Thermal Kinetics has developed a modification of the standard two bed (and three bed) molecular sieve ethanol dehydration system used throughout the fuel ethanol industry.

This patent covers a number of features including reversing the flow of 190 proof feed vapor such that the beds can be depressurized, regenerated, and re-pressurized more quickly allowing more effective use of the beds. Also the beds are regenerated to higher vacuum levels with an enhanced 200 proof sweep cycle.

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Key Elements

  • Adsorption can be operated at lower pressure. Piloting has been conducted as low as 18 PSIA.
  • Lower operating pressure and more effective regeneration from this process increases ethanol yield and reduces the amount of regenerate solution recycled to distillation.
  • Protection against bed lift because downward depressurization allows faster regeneration and provides bed lift protection.
  • Better interface with distillation through reduced regenerate recycle and a steadier more constant regenerate return flow rate.
  • Better bed regeneration due to lower regeneration pressure and modified purge sequence improves bed drying, increases 200 proof yield, and increases bed drying capacity.
  • Lower operating costs since lower vaporization temperature can allow for use of waste heat and reduced boiler steam in some plants.