Wet wastes such as food waste and biomass present a valuable opportunity for producing sustainable aviation fuel (SAF). These wastes contain triglycerides that can convert into biocrude through hydrothermal liquefaction (HTL), making them promising feedstocks for greener fuels.
Challenges in Meeting SAF Fuel Standards
However, SAF precursors must satisfy stringent criteria based on conventional fuels like Jet A. In particular, they require complete oxygen removal to prevent jet engine corrosion and must achieve a higher heating value (HHV) close to Jet A. Unfortunately, no biocrude derived from HTL has met all these standards to date.
Innovative Use of Mo2C Nanocatalysts for Biocrude Upgrading
To address this challenge, researchers from the Center for Advanced Bioenergy and Bioproducts Innovation (CABBI) investigated the use of zeolite-supported molybdenum carbide (Mo2C) nanocatalysts. According to Science X Daily, these nanocatalysts effectively upgrade wet waste-derived biocrudes into SAF precursors that meet all essential criteria for the first time.
Methodology: Generating and Testing Mo2C Nanocatalysts
The team generated Mo2C nanocatalysts in the gas phase and dispersed them onto zeolite supports. They then tested the catalysts’ ability to remove oxygen from biocrudes and used them to upgrade wet waste-derived biocrude via HTL. The upgraded biocrudes underwent thorough characterization against Federal Aviation Administration (FAA) specifications.
Promising Results in Fuel Quality and Catalyst Reusability
The results demonstrated complete oxygen removal from the biocrude and a high heating value of 46.5 MJ/kg, closely matching Jet A fuel. Additionally, prescreening tests revealed that the average carbon number of the distilled SAF fraction was 10.6, near the 11.4 typical of conventional jet fuel. The upgraded biocrude also met all key SAF prescreening standards, including surface tension, density, viscosity, flash point, and freezing point. Notably, the Mo2C nanocatalysts retained their deoxygenation activity over multiple reuse cycles.
Conclusion: Pioneering Sustainable Jet Fuel Production from Wet Waste
This study, published in Science Advances, demonstrates for the first time that zeolite-supported Mo2C nanocatalysts can catalytically upgrade wet waste-derived biocrudes into SAF precursors that satisfy all critical fuel specifications. This breakthrough paves the way for converting abundant wet wastes into sustainable jet fuel, contributing significantly to greener aviation.
