AUTHOR=Bordignon Sidnei Emilio , Ximenes Eduardo , Perrone Olavo Micali , Carreira Nunes Christiane da Costa , Kim Daehwan , Boscolo Maurício , Gomes Eleni , Filho Edivaldo Ximenes Ferreira , da Silva Roberto , Ladisch Michael R. TITLE=Combined Sugarcane Pretreatment for the Generation of Ethanol and Value-Added Products JOURNAL=Frontiers in Energy Research VOLUME=Volume 10 - 2022 YEAR=2022 URL=https://www.frontiersin.org/journals/energy-research/articles/10.3389/fenrg.2022.834966 DOI=10.3389/fenrg.2022.834966 ISSN=2296-598X ABSTRACT=

In this work, we have tested individual and combination of applications of ozonolysis and liquid hot water (LHW) to pretreat sugarcane bagasse (SCB) for the removal of enzyme and/or microbial inhibitors and generation of potential value-added chemicals. A solid content with 80% cellulose and a liquid phase (liquor) rich in phenolic derived compounds (3 g.L−1) from lignin, sugars (>20 g.L−1), and other compounds, such as furfural and hydroxymethylfurfural (HMF), were generated. Maximal (59%) glucan conversion occurred in the presence of double-pretreated bagasse, which had 32–50% more glucan available than the samples that were individually LHW or ozone-pretreated, resulting in maximal ethanol production (92% after 42 h) from double-pretreated SCB enzyme hydrolyzate. In summary, this work showed that ozone reacts effectively with lignin without the use of any other chemical reagent, and LHW pretreatment, followed by a washing step, was effective in solubilizing and cleaning up the fiber enzyme and microbial inhibitory compounds with ozone being effective against phenolics. Moreover, the generated cellulose-rich substrate is readily fermentable. The acidic liquor fraction removed by sequential washings and containing mainly sugars and phenolic compounds may be evaluated for use in green chemistry bioconversions processes.