Reusability of lactic acid on hydrolysis of nanocrystalline cellulose from pepper waste (piper nigrum L.)

Abstract

Lactic acid recovery and reusability for hydrolysis of cellulose offers an economical method and produces fewer waste streams. Successful lactic acid recovery up to three recycle times efficiently hydrolyzed NCs with rod-shape morphology. However, after four cycles, the nanocrystalline cellulose yield reduced from 72.3 % to 48.2 %, forming large nanocelluloses with high crystalline index. Large-size nanocellulose with high zeta potential and thermal stability were obtained with increasing cycles due to inefficient acid diffusion into the rigid crystalline network compared to amorphous cellulose. This study offers a green pathway for hydrolysis nanocellulose using a less corrosive and low toxicity lactic acid than inorganic acids.

Keywords

• acid recovery
• lactic acid
• Nanocrystalline cellulose
• organic acid
• hydrolysis