CLE AIChE February 2025 Newsletter Diamond Shamrock Battleground Plant Start-Up with FORTRAN Simulation

Very few of us can remember those stone age days of chemical engineering before there were fax and Xerox machines, PC’s, cell phones, email, the internet and even Word, Excel and PowerPoint. Yet it was back in those very days of 1973 when two intrepid Chem E’s attempted to create a relatively sophisticated dynamic simulation for an extremely complex chemical plant essentially from scratch using Fortran IV. The plant was Diamond Shamrock’s new steam fired quadruple effect caustic evaporation plant (with a fifth flash effect) called Battleground in LaPorte, Texas. Steam flowed 1-2-3-4-flash, but the liquor flowed 1-3-4-2-flash with a centrifuge to remove precipitated salt at the second effect. There were PI level controllers on the 4 effects, a flow controller on the steam, and a PID concentration controller on the flash effect. To our knowledge, no one had ever designed such a plant before back then, much less operated one. Would its operation be stable? Would it really produce the desired product—a 50% aqueous caustic solution from aqueous “cell liquor” containing about 10% caustic and 10% salt? Could it even be started? Exactly how? Diamond was rolling the multimillion $ dice on this plant, and we were to be the guarantors of a favorable roll. The only two tools available for answering these questions were an IBM System/360 model 44 mainframe and Roger Franks’ textbook Modeling and Simulation in Chemical Engineering. There were no other suitable “canned” software packages available for use at the time. The IBM mainframe lived up well to its middle name but was clumsy at best and often problematic for engineering use. Franks’ textbook contained rudimentary software for numerical integration, convergence, stream mixing or splitting, etc., which guided our initial efforts but often failed from the stresses caused by the plant’s complexity. The talk to be given by Bob Fowler and Don Harvey goes into some detail about the nature of the problem and goes into the history of how the available tools were employed in an attempt to answer those nagging questions posed by the new and complex chemical plant.