The World Centre for Maritime Decarbonisation’s Trial Exhibits Shipboard Carbon Seize Is a Lifeless Finish, However Refuses to Say So

Help CleanTechnica’s work by way of a Substack subscription or on Stripe.

The World Centre for Maritime Decarbonisation’s Mission CAPTURED life cycle evaluation is without doubt one of the extra vital paperwork but produced on shipboard carbon seize. Not as a result of it proves the know-how works, however as a result of it lastly grounds the dialogue in measured knowledge throughout an finish to finish worth chain. For years, onboard CCS has been misleadingly offered as a easy and pragmatic bridge. Seize some CO2, retailer it onboard, offload it in port, and let another person take care of it. The LCA reveals what occurs when that concept meets physics, logistics, vitality programs, and accounting guidelines. The result’s catastrophic and must be mirrored that manner, but GCMD’s press launch and govt abstract current it very optimistically, and as a viable choice. This framing is indicative of great challenges at GCMD.

Mission CAPTURED examined an actual pilot. A vessel burning very low sulfur gasoline oil was fitted with an onboard seize system. The system achieved a gross seize charge of a remarkably low 10.7%. The captured CO2 was liquefied, saved onboard, transferred ship to ship, transported lengthy distances, and eventually processed by way of mineralisation pathways producing precipitated calcium carbonate utilized in metal sintering. The research adopted the CO2 by way of each step. Power penalties, losses, venting, transport emissions, and processing emissions had been all counted. The LCA was independently reviewed and verified. This was not a paper train.

The headline outcome from the precise pilot is a web lifecycle greenhouse fuel discount of an approaching homeopathic 7.9%. That quantity already consists of downstream credit for displacing standard supplies. With out these credit, the worth chain doesn’t break even. Below attributional accounting, which is what regulators and compliance programs depend on, the utilisation pathway will increase emissions reasonably than decreasing them. Even when the research extrapolates to increased gross seize charges, the image doesn’t change a lot. At 40% gross seize, everlasting storage delivers roughly a 21% lifecycle discount. That’s the finest case for the storage pathway, and it assumes a set of situations that don’t exist right now at scale and are not possible to ever exist.

These outcomes matter as a result of transport wants deep reductions. Single digit or low double digit reductions aren’t transition pathways. They’re marginal effectivity enhancements. They don’t align with the Worldwide Maritime Group’s acknowledged targets. They don’t align with local weather motion necessities. They might require trivial operational modifications with very low operational and capital prices to advantage consideration. They don’t justify including advanced programs, parasitic vitality hundreds, new logistics chains, and new infrastructure necessities to vessels that already function on skinny margins.

The physics behind these outcomes is easy and unforgiving. When fossil gasoline is burned, the carbon within the gasoline combines with oxygen from the air. The mass of the ensuing CO2 is just a little over thrice the mass of the gasoline burned. That mass have to be dealt with onboard. Quantity is a fair bigger drawback. Liquefied CO2 occupies roughly 4 occasions the quantity of the gasoline that produced it. In gaseous kind at ambient situations, the quantity is nearer to 17 occasions. None of that is negotiable as a result of physics. It defines tank measurement, ship format, stability, and cargo capability.

Capturing, compressing and liquefying CO2 can also be vitality intensive. The Mission CAPTURED pilot confirmed a gasoline penalty of about 5% to six% related to seize and conditioning. That vitality comes from the identical gasoline the ship is burning. It reduces propulsion effectivity and will increase upstream gasoline demand. The LCA paperwork this penalty clearly. It additionally paperwork losses that come up as a result of storage tanks are by no means totally emptied. About 28% of the captured CO2 remained in tanks as heel within the pilot, as a result of physics. Liquid CO₂ can’t be pumped down like gasoline as a result of it should stay above a minimal stress and liquid head to keep away from flashing, cavitation, and lack of stress management. Because the tank empties, thermodynamic instability, pump limits, and pressure-vessel geometry power operators to cease unloading early, leaving a big residual “heel,” usually on the order of 20–30% with liquid CO2, decrease with LNG. One other 2.4 tons had been vented throughout transfers. These aren’t edge circumstances. They’re operational realities of dealing with cryogenic liquids in a marine setting.

These constraints sharply restrict the routes the place onboard CCS would possibly even be thought-about. Lengthy voyages accumulate an excessive amount of CO2 to retailer with out sacrificing cargo or redesigning vessels round waste storage. Brief voyages cut back the storage drawback, however that instantly raises the query of why CCS is being thought-about in any respect when options exist. To be clear, options resembling biomethanol and battery hybridification, vastly extra commercialized already, additionally embody tradeoffs, however the carbon emission reductions justify them.

