Comparison of results from life cycle assessment when using predicted and real-life data for an anaerobic digestion plant

Abstract

Increased separation of food waste driven by the European Circular Economy Action Plan will create a need for establishing new treatment plants that can turn waste resources into high value products. This paper presents a real example of how life cycle assessment was used as decision support when establishing a new anaerobic digestion plant in Norway. The aim of the paper is to investigate the accuracy of the results of the predictive study performed before the plant was built by comparing them with results from the operation of the plant. The comparative assessment revealed that both the burdens and avoided emissions were underestimated. The production volume of upgraded biogas as a fuel for transport was higher than anticipated, resulting in a higher benefit than expected associated with substitution of diesel. Conversely, the impacts from transport and from the anaerobic digestion process were higher than forecasted. In total the net results from the predictive study were within an acceptable range compared with results based on real data.