Table 1 Feasibility summary of electrochemical decarbonization methods
Technique | Lab-Scale Feasibility | Scale-Up Feasibility | Additional Remarks |
|---|---|---|---|
Aqueous Electrolysis45 | Proven; high CO2 levels ease separation and support CCUS | Needs cheaper, efficient electrolytes | High CO2 output helps capture/use, high energy |
ZeroCAL Process54 | Proven; zero-carbon Ca(OH)2 made from seawater and limestone | Medium; depends on EDTA reuse, and membrane life | Requires Ca extraction; zero emissions; co-produces H2, O2 |
Bipolar Membrane105 | Nearly 100% current efficiency; clean gas stream | Possible with smart membranes | Good ion control and gradual CaCO3 input improve performance |
HOR Electrolyzer59 | Lower energy use due to low voltage needs | Promising; needs gas handling system | Works best with low voltage and stable pH |
Sublime Systems51 | Tested on lab-scale with limestone | Being scaled; design and gas issues remain | Can link with current cement systems |
Converts CaCO3 to CaO and C/CO at lower heat | Tough; current capacity ~2 tons CO2/day | Captures carbon as solid or gas; useful for CO2 use and other processes | |
Conventional Seawater139 | Forms minerals by raising pH near cathode | Needs better flow and electrode setup | Makes CaCO3, Mg(OH)2, H2, and O2; good for SCMs and fuels |
Equatic Process87 | Proven in labs; strong CO2 capture and mineralization | Claimed scalable to gigaton-level CO2 removal | Removes CO2 and makes cement inputs; ocean helps scale process |
UF Membrane141 | >90% Ca recovery; uses cheap, tough membranes | Feasible; membrane cost and Cl⁻ resistance help scale | Direct Ca(OH)2 precipitation; suits Mg recovery; needs renewable energy to zero CO2 |
Membrane-less148 | Proven; avoids Cl-related issues | High potential; skips membrane fouling | Works for Mg-cement; simpler and cheaper; scales well with renewables |
Concept tested in labs | Uncertain; safety and scale of Cl2/SOx need work | Aims for large CO2 removal; long-term ocean and energy use need study |
