Sustainable Production of Microcrystalline Cellulose Through Gas Phase Hydrolysis for Pharmaceutical Applications: Characterization and Life Cycle Assessment

Conventional microcrystalline cellulose (MCC) production via aqueous mineral acid hydrolysis is energy- and water-intensive, generating high wastewater volumes. An alternative green chemistry approach employs concentrated gaseous acids to enhance yield and conserve resources. This work aimed to develop an efficient, sustainable gas-phase hydrochloric acid (HCl)-air hydrolysis process for MCC production from cotton linters. MCC yield, structure, powder properties, tablet performance, and environmental impacts were characterized. The gas phase method successfully produced 96% MCC yield and 87% crystallinity, higher than commercial MCC (93% yield, 39% crystallinity). MCC powder exhibited 141 mu m mean diameter, 0.91 m2/g surface area, and 245 degrees C onset decomposition. Tablet testing revealed balanced ductility and toughness. Reduced water (40 kg/kg cellulose), energy (188 MJ/kg MCC), and wastewater generation (39 kg/kg cellulose) were achieved versus conventional production. Tablet testing of MCC compacts revealed balanced ductility and toughness during compression. The HCl-air approach enabled high-yield, high-purity MCC synthesis under mild conditions while enhancing powder attributes, tablet performance, and sustainability compared to commercial manufacturing.