Modelling of multi-functional biomass systems on costs, land demand and CO2-emissions
09 / 2000 - 09 / 2004
The utilisation of biomass instead of fossil fuels to fulfil our energy needs can contribute to the reduction of greenhouse gas (GHG) emissions and the decrease of the dependence on fossil fuel energy carriers. However, a large contribution of bio-energy can only be obtained by the production and utilisation of energy crops, while the potential scarcity of land and the relative high costs of the bio-energy carriers produced are major barriers to this. Though multi-functional biomass systems might overcome these barriers. - Research. Different promising (in terms of technical and economic feasibility and energetic potential) multi-functional biomass systems are modelled and compared to reference single product systems. Methodological issues play an important role in modelling these systems, e.g. the comparison of different land use requirements, the allocation of impacts and credits over multiple outputs, the price elasticity of biomass flows and agricultural land and the time dimension of especially cascading chains. In the first part of this thesis, single parts of multifunctional biomass systems are analysed in case studies, i.e. multi-product use of wheat, hemp and poplar, cascading of short rotation poplar and land requirements of biobased polymer production. By means of these case studies a coherent methodological framework to compare different biomass systems in terms of costs, land demand and CO2 emission reductions is developed and key parameters and issues that influence multi-functional biomass systems with that regard are identified. From the results so far, it can be concluded that multi-product use and cascading have the potential to decrease costs, increase CO2 emission reduction and land use effectiveness of biomass systems. However, this does not apply in general, but depends strongly on the characteristics of biomass material uses involved, e.g. market prices, CO2 substitution factors and lifetime. - Future research. The second part of the thesis applies these methodologies to investigate integrated multi-functional biomass systems. Especially the influences of scale, land availabilities, multi-product use, recycling rates, and price elasticity on the multi-functional biomass system are analysed.