For example, a 24,000 TEU container ship crossing from Shanghai to Los Angeles will burn on the order of two,600 tons of very low sulfur gasoline oil (VLSFO), which turns into roughly 8,100 tons of CO₂ as soon as oxygen from the air is added throughout combustion. If that CO₂ had been captured and saved onboard, it will occupy about 7,500 to eight,000 m³ in liquid kind, roughly thrice the quantity of the gasoline consumed on the voyage, earlier than accounting for the extra mass of pressure-rated tanks, insulation, and refrigeration programs. Extra importantly, it reverses the ship’s regular weight trajectory. As an alternative of ending the crossing about 2,600 tons lighter as gasoline is burned, the vessel would end carrying roughly 8,100 tons of captured CO₂. The distinction between these finish states is a swing of about 10,700 tons, a number of p.c of the ship’s deadweight. In sensible cargo phrases, storing the CO2 from a single Shanghai–Los Angeles crossing would occupy roughly 7,500 to eight,000 m³, equal to greater than 200 TEU by quantity. By mass, the roughly 8,100 tons of captured CO2 is similar to 700 to 1,000 common loaded TEU on a transpacific route. Not like containers, nevertheless, that is non-revenue payload that have to be carried in insulated, pressure-rated tanks with security spacing, making its efficient area and stability influence bigger than the uncooked numbers recommend.

That swing needs to be managed longitudinally and transversely to keep away from unacceptable trim and stability impacts. As a result of liquid CO₂ have to be saved in insulated, pressure-rated tanks, it can’t merely be unfold arbitrarily by way of the hull. Possible places are restricted and compete immediately with cargo area, ballast preparations, equipment boundaries, and structural design. Concentrating massive volumes close to the engine room creates trimming moments, whereas distributing storage fore and aft requires a number of massive tanks with their very own foundations, piping, and security zones. Even with cautious placement, partially stuffed tanks introduce free floor results that erode stability margins and impose operational constraints on tank administration. All of this complexity is imposed to retailer a rising waste stream during the voyage, which helps clarify why storage losses, retained heel volumes, and dealing with emissions seem as persistent options within the GCMD LCA reasonably than pilot anomalies, and why onboard CCS scales poorly as voyage lengths improve.

The logistics of transferring captured CO2 are the place the idea turns into weakest. Within the pilot, CO2 was transferred ship to ship, then moved roughly 2,200km by truck to achieve the utilisation facility. Transport emissions had been a dominant contributor to the worth chain footprint. The LCA reviews round 375kg CO2e emitted per ton of CO2 offloaded simply from offloading and transport. That quantity alone erases a lot of the seize profit. The report treats pipeline transport and shut co-location as optimisation eventualities, not as present actuality. That distinction issues. Ports right now aren’t geared up with CO2 pipelines, intermediate storage, or sequestration hubs. Only a few are planning to construct them. If this reminds anybody of the common failure of hydrogen for transportation—lengthy distance trucking of hydrogen inflicting vital and emissions prices—it’s by no means shocking. Each applied sciences have very comparable downsides.

CO2 dealing with is waste administration. It doesn’t generate income until somebody is paid to take the waste or until accounting frameworks assign worth to averted emissions elsewhere. Everlasting storage has no intrinsic financial return. It requires subsidies or mandates. Utilisation pathways depend on displacement credit that assume good substitution of present merchandise. These assumptions are more and more scrutinised by regulators.

The broader carbon seize discourse confirms what the maritime lifecycle evaluation implicitly reveals about onboard CCS: carbon seize solely delivers significant emissions outcomes when the chemistry, geography, and economics align in its favor, not when it’s utilized to dilute combustion exhaust on a transferring ship. In my current assessment of carbon seize’s real looking future, I current the argument that CCS solely is sensible the place carbon dioxide streams are from biogenic sources, are already concentrated, the place the supply sits close to safe storage or quick pipelines to storage, and the place coverage or market incentives give captured carbon actual worth. All over the place else, seize is outcompeted by electrification, vitality effectivity, or course of substitution, as a result of the vitality, transport, and infrastructure prices outweigh the local weather profit. That framing underscores why capturing small fractions of exhaust on a container ship, compressing and transporting it lengthy distances, and counting on downstream credit produces marginal lifecycle beneficial properties at finest, and why the broader local weather group more and more sees carbon seize as a distinct segment instrument reasonably than a normal resolution to emissions.

