CC-99-142 DISTINGUISHING ON-LINE OPTIMIZATION BENEFITS FROM THOSE OF ADVANCED CONTROLS: A CASE STUDY

Description:

When a refinery processing unit has both modern multivariable predictive constraint controls (MPCC) and on-line optimization installed, how should the incremental economic benefits due to the optimizer be calculated? This is a long-standing question in the advanced control field. CITGO has a successful implementation of both MPCC and on-line optimization on an FCCU at their Corpus Christi refinery. In this paper, the methodology used to estimate incremental benefits for the optimizer is presented. Actual unit data is used to illustrate the results of the methodology. A second question has been “How important is it to use a more rigorous non-linear model of the process for optimization as opposed to a simpler linear one?” Data from this case study also provides some insight into this issue.