Continuous biodiesel production from multiple source feedstocks using zirconia catalyst

Biodiesel is a renewable petroleum diesel substitute whose use can improve air quality and help combat global warming. We propose to test the feasibility of using a novel and innovative process to synthesize biodiesel that could change the economics and commercial practices of the biodiesel industry. Our research will evaluate the feasibility of using a novel, highly efficient heterogeneous zirconia-based catalyst in a continuous flow packed-bed reactor for synthesizing biodiesel from a variety of feedstocks. The surface chemistry of zirconia is dominated by Lewis acid-base chemistry, which will allow for the controlled adsorption of acid or base moieties that can be used for catalysis of both esterification and transesterification reactions. In this research, both base, acid and unmodified forms of zirconium dioxide will be evaluated at elevated temperature and pressure for efficient, continuous transesterification of triglycerides (TGs) and esterification of free fatty acids. Phase I research will test the capability of this catalyst to produce biodiesel using a variety of feedstocks (i.e. soybean oil, algae oil, yellow grease, beef tallow and acidulated soapstock) without significant catalyst deterioration over extended periods of use. Furthermore, we will purposefully foul the catalyst with dirty feedstocks and evaluate if the catalyst can be regenerated by pyrolysis of adsorbed organic matter in order to restore its original catalytic activity. If successful, we believe this research will overcome the most significant limitations currently experienced by the biodiesel industry, namely the difficulty in using inexpensive feedstocks that contain high levels of free fatty acids, the necessity to continuously add catalyst to the reaction (in either batch or semi-continuous production modes), resulting in the need to dispose of waste products harmful to the environment and eliminating the need for extensive washing of the biodiesel with water. If successful the proposed fixed bed catalysts should stimulate use of inexpensive feedstocks, thereby lowering the cost of biodiesel production significantly. In summary, a successful phase I project will demonstrate the feasibility of using zirconia at elevated temperature and pressure to change the economics of biodiesel production and expand its role as a renewable, environmentally friendly energy source.