I see several years ago the source code from the designers (Canadian people), I reccomend you read the book "chemical process computations" raghu raman and unifac from fredeslund book, an other book to undestand the distillation and some separation read the book "calcul sour ordenatieur des équilibres liquide-vapour et liquide-liquide" Henry renon, for reactors they use several technical publication from Canadian chemical eng, I hope this will be helpfull to you. best regards

about PRSK read the book "modeling vapor liquid equilibria" autor Hasan Orbey and Stanley I Sander Cambridge series