47. Lignin Degradation of Water Hyacinth for Bioethanol Production Using Yeast

Renewable energy programs are considered as one of the primary focuses on lignocellulosic biomass-based energy. Indigenous resources and local skills development with the utilization of ecologically friendly technologies for energy services needed for sustainable development activities are considered to be a vital part of a country’s green economic development model. Aggressive invasion of floating water hyacinth (Eichhornia crassipes) has always been a big problem for sweet water reserves in tropical countries, including India. In production, using feedstocks based on second generation (2G), feedstock type may expand, and currently unused sources of lignocellulose, such as water hyacinth, can be used. This chapter presents the availability of water hyacinth, its collection, characterization, and pretreatment. The maximum percent of lignin removal is 60.15%, and the maximum sugar content would be achieved at a level of 97.5% (w/v) with 4% NaOH at 30 min at 20 lb/in² pressure. This chapter goes in greater depth into optimum carbon and nitrogen sources and influences of chemical parameters, macro-nutrients, micro-nutrients, etc. on the bioethanol yield. There is the production of the maximum amount of ethanol on alkali-treated hydrolyzed water hyacinth, which is obtained as the optimum carbon source. This detail has been discussed in the chapter and is 82.84% of the yield efficiency of ethanol.