Besides free sugars, sweet sorghum stalks contain cellulose and hemicellulose that can be used for biofuel production. The pretreatment of stalks without the extraction of free sugars is more complicated than typical lignocelluloses, because of the degradation of free sugars during most pretreatment processes. In this study, the bioconversion of sweet sorghum stalks into biogas and bioethanol was studied using an improved organosolv pretreatment within a biorefinery framework. The organosolv pretreatment was developed using an aqueous solution of ethanol (EtOH) and isopropanol (IPOH). The process was optimized to obtain a liquor containing free sugars with the least sugar degradations together with a highly degradable solid fraction. The liquor was subjected to anaerobic digestion for biomethane production, while the solid was used for ethanol production via simultaneous saccharification and fermentation (SSF). The most influencing pretreatment parameters, i.e., temperature, time, alcohol to water ratio, EtOH to IPOH ratio, and the presence or absence of sulfuric acid (as a catalyst), were adjusted to achieve the highest yields of bioconversion. The maximum methane and ethanol production yields of 271.2 mL CH4/g VS and 87.8% (equal to the gasoline equivalent of 0.170 and 0.241 L/kg, respectively) were achieved from the liquor and pretreated solid, respectively; however, they were obtained at different optimum conditions. Considering the biorefinery perspective, the highest gasoline equivalent of 0.249 L/kg was efficiently obtained from the whole process after pretreatment at 140 °C for 30 min using 60:20 EtOH/IPOH ratio in the presence of 1% sulfuric acid. Further analyses, including enzymatic adsorption/desorption, compositional analysis, FTIR, and SEM, were conducted to investigate the effects of this newly developed pretreatment on the substrate.
Applied Microbiology and Biotechnology – Springer Journals
Published: Feb 19, 2018
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.
Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera