Energy consumption of the nanofibrillation of bleached pulp, wheat straw and recycled newspaper through a grinding process

Abstract

Cellulose nanofibrils (CNF) are steadily gaining attention since this material is a renewable alternative to artificial polymers. Moreover, waste products from cellulose-based industries (e.g. paper mills) or from agriculture can be used as raw material for CNF isolation. However, the up-scaling from the laboratory to the industry can only be achieved if the energy costs are low enough to compete against low-price petroleum derivatives. The objective of this work is to present an energy-related study of the direct fibrillation of cellulose-based materials using a grinding process. Two waste materials, namely wheat straw and recycled newspaper, have been investigated as starting materials, together with bleached wood pulp for comparison purposes. The mechanical properties and specific surface areas of the resulting fibrillated materials are then presented and systematically compared with each other. The properties of the bleached wood-pulp fibres exhibited the highest values that were reached already at low energy inputs. The different properties of CNF isolated out the waste materials could reach values close to their maxima for energy inputs as low as about 5 kWh/kg compared to the ca. 10 kWh/kg needed with high pressure homogenization.

Photo-polymerization, swelling and mechanical properties of cellulose fibre reinforced poly(ethylene glycol) hydrogels

“…As reported [17], the hemicellulose and cellulose contents are of 12.6 and 81.3% respectively while the diameters of NFC are in the range of 2e100 nm and their lengths are in a few micrometers range as observed by SEM.…”

Influence of the nanofiber dimensions on the properties of nanocellulose/poly(vinyl alcohol) aerogels

“…As discussed below, this material was disintegrated in situ to form m‐CNCs. MFC (diameter: 24 ± 9 nm) was prepared from elemental chlorine free (ECF) bleached softwood pulp fibers by mechanical disintegration using a Masuko‐grinder as previously described by Josset et al . Fiber slurries of 2% dry weight content were swollen in water for 24 h and then passed 10 times through the rotating stones (1500 rpm) of the grinder.…”

Physical and Mechanical Properties of Cellulose Nanofibril Films from Bleached Eucalyptus Pulp by Endoglucanase Treatment and Microfluidization

“…Energy cost is the major concern for commercial utilization of mechanical CNF [10,11]. The GH5 hyperthermostable endoglucanase (Ph-GH5), a laboratory pure endoglcanase, can produce longer and entangled CNF, while the commercial endoglucanase (FR) that contains non-protein compounds produced shorter and more uniform CNF.…”