FEATURE — Winter 2003

Engineering 'Real Time' Reactions

At Aspen Technology, alumnus Peter Hanratty uses computer modeling to help chemical plants and refineries around the globe run more efficiently.

by David Linzee

Peter J. Hanratty's extraordinary mind ventures far out into the impalpable reaches of computer programming, and deep into the atomic complexity of chemical reactions. His two obsessions might seem remote from each other, and even farther from "real life," but Hanratty fuses them and puts them to very practical use. He creates computer models that help oil refineries (producers of gasoline to run our cars and oil to heat our homes) and chemical plants (manufacturers of plastics for our cars, toys, and packaging, and of fiber for our clothes and carpets) run more efficiently. He was one of the pioneers of this important and rapidly expanding field, called Real Time Optimization (RTO).

Hanratty's love of science was inherited. His father was a professor of chemical engineering at the University of Illinois at Urbana-Champaign. As a boy, Hanratty had a chemistry set, and he knew early on what he wanted to do. "The only wavering I did was between chemical engineering and physics," he jokes.

He discovered his other passion when he found the Illinois campus computer center. This was in the 1970s, when a computer wasn't a friendly little PC on the corner of a desk, but a mysterious bulky machine that took up an entire room. Unintimidated, Hanratty sat down at the keyboard and began to play. The computer games of the era did not hold his interest for long; by age 12, he had taught himself how to program computers.

While studying for his bachelor's degree at the University of Wisconsin-Madison, he decided the area of chemical engineering that most fascinated him was reaction engineering. He came to Washington University to pursue this interest, earning a master's degree in 1988 and a doctorate in 1991.

Reaction engineering, which is the science and mathematics to quantitatively describe and predict a chemical transformation, may sound dauntingly technical, but, Hanratty explains: "It's just taking one set of chemicals and converting it into another. You do it at home all the time." He uses baking a cake as an example. A cook combines the flour, sugar, and other ingredients and puts them into the oven. What comes out is very different and, Hanratty notes, a lot better tasting. A cook who wants to bake the best cake in the shortest time experiments, adding more sugar or less butter for a tastier result, or setting the oven at a higher temperature to see whether the cake bakes faster or burns on the outside.

Peter Hanratty, M.S.Ch.E. '88, D.Sc. '91, says that the best thing about being at the University was meeting his wife, Frieda Wang Hanratty, B.S.Ch.E. '84, M.S.Ch.E. '84, D.Sc. '92.

Hanratty asks himself analogous questions when he is trying to figure out the most efficient way for a refinery to turn oil into gasoline. First, his team members find out as much as possible about the plant. Next, they use that information to create a computer model. Then they take the model to the plant to verify how accurately it reflects the conversion process. This is tricky, because conditions are constantly changing. The age of the equipment in a particular plant affects how well it operates. The chemical properties of the oil going into the refinery vary from day to day. Shifts in the weather also affect the process. And there are a thousand other variables that the computer model has to take into account. Once the model is perfected, it can—to a considerable degree—run the plant.

"You don't need an engineer trying to figure these things out," Hanratty says. "It's automatic—24/7, the computer model is making decisions and implementing changes in the conversion process."

It might seem as if Hanratty sits in front of a computer all day, but that is not the case. As a director in global solutions at Aspen Technology, he travels from his Houston base to refineries and chemical plants all over the world. His greatest challenges do not arise from computers or chemicals—they arise from dealing with people. As a result, he has been exposed to a diverse set of business cultures. Dealing with people is a complex issue everywhere in the world. Varying company cultures and local customs make dealing with people on a worldwide basis even more challenging, he says. For example, in one company, two executives might meet to discuss a situation; in another company, 20 would meet, vying with each other to prove their savvy. In yet another company, a message has to pass through layers of intermediaries, possibly changing its substance slightly with each transmission. He has been tested all over the world on the local cuisine, Hanratty says. "They want to know if you'll eat, say, raw squid." His rule is that he'll try anything—providing his hosts eat some first.

Spending about half his time on the road, he has visited more than 15 countries, including Argentina, China, Finland, France, and Malaysia. He has also traveled widely in the United States. While some envy him, regarding his job as an endless vacation, Hanratty says wryly, "They don't tend to build oil refineries near resorts." In fact, he has spent a lot of time in remote, small towns. Yet his travels have impressed him with how the world is getting smaller. When he looks for a present for his wife and daughter, he says, he has a hard time finding anything anywhere that he can't get at home.

Aspen Technology has applied Real Time Optimization to more than 100 plants worldwide, yet the process is still relatively new. Around 1990 computer technology reached the point that made it feasible, and Hanratty, then a freshly minted D.Sc., played an integral role in its development. He sees unlimited potential for the field. "Companies are saving millions of dollars a year by running plants more efficiently," he says. "So far we've only scratched the surface."

As more plants apply RTO, they will have fewer maintenance problems, making them safer for workers. Consumers will see lower prices. The environment will benefit, too, because plants operating at peak efficiency produce less pollution and because companies getting higher productivity from their existing plants will not have to build new ones.
As more plants apply RTO, they will have fewer maintenance problems, making them safer for workers. Consumers will see lower prices. The environment will benefit, too, because plants operating at peak efficiency produce less pollution ...

In addition to RTO, Hanratty is interested in other areas of engineering, particularly reactor modeling. This application allows decision-makers to understand the chemical processes going on in their plants better and, therefore, operate their processes more effectively. Reactor modeling can transform many different pieces of information into a few valuable pieces of information. "These days, our problem is not too little information but too much," he notes.

Hanratty is married to Frieda Wang Hanratty, who earned her bachelor's, master's, and doctoral degrees in chemical engineering at Washington University. She, too, worked at Aspen but has recently left to spend more time with the couple's daughter, Monica, 7.

Looking back on his years at the University, Hanratty is particularly grateful to Professor Babu Joseph and Milorad P. Dudukovic, the Laura and William Jens Professor, chair of the Department of Chemical Engineering, and director of the Chemical Reaction Engineering Laboratory, because they helped Hanratty refine his ideas on the subject. Yet his time at the University wasn't only one of intellectual development. He made many friends, "and the best thing," he says, "was that I met Frieda."

David Linzee is a free-lance writer based in St. Louis, Missouri.