Resource recovery and reduction of tidal waste to produce cellulose through sulphur-free pulping

Abstract

The transition towards a sustainable cellulose industry needs more environmentally friendly technologies, including the use of lignocellulosic waste as alternative raw materials. This work shows the potential of dead biomass from the Andalusian Mediterranean coastline to obtain cellulosic pulp. With this purpose, predominant species in onshore residues (mainly Posidonia oceanica) were prepared, characterized, and subjected to a soda-anthraquinone pulping process. A central composite design was defined in order to relate the process conditions to the composition and characteristics of the cellulose pulp. It was concluded that polynomial models encompassing linear, quadratic, and binary effect parameters reproduce the experimental results satisfactorily. Results allowed to choose high anthraquinone dosage, alkali charge and temperature, low liquid/solid ratio and short time as a compromise solution, by which the brightness, ethanol–benzene extractives content, kappa number, lignin content and viscosity were near their optimal. Low values of liquid/solid ratio reduce water consumption, which is of utmost importance in cellulose industries likewise short time treatments to save energy.