. 2023 Nov 15;9(12):e22341. doi: 10.1016/j.heliyon.2023.e22341

Table 1.

Different CO₂ capture technologies with their potential characteristics.

CCTs	Characteristics	Novel Technologies	Existing Challenges	Future Recommendations
Absorption process	Can be used as pre-combustion carbon capture and post-combustion carbon capture. Conventional absorbents: Mono-ethanolamine Chemical absorbents Aqueous ammonia Alkaline solution Dual-Alkali Ionic liquid Deep-eutectic solvent Modified Solvay Physical absorbents-Selexol Rectisol Purisol	Instead of single solvents, mixed solvents are used in novel adsorption technologies. Some mixed solvents are as follows-MEA-DEA, MEA-K₂CO₃, PEI-SiO₂, DEA-MDEA, POSS containing NOHMs, Amine infused microgels (AIMGs), Alcohol/Amine/H₂O.	The high corrosion rate of equipment Solvent selection Type of reaction Solvent emission A large volume of the absorber is required. Energy consumption is high. The presence of SO₂ and O₂ in flue gas causes solvent degradation. The energy penalty is high due to regeneration.	Developing novel solvents with higher CO₂ absorption capacity, lower regeneration rate, less toxicity, and more stable, and will show better performance with lower volume. Establishing such systems which will consume less energy. System equipment corrosion rate should be minimum.
Adsorption process	Used for post-combustion carbon capture. Chemical adsorbents: Amine-based materials Lithium-based materials Calcium-based materials Ionic liquid-impregnated Metal salts, metal oxides, double salts. Physical salts: Metal organic frameworks (MOFs), Zeolites, Zeolitic Imidazolate frameworks (ZIFs) Blended adsorbents Microporous organic polymers. Technologies: PSA, VSA, ESA, ET-PSA, TSA.	Different mixed adsorbents have been used in novel processes of adsorption. These sorbents include-Amine Silica Aerogel, PEI-Silicagel, MOF-74(MS), K₂CO₃/Mg₂Al_0.9Ga0_0.1-CO₃, K₂CO₃/Mg₃Al–CO₃, LDHs, LDOs, AMO-LDH, FAC.	Low selectivity of CO₂ Selection of sorbent materials Large pressure drop may be problematic. Enhanced capacity with hydroxides of sodium and potassium and faster synthesis with MS.	To achieve high capacity of the adsorbent and to obtain high selectivity, adsorbent materials should be modified. The simplicity of the adsorption mechanism is required. The adsorption system should be nontoxic, and environment friendly.
Membrane-based CC	Used for post-combustion carbon capture.	Polyvinyl alcohol with DEA, PVDF with ionic liquid support, liquid in membrane pores, etc.	Adverse impact of moisture on permeability of polymeric membrane. Ionic membrane viscosity. Impact of operating conditions on performance of the membrane. Requirement of the large surface area of membrane to obtain higher flow rate of flue gases. High manufacturing cost. High selectivity is required.	Manufacturing different membrane materials with high selectivity of CO₂ and better performance. For commercialization, lab-based experiments are required to understand the behavior of different membrane materials.
Cryogenic	Suitable for high concentration and large volume of CO₂. Set-up cost is much high so at the industry level, it's feasible only if the amount of CO₂ is much higher.	CCI with MCFC, FPSC	Less suitable for a lower volume of CO₂. Solid CO₂ accumulating at the heat exchanger surface can cause poor heat transfer and lower efficiency of the system. More energy consumption Moisture can cause blockage if it's not removed before cooling.	More research must be carried out to investigate the performance of different cryogenic CC technologies. Developing novel technologies for cryogenic carbon capture.