🌫 Carbon Capture at Sea: How Newbuild Vessels Can Stay Ahead of the Regulatory Curve

Davide Ramponi
8. Okt.
5 Min. Lesezeit

My name is Davide Ramponi, I’m 20 years old and currently training as a shipping agent in Hamburg. On my blog, I take you with me on my journey into the exciting world of shipping. I share my knowledge, my experiences, and my progress on the way to becoming an expert in the field of Sale and Purchase – the trade with ships.

Illustration of onboard carbon capture systems showing a cargo ship, CO₂ reduction icons, and an engineer with a sustainability checklist.

If the last decade in shipping was defined by low-sulphur fuels and EEDI compliance, the next one will be all about carbon — how to cut it, track it, and eventually, capture it.

With decarbonization targets tightening and CII ratings driving chartering decisions, one emerging technology is gaining real momentum: onboard carbon capture (OCC).

Once seen as futuristic, OCC is now being seriously considered by shipowners, shipyards, and regulators alike. But installing a carbon capture system isn’t something you add last-minute. It demands early planning, smart integration, and a clear understanding of space, energy, and regulatory trade-offs.

In this post, we’ll explore how carbon capture is entering the world of newbuild vessel design — and why preparing today could define your fleet’s compliance tomorrow.

🔍 In this post, I’ll walk you through:

🌫 What onboard carbon capture (OCC) is — and how it works
🛠 Integration challenges during design and construction
⚖️ Space, weight, and power trade-offs to consider
📜 Regulatory support and upcoming mandates
🚢 Real pilot projects from commercial fleets leading the charge

Let’s look beyond scrubbers and slow steaming — and explore how ships may soon carry miniature carbon plants on board. 🌍

🌫 What Is Onboard Carbon Capture (OCC)?

Carbon capture technology isn’t new — but applying it at sea brings a whole new level of complexity.

🔬 The Basics: How It Works

Onboard carbon capture systems are designed to extract CO₂ from a ship’s exhaust stream, usually after combustion but before the emissions are released into the atmosphere.

Most systems use a chemical absorption process, where exhaust gases are passed through:

🧪 A solvent (like amine) that absorbs CO₂
🔄 A regeneration unit that strips CO₂ from the solvent
🪙 A compression system to liquefy and store the CO₂ on board

💡 Think of it as a compact version of a land-based capture plant — squeezed into the engine room of a moving vessel.

🔄 What Happens to the Captured CO₂?

Once captured and liquefied, the CO₂ can be:

Stored onboard for later discharge at port
Reused in industrial applications (e.g. synthetic fuel production)
Injected into carbon storage systems (e.g. offshore CCS wells)

🛠 Design and Build Challenges: Why Early Planning Matters

While OCC sounds promising, integrating it into a newbuild is not as simple as ordering a new radar system.

🧩 1. System Complexity

A typical OCC system includes:

Capture tower
Solvent storage and circulation
CO₂ compression unit
Chillers and heat exchangers
Storage tanks

Each component must be designed into the ship’s layout — not bolted on later.

📦 2. Space Constraints

Carbon capture systems are bulky. Depending on ship type and capture rate, they can consume:

200–500 m² of deck space
400–1,000 tons of displacement weight
Valuable real estate that might otherwise go to cargo, fuel, or crew amenities

For smaller ships or retrofits, this presents a major trade-off. For newbuilds, it’s an opportunity to design smarter from the start.

⚡ 3. Power Demand

OCC is energy-intensive. Key power draws include:

Pumps for solvent circulation
Compressors for liquefaction
Heat exchangers and cooling units

📉 On some ships, OCC can consume 5–10% of the vessel’s total power output — which must be factored into engine selection, genset sizing, and fuel planning.

⚖️ Weighing the Trade-Offs: Space, Weight, and Emissions

Let’s break down the core trade-offs ship designers must consider.