The mineralisation pathway examined in Mission CAPTURED illustrates this clearly. Processing the CO2 into precipitated calcium carbonate (PCC) emits near 0.95 tons of CO2e per ton of CO2 processed as soon as electrical energy, reagents, and losses are counted. About 35% of the CO2 coming into the method isn’t fastened and is launched. The pathway solely turns into web constructive as a result of the produced materials is assumed to displace standard PCC and associated inputs. Below consequential accounting, that displacement is credited. Below attributional accounting, which assigns emissions to the actor performing the exercise, these credit aren’t obtainable. In that framing, the CCU pathway will increase emissions.

The report is cautious and clear about this distinction. It doesn’t cover the accounting dependency. What it doesn’t do is draw the strategic conclusion that follows from it. If a decarbonisation pathway solely works underneath one accounting framework and fails underneath the one almost definitely to be utilized, its viability is questionable.

To enhance outcomes, the research layers on a set of optimisations. Waste warmth restoration is assumed to eradicate reboiler gasoline use. Transport distances are diminished from 1000’s of kilometers by truck to some hundred by pipeline. Venting losses are practically eradicated. Tank matching is improved in order that a whole bunch of tons of CO2 are offloaded per journey as an alternative of tens. Mineralisation effectivity is raised from 65% to 90%. Electrical energy grid depth drops from about 565g CO2e per kWh to underneath 200g. Every of those modifications improves the numbers. Collectively, they produce headline reductions of 60% to 70% in hypothetical eventualities.

The issue isn’t that these enhancements are inconceivable. The issue is that none of them are managed by shipowners, most require parallel decarbonisation and infrastructure buildout elsewhere, and most of them are deeply unlikely. This isn’t a bolt on resolution. It’s a tightly coupled system that solely works if ports, energy grids, transport networks, and industrial processes all change in coordinated methods. That could be a excessive bar, particularly when easier choices exist.

These easier choices are already being deployed. Inland and quick sea transport is electrifying. On the Yangtze River, 700 TEU container ships function on routes of round 1,000km utilizing containerised swappable batteries built-in into port operations. Absolutely battery electrical ro ro vessels carrying as much as 2,100 passengers and 700 automobiles are on order, and barely smaller ones are present process sea trials. These ships ship reductions on the order of 90% to 100% on a lifecycle foundation relying on grid combine. They don’t require waste dealing with infrastructure. They use ports that already deal with electrical energy. They scale with grid decarbonisation reasonably than combating it.

Towards that backdrop, onboard CCS seems to be much less like a bridge and extra like a cul de sac. It presents very modest reductions at excessive complexity on routes the place electrification is most viable. On lengthy haul routes the place electrification is tougher, storage constraints dominate. This leaves a slender and shrinking area of interest.

The excellence between the press launch, the chief abstract, and the physique of the Mission CAPTURED report issues as a result of every tells a special model of the identical outcomes. Learn finish to finish, the report reveals that onboard CCS has no viable path to scale and features as a distracting useless finish, regardless of by no means saying so outright. The manager abstract sits between the information and the narrative. It reviews the important thing numbers precisely, however frames the shortcomings as issues of optimisation and future enchancment reasonably than as structural limits. The press launch goes additional, leaning into finest case eventualities and “potential” outcomes in a manner that reads as validation. The issue isn’t that any of those layers are factually mistaken, however that neither the press launch nor the chief abstract is blunt about what the proof implies. When an actual world pilot delivers single digit web reductions, depends upon consequential accounting, and scales poorly with voyage size, that’s not a minor implementation hole. It’s a discovering with strategic implications. On this case, readability would have been extra beneficial than optimism.

What would a practical, correct and zero-spin press launch / govt abstract appear to be? Vastly completely different:

Utilizing generally utilized attributional accounting guidelines aligned with present IMO tips, an independently reviewed life cycle evaluation by GCMD’s Mission CAPTURED finds that onboard carbon seize delivers no web greenhouse fuel profit and may improve whole lifecycle emissions relative to working with out seize. Below these guidelines, downstream “averted emissions” from potential CO₂ use aren’t credited, and the extra vitality use, dealing with losses, and transport emissions dominate the outcomes.

Within the pilot, the system captured roughly 10.7% of onboard CO₂ emissions. After accounting for the vitality penalty of seize and liquefaction, onboard storage losses, ship-to-shore switch, and downstream transport and dealing with, the LCA reveals no significant CO₂e takeout underneath commonplace accounting, and in some circumstances a web improve in emissions in comparison with the no-capture baseline.

Solely when the evaluation shifts to consequential accounting and assumes that captured CO₂ is reliably transported to industrial services that completely bind carbon or displace high-emission supplies does the system present a modest web discount, on the order of single-digit percentages underneath pilot situations. Attaining even these marginal beneficial properties requires in depth extra infrastructure that doesn’t exist at scale right now, together with low-loss logistics, close by utilisation or storage websites, and tightly coordinated dealing with programs.

