Most awesome! You've found the Excel spreadsheets used in almost every book example. The analysis of equilibrium stage separation processes usually involves coupled, non-linear, algebraic equations: material and energy balances, phase equilibrium relationships, and miscellaneous process specifications. These can be tedious if not impossible to solve by hand. Fortunately, the Excel Solver tool uses efficient iterative methods to solve fairly complex problems. Please download these simulations and modify to your heart's delight! If you totally mess up a spreadsheet, you can always come back here and download it again.