Project Synopsis

Evaluate an existing demonstration scale distillation system containing solids in the feed stream and recommend changes that would eliminate capacity bottlenecks.

Project Summary


The client has developed a process to produce a new biodegradable superabsorbent for agricultural and landscaping applications.  The client has been operating a large pilot/small production plant for a number of years while proving their process and seeking funding for a large expansion.  Process Engineering Associates, LLC (PROCESS) was contracted by the client in a separate project to assist in designing the new full-scale process.  As part of this design effort, PROCESS was to base the new process design on data and knowledge gained from the client’s pilot plant operation.  One major problem in the pilot plant was a capacity limitation/bottleneck at the methanol solvent recovery distillation column.  PROCESS was contracted, via this project, to evaluate the existing distillation system and recommend changes that would eliminate the capacity bottleneck.

PROCESS performed the following tasks in support of this project:

  • Operated the client’s existing distillation system while on site in order to inspect the system, collect data, and understand the system more thoroughly.
  • Modeled the client’s existing methanol recovery column, column internals, and attendant heat exchangers using PROCESS' commercial computer process simulation software, CHEMCAD, in order to identify potential upgrades to eliminate process bottlenecks.
  • Modeled the existing column with new trays and packing parameters to predict the operating limits of the distillation column with new internals designed to eliminate problems with fouling and capacity limitations.
  • Developed a test procedure for the client to follow in changing out the existing packing (entire column) for larger sizes, running the column on a trial period while collecting operating data, and then proceeding to another packing size and/or type in order to test theories about packing fouling and bottlenecking due to solids entry into the column.
  • Modeled and designed new heat exchangers necessary for operating the existing column with new internals at full capacity.
  • Evaluated the existing column bottoms pump for operation at the new column capacity and found the existing pump acceptable.
  • Prepared equipment specifications and datasheets for the following:
    • New column internals including upper packing section and lower tray section
    • New distillation column Reboiler, Feed/Bottoms Interchanger, and Overhead Condenser
    • New Reboiler steam flow (column bottoms temperature) control valve
    • New column top pressure control valve (via control of liquid level in vertical Condenser).
  • Worked with column internals, heat exchanger, and control valve vendors to specify and obtain price quotes for specific internals, exchangers, and control valves best suited for this application.
  • Identified potential automatic backwashing tubular filter technology that could be used to minimize, if not eliminate, the problems caused by process solids fouling the column internals.
  • Worked with a reputable filter vendor to specify and obtain price quotes for a suitable automatic backwashing tubular filter system for this application.
  • Developed a test procedure for the client to follow in installing, operating, testing, and collecting data to determine the efficacy of an automatic backwashing filter system on the column feed stream.
  • Provided new column internals specifications, heat exchanger TEMA sheets, control valve datasheets, automatic backwashing tubular filter datasheet, as well as vendor specifications and price quotes in a technical report to the client.  This report also included recommendations on how to install and operate the new equipment.

Subsequent to the submittal of this distillation system revamp and optimization report, the client decided to purchase used equipment including heat exchangers and filter system.  To this end, PROCESS executed the following project tasks:

  • Assisted the client, and their detail engineering and fabrication firms, by evaluating the potential (used) heat exchangers for operability in this distillation system.  PROCESS recommended changes to the heat exchangers (baffling, etc.) that would improve the operability of the used exchangers in this service.
  • Assisted the client in defining the necessary steps to take to refurbish the used automatic backwashing filter system that was purchased.
  • Once the newly acquired (used) equipment was installed (minus the filter system) and operated unsatisfactorily for a short period of time, PROCESS assisted the client in troubleshooting the revamped system by modeling the column and heat exchangers to determine potential capacity limitations (e.g., the packing had not been changed to the PROCESS-specified type and size).

Industry Type

  • Agricultural Chemicals

Utilized Skills

  • Process troubleshooting
  • Distillation design with feed stream solids
  • Process debottlenecking
  • Process revamp/upgrade project assistance
  • Patience

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