(21e) Gas Concentration Absorber/Stripper Benchmarking leads to Optimization and Training Opportunity

Across the Marathon system there are thirty Absorber/Stripper systems spread over sixteen sites. The Absorber/Stripper systems are associated with FCC, Coker and Saturate Gas Plants. The design and operation of each unit is unique but the overall objectives and problems are similar.

A benchmarking of the FCC Absorber/Strippers were conducted using simple metrics such as Liquid/Vapor ratios, operating pressures and stage counts. The more complicated principles around water management turn out to be the overlapping difference between comparable system.

Operating curves for every FCC Absorber/Stripper system were generated and compared against units with similar designs. Process modeling was used to show how changes in controllable variables could improve performance. Typically the largest deltas in performance were explained by differences in water management.

The overall benefits from the benchmarking were associated with training, optimization and a project strategy. The clear differences in performance and water management provided an opportunity to train engineers. The monitoring of water removal and design of water removal equipment were a key training opportunities with process engineers. The operating curves provided key information around maximum/minimum constraints. This could be feedback into economic evaluations and daily optimization. The long-term improvement strategy was enhanced with improve knowledge around design and constraints.