They found that the bulk chemistry of the deoxygenation and isomerization was not strongly affected by bleaching, as post-isomerization products with cloud points less than −10 °C and boiling ranges within or close to specification for No. 2 diesel fuel were obtained through 10 h time on stream with or without bleaching.

Lipids extracted from algal biomass have potential to be a major feedstock source for production of biofuels, but process-relevant data on refining crude algal lipids to hydrocarbon fuels is scarce. Techno-economic analyses (TEA) have demonstrated that algal biomass cost is the largest single factor affecting process economics, but the cost of hexane for lipid extraction and hydrogen for deoxygenation are the second and third largest operating costs, respectively. Thus, there is considerable motivation to gain a greater understanding of the unit operations required for refining algal lipids, which have different chemistry than either conventional crude oils or terrestrial animal or plant lipids. Generally, these operations can be categorized into oil cleanup, deoxygenation (DO), and hydroisomerization (HI).

—Kruger et al.

Overall, they found that crude hexane extracts from dilute acid-pretreated algae can be converted to a diesel blendstock in overall yields approaching 60%.

Resources

• Jacob S Kruger, Earl D. Christensen, Tao Dong, Stefanie Van Wychen, Gina M. Fioroni, Philip T. Pienkos, and Robert L. McCormick (2017) “Bleaching and Hydroprocessing of Algal Biomass-derived Lipids to Produce Renewable Diesel Fuel” Energy Fuels doi: 10.1021/acs.energyfuels.7b01867