Saccharification of Water Hyacinth Biomass for Bioethanol Production: Optimization of Sulfuric Acid Pretreatment

Water hyacinth (Eichhornia crassipes) biomass is an ideal feedstock for bioethanol production as it is rich in hemicelluloses and the lignin content is low. This feedstock is, therefore, a good source of reducing sugars (C₅ and C₆). Water hyacinth plants were collected from five sites selected along the river Yamuna: A. Okhla West; B. Okhla East; C. Okhla Barrage; D. Najafgarh Drain; E. DND Flyover. As feedstock plants growing in different conditions of water quality in Delhi exhibited different sugar content, a comparative study reveals that plants from site A (Okhla West) possessed maximum reducing sugar content. The sugar content in plants growing in different sites was: A>B>C>D>E. Maximum saccharification (sugar extraction) was obtained after 3% sulfuric acid pretreatment for 1.5 hours at 121°C. Optimization of acid pretreatment helps in breaking strong linkages between hemicellulose and lignin, thereby making the feedstock more accessible for further enzymatic hydrolysis.