Energy economic evaluation of solar and nuclear driven steam methane reforming processes

Changing the high temperature heat supply of energy intensive industries from today's mostly fossil sources to nuclear or renewable sources offers the opportunity of massive reductions of greenhouse gas emissions. Even though the high temperature gas-cooled reactor (HTGR) as well as the solar tower is technically capable to supply heat at the required high temperature level, it is uncertain whether these technologies can compete with the fossil energy supply. Therefore, the aim of this paper is the assessment of the economic competitiveness of process heat supply by HTGR or solar tower to fossil fired processes using steam methane reforming as industrial example process. Applying a self-developed optimization model, energy economic analyses are conducted for nuclear, solar and fossil energy supply systems. The results are benchmarked with the Hydrogen Economic Evaluation Program (HEEP) of the International Atomic Energy Agency (IAEA) and compared to literature values. The analyses show that hydrogen generation costs of the solar tower system are higher than those of the HTGR system. Both technologies benefit from the support of a fossil heater, as the hydrogen generation costs can be significantly reduced even with a small amount of burned natural gas. Nevertheless, a steam methane reforming process run by HTGR or by solar tower is not yet competitive to the natural gas fired hydrogen production.