Rheological properties of concentrated slurries of harvested, incubated and ruptured Nannochloropsis sp. cells

Abstract

Biorefining of microalgae biomass requires processing of high-solids (> 10%) slurries. To date there is little knowledge of how processes for weakening and rupturing microalgae cells affect the rheological properties of these materials. To fill this gap in the literature, the rheological properties of concentrated slurries of marine microalgae Nannochloropsis sp. were investigated as a function of processing and solids concentration (12, 20 and 24% w/w). Freshly harvested, incubated (autolysed), and high-pressure homogenised (HPH) slurries were found to be shear thinning up to a shear rate of approximately 200 s− 1. Viscosity increases were far more prominent for partially processed versus u..