Techno-Economic Analysis of Biologically Derived Short-Chain Methyl Ketones As a Gasoline Blendstock

Short-chain (C5-C7) methyl ketones are promising gasoline blendstocks due to high-energy-density and low-hygroscopicity relative to ethanol. These methyl ketones can be biologically produced from plant materials by using Streptomyces albus; however, the economic viability of this conversion pathway, key cost drivers, and process optimization and intensification opportunities are not known. To bridge these research gaps, this study quantifies the minimum selling price of short-chain methyl ketones at the current state of the art of the technology and considering potential future scenarios with lignin utilization/valorization. The process model developed in this study includes biomass feedstock supply chain, ionic liquid-based biomass deconstruction method, and the downstream biological conversion, separation, and waste treatment systems. We consider switchgrass as a representative biomass feedstock. We find that the yield of methyl ketones from simple sugars, solid loading rate, sugar yield from biomass, biomass feedstock cost and quality, and coproduct credits are most influential to the selling price of the short-chain methyl ketones. The recently demonstrated methyl ketones yield of 1.6 g/g-sugar results in a very large minimum selling price (MSP) of $163/gge. This selling price could reach to $12/gge with the intermediate product yield improvement of 50% of the theoretical stoichiometric yield. Improving other most influential process parameters along with the product yield of 90% of the theoretical stoichiometric yield reduces the MSP to $2.65/gge, which is just 19% more than the last 10-year average gasoline price at the refinery gate. The results demonstrated in this study could help to develop future research strategies.