An evaporation / condensation

Device (10) evaporation / condensation comprising: a condenser (12); supply means (14) gas from the condenser (12) adapted to supply the condenser (12) with a gas (G1) at a first temperature (T1); and feeding means (16) liquid in the condenser (12) adapted for supplying the condenser (12) with a liquid (L1) to a second temperature (T2) lower than the first temperature (T1), the condenser (12 ) being adapted to direct contacting the gas (G1) and the liquid (L1) so as to condense the gas (G1), characterized in that it comprises: an evaporator (42); supply means (44) in the evaporator of gas (42) adapted to feed the evaporator (42) with a gas (G2) at a third temperature (T3); and supply means (46) liquid from the evaporator (42) adapted to feed the evaporator (42) with a liquid (L2) at a fourth temperature (T4) higher than the third temperature (T3), the evaporator (42) being adapted to direct contact gas (G2) and liquid (L2) so as to evaporate the liquid (L2), and the feed means (14) gas from the condenser (12) being formed by the evaporator (42).