CII ratings announced

In its most recent study, the International Maritime Organization (IMO) says CO₂ emissions from international shipping are estimated to have increased by more than 9% from 2012 to 2018. It also reports that in a series of planning scenarios they could be between 90 and 130% of 2008 levels by 2050. The organisation says it is committed to reducing these emissions, as it works to meet its ambition of reaching net-zero as close to 2050 as possible. In support of this goal, IMO has introduced a number of measures.

The carbon intensity indicator (CII) came into force in 2022 for ships over 5,000 gross tonnage (GT), with the collection of fuel consumption data mandatory in 2023. This allowed the first energy efficiency rating, measured in ‘grams of CO₂ emitted per cargo-carrying capacity and nautical mile’, to be made in 2024. Ships could then be given a rating from A to E, where ‘A’ is the best and the required index is ‘C’ or above. This straightforward rating system is designed to give a very clear indication of how efficiently a ship transports goods or passengers.

A ship rated ‘E’ for one year or ‘D’ for three years needs to implement a plan of corrective actions to meet the ‘C’ category.

First CII ratings awarded

IMO reports that the first set of data has been submitted by 28,620 ships, with a combined 1,301 million GT. Of those ships, for the 2023 reporting period, 24,653 ships reported operational CII ratings.

78% of the CIIs reported met the ‘C’ or better target. However, 1,541 vessels reported an ‘E’ rating, which means they must now adopt a plan of approved corrective action. However, CII gets harder to attain year on year. A 2% reduction factor will be applied every year from 5% in 2023 reaching 11% by 2026, with further reduction figures for 2027 to 2030 under development.

This means some of the 3,931 ships reporting a ‘D’ in 2024 could soon slip into the ‘E’ category and even those ships reporting A-C ratings cannot be complacent.

IMO is set to review the effectiveness of CII implementation by 1 January 2026, and to develop and adopt further amendments if needed. Penalties for non-compliance could be introduced as part of these measures.

The good news for owners and operators is that, because the IMO regulations are technology neutral, they are free to choose how ships gain and/or retain the required rating.

And, there is a long list of available efficiency options, energy saving technologies and new fuels to choose from. However, some of these require significant investment while others can impact profitability.

The use of net-zero carbon fuels, such as ammonia and hydrogen, would bring some of the largest CO₂ reductions. But, their wide availability is still some way off, and their use requires significant investment in either a new vessel or engine retrofitting, where possible.

Combustion improvers increase efficiency today

What the industry needs is a cost effective, readily available solution that is easy to introduce today. The use of proven combustion improver fuel additives, which allow more complete combustion of marine fuels through catalytic action, is just such an option.

The use of fuel additives as a way to improve fuel efficiency is endorsed by Marine Environmental Protection Committee Resolution MEPC.213(63).

In static engine testing in highly controlled conditions, Infineum’s combustion improver additive has provided significant and reproducible improvements compared to untreated fuels. In addition to CII improvement, lower emissions and better operation, improved fuel stability can help to minimise fuel lost as sludge - helping hardware stay cleaner for longer and reducing operating costs. Also, the additive can improve scrubber operation by reducing turbidity and wash water treatment.

Following extensive field trials in a variety of ships, the Infineum technology has been awarded a letter of no objection from a major four-stroke OEM and has been verified as an emissions reduction technology by an independent class society.

To reach the IMO net-zero 2050 ambition, the maritime industry will need to embrace the use of net-zero carbon fuels and Infineum is already working to develop additive technologies to support their introduction. But, in the transition period, while the production of these new fuels ramps up and industry works to introduce the infrastructure and procedures needed to safely deliver them, other carbon reduction solutions are needed.

The use of proven combustion improvers is an easy to implement CO₂ emissions reduction strategy.

Their use can contribute to an improved CII rating, without the requirement for capital expenditure, while also helping to reduce emissions, operating costs and downtime.

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