Assessment of GHG Emissions from Biofuel Production by Life Cycle Approach

Abstract

The decreasing stocks of petroleum-based fuels, increasing energy security problems, and the problems related to climate change and air pollution problems encourage the growing interest in biofuels. Biofuels are among low-carbon alternatives for road transport, as they have a much better CO2 emission performance and lesser air pollution impacts than traditional fossil transport fuels. However, it is significant to examine whether the GHG emissions from biofuels' lifecycle are lower than those from fossil fuels. In addition, biofuel production from crops should not compete with food production and should be economically and environmentally sustainable. According to Turkey’s National Greenhouse Gas Inventory, in 2020, the transport sector's share in total GHG emissions was 15.4%, corresponding to 80.7 million tons of CO2eq. Road transportation accounts for 94.9% of the country's transport sector's GHG emissions. In addition, Turkey’s domestic oil source is also limited, making her dependent on imported liquid fuels. Turkey has recently created a road map for 2053, which includes essential principles and important actions to decrease GHG emissions and climate change. In addition, the transposition and implementation of the current and future EU Directives on climate change are critical for Turkey to implement its road map for 2053. For these reasons, Turkey's biofuel potential and emission effects were analyzed in this study. As a method, BioGrace Calculation Tool is used to calculate the life cycle GHG emission reduction potentials of biodiesel from rapeseed and waste oil and bioethanol from sugar beet and corn. According to the results of each biofuel production pathway's life cycle GHG emissions, biodiesel production from waste oil has the lowest life cycle GHG emission, 21.9 g CO2eq/MJ. Bioethanol production from corn (44.9 g CO2eq/MJ) and sugar beet (46.1 g CO2eq/MJ) follows biodiesel from waste oil. Biodiesel from rapeseed has the highest life cycle GHG emission, which is 53.2 g CO2eq/MJ. Secondly, various biodiesel and bioethanol blending scenarios were implemented to estimate the GHG emissions of biofuel-blended passenger cars. This is accomplished by assuming a 5% annual rise in the proportion of biofuel-blended passenger cars will reach up to 50% of all non-blended passenger cars in 2030, starting from 2020, which is selected as the base year. Finally, crop demand analyses were conducted for rapeseed, sugar beet, and corn cultivation area to estimate Turkey’s capacity to meet biodiesel and bioethanol demands in 2030 according to various biofuel blending rates. According to projection results, blending the biofuels at 0.5% and 2% can easily meet the demand for biodiesel production from rapeseed. Consequently, bioethanol production from sugar beet and corn can be easily achieved with all blending rates by the end of 2030. However, sugar beet and corn production for food demand should also be considered since biofuel production should not compete with food production.