Abstract: The present invention concerns a contact module (10) operating with three fluids, air, coolant fluid and desiccant solution, with hydrophobic tubular membranes for the dehumidification and/or cooling of process air, said contact module comprising plurality of conduits (1) for the refrigerant fluid, in particular typically frigorific evaporating fluid, the contact module being characterized in that:—the space between said plurality of conduits (1) is substantially filled with a plurality of capillary pipes (2) in hydrophobic micro-porous membrane whose lumen is suitable to be crossed by and whose main extension direction is perpendicular to said plurality of conduits (1);—on the two opposite surfaces of the contact module at the ends of said plurality of capillary pipes, one or more closing material layers, in particular of hardening resin, are disposed, for incorporating the end parts of said plurality of capillary pipes and sealing the thus created space between said plurality of capillary pipes, said space

Abstract: A process for the recovery of ammonia contained in a gaseous purging stream produced in a synthesis process of urea.

Abstract: The present invention relates to a process for the recovery of ammonia contained in a gaseous purging stream produced in a synthesis process of urea, comprising the following phases: a) subjecting the gaseous purging stream to a washing with an aqueous acidic solution, at a pH ranging from 1 to 6, with the formation of a first purified gaseous stream and an aqueous solution containing an ammonium salt; b) subjecting the aqueous solution containing the ammonium salt coming from phase a) to stripping, after treatment with a strong base, at a temperature ranging from 50 to 250° C.

Abstract: Asymmetric membranes for osmosis and ultrafiltration are prepared from fluorinated polymers which are dissolved in one or more solvents, cast on a plate, allowed to evaporate and precipitated with a nonsolvent. The polymeric material can variously be modified by chemical reactions, irradiations or both. By varying the chemical and physical parameters of the preparation run, a variety of membranes can be obtained which have the most varied performances and properties.