Coal as a Zero Pollutant Fuel Source

A team at the EMS Energy Institute is working with Aerojet Rocketdyne in an endeavor to use coal as a zero pollutant fuel source. The project, funded by a grant from the Department of Energy, employs the oxy-fuel combustion process.

Sarma Pisupati, professor, energy and mineral engineering, said one aspect of the research involves burning coal with oxygen instead of air. The goal is to produce a pure stream of carbon dioxide (CO₂) that can be captured and sequestered into the ground.

“I’ve been working in the combustion area the past 25 years so that’s one part of it because that is what we need as a country and as a world,” Pisupati said. “Where we can capture CO₂ and put it back into the ground, otherwise the CO₂ levels are skyrocketing in the atmosphere.”

For the other facet of the project, Aditi Khadilkar, a graduate student, said they are using different types of limestone to capture another pollutant: sulfur dioxide (SO₂). She said they are trying to use a fluidized-bed reactor under high-pressure conditions and optimize the process so that the limestone in the reactor can capture the maximum amount of SO₂.

For the first phase of the project the team examined the feasibility and possible gaps in research. Currently they are in phase two, Pisupati said, where they are developing a database for Aerojet to test at a larger scale.

Pisupati said that managing the environment in which coal burns has been a difficulty. “In just a pure oxygen environment the sulfur dioxide and the amounts of moisture are highly corrosive,” Pisupati said. The challenge is figure out how to handle the sulfur without damaging the materials of construction.

Additionally, while coal is typically burned at atmospheric pressure, for this project they are revving up tests to a higher pressure to examine the effect of pressure on combustion and emissions. There are many exciting things that happen at high pressure, Pisupati said, which the team has discovered in the course of research.

Pisupati said Penn State has been involved with this type of work at atmospheric pressure in the past and this partnership with Aerojet Rocketdyne is an extension of that.

Pisupati said creating a clean and cost effective way to utilize coal is an exciting prospect. It would be comparable to other renewable fuels if the team can produce the right conditions and find a way to put the CO₂ back into the ground.