(132c) Jet Fuels From Algal Oil

Due to concerns with limited resources of petroleum-based fuels, the demand for using renewable feedstock, such as vegetable oils and animal fats, to produce hydrocarbon fuels has increased. Algae is one such feedstock that is currently being investigated as a superior source of triglyceride oils. However, conventional biodiesel is unsuitable for aviation use, a major consumer of fossil fuels. The methyl esters that comprise biodiesel fail to meet several important jet fuel specifications, including freeze point and energy density, leading to an unacceptable risk of fuel-induced engine failure during flight.

New process technologies are needed to efficiently convert these oils into the complete spectrum of transportation fuels, including jet fuel. To date, most efforts along this line have relied on hydrocracking to remove oxygen and generate the desired paraffinic species. However, these technologies suffer from excessive chain cracking and decarbonylation of the feedstock, and therefore consume significantly more hydrogen and oil than is necessary.

A new process will be presented that steps far beyond traditional biodiesel synthesis to convert next-generation energy sources like algal oil, into aviation fuel that meets or exceeds all current performance specifications. The process utilizes a sequence of catalytic reactions to selectively transform triglyceride oils and free fatty acids into long-chain isoparaffins ideal for jet fuel. The refined process chemistry consumes less than one-third of the hydrogen of conventional hydrocracking and produces none of the undesired light paraffins or naphtha-range compounds due its high selectivity and mild conditions.

Several important aspects of the process technology will be discussed, including chemical methods to prevent loss of feedstock carbon due to decarbonylation and the results of efforts to make such technologies self-sufficient through the internal production of hydrogen.