Research captures first place at biofuels conference

By Patrick Young

Crymble (left) shows his castor oil research to a biofuels conference attendee before
taking first place in the poster competition

Scott Crymble is not one of those people who can be categorized under any certain label. The Mississippi State University (MSU) graduate student, who is often mistaken for being in his early teens, loves video games and sleeping in, but he also has taken interest in the alternative energy field. Crymble was approached by his advisor Rafael Hernandez to begin a master's project looking at making biodiesel out of castor oil. More than two years later, Crymble's work was rewarded with a first place showing at the 2009 MSU Biofuels Conference. Though castor oil may not be economical in the U.S., it could be a profitable venture for Central and South American nations. The castor seed, normally used to light lamps, contains more than 50 to 55 percent oil, according to Crymble.

"The major fatty acid component of castor oil is ricinoleic acid, which comprises 90% of the fatty acids present in castor oil," Crymble said."Ricinoleic acid is a monounsaturated, 18-carbon fatty acid with a hydroxyl functional group at C-12. This hydroxyl group causes castor oil to be highly polar, simplifying the mixing of the oil with methanol for the biodiesel reaction." Crymble began his research by examining the varying concentrations and temperatures of the catalysts used to trigger the creation of biodiesel.

"I used sodium methoxide which is slightly different than what most people would use," Crymble said."By using the sodium methoxide, I eliminated any excess water and have only the wanted product."

Next, Crymble examined how the castor oil and the catalyst would react under temperature."I looked at the methoxide at room temperature and then increased it to its boiling point. Then I tried varying up the weight percents of the catalyst to anywhere from .5 to 1.5 percent." After taking samples every hour of the reaction, Crymble was able to create a profile of the concentration of biodiesel versus time. With each passing hour, the amount of bio-diesel increased until he obtained the optimal value of conversion.

"The maximum reaction conversion of 0.9964 was achieved at a temperature of 3 0°C, catalyst weight percent of 0.5%, and a molar ratio of methanol to oil of 9:1," he said."The reaction rate constants associated with the reactions that consume triglycerides, diglycerides, and monoglycerides were 0.3206, 0.7506, and 1.3873, respectively."

But Crymble didn't stop there with his research. He also wanted to make sure that the biodiesel he created would match standards set by the American Society of Testing and Materials (ASTM).

"Biodiesel must meet criteria in order for it to be put into cars," Crymble said."I had to look at the viscosity, droplet size and the flash point, which makes sure all methanol is removed from the product."

With the exception of the value for kinematic viscosity, all of the test results met specifications. In the future, Crymble said this project may evolve into work for his thesis. Also on his agenda will be looking at the size and cost of the reactors needed to produce large qualities of castor oil into biodiesel.

Upon graduating, he intends on remaining in the biofuels field."Alternative fuels research is an up-and-coming field that is growing by the day in importance and need," he said."I hope to one day find a job in this field, and this project has definitely opened that possibility for me."

In the meantime, Crymble said he plans on enjoying the money he won from the competition.

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