Carbon Capture and Storage - possibilities??

There has been a lot of discussion on Carbon Capture and Storage (CCS) technologies to help transition to Net Zero, however many of these are high energy processes in themselves requiring parasitic use of fossil fuels to drive them or they are being used to capture some of the CO? produced by burning the fossil fuel itself. Here I am trying to organising my thoughts as to what Carbon Capture technologies look the most promising and what are the best uses for this captured Carbon. With Direct Air Capture (DAC) being commercialised, there may be a time soon where we can have useful amounts of CO? extracted for better uses. ?

Carbon Capture and Storage (CCS)??

Capturing CO? directly from industrial sources or ambient air and storing it underground in geological formations such as depleted oil and gas fields or deep saline aquifers.??

The main benefit of this method is that it prevents CO? from entering the atmosphere, effectively reducing greenhouse gas emissions.?It is often used in conjunction with Enhanced Oil Recovery (EOR)?where injecting the captured CO? into oil reservoirs to increase oil recovery while sequestering the CO?. This is often the oil industry’s preferred solution as they get “green” technology kudos whilst improving levels of fossil fuel extraction from wells. It does therefore provide an economic incentive for CO? capture and storage, though it does result in the production of more fossil fuels.?

Carbon Capture and Utilisation (CCU)?

This is a good solution where any CO? captured can be used to develop higher value materials rather than hiding it underground. ?

I have worked with companies developing Synthetic Fuels?which utilised CO? in combination with hydrogen (produced via renewable energy) to create synthetic hydrocarbons like methanol, methane, and aviation fuels through processes like Fischer-Tropsch synthesis and methanol synthesis.?This is well developed technologies, it depends primarily on the catalysts and the return on energy deployed to manufacture to make it economic.? These synthetic fuels can be carbon-neutral, providing a sustainable alternative to fossil fuels.??

Perhaps more interestingly CO? is a major Chemical Feedstock and can be converted into valuable chemicals such as urea, polycarbonates, and other chemicals used in the production of plastics and synthetic fibers.?The major benefits of this approach can reduce reliance on fossil-based raw materials and lower the carbon footprint of chemical manufacturing.?

A more elegant and “natural” use would be to use it in biological processes.?Applying CO? enrichment in greenhouse agriculture to boost plant growth and yields is a relatively common practice. It increases agricultural productivity while absorbing more CO?. However, the CO? is not captured for long and through the processes of consuming what is produced the CO? is again released. Using CO? to cultivate microalgae, which can be processed into biofuels, animal feed, or bioplastics.?Algae can absorb large amounts of CO? and provide valuable co-products. The potential for manufacturing more locked-in carbon in the form of biochar as a soil enhancer is a possibility with biological processes. ?

Longer storage techniques include mineralisation through Carbonate Formation. The process consists of reacting CO? with naturally occurring minerals (e.g., magnesium or calcium silicates) to form stable carbonates.?This method has the benefit of permanently sequestering CO? in a solid, stable form and can be used in construction materials like concrete and aggregates.??

Another long-term process is Accelerated Weathering where enhancing the natural weathering process of certain minerals to sequester CO? can be induced. This can be integrated into industrial processes or soil amendment practices to enhance carbon capture in soils.?

As a chemist I am quite intrigued by the recent developments in Innovative Materials such as Carbon Fiber and Polymers?from CO?. Converting CO? into carbon fiber or carbon-based polymers for use in lightweight, high-strength materials should reduce the carbon footprint of materials used in industries such as automotive and aerospace.??

Less useful CO? can be used directly in products like fire extinguishers, refrigerants or unhelpfully carbonated drinks. ?

Challenges and Considerations??

As I have pointed out requirements for many CO? utilisation processes are energy-intensive. The source of this energy should be renewable to ensure overall carbon neutrality.?To ensure economic viability the costs associated with CO? capture, transport, and conversion need to be competitive with traditional methods.?Also the scalability of these technologies must be great enough to have a meaningful impact on global CO? levels.?This will probably only happen through Governmental Funding and Regulatory Support. Governments must support policies and incentives are crucial to promote investment and development in CO? utilisation technologies.?

EXAMPLES:

Here I rank the technologies based on their usefulness in eliminating CO? from the atmosphere involves considering their Return on Energy (RoE), capital equipment costs, and the volumes of CO? they are likely to extract and store/sequester. ?

