E cycle assessment of biofuels in Mozambique

Abstract

Non-renewable natural resources are only available in limited quantities, they will be depleted ane day. The recent high price of oit is one of the consequences of the depletion of resources. Mozambique, a country with a tropical climate, may have a comparative advantage in growing biomass feedstock, a sustainable alternative to fossil fuels. This dissertation evaluates the potential of producing biofuelsfrom various vrops (sugarcane, cassava, sunflower, jatropha), agricuture by products (cotton seeds), sugar cane molasses and waste streams (brewery waste) in the country through a life cycle assessment. The main issues addressed are net energy value, water balance, land use and greenhouse gas emissions. Calculations of greenhouse gases emissions due to land use changes weere determined assuming that tropical forest , temperate grassland and tropical savannas as the native ecosystems. The analysis indicates that there is not enough water to supply water sonsumptive crops like sugarcare. Reliance on the Massingir dam as source of water for biofuels production would create a disaster, the consequence of wich would be hunger for more than 1.200 milion people. Biodiesel prodution from sunflowers and jatropha in land intensive compared to ethanol prodution from sugarcance. This due to low agricultural yield (ton/ha), and if the biofuel crops are irrigate , the water requirements are the same as for sugarcane. Sugar cane molasses, brewery wast and cotton seed provide high net energy rations and low impact in land and water use, making them the best candidates for biofuels production in Mozambique. Mozambique has the potencial to produce 22,500,000 liters of ethanol from sugar cane molasses and 13,500,000 liters of biodiesel per year from cottonseed without displancing even 1 há of land dedicated to food crops.