Invensys Simsci-Esscor Simulator Helps Refinery to Meet EPA Regulations

Invensys Process Systems and Silver Eagle Refining Inc, a petroleum refiner located in Utah, have successfully applied simulation software in meeting upcoming Environmental Protection Agency (EPA) Mobile Source Air Toxics (MSAT) requirements for benzene emissions.

PRO/II software, SimSci-Esscor's steady-state simulator, helps meet the new requirements by applying the RATEFRAC methodology to achieve accurate and realistic column design. The RATEFRAC module in the PRO/II software is a rigorous rate-based distillation model that is used in applications where the approach to equilibrium is limited by heat and mass transfer rates. RATEFRAC allows for simulation of all types of multistage vapor-liquid columns. Through the use of a mass transfer methodology PRO/II with RATEFRAC determines both a bulk and interface composition and determines height equivalent to theoretical plate (HETP) ratios in the packing and performance of trayed sections from the column configuration.

"The new EPA regulations are prompting refiners to rethink their processes and in doing so, they are finding that advanced simulation and modeling software can help them comply with regulations cost-effectively, while improving also their operating efficiency. By offering powerful RATEFRAC column sizing functionality within our PRO/II simulation and modeling software, we provide an integrated solution that is not available from any other single supplier," said Joseph McMullen, PRO/II product manager for Invensys.

"We modeled our future benzene isomerization and saturation units ourselves, using SimSci-Esscor PRO/II software, but to be certain that we did it right, we contracted also with Invensys to perform the same analysis with the PRO/II software. I was deliberately cryptic in the beginning because I didn't want our results to skew theirs, but was comforted to see that they came up with similar results. The PRO/II software has definitely helped us verify that the changes we are making will meet the benzene regulations," said Silver Eagle Refining process engineer, Joe Brown.