Process for preparing acrylic acid from ethylene oxide and carbon monoxide

摘要

A process for preparing acrylic acid from ethylene oxide and carbon monoxide, in which ethylene oxide is carbonylated in an aprotic solvent with carbon monoxide in the presence of a cobalt catalyst system to give poly-3-hydroxypropionate, the cobalt content in the poly-3-hydroxypropionate formed is reduced with the aid of water and/or an aqueous solution as a precipitation and/or wash liquid, and the poly-3-hydroxypropionate is subsequently split by thermolysis to give acrylic acid.

主权项

1. A process for preparing acrylic acid from ethylene oxide and carbon monoxide, the process comprising:
converting by carbonylating ethylene oxide dissolved in an aprotic solvent with carbon monoxide at elevated pressure and elevated temperature in the presence of a catalyst system comprising a cobalt source in a reaction zone A to obtain a product mixture A comprising poly-3-hydroxypropionate, removing poly-3-hydroxypropionate from the product mixture A in a separation zone A, and thermolyzing poly-3-hydroxypropionate removed in separation zone A in a thermolysis zone A to form acrylic acid, wherein the removing comprises at least one of: adding water, an aqueous solution, or both, as an aqueous precipitation liquid to a portion of product mixture A, to a total amount of product mixture A, or both, in order to precipitate poly-3-hydroxypropionate presently dissolved in the portion of product mixture A or in the total amount of product mixture A; or washing poly-3-hydroxypropionate removed from product mixture A in separation zone A with water, with an aqueous solution, or both, as an aqueous wash liquid.