Method of converting thermal energy into mechanical energy and an apparatus therefor

The invention relates to a method of converting thermal energy into mechanical energy wherein a working liquid such as is evaporated to generate a stream of a working fluid. According to the invention, the stream of the working fluid is a stream of pressurized distillate produced by evaporation and condensation using a direct contact membrane distillation (DCMD) unit, said stream of pressurized distillate having a pressure of at least one bar, and a converter such as a turbine is used for generating mechanical energy from said stream of said pressurized distillate. The invention also relates to an apparatus for performing the method.