Life cycle assessment of deep eutectic solvent employment for sustainable nanocellulose production from biomass: a systematic review
Angky Wahyu Putranto, Sri Suhartini, Yusuf Wibisono, Nanang Masruchin, Adeline Seak May Chua, Gek Cheng Ngoh
Abstract
Nanocellulose has been the research focus in recent years due to its unique properties, diverse potential applications, and the availability of abundant biomass sources. In view of the use of hazardous chemicals and high temperatures via conventional solvents, deep eutectic solvents (DESs) as green solvent-based pretreatments have been explored to facilitate sustainable nanocellulose production. However, detailed and comprehensive studies on life cycle assessment (LCA) in nanocellulose production to be fully considered sustainable production are still lacking. Therefore, this review comprehensively investigates the LCA aspects of nanocellulose production from various biomass sources. The review findings underlined that the chemicals used for the pretreatment and isolation of nanocellulose significantly contributed to Global Warming Potential (GWP) in 85% of the case studies. Four scenario processes of nanocellulose production are proposed to reduce environmental impact, since DES has a recovery rate of 80–95% and the use of chlorine-free bleaching has reduced the GWP up to 70 kg CO2 equivalent. Furthermore, cradle-to-gate sustainable nanocellulose production through DES-based pretreatment and the LCA impact categories are discussed in this review paper. Future outlooks and recommendations provide insights into the potential environmental benefits of implementing DES-based pretreatment processes for sustainable nanocellulose production.