Biocrude Oil from Algal Biomass | SRI International

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researcher analyzing biocrude oil

Biocrude Oil from Algal Biomass

An SRI-led team is improving a new two-step process for the production of transportation fuels from microalgae.

Biocrude oil obtained from hydrothermal liquefaction (HTL) of algae can be an energy-efficient replacement for the fossil crude oil normally used in the production of fuels. HTL is a high-pressure, high–temperature process that allows scientists to mimic, in a matter of minutes, the natural geological processes considered responsible for the production of fossil fuels. HTL does not require drying of the algal biomass (an energy-consuming step) and enables conversion of full algae cells to fuels. However, crude oils from traditional HTL processes have a high content of nitrogen-rich aromatic heteroatoms—a major hurdle in the upgrading of crude oil to fuels using existing refinery infrastructures.

To address this challenge, researchers in SRI’s Chemistry and Materials Laboratory are improving a novel process that separates the nitrogen-rich compounds that come from proteins. The resulting side stream can be recycled back into the algae production process, as indicated by our experimental data. The nitrogen removal process reduces the amount of aromatic heterocycles in the biocrude oil, which can help meet environmental requirements and extend the lifetime of catalysts used during the upgrading to fuels.

The SRI-led team is conducting this work for the Department of Energy’s Carbon Hydrogen and Separations Efficiency (CHASE) program. We are studying chemical pathways in the hydrothermal process, analyzing products, evaluating upgrading potential of biocrude oils, executing continuous operation tests, studying scale-up, and carrying out lifecycle analysis. After in-depth evaluation of the different scenarios, we will select operating conditions that optimize carbon and energy efficiencies while maintaining product composition within industrial specifications.

Acknowledgment/Disclaimer: This material is based upon work supported by the Department of Energy, Office of Energy Efficiency and Renewable Energy (EERE), under Award Number DE-EE0000635/0000. This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness or any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United Stated Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.