Abstract: The invention concerns a process for reducing and/or removing sour gases, such as carbon dioxide and hydrogen sulfide, from natural gas or from gas associated with oil reservoirs, by means of the formation of mixed hydrates, wherein a selective separation is carried out both during the hydrates decomposition, under pressure conditions close to atmospheric pressure and temperatures little below zero, and, preferably, during a preliminary step, with pressures and temperatures close to the equilibrium values.

Abstract: A bituminous mixture having improved physical properties is obtained by adding to a bitumen a polyphosphoric acid (I) containing phosphorus, calculated as P.sub.2 O.sub.5, in amount from 80% to 87% by weight, and a polymer composition (II) comprising (A) a propylene homopolymer or copolymer, (B) optionally an ethylene copolymer fraction insoluble in xylene at ambient temperature and (C) a copolymer fraction soluble in xylene at ambient temperature.

Abstract: A mixture containing bitumen and a polymer composition, characterized in that the polymer composition comprises:A) 10-40 parts by weight of an isotactic propylene homopolymer, or a random copolymer of propylene with ethylene and/or a C.sub.4 -C.sub.10 .alpha.-olefin;B) 0-20 parts by weight of a copolymer fraction containing ethylene, which is insoluble in xylene at ambient temperature;C) 50-80 parts by weight of a copolymer fraction of ethylene with propylene and/or C.sub.4 -C.sub.10 .alpha.-olefin, said copolymer fraction being soluble in xylene at ambient temperature and having an intrinsic viscosity greater than 1.5 and up to 2.2 dl/g and having 20 to 45 wt. % ethylene.