Abstract: The invention relates to a process for the purification of ethanol wherein a dividing wall column is used. In particular, the invention relates to a process for the purification of a feed stream comprising ethanol and impurities such as higher alcohols. The invention further relates to the use of dividing wall in distillation column in an ethanol purification process.

Abstract: The invention relates to a process for the purification of ethanol wherein a dividing wall column is used. In particular, the invention relates to a process for the purification of a feed stream comprising ethanol and impurities such as higher alcohols. The invention further relates to the use of dividing wall in distillation column in an ethanol purification process.

Abstract: A method for the preparation of urea in a reactor using ammonia and carbon dioxide as starting materials, includes a) bringing the ammonia and carbon dioxide into contact in the reactor under conditions for the formation of carbamate; and b) decomposing the carbamate thus formed to give urea and water. The water formed during step b) is removed from the reaction mixture by a water-selective membrane which is preferably a pervaporation membrane, such as a porous ceramic membrane. Furthermore, a pressure difference is preferably maintained or applied over the selective membrane. The method can in particular be carried out in liquid circulating stream which, in addition to the reactants fed to the circulating stream and the carbamate formed in step a), also contains at least some of the water formed in step b) and also the urea formed in step b), the urea being recovered from the circulating stream and the circulating stream being recycled to the reactor.

Abstract: Mass transfer process, in which, in at least two contact stages, and at least two liquid or gaseous phases are brought into contact with one another, at least one component being transferred between the phases and the phases moving countercurrently. The flow through at least one of the contact stages is batchwise for one phase and continuous for another phase. The phases flow through contact stages which are formed by trays in a column, which trays are opened periodically so that the phase which flows through the column in a batchwise manner flows to the next tray.