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A critical pathway towards enhancing pulp mill biorefineries is to integrate the extraction and utilization of hemicelluloses into the pulping processes. Hence, an industrial pre-extraction strategy for hemicelluloses targeting eucalyptus kraft pulping process was developed. Alkaline solution or pulping white liquor was used to pre-extract hemicelluloses before the actual pulping process. The response surface methodology (RSM) technique was applied to investigate the most suitable conditions to maximize the yield of these hemicelluloses while simultaneously minimizing the damage to pulp yields and properties. Temperature (105 to 155 °C), alkali concentration (3 to 8%), sulfidity (20 to 30%) and retention time (19 to 221 min) were combined to evaluate their effects on hemicellulose yields and chemical structures. The optimal pre-extraction conditions identified in this work (5.75% NaOH concentration, 25% sulfidity at 135 °C for 60 min) successfully allowed recovering 4.8% of hemicelluloses (based on the wood dry mass) and limited damages to pulp yields and properties. The cellulose content in pulp can even be increased by about 10%. Hemicellulose emulsification properties were also evaluated, which were comparable to synthetic emulsifiers. This study provides an industrial pathway to effectively separate and utilize wood hemicelluloses from the pulping process, which has the potential to improve the economy and material utilization of pulp and paper mills.

Paper-based electrodes are of special interest for the industry due to their degradability, low cost, ion accessibility, and flexibility. However, the poor dispersibility and stability of loading conductive fillers, for example, carbon nanotubes (CNTs), limit their applications. In this study, bacterial cellulose (BC) was embedded within the cellulosic fiber matrix to prepare a paper substrate with a dual fiber matrix structure. BC with its unique nanoporous surface structure assisted the adsorbing, dispersing, and stabilizing of CNTs; cellulosic fibers reduced the cost, enhanced the ion accessibility, and improved the rigidity of the material. The prepared paper electrodes exhibited a high conductivity up to 5.9 × 10–1S/cm and an extraordinary durability under high bending strain; it can be rolled into a 2 mm radius 800 times while maintaining the conductivity almost constant. The paper electrode had a gravimetric capacitance up to 77.5 F/g, which remained more than 98% after 15,000 charge/discharge cycles. This study suggests that this paper electrode has potential applications in supercapacitors with high performance and durability.