The International Council on Combustion Engines
September 14

CIMAC Circle at SMM 2014

The Impact of IMO Tier III Emissions Legislation on Power Systems.

The customary CIMAC Circle held in the afternoon of 11th September 2014, during this year’s SMM marine trade show in Hamburg, Germany was well attended with 170 registered participants. In the light of the decision at the International Maritime Organization IMO on the implementation of IMO Tier III, its highly topical theme attracted 170 registered participants. With Emissions Control Areas (ECAs) initially only on North America’s coasts, the CIMAC Circle panel was selected to give the audience the views of major stakeholders on the Tier III solutions available and under development from engine builders and aftertreatment makers and provide an insight into the solutions preferred and selected by vessel operators.

The panel was chaired by Dr. Hans J. Gätjens of Bureau Veritas, Germany who presided over contributors Hanne Holstrup Poulsen, MAN Diesel & Turbo, Denmark, Jens Kohlmann, AIDA Cruises, Germany, Christian Skoudal Løth, Maersk Maritime Technology, Denmark and Robert Ollus, M. Sc., Wärtsilä Corporation, Finland. The panel’s contributions can be downloaded (see download links on the right). While the two engine builders, have, as competitors, largely parallel offerings and are essentially pursuing the same emissions reduction technologies, the audience was able to learn from the ship operators about very different needs at two extremes of the shipping spectrum: A.P. Moller-Maersk whose main business centres on the operation of container ships and tankers with low speed two-stroke engines, and leading cruise line AIDA Cruises which operates 10 floating hotels employing medium speed four-strokes. Accordingly, Hanne Holstrup Poulsen of MAN concentrated mainly on two-stroke emissions solutions and Robert Ollus of Wärtsilä on four-stroke technologies. Given the outcome of Tier III at IMO, there was a new factor for ship operators to consider, since for ships with keels laid from 1st January 2016, only those serving North America would require Tier III technology. Christian Skoudal Løth explained that this was a major consideration in the equipment of new vessels. He listed feasible Tier III solutions identified by Maersk Maritime Technology, which works like a consultancy within the A.P.Moller-Maersk Group. They comprised: exhaust gas recirculation (EGR), selective catalytic reduction (SCR), LNG fuelling; cold ironing in port.

Maersk Maritime Technology had performed long term trials of both exhaust gas recirculation (EGR) and selective catalytic reduction (SCR) on MAN two-stroke engines aboard two of its container vessels. Given its more compact, on-engine execution, a preference had emerged for the EGR option as the basic NOx reduction technology on A.P.Moller-Maersk ships. A third vessel, the Maersk Cardiff was now equipped with an EGR engine that had demonstrated full Tier III NOx compliance during testing at sea. Likewise, SOx scrubbers had been tested and found satisfactory, but an issue would be the availability at ports of the sodium hydroxide needed to neutralize the products of scrubbing and disposal of the neutralized residue. In light of the current stage of IMO Tier III, the options were to either install EGR or make provision for retrofit but to what extent? The main concerns of A.P.Moller-Maersk regarding ECAs were not primarily the extra cost for an EGR main engine nor the technical challenges but whether the vessel would operate in North American waters during its lifetime.

With its perceived duty of care for its passengers and imperative of not only projecting a green image but also living up to that image, Jens Kohlmann stated that AIDA Cruise’s obligations also included: a commitment to preserve the environment and to maintain biological diversity; investment in energy efficient technologies; close collaboration with scientific institutions and research partners; the preservation of resources; and, wherever possible, recycling in technological and biological processes. AIDA’s aim was to use comprehensive aftertreatment systems to reduce soot, NOx and SOx by 90 to 99%. From 2015 new ships would feature an innovative air carpet system would also be used to reduce hull resistance and hence fuel consumption / CO2 emissions. As a user of four-stroke engines, three vital elements in AIDA’s Tier III strategy would be dual-fuel engines and, depending on location, the provision of the electrical hotel load in port via plug-in shoreside power; the use of dedicated LNG connections for dual-fuel generator sets; and expansion of its LNG hybrid power barge strategy pioneered in Hamburg port. AIDA had also already installed and tested scrubber technology for the removal of SOx when burning HFO.

Hanne Holstrup Poulsen explained that for IMO Tier III compliance on its low speed two-stroke engines MAN Diesel & Turbo had on offer EGR and SCR for HFO and distillate fuels, with scrubbing as necessary; its ME-GI technology with high pressure injection of methane and ethane; and its ME-C-LGI system of diesel pilot ignition of liquid fuels such as methanol, liquefied petroleum gas, dimethyl ether, and ethanol, as well as other low flash point fuels. All technologies can be applied on all engine platforms giving wide flexibility. A compact scrubber system had been developed and tested and an onboard water treatment system was under development and would be available for ships with keels laid in 2016.

Focussing more on four-stroke emissions reduction, but confirming Wärtsilä’s parallel readiness with two-stroke solutions, Robert Ollus outlined the medium speed Tier III options and their relative benefits. Wärtsilä had evaluated a wide range of Tier III compliance options in terms of both capital expenditure and operating expenditure and, given the present geographic application of Tier III, for both global and regional trade. Under the heading “Otto has beaten Diesel in many respects” he pointed out that gas and dual-fuel engines were not only intrinsically low NOx prime movers, but that projections for the price of natural gas – which is also a no-sulphur fuel - made gas-fuelled engines a very competitive option. Of the two types, dual-fuel provided additional safety in its back-up diesel mode although, of course, this mode was not intrinsically Tier III compliant. At the same time technologies were available for four-stroke Tier III compliance in the forms of: SCR; EGR: high pressure common rail fuel injection with individual accumulators; 2-stage turbocharging; variable valve timing; scrubbers for high sulphur fuels. Capital expenditure was driving single or two-stage turbocharging plus EGR and light fuel oil; operating expenditure was driving two-stage turbocharging, gas fuelling, scrubbers and SCR.

Summing up the proceedings, Dr. Gätjens thanked the panel and audience and noted that tried and tested IMO Tier III solutions were available but they would certainly need to be selected according to types of vessel and the type and geography of their trading. The new legislation would definitely mean more capital investment by ship owners and, vitally, more training for crews. Likewise, ports would be required to provide new facilities i.e. shoreside power connections for cold ironing and/or a gas supply for dual-fuel generator sets to cover hotel loads etc., plus an infrastructure for urea and the disposal of scrubber residues.

Martina Pelzer
Phone: +49 69 6603 1567
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