Project Synopsis

Process evaluation of a SO2 absorber to improve performance and reduce operating costs.

Project Summary


The client owns and operates a specialty chemicals production facility that includes a process used to recover waste sulfur in the form of ammonium bisulfite (ABS).  The recovery system primary unit operation is an absorption tower that reacts SO2 with ammonia to form the ABS.  Process Engineering Associates, LLC (PROCESS) was subcontracted by a major architectural and engineering firm to perform a process evaluation of the SO2 absorber in an effort to improve its performance and reduce its associated operating costs.  Specifically, PROCESS was requested to:

  • Perform independent hydraulic calculations for the absorber to determine expected pressure drops at the current operating conditions
  • Determine if the current absorber operating parameters were conducive for producing quality ABS product and for efficient, cost-effective operation of the system.

Using absorber design drawings and information supplied by the client, PROCESS developed a tower pressure drop computer program for the purpose of determining system pressure drops at current operating conditions.  PROCESS concluded, based on the calculation results, that the column was operating in a much higher than expected pressure drop range.

Based on the results of the pressure drop calculations as well as a review of overall system operation, PROCESS developed several process and operational improvement recommendations.  These recommendations were instrumental to a modified absorption system design that resulted in an absorber that currently operates in a much more efficient and cost-effective manner than did the original system.

Industry Type

  • Chemical Manufacturing

Utilized Skills

  • Tower hydraulics
  • Operating cost minimization
  • Process optimization