Biodiesel impact assessment

The comparison of the two different impact assessment methods is made on the basis of Scenario I, the production of biodiesel from waste cooking oil without the consideration of substitution processes. Since SPI and CML results cannot be directly compared the main focus of investigation is to discuss if both methods point to the same environmental problems arising over the life cycle and identifying the process steps contributing most prominently to the ecological impact. 

Table III. Comparison between diflerent impact assessment methods of biodiesel from used vegetable oil...

The first step in any LCA is to define the scope and goals of the assessment. The goal of the study is to quantify the environmental impacts of the bioethanol conversion processes. The present study concerns the environmental impact of gas to liquid diesel and biodiesel produced from biomass source. 

As far as the absolute values of biodiesel compared to fossil diesel are concerned, both assessment methods show similar trends. Under the terms of the problem oriented approach biodiesel performs better in all impact categories except for the eutriphication potential (see Table III). The ecological footprint of fossil diesel is approximately the sixfold of the biodiesel s footprint. 

Recent life cycle assessment (LCA) studies, to assess the environmental impact and use of resources during the life cycle of biodiesel, reveal that there are less GHG emissions in second-generation biodiesel when compared with the first generation (Chatteijee et al., 2015). Therefore, research on edible oil biodiesel production is mostly focused on cost competitiveness and sustainability of the process through ... 

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