Life Cycle Assessment of Cellulose Nanofibrils Production by Mechanical Treatment and Two Different Pretreatment Processes

Abstract

Nanocellulose is a bionanomaterial with many promising applications, but high energy use in production has been described as a potential obstacle for future use. In fact, life cycle assessment studies have indicated high life cycle energy use for nanocellulose. In this study, we assess the cradle-to-gate environmental impacts of three production routes for a particular type of nanocellulose called cellulose nanofibrils (CNF) made from wood pulp. The three production routes are (1) the enzymatic production route, which includes an enzymatic pretreatment, (2) the carboxymethylation route, which includes a carboxymethylation pretreatment, and (3) one route without pretreatment, here called the no pretreatment route. The results show that CNF produced via the carboxymethylation route clearly has the highest environmental impacts due to large use of solvents made from crude oil. The enzymatic and no pretreatment routes both have lower environmental impacts, of similar magnitude. A sensitivity analysis showed that the no pretreatment route was sensitive to the electricity mix, and the carboxymethylation route to solvent recovery. When comparing the results to those of other carbon nanomaterials, it was shown that in particular CNF produced via the enzymatic and no pretreatment routes had comparatively low environmental impacts.

Prospective Life Cycle Assessment of Epitaxial Graphene Production at Different Manufacturing Scales and Maturity

“…Including impacts from transport in prospective LCA is difficult, given that the location or future production processes and modes of transport are inherently unknown (Arvidsson et al. , , ). The mass that could potentially be transported is the combined mass of the SiC wafer, argon, and materials for SiC production (SiC powder, or silane and methane).…”

Wood‐Derived Ultrathin Carbon Nanofiber Aerogels

“…In this regard, the nanofibrillated cellulose (NFC) produced by disintegration of plant cellulose that is the most abundantly and sustainable biopolymer on the earth would be an ideal precursor for the synthesis of CNFs aerogels . The estimated global production capacity of nanocellulose in 2013 was on the order of 600 metric tonnes, and the future global market potential was estimated to be 35 million metric tonnes/year . Despite of great efforts made by several groups, it is still an urgent challenge so far to prepare uniform CNFs aerogels from wood cellulose, as the thermal decomposition of cellulose happened at high temperature lead to significant weight loss and serious destroy of the nanofibrous morphology .…”

Nanobiopolymers Fabrication and Their Life Cycle Assessments

“…Additionally, suggestions have been made to reduce water usage for washing in enzymatic and carboxymethylation pretreatment to lower terrestrial acidification. And solvent recovery or less solvent usage will make less impact for carboxymethylation pretreatment …”

“…And solvent recovery or less solvent usage will make less impact for carboxymethylation pretreatment. [172] The life-cycle assessment also analyzed the twelve kinds of the combination of isolation techniques towards obtaining CeNCs with high crystallinity. These twelve isolation techniques were established based on the variates of the pretreatment solvent (with NaOH or NaClO 2 ), hydrolysis solvent (HNO 3 or H 2 SO 4 ), the hydrolysis period (30 and 60 min) and the number of the bleaching stages (1 and 4).…”