Explosion Protection in Carbon Capture, Utilization & Storage (CCUS) Systems

Carbon Capture, Utilization, and Storage (CCUS): Overview and Explosion Risk

CCUS includes technologies that reduce CO₂ emissions from industrial and energy sectors. It involves three steps: capture, utilization, and storage, each with specific risks and safety needs.

 

 

1. Carbon Capture

First, carbon capture separates CO₂ from gases before or after combustion. Specifically, capture methods include:

• Pre-combustion: First, it converts fuel into hydrogen and CO₂ before burning.

• Post-combustion: Then, it captures CO₂ from flue gases after combustion in facilities like power plants.

• Oxy-fuel combustion: Instead, it burns fuel in oxygen to produce a pure CO₂ stream.

Moreover, several technologies assist the process:

• Chemical solvents (e.g., amines) efficiently absorb CO₂.

• Physical solvents (e.g., Selexol) remove CO₂ using pressure.

• Membranes selectively filter CO₂ from gas streams.

• Solid sorbents capture CO₂ using surface interactions.

Explosion risks arise under certain conditions:

• For instance, flammable solvents such as amines or methanol increase fire hazards.

• Additionally, hot gas streams and reactive chemicals create ignition sources.

To address this, engineers apply:

• Zone classification to define hazardous areas.

• Ventilation systems to disperse flammable vapors.

• ATEX and IECEx compliance for all equipment.

2. Utilization (Carbon-to-Value / C2V)

Next, captured CO₂ can generate value through reuse. Utilization methods include:

• Enhanced Oil Recovery (EOR): Inject CO₂ to recover more oil.

• Concrete carbonation: Then, react CO₂ with cement to boost strength.

• Synthetic fuels and chemicals: Use CO₂ to produce methanol, plastics, or urea.

• Algae cultivation: Meanwhile, grow algae for fuels or food using CO₂.

Explosion risks appear due to:

• Pressurized reactors containing volatile materials.

• Combustible by-products during synthesis.

Thus, protection measures include:

• Gas detection systems for continuous safety.

• LEL monitoring to detect explosive atmospheres.

• Pressure-relief valves to prevent overpressure.

3. Storage

If reuse is not feasible, companies compress and transport CO₂ for underground storage. Storage options include:

• Depleted oil and gas reservoirs, which already contain infrastructure.

• Deep saline aquifers hold CO₂ securely under pressure.

• Unmineable coal seams that can trap CO₂ over time.

Explosion risks may occur when:

• High-pressure CO₂ releases suddenly.

• Injection processes trigger underground blowouts.

Therefore, safety measures involve:

• Blowout preventers to control sudden surges.

• Overpressure devices to maintain system integrity.

• Monitoring systems for early leak detection.

Why CCUS Matters

Importantly, CCUS helps reduce emissions in sectors like cement and steel. Additionally, it supports net-zero goals, especially when integrated with BECCS and DAC. Moreover, it opens economic opportunities in carbon management and clean energy.

Challenges

However, CCUS faces several hurdles. First, high costs for capture and infrastructure limit adoption.  Next, storage sites require long-term monitoring and liability frameworks. Also, without subsidies or carbon pricing, commercial demand remains low. Lastly, regulatory uncertainty and public concerns slow deployment.

Recent Trends

Recently, demand has surged for blue hydrogen, combining natural gas and CCS. Governments also support CCUS through incentives like the US 45Q tax credit. Furthermore, countries like the US, UK, and China develop carbon capture hubs.

4. Explosion Protection in CCUS

Key Explosion Hazards

• Solvent vapor ignition from chemicals like amines and methanol.

• Combustible dust during CO₂ mineralization processes.

• Gas releases from high-pressure pipelines or tanks.

• Auto-ignition in high-temperature synthesis reactors.

Safety Engineering Essentials

To begin, design systems with intrinsic safety using ATEX or IECEx standards. Install gas and fire detectors for CO₂, hydrogen, and hydrocarbons. Use pressure relief devices such as rupture discs and PSV. Then, classify hazardous zones through HAC and follow DSEAR requirements. Finally, conduct HAZOP and SIL studies for all CCUS phases.