Project Synopsis

Carboxylic acids production system refining and stripping capacity expansion study, i.e. evaluate expected additional refining capacity needed versus available equipment, equipment service allocation, and unit on-line time.

Project Summary


The client owns and operates a major chemical manufacturing facility that produces many organic specialty and non-specialty chemical products.  Process Engineering Associates, LLC (PROCESS) was contracted by the client to lead a carboxylic acids production system refining and stripping capacity expansion study project.  More specifically, PROCESS was asked to evaluate the expected additional capacity needed in the refining and stripping area versus available equipment, equipment service allocation, and unit on-line time.

PROCESS completed the following tasks in support of the capacity expansion study and design:

  • Determined column and tray specifications from drawings and by working with client plant engineers which included determining the condition of trays due to corrosion and changes made in the plant that had not been made on drawings
  • Modified Aspen models of each refining and stripping service provided by the client to accurately represent specific columns and produce hydraulic data to be used for tray ratings
  • Rated the column trays using vendor software (including Sultray, KG Tower, FRI Device Rating Program, and client-developed software) to verify if the client-specified maximum feed capacity of the columns in their current services was accurate and determined the feed capacity at 80% and 100% flood to predict the actual column capacities
  • Rated several columns for services that they are not currently used for to determine if required product specifications could be met by switching services to different columns in an effort to free up other columns so that they could be used more efficiently in another service
  • Produced heat curves from the Aspen models of each refining and stripping service for the client to use to rate the existing heat exchangers to determine their capacities
  • Produced a preliminary design of a new column with increased capacity to be used in at least two services in which the design was hampered by significant height constraints
  • Determined that an addition to an existing column so that two higher grade products could be produced in this column would require a more in-depth study into the kinetics of the reaction in the column and extensive plant data so that a more accurate model could be developed
  • Prepared a final report summarizing findings, including a spreadsheet showing the capacity of the refining and stripping columns in various services and a basic design for a new column with a capital estimate which will allow the client to make a decision on how to meet the projected capacity requirements with the optimum combination of capital cost, risk, and operational changes.

Overall, a total of 24 column rating packages were completed.  Each package included column descriptions, modeling information, column mass and energy balances, liquid and vapor stage compositions, and vendor tray rating software summaries.  Some packages included rating a set of up to four columns which are used together to achieve a particular product specification.

Industry Type

  • Chemical Manufacturing

Utilized Skills

  • Chemical distillation and stripping tower design
  • Tower modeling using Aspen
  • Existing equipment evaluation

Contact Us