Sustainability life cycle comparison of biofuels: sewage the saviour?

Abstract

PurposeThe aim of this research is to conduct a holistic sustainability life cycle assessment (LCA) comparison of different kinds of biofuels, integrating environmental, social, cultural and economic sustainability. The feasibility of a vision that by year 2015 households, companies, and other organizations all over the world will turn their sewages into biofuels, instead of discharging them into the environment is tested through these comparisons.Design/methodology/approachSemi‐structured interviews of biofuels' experts in Finnish companies, industry organizations, research institutions, and non‐governmental organization were conducted.FindingsBiogases are environmentally more sustainable than bio‐oils, field biomass, wood‐based biomass and peat, all of which cause loss of biodiversity. Bio‐oils and field biomass are socio‐culturally unsustainable when they affect farming for food. Launching any kind of biofuel system is expensive, but running it reaps benefits. Biogases, bio‐oils and liquid field biomass use the cradle‐to‐grave approach; solid field biomass, wood‐based biomass and peat use the cradle‐to‐cradle approach in their life cycles. Biogases made of sewage have an endless supply with little need for an endless life cycle, which, however, could also be developed.Practical implicationsRefining sewage into biofuels solves two global environmental problems at once: carbon dioxide emissions from fossil fuels contributing to climate change and over‐fertilization of waterways causing sea, lake and river deaths. Hence, the launching expenses are well worth the effort. Yet other biofuels compete so heavily that large‐scale global turning of sewage into biofuels by 2015 is unlikely.Originality/valueThis is the first holistic sustainability LCA comparison of biofuels which integrates environmental, socio‐cultural and economic sustainability views of industry, research and civil society experts.