Potential to use invasive plants in biomass energy production: A case study Prosopis juliflora in coastal wetlands of Sri Lanka

Abstract

Prosopis juliflora is an invasive plant species rapidly expanding in the Asian and African continents. The invasion of P. juliflora in Bundala Ramsar Wetland (BRW) in Sri Lanka has created several biodiversity conservation issues. This study was conducted to assess the possibility of utilizing invasive P. juliflora as an alternative energy source. P. juliflora performed better than L. leucocephala for most evaluated fuelwood properties. Ash content was comparatively higher in P. juliflora than L. leucocephala. However, biomass to ash ratio of P. juliflora was significantly lower (<0.05) and the Fuel Value Index (FVI) of P. juliflora (3,276) was slightly lower than that of L. leucocephala (3,336), a non-significant difference. P. juliflora and L. leucocephala reached Fiber Saturation Point within 24 and 27 days of drying, respectively. Results show that 1 kg of P. juliflora would produce an estimated energy equivalent to 0.5 L of diesel and furnace oil and 5 kWh of electricity. As such, we recommend further study on harvesting and commercialization of P. juliflora as a potential wood energy source.