Evaluation of OrganoCat process as a pretreatment during bioconversion of rice straw

Rice straw is deemed as an attractive feedstock for biofuel and platform chemical production owing to its renewability and availability on regional as well as global scale. However, the recalcitrance of rice straw compels an ancillary pretreatment step in the bioconversion process that effectively fractionates the lignocellulosic components. The present article evaluates the OrganoCat process as a pretreatment for rice straw and its effect on the subsequent enzymatic hydrolysis owing to the novel application of OrganoCat pretreatment to rice straw. The maximum cellulose recovery of 98.99%, hemicellulose solubilization and lignin removal of 88.79% and 71.46% respectively was achieved during the OrganoCat pretreatment of rice straw along with improved cellulose accessibility leading to maximum glucose release of 160.57 ± 2.7 g/kg untreated rice straw at different pretreatment conditions included under the range of operating conditions examined in the present study. OrganoCat pretreatment also led to effective fractionation and cell wall breakdown, thereby, enhancing the cellulose accessibility as distinctly evident from the adsorption studies and indirectly deduced from SEM and FT-IR analysis. The material balance of the input & output streams indicated an efficient one-step fractionation with 50% catalyst recovery and 80% solvent recovery. The significance of the obtained results are reported and discussed to gain an insight into the overall potential of the process.