Purdue doctoral students, from left, Indraneel Sircar, Brent Rankin, Rohan Gejji, and Anup Sane. (Purdue University/Mark Simons)
Purdue University researchers have developed a facility aimed at learning precisely how coal and biomass are broken down in reactors called gasifiers as part of a project to strengthen the scientific foundations of the synthetic fuel economy.

"A major focus is to be able to produce a significant quantity of synthetic fuel for the U.S. air transportation system and to reduce our dependence on petroleum oil for transportation," said Jay Gore, the Reilly University Chair Professor of Combustion Engineering at Purdue.

The research is part of work to develop a system for generating large quantities of synthetic fuel from agricultural wastes, other biomass, or coal that would be turned into a gas using steam and then converted into a liquid fuel. Other aims are to learn how to generate less carbon dioxide than conventional synthetic-fuel processing methods, while increasing the yield of liquid fuel by adding hydrogen into the coal-and-biomass-processing reactor.

The researchers are using the facility to learn how coal and biomass "gasify" when exposed to steam under high pressure in order to improve the efficiency of the gasification process. Findings published last year showed carbon dioxide might be reduced by 40 percent using the technique.

Synthetic fuels currently are being blended with petroleum fuels for performance improvement in automobile and aircraft applications. However, new techniques are needed to reduce the cost and improve the efficiency of making the fuels.

The 2-meter-tall stainless steel reactor is part of a system that borrows technology from aerospace applications, including a "spark igniter" used in space shuttle engines. Materials inside the spark igniter may briefly reach temperatures of up to 3,000 degrees Celsius.

The researchers also integrated an advanced optical diagnostics system: A laser is transmitted through a window in the stainless steel vessel, passing through the gases being processed inside. An optical sensor on the other side of the vessel decodes the light to determine the precise temperature and composition of the gases.

"It's a modular design, so the optical diagnostics part can be moved to various points to analyze how the gasification proceeds," said Robert Lucht, the Ralph and Bettye Bailey Professor of Combustion in Mechanical Engineering.

Mechanical engineering doctoral students Anup Sane, Indraneel Sircar, Rohan Gejji and Brent Rankin also designed a special feeder to transport the coal or biomass into the reactor vessel.

(Purdue University)