(84a) Eliminating Difficult Start Ups with State Based Controls | AIChE

(84a) Eliminating Difficult Start Ups with State Based Controls

Authors 

Beebe, D. - Presenter, ProSys, Inc.
Huggins, J. - Presenter, Dow Chemical


Some processes are just difficult to start up. Every year, significant production is lost due to start up delays, product quality issues after startup, mistakes or gaps in operator expertise and other reasons. In fact, the U.S. Chemical Safety Board has estimated that the total loss due to operator error is $10B per year. In addition, because 70% of process incidents occur during start-up and shutdowns, safety can also be positively impacted by automating the process start-up.

 Process start-ups can be completely automated and places the operator in supervisory mode approving the continuation of the process at specific intervals. The automation of start-up allows every start up to be exactly the same, no matter which operator is at the controls. The automation eliminates potential errors and overshoots which preserves the integrity of the startup and eliminates most recycle, purges, safety trips and lost production.

 Using state based controls has cut average start-up time by a substantial amount, some as much as 50% or more. This is accomplished by streamlining the process and using the logic tools for automation. Automated start-up improves profitability and enhances flexibility of the process. Project ROI estimates show that the project typically pays for itself in about 3 months.