Agricultural palm oil tree residues as raw material for cellulose, lignin and hemicelluloses production by ethylene glycol pulping process

Agricultural crop residues (palm oil empty fruit bunches—EFB) were used as raw material for cellulose, lignin and hemicelluloses obtaining following sustainable criteria. An organosolv pulping process based on ethylene glycol–water mixtures, which allowed an easy recycling of solvents as well as the recovery of generated by-products, was used to induce delignification. Computer simulations using commercial software (Aspen Plus) were made on the whole process in order to design the solvents recovery stages and optimise the operation conditions. Laboratory experiments were carried out with the aim of characterizing raw material, black liquors and released by-products. Considerable high proportion of recycled solvents (91 wt% ethylene glycol and 88 wt% water) was reached with the proposed scheme. This resulted in 70 and 80 wt% reduction of fresh solvent input for ethylene glycol and water respectively, thus reducing the environmental impact of the process. EFB organosolv pulp could be considered an acceptable alternative for producing certain paper qualities with moderate strength requirements while allowing an agricultural residue from a major economic activity (viz. oil palm production) to be exploited.