Even in modelled enchancment eventualities with increased seize charges and optimized logistics, enhancements are within the low double digits and outcomes stay extremely delicate to assumptions and rely on constructing and working a fancy, capital-intensive shore-side worth chain.

The evaluation subsequently signifies that onboard CCS isn’t a plug-and-play decarbonisation measure, delivers little to no profit underneath prevailing accounting guidelines, and solely turns into marginally constructive underneath various accounting frameworks that assume substantial new infrastructure and idealised downstream outcomes.

GCMD recommends primarily based on the in depth work finished on this pilot that onboard carbon seize and sequestration schemes not be thought-about viable as a decarbonization method. For its half, GCMD is terminating its shipboard carbon seize pilot efforts as a way to dedicate extra sources to approaches which have advantage, resembling electrification and biofuels.

The scope of the research didn’t embody options, so the essential selections don’t have to be spelled out, however at the least talked about. The entire failure of onboard carbon seize and the absurd stage of infrastructure required to get to not practically adequate is ample to make it not an choice. GCMD ought to have stated that, however didn’t.

An analogous sample seems in GCMD’s ammonia bunkering pilot, which suffered from the identical narrowing of scope that blunted the worth of the onboard CCS work. The pilot was framed so tightly round protected switch procedures that its main discovering was that ammonia may be moved from shore to ship with out spilling. That’s not a significant discovery. Ammonia has been produced, saved, transferred, and transported globally for many years, together with in massive volumes by tanker, rail, and pipeline. Demonstrating that hoses, valves, and procedures may be designed to keep away from leaks doesn’t tackle the arduous questions that decide whether or not ammonia is a viable marine gasoline at scale. The pilot didn’t meaningfully have interaction with upstream manufacturing emissions, gasoline price, engine effectivity penalties, NOx management, crew security over lengthy voyages, port publicity threat, or the systemic challenges of constructing a worldwide bunkering community for a poisonous gasoline. By constraining the experiment to what was best to show, the pilot averted the problems that matter most and ended up confirming solely what was already properly established. As with onboard CCS, the outcome was technically tidy however strategically uninformative, and it missed a possibility to make clear whether or not ammonia is a critical decarbonisation pathway or an alternative choice that appears believable solely when examined in isolation. For anybody , ammonia isn’t remotely a viable alternative as a maritime transport gasoline.

This issues as a result of establishments don’t simply generate knowledge, they set course. When pilots show {that a} pathway delivers marginal reductions, scales poorly, and depends upon accounting selections which can be unlikely to outlive regulatory scrutiny, saying so clearly isn’t non-obligatory, it’s the level of doing the pilot. GCMD did the arduous half properly. The underlying work is cautious, the information is strong, and the report is unusually clear about losses, vitality penalties, transport emissions, and the distinction between consequential and attributional outcomes. That makes the failure extra consequential, not much less. Having assembled proof that strongly undermines onboard CCS as a decarbonisation pathway, GCMD selected not to attract the strategic conclusion its personal evaluation helps. By deeply downplaying the implications within the govt abstract and amplifying optimistic interpretations within the press launch, it formed a story of potential the place the proof factors to a scuppered ship. In doing so, it failed in its most vital institutional function, which isn’t to advertise exercise, however to assist the sector cease pursuing choices that don’t work and redirect capital, engineering effort, and coverage consideration towards those who do.

I had hoped GCMD would grow to be a filter for the maritime sector, closing doorways in addition to opening them, and stated so to Lynn Bathroom, GCMD founder and CEO a few years in the past once we spoke. The ammonia and CCS pilots had been each clearly for useless ends that couldn’t compete with electrification, effectivity, and sustainable biofuels on carbon discount, security or economics. Helpful pilots would have been structured to check them, not justify losing extra time on them. The biofuels markers work reveals extra promise, grounded in actual displacement reasonably than speculative chains. The problem for GCMD now’s institutional. Persevering with to advertise pathways that ship single digit reductions dangers delaying choices that ship order of magnitude enhancements. My advice is that Bathroom and the GCMD Board rethink their goal and governance. The yawning chasm between the optimistic press launch and the report makes it clear that they’ve backed into being a useless finish promotion company, not a reputable tester of decarbonization pathways.

The Mission CAPTURED LCA doesn’t show onboard CCS works. It reveals why it it’s a useless finish. The physics, the logistics, the vitality penalties, and the accounting realities all level in the identical course. Onboard CCS isn’t a reputable decarbonisation pathway for transport. The info says so, very clearly. The yawning chasm between the optimistic press launch and the small print within the report makes it clear that GCMD has backed into being a promoter of useless ends that it’s properly funded to pursue, not a reputable tester of decarbonization pathways.