EERC produces jet fuel from coal/biomass feedstock

| June 08, 2011

If early fuel property tests are any indication of future success for the Energy & Environmental Research Center’s (EERC) work on a combined coal and biomass feedstock-based fuel, the future looks pretty good. Led by Ramesh Sharma, EERC research manager, the fuel has already been tested for thermal stability properties by a third party laboratory.

For Ted Aulich, senior research manager at EERC, the thermal stability qualifications are necessary if the fuel is to be used for one of its main purposes, jet fuel. Thermal stability is important he said, because the fuel needs to withstand very high temperature exposures that will be occur for a long period of time. “In a lot of cases,” he said, “especially in military jets, the jet fuel itself is utilized as a way to take heat away from the parts of the aircraft that get hot,” which he added, means the fuel acts as a heat exchange liquid. “If the fuel is not stable, what can happen at those high temperatures is polymerization, or gum forming,” he also said. That formation of gum can hinder the flow properties of the fuel.

The process to produce the fuel is based on the combination of coal with other waste oils, waste grease, grasses, algae biomass, algal oil and a number of other feedstocks. “It coprocesses these together using liquefaction and gives you a distillate fuel,” Sharma said, “and then we developed a unique scheme to upgrade that fuel into a fuel for the aviation industry.”

That scheme, which follows a liquefaction process of 450 degree Celsius and roughly 2,000 PSI, is similar to hydroprocessing, and after distillation, the resulting liquid can be made into renewable gasoline, diesel or other biobased chemicals, Aulich said. To this point, the research team has used three different feedstocks in combination with the coal, including soy oil, algae oil and one from petroleum rejects. The plan is to expand to several other feedstocks. When the process is intended for aviation fuel, Sharma said, the coal portion of the fuel will be roughly 60 percent while the biomass used will make up the other 40.

Although the fuel has been verified and already met the qualifications of many of the ASTM tests for jet fuel, Aulich and Sharma both said the next step will be to test the fuel in a turbine, an engine and at a soon to be running pilot facility at EERC. “Based on the fuel properties you can make a lot of pretty valid assumptions about how the fuel will perform,” Aulich said, “but people will always want to see how the fuel will perform once you put it in an engine or a turbine.” The testing is expected to run for the next year and will take place at the pilot facility after roughly six months.