METHOD FOR PREPARING GLYOXAL-CONTAINING PRODUCTS Russian patent published in 2008 - IPC C07C47/127 C07C47/19 C07C47/04 C07C45/38 

FIELD: chemical technology.

SUBSTANCE: invention relates to a method for continuous synthesis of glyoxal-containing products of the desired concentration in a single-step technological cycle. Method involves vapor-phase catalytic process of partial oxidative dehydrogenation of ethylene glycol with oxygen diluted with steam and nitrogen in the mole ratio from 1/6.5 to 1/13.0 at temperature 400-700°C on carrier Ag-contacts and massive Ag-catalysts made of materials of electrolytic origin of particles size 0.1-4.0 mm. Then the process involves continuous the vat-less separation of vapor-gaseous oxidate for liquid fractions and gaseous phase wherein prepared aqueous aldehyde solutions contain 4-40% of glyoxal, 6.2% of glycolic aldehyde, not above, 4.6% of formaldehyde, not above, 4.0% of ethylene glycol, not above, at the total acidity index 2%. The end product comprises 39.8% of glyoxal, 5.5% of glycolic aldehyde and 0.4% of formaldehyde. The process of continuous the vat-less separation of synthesis products for glyoxal-containing liquid fractions and depleted gaseous phase is carried out continuously in the range of temperature 10-400°C as result of subcontact cooling in combination with three-step combined condensation of components of vapor-gaseous oxidate in a cascade block-unit in fractional isolation of liquid and gaseous products of synthesis, and in regulation of heat regimen of the combined condensation and change of the ratio of liquid fractions.

EFFECT: improved method of synthesis.

1 dwg, 13 ex