Description of the overall initiative

"Energy System 2050" is a joint initiative of the research field energy of the Helmholtz Association. Running until 2019, it is aiming at improving the concrete understanding of energy systems and at developing technological solutions for use by politics and industry. The initiative explores the integration of technological key elements into the energy system and the respective links. It also elaborates solutions to integrate the partially fluctuating renewable energies successfully into German and European energy systems. Its five selected research topics (RT) address fundamental challenges of the Energiewende:

1. Storage and Grids
2. Bioenergy
3. Hydrogen-based Energy and Resource Pathways
4. Life-Cycle-Oriented Sustainability Analysis at System Level
5. Toolbox and Data Models

Description of research topic 4: Life-cycle-oriented sustainability analysis at system level

To successfully continue and complete the Energiewende, it is important that technical and scientific, ecological, economic, and social aspects of the transformation are analyzed comprehensively and at an early stage and incorporated in the process. In research topic 4, a joint method for the sustainability assessment of technologies is developed. This method consists of the elements Life Cycle Costing (LCC) and Life Cycle Assessment (LCA) and an assessment according to social indicators (Figure 1). The method is used to assess three case studies in three research topics (RT 4.2, 4.3, 4.4) exemplarily. The findings and results of the case studies provide the basis for a sustainability assessment at the system level (RT 4.1).

Detailed information on the research topics 4.1 to 4.4 can be found at the following links:

RT 4.1: Development of Methods for Sustainability Assessment at System Level – DLR
RT 4.2: Storage and Grids – KIT-ITAS
RT 4.3: Bioenergy – KIT-ITAS
RT 4.4: Pathway Analysis Hydrogen – FZJ-IEK

Description of research topic 4.3: Case study "Bioenergy"

Based on the findings of RT 2 "Bioenergy", a sustainability analysis of the thermochemical conversion of biomass (Bioliq process chain) is carried out in this research topic.

Starting with a virtual industry location and taking into account the availability of suitable types of biomass, an economic design of the components of the Bioliq process chain for the production of liquid fuels and chemicals is carried out. The modeling of material and energy flows in the process chain provides the basis for both the design of the components and the related estimations of investments and costs. In addition, a life-cycle inventory is created along the whole value chain as a basis for the ecological assessment using the openLCA software in combination with the data base ecoinvent.

The following process steps for the production of liquid and gaseous fuels are assessed for the Bioliq process chain: Shredding and drying of biomass, pyrolysis, gasification, gas purification and conditioning, methanation, DME synthesis/Fischer-Tropsch process (see Figure 2). In addition, the gaseous components of the DME synthesis/Fischer-Tropsch process are fed into a combined-cycle gas and steam process, the pyrolysis gas is burnt in a combustion chamber (see Figure 2). The combined-cycle gas and steam process and the combustion of the pyrolysis gas are mainly intended to satisfy the internal demand for electric energy and heat. Different pathways shall be analyzed for the use of heat and electricity which are not required for intra-system processes. Both, the use by a direct heat and/or electricity consumer and the export into a local or district heating network and/or electricity grid are assessed. In addition, alternatives for a flexible operation and the coupled large-scale production of chemicals (fuels), heat, and electricity are analyzed on the basis of modeled material and energy flows. The optional material flows indicated in Figure 2 form the basis for the analysis of these alternatives.

Statements on the sustainability of the assessed bioenergy system will be made by determining economic, ecological, and social indicators for the different alternatives and the comparison of the process/system with reference processes/systems.