Insights into the economic viability of cellulases recycling on bioethanol production from recycled paper sludge

• Autor(a) principal: Gomes, Daniel G.
• Data de Publicação: 2018
• Outros Autores: Serna-Loaiza, Sebastián, Cardona, Carlos A., Gama, F. M., Domingues, Lucília
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/1822/55610
• topic: Economic analysis; Cellulase recycling; Lignocellulosic ethanol; Recycled paper sludge; Science & Technology

The economics of Recycled Paper Sludge conversion into ethanol was here assessed with emphasis on integrating a cellulase recycling system. Without cellulases recycling this process presented positive economic outputs (payback period of 7.85 years; 10.90 Million US$ of accumulated NPV) despite the modest ethanol titers. Recycling both free and solid-bound enzymes allowed considerable savings of enzyme but also an increase on annual costs (0.88 %), resulting on a superior economic output: payback period decreased to 7.25 years; accumulated NPV increased to 14.44 Million US$. Recycling exclusively the liquid fraction enabled a clear costs reduction, however, also total ethanol decreased, attenuating the abovementioned benefits. Targeting higher ethanol concentrations, superior solids consistencies were also evaluated. Despite a costs reduction, total ethanol decreased due to a higher ethanol retention on the solid. A sensitivity analysis further revealed that the cost of enzymes and ultrafiltration membrane may be critical on enzyme recycling economic feasibility.