Diana Tuomasjukka

Trade-offs in sustainability impacts of introducing cascade use of wood

ABSTRACT The aim of this study was to analyse the sustainability impacts of allocating material from energy use to material use by adding cascaded wood into production of wood products. A case study is presented, where we analyse sustainability impacts of cascade use alternatives compared to the non-cascade use practice in particleboard production within the province of North Karelia, Finland. Direct impacts are captured using sustainability indicators representing environmental, economic and social aspects of sustainability. Results show that introducing cascaded wood can increase carbon storage in wood products, employment and production costs. Energy use and GHG emissions increase as well, when the total industrial activity during the lifetime of wood increases. We conclude that cascade use can improve resource efficiency as it enables the use of wood multiple times before combustion; however, the amount of waste wood for energy generation decreases locally, and alternative sources of energy need to be identified.

Threefold sustainability impact assessment method comparison for renewable energy value chains

ABSTRACT There is a variety of different methods for carrying out sustainability impact assessments of energy value chains. The different methods can use the same, or similarly named, indicators, but the methods make different assumptions about the system boundaries and differ in the purpose of the assessment, and this can lead to confusion when communicating the results of different studies. A method expansion of Sustainability Impact Assessment (SIA) was developed and tested to allow comparison of environmental indicators of energy use and generation, energy balance and greenhouse gas emission as calculated according to three different methods: (1) direct value chain environmental impacts (referred to as SIA in this paper), (2) direct plus indirect impacts following a Life Cycle Assessment (LCA) approach, and (3) a method based on European Sustainability Criteria (ESC) for solid biomass. The Tool for Sustainability Impact Assessment (ToSIA 2.0) was used for this method expansion. Indicator values following the three different approaches were calculated for a typical Nordic bioenergy harvesting chain producing forest wood chips. The indicator values for SIA, LCA and ESC are made comparable side by side, and give thus more insight on the difference and purpose of the three different methods when applied to the same harvesting chain.

Sustainability impacts of increased forest biomass feedstock supply – a comparative assessment of technological solutions

ABSTRACT Sustainably managed forests provide renewable raw material that can be used for primary/secondary conversion products and as biomass for energy generation. The potentially available amounts of timber, which are still lower than annual increments, have been published earlier. Access to this timber can be challenging for small-dimensioned assortments; however, technologically improved value chains can make them accessible while fulfilling economic and environment criteria. This paper evaluates the economic, environmental and social sustainability impacts of making the potentially available timber available with current and technologically improved value chains. This paper focuses on increasing the biomass feedstock supply for energy generation. Quantified impact assessments show which improvements – in terms of costs, employment, fuel and energy use, and reduced greenhouse gas emissions – can be expected if better mechanized machines are provided. Using three different methods – Sustainability Impacts Assessment (SIA), Life Cycle Assessment (LCA), and Emission Saving Criteria (ESC) – we calculated current and innovative machine solutions in terms of fuel use, energy use, and greenhouse gas emissions, to quantify the impact of the technology choice and also the effect of the choice of assessment method. Absolute stand-alone values can be misleading in analyses, and the use of different impact calculation approaches in parallel is clarifying the limits of using LCA-based approaches. The ESC has been discussed for the recast of the Renewable Energy Directive. Potential EU-wide results are presented.