Production of bioethanol by an innovative biological pre-treatment of a novel mixture of surgical waste cotton and waste card board

ABSTRACT

An optimized innovative biological pretreatment (avoiding the generation of inhibitors) of a novel mixture of surgical waste cotton and card board was performed for 14 ± 0.5 days using a fungi Paecilomyces inflatus ATCC® 32919™ resulting in 76 ± 0.14% and 25 ± 0.009% lignin and hemicellulose degradations, respectively. SEM analysis, X-ray diffraction analysis, and FT-IR spectroscopy revealed changes in the pretreated biomass mixture. Saccharification (57.09 ± 1%) was achieved for the pretreated mixture using in-house cellulases. Fermentation of the enzymatically saccharified hydrolysate using Saccharomyces cereviseae RW143 yielded 51.24 ± 1.2 g/L ethanol, with a cellulose conversion of 58.42 ± 1%. The biological pretreatment was 80% cheaper than conventional pretreatments giving a fermentation yield of 0.42 ± 0.08 g ethanol/g of glucose. A total of 90% (v/v) with 180 proof purity (twice the volume percentage by US standard) ethanol was obtained. A total of 96 ± 1.4% of diesel fuel’s cylinder pressure was achieved in an internal combustion engine testing for the produced ethanol’s blend with diesel.

KEYWORDS:

• Reclacitrance
• biological pretreatment
• saccharification
• fermentation
• inhibitors