Parallel Session 6 – Heat and power from biomass and waste

Moderator: Oshada Mendis (NRCan, Canada)

Speakers:

       

Selected conclusions and key messages:

  • Biomass combustion plants provide biogenic CO2 that can be utilized to deliver negative emissions (CCS) or serve as input for green fuels or chemicals (CCU). The first presentation modeled the impact of implementing CCS or CCU at a large wood chip fueled combined heat and power (CHP) plant in Denmark, connected to district heating. The addition of carbon capture has impact on the operation of the plant (less electricity and more heat output), but carbon markets and e-fuel demand also impact the operating hours of the plant and the way it is operated, e.g. changed dynamics of electricity production.
  • Waste-to-Energy (WtE) is defined as processes that extract energy contained in waste/feedstock and convert it into electricity, heat or fuels. Waste-to-energy technologies are critical for achieving net-zero targets as they not only reduce the volume of waste going to landfills but also provide a renewable energy source that can offset fossil fuel use. By converting waste materials into heat and power, these technologies offer a dual benefit—waste management and clean energy generation—while helping countries transition to a circular economy.
  • WtE needs to be considered in a broader perspective, taking a systems perspective that considers how different actors influence each other in the whole system. Participatory system dynamic modelling is a tool that supports the implementation of strategies for the deployment of bioenergy in complex systems where WtE are part of. By adopting a more systematic approach, beyond just the technical conversion, the model incorporates economic, environmental, and social benefits of waste-to-energy projects. Dynamic models can reveal potential synergies in waste management and energy production that otherwise may go unnoticed, optimizing resources and reducing environmental impact.
  • Smart embedding of flexible bioenergy in the energy system is one of the key tools to improve the stability, resilience and security of future energy systems that have increasing shares of variable renewables and higher flexibility demands. Flexible bioenergy provides multiple services and benefits to the energy system under varying operating conditions and/or loads contributing to energy security. Such flexibility makes bioenergy systems a critical component of a resilient and decarbonized energy mix.

  • Residues of enzymatic hydrolysis processes (for the production of ethanol) can be used as solid fuel, e.g. for ovens or steel industries. Nevertheless, properties (energy density, ash content) differ depending on the original feedstock and the pretreatment process and these also determine their usability as fuel.
  • There is a variety of biomass feedstocks and the focus is moving from (clean) wood based material to a diverse range of agricultural material (with higher ash content). Biomass plants in future will need to be more flexible in their feedstocks. Pelletization of agricultural biomass is sometimes difficult due to having very low lignin, which acts as glue during densification. By co-densifying raw biomass with pretreated biomass (torrefied or steam exploded biomass) at optimum ratio, producers can create higher-quality pellets that are more stable, easier to transport, and more efficient in energy production.