(219d) Nuclear Energy Application in Refinery and Chemicals Operations

The U.S. oil refining and chemicals productions are essential to national economy and account for about 8% of GDP; however, they are also among the most energy-intensive industrial processes, consuming great amounts of heat, steam and electricity, results in significant greenhouse gas (GHG) emissions. There is a great interest in applying nuclear energy in chemical and refining plants given nuclear is a low carbon and highly reliable and affordable energy source. This study explores opportunities of applying nuclear energy in chemical and refining operations to supply not only electricity, but also heat, steam, and hydrogen[1].

For refinery operation, we simulated the Delaware City Refinery (DCR) plant as a representative case using PRELIM v1.6[2]. Through the simulation, we quantified the DCR refinery energy demand (at unit level) and identified the current energy supply breakdown (e.g. fuel gas, FCC coke, natural gas, etc.). After establishing the baseline information (incumbent operation), we identified opportunities for applying nuclear energy (taking example of small modular nuclear reactor, or SMNR), including providing H2 via high-temperature steam electrolysis, supplying power and steam directly (to replace combined heat and power plant), supplying unit heat directly, providing energy for carbon capture from FCC unit and fluid coker unit. By integrating SMNRs with refinery operations, we can reduce onsite emission by 54% and increase the refinery cost by $4.7-8.7/bbl crude, based on the price spread between SMNR energy and natural gas [3]. The potential scaling and advancement of SMNR can shrink refinery cost increase to 2.5-4.9/bbl crude. The potential economic impact of tax credit is also discussed, narrowing the refinery cost increase by $2-3/bbl.

For nuclear applications in chemical industry, we studied steam cracking operation, one of the most important chemical processes. The steam cracking process is an energy-intensive, endothermic process that converts feedstocks such as ethane, natural gas liquids, naphtha, or gas oil into olefins like ethylene and propylene, operating at approximately 850 °C. Traditionally, steam cracking employs external natural gas or internally generated hydrocarbon (HC) fuel gas for heating, which leads to significant CO₂ emissions—ranging from 0.9 to 1.8 metric tons of CO₂ per metric ton of olefins [4]. Given the challenges of directly substituting these internal fuels with external clean energy sources, we investigated and modeled an alternative approach using Aspen Plus: utilizing nuclear energy to convert the internally generated HC fuels into H2 and solid carbon. The produced hydrogen is then fed into the steam cracking furnace for combustion, thereby eliminating CO₂ emissions associated with traditional fuel gas combustion, while the separated carbon solid can be marketed as a by-product. The process economics and GHG emissions are also evaluated, varying greatly with the grade/property of the carbon by-product.

In conclusion, the combined evaluation demonstrates the versatile role of nuclear energy in reducing greenhouse gas emissions and increase operation resilience in both refinery and chemical operations. The findings offer valuable insights to inform the development of future nuclear integration projects across energy-intensive sectors.

[1] Sun, P.; Cappello, V.; Elgowainy, A.; Vyawahare, P.; Ma, O.; Podkaminer, K.; Rustagi, N.; Koleva, M.; Melaina, M. An Analysis of the Potential and Cost of the U.S. Refinery Sector Decarbonization. Environ. Sci. Technol. 2023, acs.est.2c07440. https://doi.org/10.1021/acs.est.2c07440

[2] J. P. Abella, et al., the Petroleum Refinery Life Cycle Inventory Model, by University of Calgary, https://ucalgary.ca/energy-technology-assessment/open-source-models/pre…

[3] Abou-Jaoude, A.; Lohse, C. S.; Larsen, L. M.; Guaita, N.; Trivedi, I.; Joseck, F. C.; Hoffman, E.; Stauff, N.; Shirvan, K.; Stein, A. Meta-Analysis of Advanced Nuclear Reactor Cost Estimations; INL/RPT-24-77048-Rev001; Idaho National Laboratory (INL), Idaho Falls, ID (United States), 2024. https://doi.org/10.2172/2371533

[4] B. Young et al., Environmental life cycle assessment of olefins and by-product hydrogen from steam cracking of natural gas liquids, naphtha, and gas oil, Journal of Cleaner Production, Volume 359, 20 July 2022, 131884