Evaluation of rice straw biopowder from alkaline-mechanical pretreatment by hydro-textural approach

Apretreatment step forlignocelluloses is responsible to alter the complex structure which allows enhancingenzymatic accessibility and bioconversion of the materials.However, there is a gap on the methods to characterize physicalevolutions of the material throughout its pretreatment.The aim of this study is to evaluate the physical changes in rice straw (RS)pretreated with alkaline followed by grinding to produce biopowders.A hydro-textural approach was applied to evaluate the physical changes of RS pretreated byimpregnation and soaking in NaOH.The results indicated that the volume deformation increased by 110%, whilethe energy consumptiondecreased by 11.3% compared to unpretreated RS.Moreover, the cellulose content and glucose were 66.8 and 212 mg/gRS obtained by RSsoaking. Thealkaline-mechanicalpretreatment was shown asan effective process to providehigh glucosereadily converted to bioethanol.Additionally, the hydro-textural approach can be considered an alternative method for biomass structural characterization.