ARBOK-LLS: Surface-Controlled Separation of Water-Ethanol Mixtures Beyond the Azeotrope

Ethanol and water form an azeotrope at about 96% ethanol, so distillation alone cannot go further. Anhydrous alcohol (99.5% and above) is therefore produced by an extra dehydration stage, which adds equipment and energy to every liter. This preprint describes ARBOK-LLS, a non-equilibrium, surface-controlled separation of water-ethanol mixtures. A thermally expanded graphite powder (TEGA) in a special activated form is placed on the free surface of the mixture and driven by pulsed electromagnetic radiation. Only ethanol evaporates from the powder surface; the bulk liquid warms by no more than 5-7 °C and water does not undergo a phase change. The process runs at atmospheric pressure without columns, membranes, vacuum or chemical additives. Reported performance: ethanol purity 99.8-99.99%, water carryover below 0.05%, selectivity above 100:1 for feeds from 5 to 96% vol, and a specific energy of 1.5-2.5 MJ per liter of absolute ethanol against 4.5-6.5 MJ for classical rectification with dehydration, a reduction of 2-3 times. We place these figures against the structure of the anhydrous ethanol market, in which fuel use dominates by volume and pharmaceutical and electronic use by purity requirements. Keywords: ethanol dehydration; azeotrope; anhydrous ethanol; thermally expanded graphite; TEGA; energy efficiency; separation