Carbon-Negative Production of Soda Ash: Process Development and Feasibility Evaluation

Area of Science:

• Chemical Engineering
• Sustainable Chemistry
• Carbon Capture and Utilization

Background:

• Traditional soda ash production is energy-intensive and contributes to CO2 emissions.
• Developing carbon-negative chemical production processes is crucial for climate change mitigation.
• The CODA process integrates multiple technologies to achieve carbon negativity in soda ash manufacturing.

Purpose of the Study:

• To develop and evaluate four distinct variants of the CODA process.
• To analyze the impact of CO2 absorption technology and crystallization strategy on process economics.
• To assess the overall profitability and scalability of the carbon-negative soda ash production.

Main Methods:

• Process modeling and simulation were employed to evaluate different CODA process configurations.
• Techno-economic analysis was performed to compare capital expenditures (CAPEX) and operational expenditures (OPEX).
• The influence of byproduct valorization (hydrogen, chlorine, CO2 certificates) on profitability was investigated.

Main Results:

• The CODA variant utilizing a cross-flow packed absorber demonstrated lower CAPEX (195-209 USD/ton soda) compared to a droplet absorber (337 USD/ton soda).
• A two-step crystallization strategy, combined with the cross-flow packed absorber, resulted in lower OPEX (150 USD/ton soda) than one-step crystallization (175 USD/ton soda).
• Byproduct revenue significantly impacts the CODA process's profitability, with the most promising variant earning approximately 200 USD/ton soda ash.

Conclusions:

• The optimized CODA process variant (cross-flow packed absorber, two-step crystallization) is a technically and economically viable method for carbon-negative soda ash production.
• This process captures approximately 0.15 tons of CO2 per ton of soda ash produced.
• The CODA process presents an attractive, scalable alternative to conventional soda ash manufacturing, offering significant environmental benefits.