Torrefaction of Conservation Reserve Program biomass: a techno-economic evaluation

Abstract

The Conservation Reserve Program (CRP), which was initiated to prevent soil erosion, provides a large amount of cellulosic biomass that is potentially useful for bioenergy production. We investigated the effects of torrefaction conditions on the physicochemical properties of CRP biomass using an elemental analyzer, a thermogravimetric analyzer, and a calorimeter. Results suggest that the upgraded biomass is a hydrophobic, high-energy density, and low-moisture-content material. The study on biomass polymer composition showed how polymer components changed with processing conditions. The polysaccharides in biomass were degraded significantly at 300 °C, suggesting that processing conditions should be managed properly for sugar or energy recovery. Our economic analysis suggested that the processing cost for a torrefaction plant with an annual capacity of 100,000 tons of CRP biomass is $16.3 per ton of feedstock. Further analysis of the effects of torrefaction on the biomass supply chain suggested that processing could save pelletization and transportation costs.