Development of a Blended Feedstock Strategy to Address Challenges of Feedstock Cost for Biochemical Conversion of Lignocellulosic Biomass

A blended feedstock strategy is currently under investigation at Idaho National Laboratory to address challenges associated with the high cost of feedstock access in order to enable biomass supply systems. Blending provides a mechanism to reduce risk to the supply chain and reduce feedstock cost by coupling location-specific resource utilization with biofuel production. Using corn stover as a baseline, this study examines a variety of biomass resources, including switchgrass, Miscanthus, wheat straw, non-recyclable paper, lawn clippings, energy cane, and sorghum to formulate  feedstock blends for biochemical conversion. The objectives of this work are: 1) to characterize and understand the effects of blending and logistics on the efficacy of pretreatment and conversion of single feedstocks and blends; 2) to examine the potential for blends to reduce feedstock production costs using least cost formulation models and feedstock supply chain technoeconomic analysis. Feedstocks and blends were screened using an automated dilute-acid pretreatment method combined with enzymatic hydrolysis; sugar yields were used to develop conversion performance relationships among single feedstocks and blends. Physical and chemical characteristics before and after pretreatment were also used to evaluate the conversion performance of biomass blends. In order to enable biomass supply chains and achieve biochemical conversion targets, feedstock blending has shown promise as a strategy to supply biomass in quantities sufficient for meeting cost, quality, sustainability, and performance targets.