Screening the potential of plant species to be used for dendro energy generation

Abstract

According to the reports of the Intergovernmental Panel on Climate Change (IPCC), CO2 concentration of the atmosphere at present isn360 ppm as against 280 ppm in the 1750. It has been predicted that by the year 2100, projected CO2 concentration will be in the range 540 – 970 ppm. As a consequence global average temperature is projected to increase by 1.4 to 5.80 C over the period 1990 to 2100. Energy generation contributes very significantly to the climate change as emissions of green house gases occur from the raw material used therein ie petrol, diesel, coal, fuel oil, LPG, kerosene etc.

In the National Energy Policy of Sri Lanka 2008, under the clause fuel diversity and security, development of non conventional energies have been given much emphasis. It spells out a target of satisfying 10% of the grid connected energy demand from non conventional sources by 2015 which include biomass, mini hydropower, wind, solar etc. Despite being a carbon neutral fuel, the development of biomass for electricity has experienced a slow progress for which several factors had contributed such as not having a diverse feed stock (at the moment the major emphasis is on Gliricidia), dearth of readily available land for energy plantations, tariff etc. Therefore, the main objective of this research was to screen several tree species for their suitability of being used as feedstock for dendro power. Ten tree species were screened for a selected number of attributes for use in dendro energy such as wood density, specific gravity, calorific value, moisture content, biomass in two climatic zones (wet zone and dry zone) and during two specific seasons ie dry season and wet season. Samples were taken from three age categories ie. less than one year old, between 1-5 years old and more than 5 years old. Gliricidia sepium, Calliandra calothyrsus, Erythrina variegate, Grevillea robusta, Acacia mangium were selected for the wet zone while Prosopis juliflora, Leucaena leucocephala, Acacia auriculiformis, Sesbania grandiflora, Eucalyptus camaldulensis were selected for the dry zone.

The results indicates that for the dendro plants in the wet zone, Gliricidia sepium, Calliandra calothyrsus shows the best performance while for the dendro plants in the dry zone, Leucaena leucocephala, Prosopis juliflora were the best.