Biomass utilisation in all its facets
The sensible handling of green waste does not prove to be a clear matter. While for many years composting was considered to be the most ecologically sensible use of biomass, for some time now green waste has been increasingly used in biogas plants to generate energy – in conjunction with alternative energies. As part of a project by the Swiss Federal Office of Energy (SFOE), various types of utilisation were investigated and life cycle assessments were drawn up for biomass utilisation.
What is the most ecologically sensible way to recycle green waste? For many years composting was the solution to this question. In connection with alternative energies, green waste is now increasingly being used in biogas plants – energetically. In addition, the efficiency with which the resulting energy can be used has risen sharply in waste incineration plants (MWIP) in recent years. So from an ecological point of view, what is the best way to utilise biomass today?
Project “Life Cycle Assessment of Biomass Utilisation
As a sustainable resource, biomass is an important component of our ecological system. But what is the optimal utilization like? We sought the answer to this question within the framework of a project of the Swiss Federal Office of Energy. In this project, the various types of recycling were investigated using the life cycle assessment method. The aim was to ultimately have a basis for decision-making on the basis of which optimal material or thermal recycling of green waste can be provided. To this end, ecoinvent inventories in ecoinvent quality were first compiled for various processes for different types of green waste:
- thermal use of a waste incineration plant.
As a result, the basis of a tool was developed with which the system of biomass utilisation of a certain municipality or region could be modelled – taking into account the various interactions and regional conditions.
In the course of the project, the following research questions were clarified in order to achieve the goal:
- What are the emissions during composting and fermentation?
- How is humus formation to be assessed?
- Which heavy metals are present in compost and digestate and to what extent?
All questions could be answered during the research phase as far as possible. The resulting data sets for the biomass utilisation of different types of green waste will be made available to the users of life cycle assessments via ecoinvent. In summary, it can be said that not one recycling process is the only one that is right and ecologically superior to the others. Rather, the type of recycling depends on the type of green waste and the given circumstances. This must always be taken into account. If you also want to work with us within the framework of a project, please contact us!