(583fb) Understanding the Gas-Phase Epoxidation of Propene With Hydrogen Peroxide Vapor

The production of propylene
oxide (PO) with aqueous hydrogen peroxide over TS-1 is an efficient and clean process
where water is the only by-product. If the H₂O₂ is
generated in situ in a plasma reactor, no solvent is required and the peroxide
obtained has high purity. After the plasma, the produced vapor peroxide can
react directly with propene, avoiding intermediate capturing steps and resulting
in a simple integrated process. On the other hand, working with hydrogen
peroxide vapor is a challenging task, due to its fast decomposition into oxygen
and water. In this project the gas-phase epoxidation of propylene was studied
in a packed bed reactor, analyzing the main factors involved.

The complications encountered when
working at high temperatures with H₂O₂ vapor are evaluated
and solutions are proposed. Factors like the equipment materials used, as well
as the presence of a catalyst were identified as very relevant to the matter.
However, besides the high tendency of hydrogen peroxide to decompose, we could
demonstrate that the epoxidation of propene is fast enough so that propene
oxide is obtained with productivity values of up to 12 kg_PO·kg_cat^-1·h^-1,
which are higher than the minimum required for industrial implementation. Selectivities
of hydrogen peroxide and propene to PO of 40% and close to 90% respectively
have been obtained.

In our presentation we will
describe the effects of the process parameters on the reaction and make a
comparison with other direct epoxidation routes.