Project Synopsis

Provide a process design for a distillation train to produce ethanol, from a waste sugar fermentation facility, that was height restricted and had solids materials in the feed stream.

Project Summary


Process Engineering Associates, LLC (PROCESS) was contracted by the client, a technology provider, to provide process design and engineering services for a distillation train to produce ethanol from a waste sugar fermentation facility.  Specifically, PROCESS was contracted to design the distillation column and associated condenser, reboiler, and feed interchanger.  The distillation column was to be designed to produce 95% ethanol from a feed stream containing 10-15% ethanol, along with yeast and sugar.  The column is intended for use in skid mounted packaged plants, and is subject to size limitations.

PROCESS‘ licensed commercial computer process simulation software, CHEMCAD, was used to develop a design for the column.  Sensitivity analyses were performed to identify the optimal feed location, reflux ratio, and the required number of stages to achieve the process goals within the allowable size envelope.  Additional analyses were performed to check the performance over the wide range of feed compositions, as well as at different feed temperatures and distillate temperatures.

Initial size constraints, desired purity, and ethanol recovery requirements dictated the use of two columns in series.  Further work identified a solution that would achieve the process goals in a single column with only a modest increase in height.  This solution includes high efficiency structured packing above the feed point and fouling-resistant trays below the feed.

PROCESS used CHEMCAD to develop a complete mass and energy balance for the new distillation train.  From this design information, a Process Flow Diagram (PFD) and a control strategy were developed.

Equipment duty specifications were prepared for the main equipment items associated with the process.  Preliminary duty specifications were prepared for the distillation column, condenser, reboiler, feed interchanger, and reflux pot.

The operating conditions and equipment limitations determined in the study were summarized in a letter report submitted to the client.

Industry Type

  • Ethanol Fuels
  • Alternative Energy

Utilized Skills

  • Ethanol purification process knowledge
  • Dirty feed distillation systems design
  • Height restricted distillation column design

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