Turning curse into cure: Potential of water hyacinth for bio-refining - A contextual investigation of Lake Tana
Derese T. Nega, A. Venkata Ramayya, Flavio Manenti, Andre Furtado Amaral
Abstract
Water hyacinth (WH, Eichhornia crassipes, ’Emboch’ in Ethiopia) is a highly disturbing class of invasive and noxious aquatic plants found worldwide in other water bodies and as such is a prime problem in Lake Tana. One approach to successfully control the rapid invasion of WH is to utilize it as a feedstock to produce high-valued commodities in a biorefinery framework. Preliminary life cycle analysis carried out in the study shows that WH biomass is a competitive feedstock for biorefinery systems with a unit cost at $ 24.40 per ton of dry matter. Based on the annual generation capacity of 0.71 million tons of dry mass in lake Tana and following the standard biorefinery process protocols, the predictions indicate that the economic potential of converting WH biomass into 38.8 billion liters of biomethane alone to be at $ 38.8 million, 74.2 million liters of bioethanol alone at $ 51.9 million, and o.52 million tons organic agro-fertilizer alone at $ 130.5/78.3 million as a partial substitute for Anhydrous Ammonia or Muriate of Potash (MOP) fertilizers. Hence the integrated WH management and utilization as a biorefinery feedstock ranks it among the world’s most competitive feedstocks with attractive socio-economic and environmental benefits.