November 16, 2021
Staff Accomplishment

PNNL Bioenergy Team Releases Report on Path to Sustainable Aviation Fuel

Bioenergy experts identify critical areas, opportunities for bringing technology to aviation industry

Jet flying with white puffy clouds behind it

A workshop report outlines critical areas to be addressed and associated opportunities to accelerate the commercialization of a PNNL-developed technology for producing sustainable aviation fuel.

(Image by Pixabay |

A report has been published summarizing a workshop designed to accelerate the commercialization of hydrothermal liquefaction (HTL) technology for producing sustainable aviation fuel (SAF).

The report, “Hydrothermal Liquefaction: Path to Sustainable Aviation Fuel,” describes the results of the workshop led by bioenergy experts from Pacific Northwest National Laboratory (PNNL) on November 17–19, 2020.

The virtual workshop brought together more than 250 national and international experts in HTL and SAF to discuss the current state of the technology and identify research opportunities for commercializing this technology and making an impact on decarbonizing the aviation industry.

“What we found from our discussions is that there are four critical areas that must be addressed to deploy HTL more quickly to produce the sustainable aviation fuel,” said Karthi Ramasamy, the PNNL bioenergy expert who led the workshop. “In other words, it’s a call to action for the biofuels industry.”

This call to action includes the following:

  • Understanding and eliminating the scale-up risk for this technology and then demonstrating process stability over time in a scalable HTL reactor. Opportunities include producing large quantities of finished fuels that can then be used for fuel stability and jet engine testing, which is required to receive American Society for Testing and Materials (ASTM) approval for commercial aviation use.
  • Meeting stringent fuel quality specifications, including nitrogen levels, that achieve the aviation industry’s safety requirements. This includes demonstrating that the fuel can consistently meet ASTM specifications despite varying feedstock composition, such as algae, food waste, manure, sludge, and more.
  • Evaluating and integrating the process steps that help reduce overall capital costs of the system, including the use of heat in system operations that otherwise might raise energy costs.
  • Achieving balanced economic, social, and environmental sustainability that could be addressed through actions such as understanding how the supply chain can create jobs while mitigating environmental concerns related to waste feedstocks.

See the report for the full list of opportunities and discussion.

The workshop was sponsored by the Department of Energy’s Bioenergy Technologies Office (BETO). Besides Ramasamy, those responsible for the workshop and report include PNNL’s Michael Thorson and Corinne Drennan, former PNNL researchers Justin Billing and Jonathan Holladay, and BETO’s Beau Hoffman and Zia Haq.

Published: November 16, 2021