Physicochemical investigation of microalgal cell disruption technologies with energy consumption analysis

Abstract

Effective microalgae biomass disruption is essential to generate free carbohydratesfor utilization in bioethanol production. The disruption of microalgae cells, usingsonication, high pressure homogenization (HPH), and microwave methods wasinvestigated under different treatment conditions including the applied electrical powerand process time. The biomass samples after disruption were characterized to assess sizereduction, morphological changes, structural, and elemental compositions. Under theinvestigation conditions, sonication was found to be the most efficient method to disruptmicroalgae cells, followed by HPH, and microwave exposure. Analysis of biomasssamples obtained after 100 % power sonication in 30 min showed ~40 % reduction incarbon content compared to the untreated sample, whereas ~30 % and ~20 % carbonreduction were obtained by HPH operated at 60 bar and microwave irradiated at 100 %power. The distorted morphology of the ruptured cells was more pronounced in thesonicated samples compared to the others. The energy consumption analysis showedmicrowaving at 100 % power level consumed the highest energy of 323.7 kWh per kgcarbon-released, whilst HPH at 20 bar utilized the lowest energy of 18.1 kWh per kgcarbon-released. Sonication proved to be a potential technology for optimal disruption ofmicroalgal cells to enhance biomass digestibility for bioethanol production with optimum economy. © 2013 by Nova Science Publishers, Inc. All rights reserved.