A Small World

By Beth Wittbrodt

From fuel cells to nanotechnology, Professor Dimitri Gidaspow has built a distinguished career through innovative work at the particle level.

A Small World
Professor Dimitri Gidaspow next to a fluidized bed in his lab in Perlstein Hall

Professor Dimitri Gidaspow is an IIT institution. His work as both a researcher and a lifelong teacher has made him one of the most well-remembered and well-loved faculty members at the university. IIT even awarded him its highest honor: the title of “Distinguished Professor.” The university only elevates to this rank those professors who have achieved preeminence in their field of expertise and who have amassed a record of service to the university. Of the nearly 600 instructors on campus, there are only eight active distinguished professors.

Gidaspow has left his mark on IIT, not only in his exhaustive research but through the students he’s mentored. His research and teaching spans some of the most critical areas of chemical engineering, including transport phenomena, fluidization, heat transfer, computational techniques, and thermodynamics. Over his years at IIT, Gidaspow has registered for nine patents and authored more than 170 publications. He has served as the principal advisor to more than 50 Ph.D. students, not to mention the hundreds, even thousands, of undergraduate and graduate students who have made their way through his classroom over the past 40 years. And in 2005, he was awarded the IIT/Sigma Xi Research Award in the senior faculty division (only one award is given annually in three divisions: senior faculty, junior faculty, and graduate student).

“I think we created a new science.” - Professor Dimitri Gidaspow

From Just a Year to Half a Century

A native of the Ukraine, Gidaspow studied in Germany before coming to the United States in 1949 at the age of 15. He attended Seward Park High School in New York, graduating at the top of his class. He earned a bachelors degree in chemical engineering from City College of New York in 1956 and spent two years as a teaching assistant at Polytechnic Institute of Brooklyn.

Gidaspow came to IIT in 1958 as a work-study student at the Institute of Gas Technology (IGT), which was then affiliated with IIT and allowed its students and employees to complete degrees there. He studied under the famed Ralph Peck, and when the latter went on sabbatical, Gidaspow took over Peck’s thermodynamics class. Little did he know then that he would become a part of IIT for nearly half a century. In fact, when Peck offered him the teaching job, he responded, “Fine. But chances are I won’t be in Chicago for long—maybe one year.”

That one year turned into decades. Gidaspow enjoyed teaching, and although he returned to IGT (after passing up unprecedented offers from DuPont and NASA), he continued to teach night classes to students from both institutions. He also joined one of his former students, Bernie Baker, on pioneering fuel cell research supported by a multimillion dollar grant from United Technologies Corporation. For his work on fuel cells, Gidaspow received two patents and was recognized by NASA with an award from the Marshall Space Flight Center. But in the spirit of a great teacher, Gidaspow says that “the best opportunity at IGT was advising good Ph.D. students and cooperating with Bernie Baker.”

Gidaspow officially returned to IIT’s Department of Chemical Engineering in 1977 and has taught here ever since. “The students have not changed much in 50 years,” says Gidaspow. “But computers have revolutionized engineering. A half a century ago, doing a Ph.D. thesis meant doing lab work, a lot of it useless for an engineer. Today, students have to acquire computer skills that are immediately useful on their first job.”

Flow and Turbulence

Understanding Gidaspow’s research is challenging for the layperson, in part because it is a blend of applied science and fundamental research. It is extraordinarily significant, however, for its potential impact on myriad fields. His work falls under the rubric of computational fluid dynamics, which involves using computer modeling to study the physical behavior of fluids, including calculating their properties, such as density, velocity, temperature, and pressure. His specialization is the mixing of gases and solids, particularly in the fields of energy and coal gasification, though his most fundamental research could ultimately be used in applications as diverse as achieving a better understanding of blood flow or creating safer nuclear reactors.

Gidaspow’s most famous work is on multiphase flow and fluidization, a processing technique used in the chemical, petroleum, pharmaceutical, and power generation industries. To understand Gidaspow’s research, it is necessary to understand the practical use of fluidization. A fluidized bed is used to suspend solid particles by passing a stream of air through them, thus setting them in motion. This tumbling action works like a bubbling liquid and produces more effective heat transfer and chemical reactions. The technology is extremely flexible and therefore popular; it evolved from efforts to develop cleaner combustion processes, which had the potential to yield fewer pollution emissions. For example, in the coal industry, fluidized bed combustion results in a decreased number of sulfur emissions.

The design of industrial-scale fluidized beds remains challenging, and this is where Gidaspow’s work on computational fluid dynamics comes into play. He uses a computer to simulate the behavior of particles in order to relate their behavior to certain process and geometric variables. Gidaspow employed a kinetic theory-based particle image velocity method to illustrate that there are two kinds of turbulence in fluidization: random oscillations of individual particles and turbulence caused by the motion of clusters of particles—a theory that revolutionized the field.

Cleaning Up Coal Technology

Funding for Gidaspow’s area of research eventually decreased, an occurrence familiar to scientists who rely in large part on external grant agencies, such as the National Science Foundation, whose research dollar allocation priorities may change more rapidly than it takes to satisfactorily finish research. However, thanks in part to Gidaspow’s former Ph.D. student Madhava Syamlal (M.S. CHE ’81), now a government employee at the Department of Energy (DOE), and U.S. Secretary of Energy Samuel Bodman, Gidaspow’s research is experiencing a renaissance. One of the areas most affected by fluidization technology is the coal industry. Gidaspow recently received a grant from the DOE to work on the FutureGen project, a $1 billion government initiative aimed at creating the first zero-emissions fossil fuel plant-the cleanest fossil-fuel-fired power plant in the world.

Gidaspow will be experimenting with sequestering coal to make hydrogen. All fuels consist of carbon and hydrogen, and coal has a high content of both. When coal is burned, it emits CO2, which adds to global warming (thus its reputation as a dirty fuel). By reacting coal with oxygen, however, CO2 can be separated out, thus preventing ozone depletion and creating a highly desirable, clean fuel in the form of hydrogen. The process sounds simple, but according to Gidaspow, “If you gasify coal with oxygen, you’re going to get huge bubbles inside. No one is going to build a reactor like that, with oxygen bubbles going out. It’s not safe.”

Tapping into Nanotech

And that’s where nanotechnology comes in. Nanosize particles don’t have any bubbles at all, which makes them ideal, and they flow in a unique way. Naturally, fluidization presents a whole new series of challenges on the nanolevel. As the size of particles decreases, fluidization becomes more difficult because the nanoparticles seem to stick together, forming large agglomerates. Gidaspow and Armour College of Engineering Dean Hamid Arastoopour have partnered with New Jersey Institute of Technology on a project to improve nanoparticle fluidization. Gidaspow theorizes that nanoparticles collide with the molecules and oscillate, and therefore the undesirable bubbles don’t form. He is currently working to come up with a mathematical description of nanoparticles using silica particles.

A High Water Mark

According to Gidaspow, his greatest career milestone came in 1985 at the Heat Transfer Conference, where he received the Donald Q. Kern Award for his energy conversion research relating to fuel cells and air conditioning: “I presented my then-current research on the hydrodynamics of fluidization and heat transfer. The lecture hall in Denver was packed. The editor of Applied Mechanics Reviews asked me to publish in their journal, and the American Society of Mechanical Engineers asked me to write a book.”

That book, Multiphase Flow and Fluidization: Continuum and Kinetic Theory Descriptions, appeared in 1994. Groundbreaking in the field when it was published, it remains the seminal text on the subject today and is used in classrooms all over the world. “I think we created a new science,” says Gidaspow.