Enhancing cellulose regeneration from sugarcane bagasse and pulp via ozone pretreatment: A comparative study of delignification for producing regenerated cellulose films

This study addressed the knowledge gap in comparative ozonation effects on raw and partially delignified biomass by optimizing ozone pretreatment conditions for enhancing fractionation and cellulose regeneration from sugarcane bagasse and unbleached soda bagasse pulp. Ozone pretreatments were conducted under acidic (pH 3), neutral (pH 7), and alkaline (pH 12) conditions at varying durations. Acidic ozonation effectively delignified raw bagasse, achieving up to 44.76 % delignification with minimal cellulose degradation. The lower-lignin bagasse pulp exhibited further delignification (up to 92.51 %) across all pH conditions. For raw bagasse, both pH and ozonation time significantly affected delignification, DP, carboxyl content, and dissolution yields. For bagasse pulp, time was the primary significant factor. This systematic comparison revealed that optimal short ozonation (20 min) under acidic conditions improved dissolution yields by 21 % for bagasse and 6 % for pulp compared to untreated substrates. Cellulose recovery during regeneration was also enhanced, with bagasse exhibiting higher absolute yields of around 43 % versus 60 % for pulp. The pretreatment enhanced cellulose dissolution, which upon regeneration reassembled into uniform nanofibers (250–400 nm), enabling the formation of smooth, homogeneous cellulose films. The experimental investigation thoroughly evaluated the effectiveness of paraffin and microfiber lignocellulose coatings in mitigating apple weight loss over a 90-day storage period. The results highlighted the significant preservation potential of these coatings, with the microfiber lignocellulose coating showing the most substantial reduction in weight loss. This study provides new insights into the influence of initial lignin content on ozonation efficacy and subsequent regeneration processes, highlighting the potential of optimized green ozonation as an effective pretreatment for valorizing sugarcane biomass into value-added regenerated cellulose products while preserving cellulose integrity.