Enhancing liquid hot water (LHW) pretreatment of sugarcane bagasse by high pressure carbon dioxide (HP-CO2)

Author(s)

Alves Gurgel, Leandro Vinicius ^{[1, 2]} ; Borges Pimenta, Maria Teresa ^[3] ; da Silva Curvelo, Antonio Aprigio ^{[2, 3]}

Affiliation

^[1] Univ Fed Ouro Preto, Inst Ciencias Exatas & Biol, Dept Quim, Grp Fis Quim Organ, BR-35400000 Ouro Preto, MG - Brazil

^[2] Univ Sao Paulo, Inst Quim Sao Carlos, Dept Fis Quim, Grp Fis Quim Organ, BR-13560970 Sao Carlos, SP - Brazil

^[3] Ctr Pesquisa Energia & Mat CNPEM, Lab Nacl Ciencia & Tecnol Bioetanol CTBE, BR-13083970 Campinas, SP - Brazil

• Document type: Journal article
• Source: INDUSTRIAL CROPS AND PRODUCTS; v. 57, p. 141-149, JUN 2014.
• Web of Science Citations: 29

Abstract

Liquid hot water (LHW) pretreatment associated with high pressure carbon dioxide (HP-CO2) was evaluated as a potential green pretreatment technology for extraction of hemicelluloses from depithed sugarcane bagasse to produce fermentable sugars. Developing a technology based on the use of low cost, non-corrosive, and recoverable chemicals as CO2 can result in a more efficient and economic process. In this study, depithed sugarcane bagasse was treated with LHW and HP-CO2 at milder temperatures in comparison with LHW pretreatment alone. To assess the effects of varying pretreatment operational conditions on extraction of xylo-oligosaccharides and xylose release with cellulose preservation a central composite design (CCD) of experiments was used. The pretreatments were carried out at temperatures ranging from 93.8 degrees C (8.62 MPa) to 136.2 degrees C (12.96 MPa) and times from 17.6 to 102.4 min with a liquid-to-solid ratio of 12:1. The maximum xylan and xylose concentrations were achieved by treating depithed bagasse at 100 degrees C for 30 min and 115 degrees C for 60 min, respectively. At these conditions the amount of xylan equivalent ranged 10-12 g/L. At 115 degrees C for 60 min, the cellulose preservation achieved 97.2%. The obtained results showed that HP-CO2 proved to be an efficient hydrolysis agent. Samples of LHW-HP-CO2 pretreated bagasse were tested for enzymatic digestibility. Depithed bagasse pretreated at 115 degrees C for 60 min after enzymatic hydrolysis had a glucose yield of 30.43 g/L and a cellulose conversion of 41.17%. (C) 2014 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 07/51755-0 - Development of analytical methodologies and organosolv delignification processes applied to bagasse and straw from sugarcane
• Grantee: Antonio Aprigio da Silva Curvelo
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - Research Partnership for Technological Innovation (PITE)