Pulp and paper mill steady state analysis for carbon neutral integration of a small modular reactor

Small modular reactors (SMRs) are small-scale reactor designs (< 300 MWe), generally planned for deployment as multi-module nuclear power plants. Due to their small size, SMR modules could be manufactured in a factory and deployed to a site via truck or rail for installation and fueling. SMRs are being evaluated for their ability to provide both power and steam, such that they could be a viable replacement for fossil fuels. SMRs have been considered for coupling to manufacturing processes in addition to being connected to the grid, allowing them to follow the net grid demand in a "load following"operational mode during times of high renewable generation. Alternately, SMRs could be used to replace cogeneration and combined-cycle processes at manufacturing plants which utilize natural gas and other fossil fuels. Idaho National Laboratory (INL) is studying the use of SMRs for large-scale manufacturing processes that require both electricity and steam. The current study examines the integration of a SMR with two mid-size pulp and paper mills in the southeastern United States. The study consists of three parts: steady-state analysis of the mill, elimination of fossil fuel use in the lime kilns, and economic analysis of the modified plant operations. A steady-state model of each mill is developed in Aspen HYSIS based on real data from the operation of each mill. The steady-state model is then modified to include the SMR while maintaining production steam quality and making as few changes to existing equipment as possible. This model gives an estimate of the minimum requirements for SMR output, as well as the change in generation by existing boilers and turbines. With an overall picture of the new plant operation and determining the number of SMR modules required, further changes are suggested to minimize or completely eliminate fossil fuel use from the plant. Apart from steam generation, the largest consumer of fossil fuels at the plant is typically the lime kilns. Conversion of the lime kilns from fossil fuel combustion to electric heating is the most feasible solution to eliminate fossil fuels. This study finds that electric lime kilns are economical when the plant has a surplus This study presents a feasible example of using an SMR as a substitute for fossil fuel cogeneration. If this approach were expanded across the manufacturing industry, it would have a significant impact on environmental emissions and air quality.