Preparation of acrolein, useful for preparing acrylic acid, comprises introducing aqueous glycerin phase into acrolein reaction zone to obtain aqueous acrolein reaction phase and recycling acrolein free acrolein reaction phase

摘要

Preparation of acrolein comprises introducing an aqueous glycerin phase into an acrolein reaction zone to obtain an aqueous acrolein reaction phase, removing the acrolein from the acrolein reaction phase and recycling the acrolein free acrolein reaction phase into the acrolein reaction zone. Independent claims are included for: (1) a method for the preparation of acrylic acid comprising introducing an aqueous glycerin phase into an acrolein reaction zone to obtain an aqueous acrolein reaction phase, removing the acrolein from the acrolein reaction phase, recycling the acrolein free acrolein reaction phase into the acrolein reaction zone and oxidizing the acrolein to acrylic acid in the gas phase using gas phase catalyst; (2) a dehydration and oxidation device comprising a dehydration unit (2) containing an educt feed, an acrolein reaction zone (5) and pressure control valve (6), gas-phase oxidation unit (3) at the bottom of the dehydration unit and depletion unit (7) at the bottom of the pressure control valve, where the depletion unit is fluidically connected to the oxidation unit, which contains a reactor (8) containing multi-oxide catalyst and a processing unit (10); (3) a method for the preparation of water-absorbing polymer comprising allocating a partially neutralized acrylic acid and a monomer phase containing a crosslinking agent, radically polymerizing the monomer phase using a hydraulic gel, optionally breaking the hydraulic gel, drying the gel to obtain a particulate water-absorbing polymer, grinding the polymer, post cross-linking the polymer and contacting the polymer with a coating agent; (4) the water-absorbing polymer obtained using the above process; (5) a group comprising the water-absorbing polymer and a substrate; (6) a method for the preparation of the group comprising contacting the water-absorbing polymer and substrate; (7) a composite obtained by the preparation of the group; and (8) a sanitary article comprising a lower layer, intermediate layer, an upper layer and the water-absorbing polymer.