The methanol distillation section
Water and by-products are removed from the raw methanol in the distillation section, which is most commonly designed for production of methanol conforming to American Federal Grade AA.
Methanol distillation lay-out
The conventional layout is a two-column system with a stabiliser for dissolved gases and light by-products and a concentration column separating methanol and water.
The Topsoe system features a split concentration column and an optional ethanol column so as to operate the first column at lower pressure, allowing the overhead condenser duty of the second column to be reused as reboiler duty for the first column. This solution leads to savings in the overall energy consumption.
Low energy consumption and operational stability are the key issues to be considered.