Organosolv Pulping of Hemp Stem for a Potential Papermaking Pulp

Glycol ether-based organosolv pulping process was applied to hemp stem to identify a possible sustainable source for papermaking. The hemp organosolv pulps were produced by controlling the content of glycol ether with water, ranging from 30% to 90% at a fixed cooking temperature, time, and acid catalyst. Hardwood bleached kraft pulp (HwBKP) was used as a reference. In this study, the hemp stem including the bast and core consisted of 33.9% of α-cellulose and 36.7% of hemicellulose. The length-weighted length of the organosolv hemp pulp was 0.5-0.8 mm, which was similar to HwBKP. Morphology of organosolv hemp pulps was fibrillated higher than the HwBKP, resulting in a high tensile index in handsheets. In addition, the air permeability of handsheets of the organosolv hemp pulps increased with the increase of the glycol ether contents in pulping conditions.