1. Direct Air Capture (Climeworks, Global Thermostat)?

• RoE: Moderate. Requires significant energy input, but can be optimised with renewable energy sources.?
• Capital Equipment Costs: High. Advanced technology and infrastructure are expensive.?
• Volume of CO? Extracted: High. Capable of capturing large volumes directly from the air.?
• Overall Usefulness: Very High. Directly targets atmospheric CO? and can be coupled with storage or utilization technologies.?

2. Mineralization (Blue Planet Ltd., Skyonic)?

• RoE: High. The process can be exothermic and integrate with existing industrial processes.?
• Capital Equipment Costs: Moderate to High. Requires setup for reaction processes and material handling.?
• Volume of CO? Extracted: High. Permanently sequesters CO? in stable forms like carbonates.?
• Overall Usefulness: High. Provides long-term storage with the potential for significant CO? reduction.?

3. Mineralisation of Concrete (Solidia Technologies, Carbon Cure Technologies)?

• RoE: High. Embeds CO? in concrete, a widely used material, which can be done with minimal energy input.?
• Capital Equipment Costs: Low to Moderate. Integrates with existing concrete production facilities.?
• Volume of CO? Extracted: Moderate to High. The construction industry has vast potential for CO? utilization.?
• Overall Usefulness: High. Combines CO? reduction with the production of essential construction materials.?

4. Enhanced Oil Recovery (Using CO?)?

• RoE: High. The process itself is energy-efficient.?
• Capital Equipment Costs: Moderate. Requires infrastructure for CO? injection and oil recovery.?
• Volume of CO? Extracted: Moderate to High. Utilizes significant amounts of CO?.?
• Overall Usefulness: Moderate. Helps store CO?, but results in additional fossil fuel production.?

5. Synthetic Fuels (LanzaTech, Twelve)?

• RoE: Moderate. Conversion processes are energy-intensive but can be powered by renewables.?
• Capital Equipment Costs: High. Requires advanced catalytic and fermentation technologies.?
• Volume of CO? Extracted: Moderate. Converts CO? into usable fuels, recycling it rather than storing.?
• Overall Usefulness: Moderate. Provides a sustainable fuel source but does not permanently sequester CO?.?

6. Biological Utilization (Algae Cultivation) Article?

• RoE: Moderate. Biological processes can be energy-efficient but require optimal conditions.?
• Capital Equipment Costs: Moderate. Requires bioreactors and cultivation facilities.?
• Volume of CO? Extracted: Moderate. Algae can absorb large amounts of CO? but have limits based on cultivation scale.?
• Overall Usefulness: Moderate. Produces valuable biomass but requires large areas and specific conditions.?

7. Carbon to Chemicals and Polymers (Covestro, Newlight Technologies)?

• RoE: Moderate to High. Chemical processes vary in energy requirements.?
• Capital Equipment Costs: Moderate. Requires chemical processing infrastructure.?
• Volume of CO? Extracted: Moderate. Can significantly reduce CO? footprint in the chemicals industry.?
• Overall Usefulness: Moderate. Converts CO? into valuable products but not typically in large volumes.?

8. Conversion to Graphene (Levidian Nanosystems Limited)?

• RoE: Moderate. Plasma-based processes can be energy-intensive.?
• Capital Equipment Costs: High. Advanced plasma reactors and supporting infrastructure are costly.?
• Volume of CO? Extracted: Moderate. Produces high-value graphene but in smaller volumes relative to other methods.?
• Overall Usefulness: Moderate. Converts CO? into high-value materials but with limited volume impact.?

Summary?

Direct Air Capture - Most direct method, though costly and energy-intensive.?

Mineralization - High potential for permanent CO? storage.?

Carbon Cure Technologies - Practical integration with concrete production.?

Enhanced Oil Recovery - Efficient but linked to fossil fuel production.?

Synthetic Fuels - Sustainable fuel production, not permanent sequestration.?

Biological Utilization - Effective but scale-limited.?

Carbon to Chemicals and Polymers - Valuable products, moderate CO? impact.?

Reduction to Carbon - High-value graphene, moderate volume impact.?

Direct use Applications e.g. Carbonated Beverages - Low overall impact, niche applications.?

This ranking considers a balance between technological feasibility, economic factors, and the potential for large-scale CO? reduction.?