Optimal use of lignocellulosic biomass for the energy transition, including the non-energy demand: the case of the Belgian energy system

Biomass is a key player as a renewable resource for the energy transition required to mitigate climate change. Versatility is its strength as it can be used to produce heat, electricity, fuels or chemicals for the non-energy demand (NED). Therefore, the question arises of the optimal use of biomass in energy systems. In the literature, this optimal use is often determined for one specific situation in terms of greenhouse gas (GHG) emissions and rarely considering the NED. The NED is defined as the demand for energy products used as raw materials. Given the expected simultaneous changes in all industrial sectors, it is important to include the NED in the models of energy systems as they will share common resources. This paper: (1) studies the optimal use of lignocellulosic biomass within an energy system including the NED and (2) analyses the evolution of its role throughout the energy transition. Belgium is taken as case study as it presents a NED corresponding to ~15% of its primary energy mix. The energy system is modelled with EnergyScope TD which optimises whole-energy systems in terms of costs under GHG emission constraints. Local and imported biomass is considered with two potential scenarios. 14 biomass converting technologies are included in the model. It is shown that high temperature heat remains a significant application for biomass in all scenarios and increases when moving towards carbon neutrality. For GHG savings below 50%, biomass is largely used for low temperature heat. However, when aiming at reducing GHG further (>50% reduction), biomass is substantially exploited for the NED. The integration of the NED in the simulations impacts the allocation of biomass in the system, depending on the scenario of potential considered. Electricity from biomass appears for large GHG savings only.