Ramesh Agarwal, the William Palm Professor of Engineering in the Department of Mechanical Engineering & Materials Science, has an excitement in his voice when he talks about the possibilities of CO2 capture during combusting of coal. His work on the emerging energy-efficient chemical looping combustion technology, with support from the Consortium for Clean Coal Utilization, still has as many questions as answers — but his passion for this area of research pushes him forward.
Focusing on simulation and optimization of chemical looping combustion (CLC), Agarwal draws from his more than 35 years of experience in computational fluid dynamics applications in areas such as aerodynamics, energy efficient buildings and bio-fluid dynamics.
“In this work, I am looking at both gaseous fuel and coal,” he says. “The amount of CO2 generated and the amount of energy generated depends on the type of coal (bituminous, anthracite or lignite, for example). And when you’re looking at the amount of coal being combusted, it is important to ask what is the optimal amount of air required, along with the optimal amount of a particular oxygen carrier for maximum energy output. Figuring this out is important for design of CLC-based power plants.”
He reflects that the selection of the type of oxygen carrier is critical in this work.
“I am trying to find out the maximum possible energy output from the coal with the optimal amount of air supplied,” he says, “and I want to know the amount of a particular type of oxygen carrier that will be required for greater reactivity. It is also important from a cost consideration.”
Agarwal explains that CO2 is a commodity. After coal is combusted, he says, the CO2 that is generated can be used for many applications, such as enhanced oil and gas recovery from depleted reservoirs and for generating geothermal energy — just to name a few. He is also presently working on techno-economic models to specifically quantify the cost of CLC-based power plants and the cost/benefit analysis when it comes to utilization of the CO2.
“Many people don’t realize how you can sell CO2 for different applications,” he says.
Carbon storage is also a huge part of his focus.
“In optimizing CO2 storage in saline aquifers, the idea here is to take CO2 and inject it underneath the ground,” says Agarwal, who previously was the chair of the aerospace engineering department and executive director of the National Institute for Aviation Research at Wichita State University and had high level managerial positions at McDonnell Douglas Research Laboratories. The ultimate goal of his work is to maximize storage and reduce CO2 plume migration in saline aquifers using an optimization algorithm. The optimization code created has been combined with a U.S. Department of Energy multi-phase flow solver and applied to various CO2 injection strategies.
Agarwal says he believes his passion for this work relates to his interest in fluid flow and heat transfer — the areas that have seen his career delve into many projects, ranging from hypersonic space vehicles to the study of medical devices.
“I can say that my focus on chemical looping has been on energy optimization and no one, to my knowledge, has focused on this,” he says. “But it’s really that I feel confident about my work in any application where fluid flow and heat transfer are involved, whether it’s about energy or the human body. If we keep asking the right questions, we can understand all of these subjects better and accelerate innovation.”