A life cycle assessment of tri-generation from biomass waste: The experience of the “agro-combined” of Thibar

The study presents a life cycle assessment of energy produced by biogas obtained by biomass waste and fuelled in a tri-generation pilot plant located in Tunisia. The results, referred to 1 MJ of exergy, showed that the plant construction causes 76% of primary energy consumption and gives a contribution higher than 90% on resource depletion and ionising radiation, and of 50% on ozone depletion. Operation causes 66% of the impact on human toxicity - cancer effects and more than 90% of the other impacts, except for ecotoxicity of freshwater mainly caused during the end-of life. The study is one of the first applications of environmental analysis to tri-generation from waste in developing countries; it can be considered a guideline for similar countries for transforming the threat of waste in opportunity. Furthermore, it gives suggestions for a cleaner management of biomass waste to achieve a bio-economy based on energy from renewable sources.