Environmental, Economic, and Scalability Considerations and Trends of Selected Fuel Economy-Enhancing Biomass-Derived Blendstocks

Twenty-four biomass-derived compounds and mixtures, identified based on their physical properties, which could be blended into fuels to improve spark ignition engine fuel economy, were assessed for their economic, technology readiness, and environmental viability. These bio-blendstocks were modeled to be produced biochemically, thermochemically, or through hybrid processes. To carry out the assessment, 17 metrics were developed for which each bio-blendstock was determined to be favorable, neutral, or unfavorable. Cellulosic ethanol was included as a reference case. Overall economic and, to some extent, environmental viability is driven by projected yields for each of these processes. The metrics used in this analysis methodology highlight the near-term potential to achieve these targeted yield estimates when considering data quality and current technical readiness for these conversion strategies. Key knowledge gaps included the degree of purity needed for use as a bio-blendstock. Less stringent purification requirements for fuels could cut processing costs and environmental impacts. Additionally, more information is needed on the blending behavior of many of these bio-blendstocks with gasoline to support the technology readiness evaluation. Overall, the technology to produce many of these blendstocks from biomass is emerging, and as it matures, these assessments must be revisited. Importantly, considering economic, environmental, and technology readiness factors, in addition to physical properties of blendstocks that could be used to boost engine efficiency and fuel economy, in the early stages of project research and development can help spotlight those most likely to be viable in the near term.