Chemical composition and pulp characterization of Tunisian vine stems

In this study, the valorisation of Tunisian vine stem wastes was investigated. The chemical composition of the vine stems was studied, and it was found that when compared to non-wood plants, they contain greater amounts of extractives, lignin, and comparable holocellulose content. An elementary analysis of the ashes showed that the major constituents were mineral elements (K and Ca). Soda pulping of vine stems led to a yield of about 35% after the bleaching step. This amount is lower than that obtained for wood plants and similar to that observed for annual plants. The morphological properties, Kappa number, and degree of polymerization of the resulting pulp were determined. Finally, paper handsheets were prepared from the pulp, and their physical properties were investigated. The breaking length, Young's modulus, and burst index of the produced paper presents quite acceptable values. Further, the silica content of the stems is low, which is advantageous for the pulping process. Experimental results obtained for both the pulp and paper show that this agricultural residue has the potential to be used for papermaking applications.