Determination of Environmental Impacts using Life Cycle Assessment of Plants Grown for Bioenergy: Example of Sorghum x Sudan Grass Hybrid

Abstract

Renewable energy sources are the most effective and cheapest method for combating climate change. Biomass, which is one of the renewable energy sources, is also one of the raw materials for biofuels. Sorghum x Sudan grass hybrid, which is drought tolerant and has a short vegetation period, is a biomass source. This study was carried out to determine the ethanol yield of sorghum x Sudan grass hybrid plants grown in an area with a semi-humid climate and to determine the environmental impacts of biomass. Environmental impacts were assessed using the life cycle assessment method. Environmental impact categories are divided into 11 categories according to the CML-IA Baseline model. As a result, the biomass yield was 49888 kg ha-1 and the ethanol yield was 1674.1 l ha-1. According to the life cycle impact category of sorghum x Sudan grass hybrid biomass production, the highest environmental impact was 79.21%, causing marine aquatic ecotoxicity. According to the life cycle interpretation, it caused a global effect with a rate of 83.87%. In addition, the global warming value was calculated as 0.195 kg CO2-eq kgbiomass-1 (9728.16 kg CO2-eq ha-1). The agricultural phases with the most negative impact on the environment are irrigation and fertilization.

Keywords

• global warming
• climate change
• energy crops
• biofuels
• bioethanol