Toward sustainable soda ash production: A critical review on eco-impacts, modifications, and innovative approaches
Hamed Rahimpour, Ahmad Fahmi, Sahar Zinatloo‐Ajabshir
Abstract
This article explores the evolution of soda ash production methods, highlighting the shift towards more sustainable practices. It analyzes the environmental and economic challenges of traditional methods, including high energy consumption, pollution, and waste generation. The discussion progresses chronologically, examining obsolete natural methods and their gradual replacement by more efficient techniques like the Solvay Process. However, the production of calcium chloride (CaCl2) as a byproduct in the Solvay Process necessitates further advancements. The article explores promising alternatives such as modified Solvay methods utilizing external CO2 sources and exciting new frontiers like microbial-assisted production. Additionally, it delves into methods utilizing wastes like CaO (calcium oxide) and the potential of layered double hydroxides (LDHs) and cyclic CO2, even though these may generate hydrochloric acid (HCl) as a byproduct. The primary focus remains on the potential of innovative methods based on physical and biological processes to achieve enhanced efficiency, decreased environmental impact, and reduced energy and resource demands.