Abstract: A process for the epoxidation of propene involves reacting propene with hydrogen peroxide, in the presence of a methanol solvent and a shaped titanium zeolite epoxidation catalyst in a fixed bed reactor. The process then involves recovering methanol from the reaction mixture, treatment of the recovered methanol by passing it through a bed of an acidic ion exchange resin, and recycling the treated methanol to the epoxidation reaction; as well as regeneration of the acidic ion exchange resin. Catalyst breakage can be reduced or avoided by washing the regenerated bed of an acidic ion exchange resin with methanol until the methanol exiting the resin bed has an apparent pH higher than 1.8, before methanol treated with the acidic ion exchange resin is recycled to the epoxidation reaction.

Abstract: The present invention relates to nucleic acids coding for promoters, which are both tapetum-specific and pollen-specific, as well as the use thereof for producing male sterile plants.