Origins of PD-PLUS

The following is some background on how PD-PLUS came to exist. It is the work of R. A. Russell, and actually is his second simulator. His first was an in-house simulator he developed from 1968-1990 for what was then the Badger Company, in Cambridge, Massachusetts. The program was used by their various offices for nearly all of their process modeling. As time progressed, some use was made of other simulators to provide additional capabilities or to satisfy client requests.

Work on what eventually became PD-PLUS began in 1983. That effort was not a rewrite of the earlier program developed for and owned by Badger, but a completely new program, written independently of that company. The initial result was a PC-based distillation program called "Professional Distillation," first brought to market in 1985. It was the first PC-based distillation program to use the "inside-out" class of convergence algorithm and featured a method developed and published by the author. It gave users a level of flexibility, speed and robustness not seen before in a distillation program.

By 1988, work on the flowsheeting structure had been completed, the column block and physical property options of the distillation program had been ported to the new structure, and the initial set of other unit operations had been added. Whereas many users of the distillation program had been referring to it simply as "PD," the flowsheeting tool was given the name PD-PLUS (officially the "PD-PLUS Chemical Process Simulator"). Since then, additional capabilities have been added, to address the needs of a wider range of users.

In 2001, yielding to the obvious movement by Microsoft away from DOS-based applications, work began on recompiling the program with a Windows-based compiler, replacing the launch menu with a formal Windows menu window, and integrating all of the parts into a single executable. By mid-2002, this effort was completed, tested, and released.

In 1993, shortly before Badger was absorbed into what became Raytheon Engineers & Constructors (and in 2000 "Washington Group International," a merger with what formerly was Morrison-Knudsen), Badger began using PD-PLUS as a replacement for the older simulator for nearly all of the modeling work done by the Process Department in Cambridge and its other offices. Several years later, Badger was acquired by Stone & Webster, part of The Shaw Group. PD-PLUS remains in use at Cambridge today for the great bulk of the simulation load, involving large models of processes for such things as ethylbenzene, styrene, cumene, oleochemicals, lube oil, and other petrochemical products. Throughout the world, the number of other PD-PLUS licensees of the program went over the 100 mark years ago.