The crude glycerol, co-product of biodiesel production, became a problem for the mill owners due to low value of trade, in addition to not find space in the industrial sector for its application, because it has high amount of NaCl (~ 7%) preventing its absorption by the industry due to technological difficulties. This work applied the methodology of Life Cycle Assessment in order to evaluate the environmental performance of the purification process of crude glycerol by distillation. The boundaries of the system were evaluated from cradle to gate, in other words, we evaluated the glycerin from soybean cultivation for the biodiesel production, oil extraction, transesterification and purification. The results for Greenhouse Gases indicate the agricultural phase as critical step in the life cycle of glycerol, representing 82% of 4167 kg CO2 Eq. to each 1.0 tonne of glycerol purified, the purification process represents 10% of this category of impact