Hydrodeoxygenation of Microalgae Oil in a Microreactor

Removal of residual oxygen from long chain lipids via hydrodeoxygenation (HDO) will produce a liquid fuel comprising mostly straight chain alkanes, which mimics diesel. Green diesel is chemically similar to petroleum-derived diesel, and it can be used in existing internal combustion engines without any modification. Microalgae has been favored as a feedstock for green diesel, on account of its high acylglycerols contents and faster growth rate than terrestrial oil crops. Moreover, HDO, a process that uses high pressure hydrogen to remove oxygen is CO₂ neutral.

In the present work, sulfided NiMo/Al₂O₃ catalyst was evaluated for HDO with the aim of converting algae oil to diesel-like hydrocarbons. Microreactor was used due to its advantages compared to conventional reactors. These advantages include: 1) enhanced mass and heat transfer, 2) less energy consumption, 3) faster and cost-saving screening of materials and process, 4) easier scale-up, and 5) improved safety. Changes in the hydrogen consumption and the product composition as a function of operating conditions: reaction temperature, hydrogen partial pressure, residence time were determined quantitatively by GC-TCD and FID.

This work will provide baseline data which will guide future work on the HDO of algae oil.