Different action of alkali/alkaline earth metal chlorides on cellulose pyrolysis

Abstract

The influence of alkali metal chlorides (NaCl, KCl) and alkaline earth metal chlorides (MgCl₂, CaCl₂) on cellulose pyrolysis was studied with thermal analysis and isothermal pyrolysis in N₂ at 150–400 °C. Alkali and alkaline earth metal chlorides affected the cellulose pyrolysis in different way. Although alkali metal chlorides did not change the weight loss temperature of bulk cellulose (main part of cellulose) so much, alkaline earth metal chlorides substantially reduced the temperature. Furthermore, the influence of alkaline earth metal chlorides on the weight loss behavior (<400 °C) was very dependent on the amount of loading bellow 0.30 mol/mol of the glucose-unit of cellulose, while the influences of the alkali metal chlorides were almost independent of the amount. Both metal chlorides significantly changes the low MW product composition even at a very low level of addition.