Chemistry Projects

Projects are subject to change without advance notice.

Title:  Enzymatic Sulfur Reduction with Potential Applications to Diesel Fuels

Introduction:  Beginning in 2006, the Environmental Protection Agency (EPA) began implementing more stringent regulations for diesel fuels.  The new requirements are that diesel should contain no more than 15 ppm sulfur, a drastic reduction from the 5000 ppm of sulfur found in diesel prior to regulation.  Although many methods exist for removing sulfur from diesel, they are all chemical in nature and have potentially harmful side products. This project will attempt to use a water soluble, sulfur-reducing, enzyme in diesel-like solvents.

Methodology:  Students in this project will use microbiology and biochemistry techniques to clone, overexpress, and purify the enzyme coenzyme A persulfide reductase from the organism Pyrococcus horikoshii.  Due to the organism’s tolerance for high temperatures, this enzyme is not only stable but also rather robust and a good target for sulfur reduction in diesel.

Once purified, the group will test the enzyme’s activity on sulfur compounds dissolved in various diesel like solvents and ultimately on a diesel sample.  The project will determine an optimal enzyme concentration for sulfur reduction, the optimal solvent for this enzyme as it cannot be used in water-based buffers, and the level of activity in diesel-like solvents at varying sulfur concentrations.