Life cycle assessment of safflower and sugar beet molasses-based biofuels

This study aims to evaluate the environmental effects of using safflower oil and molasses-based bioethanol by calculating the environmental impacts of safflower oil methyl ester (SOME), safflower oil ethyl ester (SOEE), and molasses-based bioethanol. The results were compared to fossil-based fuels (diesel and gasoline) within the life cycle assessment framework. Characterization results obtained with Eco-indicator 99 method indicate all three biofuels are more advantageous than fossil fuels in all categories (carcinogens, climate change, respiratory effects, acidification/eutrophication, ecotoxicity, fossil fuel use) except mineral and land use. Based on the normalization results, fossil fuel and land use are the most important environmental impact categories. Using the IPCC method, the carbon intensity was calculated at 16.72, 15.24, 22.23, 99.45, and 108.48 g CO₂ per MJ for SOME, SOEE, bioethanol, diesel, and gasoline, respectively. The weighted impacts were calculated at 0.675, 0.876, 0.98, 1.65, and 2.1 for bioethanol, SOEE, SOME, diesel, and gasoline, respectively. The main environmental impact of fossil fuels comes from using fossil resources, while the essential part of the environmental effects of biofuels comes from the agricultural stage, indicating the importance of choosing pesticides, fertilizers, irrigation, and used fuels. This effect was even more critical for safflower-based biofuels; however, the impact of processing steps is lower than for bioethanol. Although the environmental effects of these biofuels vary in different categories, they are sustainable and cleaner alternatives to fossil-based fuels.