Biofuel molecules commercialized to date primarily rely on high-flux metabolic pathways to native products, including short-chain alcohols and long-chain fatty acid derivatives. These pathways are well-suited for rapid deployment but result in a limited suite of biofuel candidates and associated fuel properties.

Continued advances in synthetic biology create the potential for enhanced tunability of molecular structures, leveraging the specificity of biological pathways for targeted improvements to chemical properties. These improvements can yield performance advantages over incumbent bio- and petrochemical fuels, including enhancements to energy density, cold flow, research octane number, soot formation, and octane sensitivity.

Alternatively, new fuels may be engineered for production advantages, including reduced toxicity or enhanced separability. To illustrate these possibilities, researchers at LBNL will describe recent advances in bio-advantaged fuel production, coupling fuel properties modeling, metabolic engineering, and process development.