Publication: The effect of enzymatic hydrolysis of pretreated wastepaper for bioethanol production
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Date
2021
Authors
Hossain N.
Hoong L.L.
Barua P.
Soudagar M.E.M.
Mahlia T.M.I.
Journal Title
Journal ISSN
Volume Title
Publisher
Springer
Abstract
Enzymatic hydrolysis of waste biomass for bioethanol production is considered a decades old traditional, inexpensive, and energy-effective approach. In this study, waste office paper was pretreated with diluted sulfuric acid (H2SO4) and hydrolyzed with one of the most available and cost-effective enzymes, cellulase derived from Trichoderma reesei, under submerged static condition. Three different pretreatment approaches�cut into 2 cm2, blended with distilled water, and pretreated with diluted H2SO4�have been implemented, and pretreatment with diluted H2SO4 was the most effective. Hydrolysis with different concentrations�0.5 M, 1.0 M, 1.5 M, 2.0 M of H2SO4�was performed. The maximum glucose content was obtained at 2.0 M H2SO4 at 90 min reaction time, and glucose yield was 0.11 g glucose/g wastepaper. The cut paper, wet-blended, and acid-treated wastepaper was hydrolyzed with cellulase enzyme for 2, 4, and 5 consecutive days with 5 mg, 10 mg, 15 mg, and 20 mg enzyme loadings. The maximum glucose content obtained was 9.75 g/l from acid-treated wastepaper, after 5 days of enzymatic hydrolysis with 20 mg enzyme loading and a glucose yield of a 0.5 g glucose/g wastepaper. The wastepaper hydrolysate was further fermented for 6, 8, and 10 hours continuously with Saccharomyces cerevisiae (yeast), and at 10 hours of fermentation, the maximum glucose consumption was 0.18 g by yeast. Further, HPLC analysis of the fermented medium presented a strong peak of bioethanol content at 16.12 min. The distillation of bioethanol by rotary evaporator presented 0.79 ml bioethanol/fermented solution, which indicated the conversion efficiency of 79%. � 2021, The Korean Institute of Chemical Engineers.