Ethanol is flammable. ORCs use non-flammable fluids for safety reasons. While alcohols do have very high specific and latent heats, the risk is not worth it and there are a variety of more attractive fluids. There are even incentives available for using some, like NOVEC. I have supplied the design calculations and also performed tests on several ORCs around the world. I discuss many of these things in my book, Azeotropes https://www.amazon.com/dp/B084HKJTDZ The software and examples in the book are free. I have attached a spreadsheet with lots of properties and a few cycles. I have more free stuff if you're interested. ORCs is an important and timely topic to study, as these can be used to recover what is now waste heat from a variety of sources.