FIELD: chemistry.
SUBSTANCE: invention relates to improved combined methods of producing acetic acid and vinyl acetate involving the following steps: (a) obtaining a first stream of product from the first reaction zone containing acetic acid, where the acetic acid is obtained via an exothermic carbonylation reaction, and where at least part of the heat obtained from the acetic acid is tapped from the first reaction zone and at least part of the heat tapped during production of acetic acid is transferred to a heat exchange system; (b) bringing the reaction stream of acetic acid containing at least a portion of acetic acid from the first stream of product into contact an oxygen-containing gas in a second reaction zone in the presence of a catalyst to obtain a second stream of product which contains vinyl acetate monomer; (c) directing at least a portion of the second stream of product to purification section for purification of at least a portion of vinyl acetate in the second stream of product; and either (d) tapping at least part of heat transferred to the heat exchange system, and delivering at least part of the heat tapped from the heat exchange system to at least one reaction stream of acetic acid and the vinyl acetate purification section, and where the heat exchange system contains a stream of a steam condensate, and where at least part of the heat tapped during production of acetic acid is delivered to the stream of steam condensate which is used to provide at least one reaction stream of acetic acid and the vinyl acetate purification section with heat tapped during production of acetic acid, where the stream of steam condensate containing heat from production of acetic acid is directed to a low-pressure evaporation vessel kept at pressure between 4.0 kg/cm2 and 5.3 kg/cm2, or (d) tapping at least part of the heat transferred to the heat exchange system, and delivering at least part of heat tapped from the heat exchange system to at least one reaction stream of acetic acid and the vinyl acetate purification section, in which a loop is used to cycle the condensate in order to remove most of the heat from production of acetic acid by directing a stream of a hot reaction solution through the heat exchanger for transferring heat to the stream of steam condensate, where the stream of steam condensate which contains heat from production of acetic acid is directed to the low-pressure evaporation vessel kept at pressure between 4.0 kg/cm2 and 5.3 kg/cm2.
EFFECT: proposed methods are useful for lowering expenses and reducing power consumption during vinyl acetate production.
10 cl, 1 dwg