Parameter	Impact	Mitigation Strategy
Space	Reduced deck or engine room flexibility	Build into design early; elevate or modularize
Weight	Increased fuel burn and structural loads	Optimize hull, use lighter materials
Power	Higher fuel consumption	Recover heat; integrate with hybrid systems
OPEX	Solvent management, maintenance	Plan for service contracts and remote support

💡 Designing for OCC means rethinking the entire propulsion and energy profile of the ship.

📜 Regulation: From Incentives to Mandates

Why consider carbon capture now? Because the regulatory environment is shifting — fast.

🎯 IMO and EU: What’s Happening?

CII ratings will affect charter decisions and vessel profitability
EU ETS (starting 2024) prices carbon per ton emitted — making capture financially attractive
FuelEU Maritime incentivizes low-carbon intensity fuels — OCC may be allowed as a compliance tool
IMO MEPC discussions now regularly include OCC in emissions strategy papers

🌐 In the next 5–10 years, OCC could move from “innovative option” to “required feature” on certain routes, trades, or segments.

💰 Incentives and Support

Some ports are developing CO₂ offloading infrastructure
Flag states like Norway and Japan offer R&D subsidies for low-carbon ships
Charterers are starting to favor vessels with OCC capability in their ESG scoring

💬 Bottom line:

Regulatory and commercial momentum is building fast — and newbuilds without capture-ready design may face future retrofitting costs.

🚢 Real-World Projects: Who’s Already Capturing at Sea?

Let’s take a look at some pilot programs and commercial pioneers pushing OCC forward.

📍 Case 1: Kawasaki Kisen Kaisha (“K” Line) – CCS Demonstration Project

K Line installed a small-scale carbon capture system on the Corona Utility, a coal carrier.

Capture rate: ~1 ton/day
Goal: Validate performance under real sea conditions
Result: System performed well across multiple voyages, confirming OCC feasibility

🔍 Key insight:

K Line is now exploring scaling up for larger vessels and fleet-wide adoption.

📍 Case 2: Samsung Heavy Industries – OCC-Ready Tanker Design

SHI announced a tanker design with integrated OCC layout, including:

Capture tower position
CO₂ storage tanks
Engine integration for waste heat reuse

🧠 Advantage:

By planning OCC from the concept phase, the ship avoids retrofitting — and maximizes cargo capacity despite the added systems.

📍 Case 3: Value Maritime – Compact OCC for Shortsea Fleet

Dutch firm Value Maritime offers a plug-and-play capture scrubber that:

Combines SOx scrubbing with CO₂ capture
Uses onboard storage tanks for liquid CO₂
Targets feeders, coastal, and shortsea ships

⚙️ Rollout:

Several shortsea vessels in Northern Europe have already installed the unit, showing OCC isn’t just for VLCCs.

🔮 What Comes Next: OCC and the Future of Shipbuilding

Here’s what we can expect in the near future:

🧪 More standardized OCC modules from engine and scrubber OEMs
🧭 Design guidelines from classification societies like DNV, ABS, and LR
⚓ CO₂ offloading infrastructure in major bunkering ports
🧠 Digital twins to optimize capture performance and OPEX
🚢 Larger-scale OCC deployment on container, LNG, and cruise vessels

The question is no longer if carbon capture comes to shipping — it’s how soon you’ll be ready.

✅ Conclusion: Building for the Future, Not Just Today

Carbon capture is more than a buzzword — it’s an emerging reality that’s shaping how ships are designed, built, and operated.

Key Takeaways 🎯

🌫 OCC technology captures exhaust CO₂ for onboard storage

🛠 It must be considered during the early design stages

⚖️ There are trade-offs in space, weight, and energy

📜 Regulators and charters are already creating incentives

🚢 Real-world pilots are proving that OCC is technically feasible and commercially viable

Whether or not you install a carbon capture system now, designing for future readiness is one of the smartest decisions you can make during the newbuild phase.

👇 Are you planning for OCC in your fleet?

What challenges — or opportunities — do you see in integrating carbon capture systems at sea?