Energy Analysis for Biodiesel Production from Rapeseed Oil

Abstract

The objective of this study was to evaluate the energy input and output for winter rapeseed cultivation and biodiesel production from rapeseed oil. The total energy use for winter rapeseed cultivation and biodiesel production proceses were 10485.04 MJ/ha and 9199.48 MJ/ha, respectively. The total energy inputs for winter rapeseed cultivation were consisted of 2599.15 MJ/ha direct energy input and 7885.89 MJ/ha indirect energy input. The total energy input was calculated as 4889.66 MJ/t for winter rapeseed cultivation. The average rapeseed and straw yield were 2144.4 kg and 1154.6 kg per hectare cultivated area, respectively. The energy output of rapeseed 56826.6 MJ/ha, if only the seed was taken into account. The output/input ratio for rapeseed cultivation was 7.30 if straw was included. The net energy production was calculated as 66085.22 MJ per hectare of cultivated area. The total energy input was 19684.52 MJ/ha for rapeseed biodiesel production. The energy consumed for the conversion of refined rapeseed oil into biofuel was 6197.32 MJ/ha, which accounted for 67.37% of the total energy consumtion of biodiesel production processes. The total energy output of rapeseed biodiesel processes was consisted of 26768.97 MJ/ha in the form of biodiesel, 4095.8 MJ/ha of in the form of rapeseed meal (cake) and 2558.99 MJ/ha in the form of glycerin. The energy ratio was 2.70 for the rapeseed biodiesel production chain. The specific energy and the energy productivity for rapeseed biodiesel production were calculated as 24.41 MJ/kg and 0.0409 kg/MJ, respectively. The net biodiesel production was 7084.45 MJ/ha, which correspond to 213.39 L biodiesel per hectare of cultivated area.