The overlooked interaction between cellulose and CO2(g) in NaOH(aq) turned into the potential for cellulose technology and carbon dioxide capture

Övrigt konferensbidrag, 2022

In the world finally turned towards sustainable and environment-friendly solutions cellulose could play the first fiddle in almost any industrial sector. The only obstacle standing in the way to unlimited applications follows from the characteristic of cellulose itself, namely, the remarkable stability of the polymer. Due to low degradation temperature, the range of processing methods to access industrially attractive cellulose is limited to dissolution. Amongst many studied cellulose solvents, the aqueous NaOH, even if limited in terms of concentration and temperature, has a great perspective. The NaOH (aq) is cheap, vastly available and carry real green potential. Although the concentration/temperature limitations of NaOH (aq) have been continuously studied, the natural, well-established ability of NaOH (aq) to sorpt environmental CO2 (g) has been consequently omitted in cellulose research. The results of the initial analysis carried out in our group demonstrated the pitfalls of such a proceeding. It was shown that cellulose exhibit a strong affinity for alkali-dissolved CO2 that could lead to the formation of carbonate intermediates.

In follow up to previous studies, here we took the control over the gas delivery and conclusively studied the effect of CO2 upon cellulose in NaOH (aq). Here, we present the results of our complex analytical approach based on in-situ studies of reaction between cellulose and CO2 (g), with perspective to carbonation, pH and temperature changes in the system. Furthermore, we introduce the potential of cellulose carbonation in the regeneration of polymer; subsequently, the carbonation process is discussed in terms of mechanism, reversibility and its effect on the cellulose crystal structure. Our findings are presented with the implication for cellulose processability in the context of cellulose derivatives and regenerated fibres production.