Quantifying integration and cascading benefits when optimizing use of residual biomass

In the future, residual biomass can be a valuable substitute for fossil fuels to satisfy end-use demands both in the energy sector i.e. electricity, heating and for various fuels, but also for non-energy uses such as plastics, feed, fertilizer, flooring and insulation. However, it is still unclear which end-use sectors that should rely on residual biomass and what the benefits of integration and cascading utilization of the residual biomass resources are. This study applies a framework that co-optimizes a network flow model that represents the fuels and non-energy uses with an electricity and district heating model, with the objective of identifying the least-cost system. Apart from global warming, the environmental indicators: eutrophication, and particulate emissions are included in the modeling framework and each associated with a cost. The study is applied to China for the year 2050, and scenarios are defined to illustrate the benefits of making residual biomass available for both energy and non-energy uses as well as including cascading possibilities. The study finds that including use of residual biomass in non-energy sectors leads to 15% lower CO2e emissions. Going further and including cascading uses leads to even more benefits in terms of reduced system costs, emissions of greenhouse gases as well as nutrient losses and particulate emissions. The study quantifies the value of residual biomass and shows that extended possibilities for use of residual biomass has significant economic and environmental benefits not least in terms of reduced eutrophication.