxide which is maintained in the hydrated state by water vapour present in the reaction mixture as described in the parent Specification, the tungsten oxide is prepared from a solid tungstate such as para ammonium tungstate and an aqueous acid, preferably nitric acid, and is dried below about 500 DEG  C., preferably 150--180 DEG  C.  The acetic acid reaction may be effected at 300--400 DEG  C. at 100--700 atmospheres pressure, the reaction mixture preferably containing 5--25 mols. carbon monoxide and about 4 mols. water to one mol. of methanol.  The catalyst may be made by slowly adding para ammonium tungstate to boiling dilute nitric acid while agitating, then filtering, or evaporating the liquid, and drying at 165--170 DEG  C.; or the para ammonium tungstate may be agitated with boiling water and concentrated nitric acid added, the precipitate being separated and dried at about 170 DEG  C.  The Specification as open to inspection under Sect. 91 includes the production of other aliphatic acids such as propionic and butyric acids from ethanol and propanol and alternative methods of preparing the catalyst in which a solution of para ammonium tungstate is treated with nitric acid.  The wet hydrated tungsten oxide may be mixed with promoters such as aluminium, beryllium, and bismuth nitrates; titanium, bismuth and beryllium nitrates; and copper and beryllium nitrates, the mixtures being then dried and heated as before.  This subject-matter does not appear in the Specification as accepted.  Reference has been directed by the Comptroller to Specification 400,189.ALSO:For the production of acetic acid from carbon monoxide and methanol in presence of hydrated tungsten oxide which is maintained in the hydrated state by means of water vapour present in the reaction mixture, as described in the parent Specification, the tungsten oxide is prepared from a solid tungstate such as para ammonium tungstate and an aqueous acid such as nitric acid, and is dried below about 500 DEG  C., preferably 150--180 DEG C.  The catalyst may be made by slowly adding para ammonium tungstate to boiling dilute nitric acid while agitating, then filtering, or evaporating the liquid, and drying at 165--170 DEG  C.; or the para ammonium tungstate may be agitated with boiling water and concentrated nitric acid added, the precipitate being separated and dried at about 170 DEG  C.  The Specification as open to inspection under Sect. 91 includes alternative methods of preparing the catalyst in which a solution of para ammonium tungstate is treated with nitric acid.  The wet hydrated tungsten oxide may be mixed with promoters such as aluminium, beryllium and bismuth nitrates; titanium, bismuth, and beryllium nitrates; and copper and beryllium nitrates, the mixtures being then dried and heated as before.  This subject-matter does not appear in the Specification as accepted.  Reference has been directed by the Comptroller to Specification 400,189.