Cleaner soda ash production: A techno-economic assessment of electrochemically-based alternatives to the Solvay process
Year: 2025
Type: article
Abstract: Although environmentally friendly alternatives to the Solvay process for Na2CO3 production have been known for some time, they have not yet been widely adopted in the industry. A systematic evaluation of their energy demands and costs remains limited. In this work, six electrochemical alternatives to the Solvay process are thoroughly assessed, focusing on their energy efficiency and economic viability. The investigated processes consider an NaOH production step by chlor-alkali electrolysis or electrodialysis with bipolar membranes, a concentration step with mechanical vapor compression, the carbonization of NaOH with CO2 in a bubble column, the crystallization of NaHCO3 or Na2CO3∙H2O and finally the calcination of these solids to Na2CO3. The results indicate an 18 to 40 % lower energy demand for five of the investigated process configurations in comparison to the established Solvay process. Apart from that, it has been found that electricity could replace fossil fuels as the main energy source for Soda production. Under the assumptions of a 25-year plant lifetime and a plant capacity of 1,000 t Na2CO3 per day, the processes based on electrolysis could demonstrate economic viability, with net production costs ranging from 0.31 to 0.37 € kg-1 Na2CO3. The processes involving electrodialysis tend to have much higher production costs under conservative assumptions. However, sensitivity analyses show that economic viability can be achieved under favorable conditions, such as reduced energy costs and valorization of low-concentration by-product hydrochloric acid.
Source: Energy Conversion and Management
Authors: Tom Wenzel, Stefan Fogel, Holger Kryk, Uwe Hampel
Language: English
Subfield: Biomedical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,600
OpenAlex ID: W7105987361