Multiple light scattering as a powerful tool to fast quantify biomass slurry towards continuous bioenergy production

Abstract

Feedstocks with stable slurryability are one of the key factors enabling the continuous operation of bioenergy processes fed with wet biomass. Here, we developed a fast and accurate method quantifying biomass slurry and unlocked the different stability behaviors of various wet biomass via multiple light scattering (MLS) technology. The results revealed that both cow manure slurry (CMS) and Spirulina slurry (SS) at low concentrations (5 wt%–10 wt%) had obvious sedimentation phenomena. Under medium concentration conditions (15 wt%–20 wt%), a saturated state gradually formed between the biomass and water, with weakening settling behavior. At 25 wt%, the raw ΔBS spectra reflected the discrepancies between CMS and SS where spirulina particles (SP) occurred notable agglomeration due to molecular adsorption caused by hydrogen bonding, contrasting with mutual movement of cow manure particles (CMP). Turbiscan stability index (TSI) values of CMS and SS declined with increased concentrations, indicating the slurry became stabler until saturation. Combining MLS with rheology, contact angle, and zeta potential analysis, an optimized slurry preparation formula of 20 wt% with particle size below 120 mesh was obtained for CMS and SS, where the slurry possessed sufficient viscosity for stability while pseudoplasticity prone to a stable and continuous flow. This study engineered MLS as a powerful tool to fast quantify biomass slurry towards continuous bioenergy production.