Closing the Sustainable Life Cycle Loop of Membrane Technology via a Cellulose Biomass Platform

Abstract

Membrane technology has become an indispensable part of our daily lives. The rapid growth of membrane technology has been breeding an unavoidable yet critical challengethe unsustainable disposal of used membranes. Commercial polymer membranes are fabricated from fossil-based monomers and polymers that are not biodegradable. Hence, there is an urgent need to develop membranes that are sustainable from cradle to grave, i.e., both bioderived and biodegradable. Cellulose is one of the most abundant biopolymers that are biodegradable upon disposal. However, it is only soluble in a handful of solvents, limiting its fabrication into membranes at an industrial scale. To circumvent this bottleneck, in this work, we propose a sustainable and scalable method to fabricate cellulose membranes from cellulose acetate with a sacrificial acetate group. The proposed method allows cellulose membrane fabrication utilizing green solvents, and the fabrication procedure is sustainable with minimal solvent consumption. One of the most appealing applications of cellulose membranes is organic solvent nanofiltration (OSN). It is an emerging technology to separate solutes in nanoprecision in harsh organic solvents, requiring solvent-stable materials. Surprisingly, the cellulose membranes exhibited unique transport behaviors, with solute rejection ranging from 100 to −100% depending on the solvent medium. Such trends were not previously observed in the OSN literature, and the underlying mechanism was thoroughly investigated. Importantly, the membranes were completely biodegradable in a carbon-neutral manner upon disposal. The life cycle of cellulose membranes was compared with that of conventional OSN membranes in a qualitative and comparative study. The proposed methodology can be applied to substitute fossil-based polymers in all aspects of membrane technology, and it has the potential to become a sustainable fabrication platform for membrane materials.

Biobased thin-film composite membranes comprising priamine–genipin selective layer on nanofibrous biodegradable polylactic acid support for oil and solvent-resistant nanofiltration

“…The presented TFC fabrication methodology takes us a step closer to achieving cradle-to-grave sustainable-membrane fabrication, which is among the recent grand challenges in the field. 57,58…”

“…The presented TFC fabrication methodology takes us a step closer to achieving cradle-to-grave sustainable-membrane fabrication, which is among the recent grand challenges in the field. 57,58 We encourage future research on the solvent volume and the monomer concentration per unit membrane area to improve accuracy when evaluating sustainability. A direct and straightforward comparison between various studies can also contribute to sustainable membrane research and development.…”

Membrane Life Cycle Management: An Exciting Opportunity for Advancing the Sustainability Features of Membrane Separations

“…One relevant strategy for addressing the challenges regarding the sustainability of membranes is to shift from the utilization of fossil-based materials to those derived from renewable resources. ,, This not only promotes the degradability of the spent membranes but also creates extra benefits within the framework of the circular economy. This is well supported by the emergence of new trends in membrane materials research devoted to “better” and/or “novel” and/or “more sustainable” membranes.…”

Hollow Fiber Membrane for Organic Solvent Nanofiltration: A Mini Review

“…From a sustainable and green point of view, the major membrane manufacturing processes are environmentally unfriendly [ 130 ]. In recent years, many published papers have reported on sustainable, environmentally friendly membrane materials and membrane preparation processes [ 52 , 61 , 131 , 132 , 133 , 134 , 135 , 136 , 137 , 138 , 139 , 140 , 141 , 142 ]. It is foreseeable that one of the common areas for future HF OSN membrane R&D should be the green and sustainable preparation of HF OSN membranes.…”