(311c) From Waste to Resource: Pilot-Scale Demonstration of Sustainable NaHCO? Manufacturing

Sodium bicarbonate (NaHCO₃) has been traditionally produced via the Solvay process using sodium chloride (NaCl), ammonia, and carbon dioxide.^[1,2] While NaCl has served as the primary sodium source for over a century, its extraction poses environmental challenges. Recently, sodium sulfate (Na₂SO₄), a byproduct of secondary battery raw material production, has emerged as a promising alternative feedstock, offering opportunities for resource circularity and reduced environmental impact.^[3]

This study presents the first pilot-scale NaHCO₃ production system (1,000 tons/day) using Na₂SO₄ as a sodium source via carbonation in a bubble column reactor. To complement the experimental work, a dynamic process model was developed to capture the temporal evolution of particle size and production yield under varying temperature values.

Experimental results showed a strong dependence on temperature. As the temperature increased from 298 K to 343 K, the average particle size increased significantly (from 8.86 μm to 135.4 μm), while production yield decreased from 69.3% to 12.5%. The developed model successfully reproduced these trends, accurately capturing particle growth stabilization within approximately 7 hours and oscillatory fluctuations in yield over a 20-hour period, attributed to supersaturation and nucleation dynamics.

These findings highlight the potential of combining pilot-scale experimentation with predictive dynamic modeling to optimize NaHCO₃ production using Na₂SO₄. Beyond technical contributions, this approach enables the upcycling of industrial byproducts and presents a sustainable alternative to conventional NaCl-based processes, aligning with carbon neutrality and circular economy objectives in the battery materials industry.

References

[1] Steinhauser, G. Cleaner Production in the Solvay Process: General Strategies and Recent Developments. J. Cleaner Prod. 2008, 16, 833–841.

[2] Steinhauser, G. Cleaner Production in the Solvay Process: General Strategies and Recent Developments. J. Clean. Prod. 2008, 16, 833–841.

[3] Han, Y.; Caamano, T. M.; Yeung, R.; Koc, D.; Bedrossian, S.; Fraser, R.; Stamatiou, A. Sodium Sulfate: Challenges and Solutions in the Lithium Production Industry. Presented at the 63rd Conference of Metallurgists (COM 2024), Montreal, QC, Canada, Aug 21–24, 2024; Springer Nature Switzerland: Cham, 2025; pp 937–943.