Drying Enhancement Through PEF Processing

Biomass used for the production of ethanol and other biofuels is processed in biorefineries operating year-round. However, the biomass is typically harvested in a short timeframe, so must be dried sufficiently for storage. Current methods of drying biomass, such as mechanical presses and propane dryers, are expensive and energy-intensive. In this SBIR, a novel pre-treatment process using high voltage pulsed electric fields (PEF) is proposed to rupture the cell walls of the biomass material. Ruptured cells release their intracellular water, potentially making the following drying processes faster and much less energy intensive. While the impact of PEF on food drying has been quantified in several studies for foods such as sliced potatoes, carrots, sugar beets its impact on biomass drying has barely been assessed. In Phase I, we will quantify the potential energy savings experimentally, and begin the design of large-scale PEF systems for biomass processing. In Phase II, we will verify this energy and cost savings in a pilot biofuel processing plant, as a prelude to full commercial introduction of this process. Commercial Applications & Other Benefits: Our preliminary assessment is that PEF processing can reduce drying times (and energy use) by 25% - 60%, conservatively saving over $10 in drying costs for every $1 in PEF process costs. The speed of adoption of PEF into biomass drying processes will be driven by straightforward economics once its impact can be clearly demonstrated.