Vegetable oils for biofuels versus surfactants: an ecological comparison for energy and greenhouse gases

This paper compares the use of vegetable oils as energy carriers on the one hand and for the production of chemicals on the other hand. The bio-based energy carriers analyzed are rapeseed oil, rapeseed oil methyl ester, and palm oil methyl ester, all of which can be used as substitutes for diesel fuel. The chemicals studied are surfactants. Surfactants can be produced from plant-based feedstocks (oleochemical surfactants) and from petrochemicals. The various options are studied with regard to two ecological indicators, i.e. the consumption of finite energy resources and the global warming potential. First of all, for these two aspects plant-based sources show clear advantages when compared with their fossil counterparts. Secondly, the transesterified types of biofuels are more advantageous than pure vegetable oils. Thirdly, the conservation of finite energy and reduction in emissions of greenhouse gases are higher if vegetable oils are used as a feedstock to produce oleochemical surfactants compared to their use as biofuels. Comprehensive life-cycle analyses must be carried out in order to determine whether these results can also be applied to other ecological indicators. The results presented in this paper support developing strategic goals for bio-based feedstocks, including quantity and cost targets.