I found an interesting page about the ORC technology from the KCORG, and particularly about history of the ORC technology : ORC machine existed before even W. M. Rankine himself
While William M. Rankine (Scotland) developed a theory of the steam engine in 1859, engines using alcohol or ether as working fluid were designed as early as 1825/1826 (Thomas Howard). However leak rate and market price of the working fluid did not allow a full development of the technology for economical reasons.
It is worth also to mention the Du Trembley initiative in 1850, with a cascading steam/ether engine for ships. Du Trembley, an engineer from Lyon in France, developed its solution for ships on the Rhône river, reducing by more than 2 the specific consumption of the engine ! Invention was called « procédé à « vapeur combinées » », allowing to reach a better expansion in 2 stages with 2 fluids :
- first stage with steam at 6 bar
- second stage with ether vapor at 2 bar (vaporized at 60°C and condensed at 20°C)
It is worth to note that multiple stages expansion with saturated steam was not technically possible, and available steam boiler were not designed with superheaters.
While it is said that production of such motors was interrupted in 1856 due to an explosion in Bahia of such ship (1), but others authors (2) mention that explosion happened for other reasons, and that the production and use of the technology kept being used for navigation the following decades.
(1) Closed Power Cycles: Thermodynamic Fundamentals and Applications, by Costante Mario Invernizzi, page 119
(2) Vapeurs sur le Rhône, Jean-Marc Combe, Bernard Escudié, Jacques Payen, Presses Universitaires Lyon, 1991
note : Picturesare from (2) Vapeurs sur le Rhône, Jean-Marc Combe, Bernard Escudié, Jacques Payen, Presses Universitaires Lyon, 1991.