Process for producing formaldehyde
AssigneeSumitomo Chemical Company, Limited
InventorsMasakazu Sagou, Hideyo Fujii
Life of this patent
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Abstract
Formaldehyde is prepared by dehydrogenating methanol in the substantial absence of oxygen and in the presence of a catalyst which is a zinc-silicon complex oxide obtained by mixing a solution containing a zinc salt of an inorganic or organic acid with a solution containing an inorganic silicate compound, or by adding urea to a solution containing a zinc salt of an inorganic or organic acid and an organic silicate compound, until a precipitate is formed, and subsequently baking the precipitate at at least 500.degree. C.
Claims18
A process for producing formaldehyde comprising:
- dehydrogenating methanol in the substantial absence of oxygen wherein the dehydrogenation is performed in the presence of a catalyst which is a zinc-silicon complex oxide obtained by
- (A) either (i) mixing a solution containing a zinc salt of an inorganic or organic acid with a solution containing an inorganic silicate compound, or (ii) adding urea to a solution containing a zinc salt of an inorganic or organic acid and an organic silicate compound until a precipitate is formed;
- and
- (B) subsequently baking the precipitate at a temperature of at least 500.degree. C.
The process for producing high-purity formaldehyde consisting essentially of:
- dehydrogenating methanol in a flowing gas reaction system in the substantial absence of oxygen in the presence of a zinc-silicon complex oxide obtained by:
- (A) mixing a solution containing (a) a zinc carboxylate or a zinc salt of an inorganic acid with (b) a solution containing an inorganic silicate compound selected from the group consisting of sodium silicate, potassium silicate, and ammonium silicate;
- and
- (B) subsequently baking the thus obtained precipitate at a temperature of from least 500.degree. C. to about 1200.degree. C.
- wherein
- said catalyst contains 5-75 Wt. % zinc and an amount of silicon such that the atomic ratio of silicon/zinc is 1:10 to 10:1,
- the feed rate of methanol to said catalyst is about 0.1 to 10 kg/hr per kg of said catalyst, and
- the catalyst is in a layer at a temperature of about 450.degree. C. to about 650.degree. C.
The process of producing high-purity formaldehyde consisting essentially of:
- dehydrogenating methanol in a flowing gas reaction system in the substantial absence of oxygen in the presence of a zinc-silicon complex oxide obtained by:
- (A) adding a selected amount of urea in the range of 1-20 mol per urea per mol of zinc of a solution obtained by mixing (a) a zinc carboxylate or a zinc salt of an inorganic acid with (b) a solution containing an organic silicate compound represented by the formula:
- ##STR4## wherein said formula R.sup.1, R.sup.2, R.sup.3, and R.sup.4 independently represent alkyl, alkenyl, alkynyl, aryl, aralkyl or organic carbonyl and n is an integer from 1 to 10, whereby a precipitate is obtained;
- and
- (B) subsequently baking the thus obtained precipitate at a temperature of from least about 500.degree. C. to about 1200.degree. C. wherein
- said catalyst contains 5-75 wt. % zinc and an amount of silicon such that the atomic ratio of silicon/zinc is 1:10 to 10:1,
- the feed of methanol to said catalyst is at a rate of about 0.1 to 10 kg/hr per kg catalyst, and
- the catalyst is in a layer at a temperature of about 450.degree. C. to about 650.degree. C.
Dependencies are inferred from the claim text.