Details

Autor(en) / Beteiligte

• Gomes, Daniel
• Domingues, Lucília
• Gama, Miguel

Titel

Valorizing recycled paper sludge by a bioethanol production process with cellulase recycling

Ist Teil von

• Bioresource technology, 2016-09, Vol.216, p.637-644

Ort / Verlag

England: Elsevier Ltd

Erscheinungsjahr

2016

Quelle

MEDLINE

Beschreibungen/Notizen

• •The recycling of cellulases on the hydrolysis of recycled paper sludge was assessed.•Cellulases and yeast cells showed good performances towards the substrate.•Both cellulase fractions were shown to be easily recovered with good efficiencies.•The hydrolysis of RPS was successfully conducted over 4 cycles.•Cellulase recycling enabled enzyme savings between 53 and 60%. The feasibility of cellulase recycling in the scope of bioethanol production from recycled paper sludge (RPS), an inexpensive byproduct with around 39% of carbohydrates, is analyzed. RPS was easily converted and fermented by enzymes and cells, respectively. Final enzyme partition between solid and liquid phases was investigated, the solid-bound enzymes being efficiently recovered by alkaline washing. RPS hydrolysis and fermentation was conducted over four rounds, recycling the cellulases present in both fractions. A great overall enzyme stability was observed: 71, 64 and 100% of the initial Cel7A, Cel7B and β-glucosidase activities, respectively, were recovered. Even with only 30% of fresh enzymes added on the subsequent rounds, solid conversions of 92, 83 and 71% were achieved for the round 2, 3 and 4, respectively. This strategy enabled an enzyme saving around 53–60%, while can equally contribute to a 40% reduction in RPS disposal costs.