Biorefineries hold the potential to provide products and energy carriers at reduced environmental impact compared to their fossil-based counterparts. Thus, they can contribute to the decarbonization of sectors in which electrification of demands is challenging, such as freight transportation or aviation. Furthermore, operating biorefineries in line with renewable electricity availability can help to balance mismatches between electricity availability and demand. This paper investigates the potential of industrial biorefineries to assist the energy transition by providing fossil fuel alternatives and balancing opportunities for the electricity grid. At the example of a Kraft pulp mill, biofuel production potential is explored in consideration of power-to-X technologies. Furthermore, emission reduction and resource efficiency increase by means of carbon capture, utilization and storage applications are investigated. Results reveal that the mill's carbon efficiency can be increased from 50% to 90%, profiting from carbon capture, utilization and storage. Proposed mill configurations provide energy mixes with environmental impact factors well below the average of comparable conventional products. Furthermore, significant shares of energy from imported electricity can be stored over the course of one year, and provided either in form of electricity or biofuels. The profitability and emission mitigation potential of the analyzed system are highly dependent on the available electricity mix and the respective market portfolio. Therefore, future work requires a detailed analysis of the mill's environment in order to identify relevant investment decisions for the provision of low-impact heat, fuels, and storage opportunities for renewable electricity.