4. Conclusions
After the pretreatment with ionic liquid and co-solvent, 27.1–
60.4% of the lignin was removed from the water hyacinth, the crystallinity
of the structure was decreased, and the biogas yield and
methane concentration were increased by 16.3–97.6% and 13.2–
28.3%, respectively. When the water hyacinth was pretreated at
120 C for 120 min by [Bmim]Cl/DMSO, the biogas production
was the highest and the lag phase was one day. Higher pretreated
temperature and longer pretreated time against the anaerobic
digestion of the water hyacinth. The recovery rates of ionic liquid
and co-solvent were all over 90%.
Acknowledgements
The authors would gratefully acknowledge the support from the
Guangdong Provincial Laboratory of Green Chemical Technology.
They would also like to acknowledge the support from the Key Social
Development Program. Foundation of Guangdong Province
(No.: 2011A030600011).