Comparison of rapeseed and mineral oils using Life-Cycle Assessment and Cost-Benefit Analysis

A combination of life-Cycle Assessment (LCA) and Cost-Benefit Analysis (CBA ) was used to evaluate and compare the relative environmental impacts and s ocio-economic costs of several products, made from either rapeseed oil or m ineral oil in the UK. The chainsaw bar oil case study is used to demonstrat e the methodologies used and results obtained. Chainsaw bar oil is a total- loss oil, and has considerable potential for substitution of the convention al base oil (mineral oil) with rapeseed oil. Results are presented from LCA impact assessments of the mineral oil and rapeseed oil chainsaw lubricants Several scenarios were compared using different co-product allocation and alternative land-use assumptions. Global warming potential (GWP) impacts we re lower for rapeseed chainsaw oil, in ail scenarios, than for the mineral oil product. Other environmental impacts illustrated that both assumptions (i.e. whether to examine the total or marginal impacts) and allocation can strongly influence conclusions. The most realistic scenario for rapeseed oi l was considered to be 70% allocation of burdens to the oil, with winter wh eat impacts subtracted from those of oilseed rape. With this scenario, ail environmental impacts considered for chainsaw lubricants were lower for rap eseed oil. Monetary valuation of impacts through CBA varied, depending on t he valuation system used, but in general rapeseed oil chainsaw lubricant ha d lower costs than the mineral oil product. Allocating some of the environm ental burdens of crop production and crushing to rapeseed meal, and conside ration of marginal impacts relative to alternative land uses increased the apparent environmental benefits of rapeseed oil chainsaw lubricant. Combina tion of ICA and CBA will require further development but affords new opport unities for socio-economic interpretation of environmental aspects.