High-Octane Gasoline from Lignocellulosic Biomass via Syngas and Methanol/Dimethyl Ether Intermediates: 2018 State of Technology and Future Research

This report was developed as part of the U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy Bioenergy Technologies Office’s (BETO’s) efforts to enable the development of technologies for the production of infrastructure-compatible, costcompetitive liquid hydrocarbon fuels from lignocellulosic biomass feedstocks. The research funded by BETO is designed to advance the state of technology of biomass feedstock supply and logistics, conversion, and overall system sustainability. Current projections include research improvements deemed feasible within the 2022 timeframe. As part of their involvement in this research and development effort, the National Renewable Energy Laboratory, Idaho National Laboratory, and Argonne National Laboratory investigate the economics of conversion pathways through the development of conceptual biorefinery process models and techno-economic analysis models, delivered feedstock quality and cost, and supply chain sustainability assessment, respectively.

This report covers the 2018 state of technology (SOT) assessment and a revision of previous 2022 projections. The 2018 SOT assesses research progress made since 2014 toward the 2022 goal of developing technologies to produce cost-competitive, high-octane gasoline from woody biomass. It captures current research results as well as projected future technical improvements necessary to achieve the projected 2022 minimum fuel selling price (MFSP). Previous 2022 cost projections published in the BETO Multi-Year Program Plan have been revised based on current understanding of the research trajectory. The techno-economic analysis (TEA) model revisions include changes in the feedstock composition, delivered feedstock cost, the income tax rate, and the cost year basis. Additionally, to improve the model predictions, the model compounds used for modeling the process and bulk properties of the gasoline product have been updated to reflect the actual isomers from experiments. The process and economic models for the revised 2022 projection will serve as the framework for developing future annual SOT assessments. The National Renewable Energy Laboratory research and analysis teams will continue to work together to incorporate demonstrated experimental research results into the process and economic models to assess progress toward the 2022 goals. Table ES-1 summarizes the performance metrics for the 2018 SOT and the 2022 projection. The summary of the TEA results for the 2018 SOT and the 2022 projection are presented in Table ES-2 and Table ES-3, respectively. The modeled MFSP for the 2018 SOT is $3.79 per gallon of gasoline equivalent (GGE) in 2016 dollars, compared to the 2022 projection of $3.30/GGE.

Experimental research efforts to achieve the 2022 MFSP projection are ongoing. As seen in Table ES-1, a significant increase in the overall C5+ C-selectivity and a corresponding decrease in aromatics C-selectivity are required. To achieve this shift in C-selectivity away from aromatics and toward the desired C5+ products, catalyst development research is underway to control hydrogenation activity to reduce aromatic formation, with a complementary effort to control the chemistry to convert the resulting intermediates to C5+ products. These research improvements directly address the fuel synthesis cost, representing a $0.16 reduction in capital and operating costs in that area; combined with yield increases this will allow a total $0.49/GGE reduction in the MFSP. Research through 2022 and beyond will focus on process intensification and increasing the overall carbon efficiency as the primary avenues to address further cost reduction. Toward that goal, process analysis research is underway to identify the most impactful opportunities to recycle lost carbon back into the process. For example, carbon dioxide from vi This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications. syngas cleanup could potentially be recycled back to the methanol synthesis reactor to recover this otherwise lost carbon. Similarly, carbon lost to char could be recovered. Based on the findings of this analysis, complementary experimental research will be performed to explore the viability of these opportunities to increase carbon efficiency and reduce the overall cost.