Carnot Efficiency Used to Demonstrate a Second Law Fault in Defining Limits on Heat Energy Conversion

A closed transcritical power cycle using an ethanol and 2-Naphthaldehyde solution as its working fluid provides a format for using Carnot efficiency to define conjectural second law limits on positive excess enthalpy of solution reactions and heat energy conversion. Changes in the solvent’s density with resultant changes in solubility between the closed cycle’s low and high temperatures establish an internal heat transfer where heat input near the cycle’s T2 to satisfy the excess enthalpy reaction is transferred by retrograde solubility to near the cycle’s T1 before it affects gas expansion. The effect of this heat transfer causes this closed cycle’s Q efficiency to exceed the Carnot T efficiency of its input heat.