Ethanol dehydration: reactor + separator written as one custom block

Bio-ethanol to ethylene (C2H5OH -> C2H4 + H2O), the route behind bio-based polyethylene, modeled as a single user-written custom block with two named inlets and two named outlets. The ethanol vapour feed and a dilution-water feed enter on the feed and water ports; the block's own equations convert 80% of the ethanol (xi = 0.8 * (feed.n_ethanol + water.n_ethanol)), send the ethylene and 10% of the water overhead on gas, and the condensed water with the unreacted ethanol out on liquid — a reactor and its quench separator in one model, which no fixed unit op is. Each outlet is flashed through Peng-Robinson at the temperature the model sets (330 K), and the block reports its mass balance: one mole of ethanol makes two moles of product, so moles are not conserved, but mass is, to round-off (46.07 = 28.05 + 18.02 g/mol). Edit the stoichiometry so it makes twice the ethylene and the block warns that the model creates mass. Notes: the 80% conversion and the 10%/5% overhead splits are stated by the model, not computed from kinetics or vapour-liquid equilibrium — this is a custom model a user writes when they have their own correlation, and it is exactly as good as that correlation.