Mechanical treatment to produce NFC and / or CNC (ITENE, ES)

The production of nanocellulose (NCFs) in the PL13 will be carried out through a mechanical disintegration of cellulosic fibers suspension, depending on the raw material and the extraction process used to obtain the cellulose pulp.

A grinder will be used to carry out the disintegration of the cellulosic fibres, allowing the processing of different kinds of cellulosic pulp.

To optimize the disintegration process, prior to the mechanical disintegration, the optimization of the degree of refining of the pulp through a mechanical pre-treatment will be carried out through means of an auxiliary disc refiner. In this process, cellulose fibers will be suspended in a proportion of water and will be refined to a Schopper-Rieger degree of 90. Afterward, the refined pulp will be subjected to mechanical disintegration to obtain nanocellulose. The process is facilitated by other pre-treatments that weaken cellulose fibers, reduce energy consumption and produce NCFs with different characteristics and qualities to mechanically and chemically produced nanocellulose.

The nanocelluloses (NCFs) obtained will be modified to enhance dispersion in polymers and coating, and to improve compatibility. Based on the final application, different chemical modifications will be evaluated, such as surface adsorption, grafting, and covalent functionalization, among others. The final format of the NCFs (wet or dry) will depend on the final.

pilot lines templates image
pilot lines templates image

To increase this productivity and the final product quality, this pilot line will be upgraded, implementing a continuous process to duplicate the production capacity (from 1kg/day to 2kg/day) and in-line monitoring to determine maximum quality by the automatization of the process. For this purpose, a system of automatic valves and a peristaltic pump controlled by a flowmeter will be installed. NCFs suspension viscosity will be the parameter used to conclude when the process ends, for this aim a continuous viscometer will be include in the developed control system.

In the PL13, nanocrystals of cellulose (CNC) will also be produced from the cellulosic pulp obtained in the previous pilot lines by “chemical treatments”. These acid hydrolysis processes will be carried out in an acid reactor, and the operating conditions (acid concentration, temperature, time, etc.) will depend on the properties of the cellulose pulp used as raw material.