Utilization of fossil and renewable fuels in clean and value-added ways remains a key issue. Fossil fuels like petroleum and coal are among the most chemically complex natural mixtures in the world. As a renewable energy source, biomass is complex biogenic organic feedstock for renewable fuels. Knowledge of the molecular composition of fossil and renewable fuels is critical to selection and optimization of chemical processing conditions and ultimately determines the economic value of products. However, insufficient understanding of the structure and composition of fossil fuels and biomass at the molecular level will further limit clean and value-added utilization of the energy sources.

The present special issue aims to provide contributions from a variety of topics relating to the characterization of properties, structures or molecular compositions of fossil fuels, and biomass, as well as the corresponding derivatives or products through thermal, chemical, and biochemical methods. Any developments in the analytical or instrumental techniques used in the investigation on fossil fuels and biomass are encouraged.

Potential topics include but are not limited to the following:

• Novel analytical techniques/methods/instruments for the characterization of fossil and renewable fuels
• Analysis of derivatives or products of fuels through refining, pyrolysis, liquefaction, upgrading, fermentation, and so on
• Separation of complex raw fuels, derivatives, or products by chromatographic or/and electrophoretic methods
• Bioanalytical techniques for biomass, bio-oil, and biofuels
• Sample preparation for the characterization of raw fuels, derivatives, or products
• Online characterization during fuel processing
• Petroleomics
• Analysis of contamination or/and trace elements during the utilization of fuels
• In-depth interpretation for analytical data
• Reviews of the foregoing areas