HISTORIC EXPANSION OF MAN’s EGR TECHNOLOGY CONTINUES

Last May, MAN Energy Solutions’ Two-Stroke Business announced that it has surpassed 2,000 orders for IMO MARPOL Annex VI NOx Tier III-compliant technologies for its portfolio of MAN B&W two-stroke engines. Today, the company reviews the evolution that has taken place to meet industry demand

NOx Tier III limits were introduced in 2016, and the milestone of 2,000 orders for MAN’s NOx technologies occurred just over a year after the company announced the passing of the 1,000 milestone in January 2021.

Among other statistics, MAN Energy Solutions reported that, determined by bore size, 50- and 60-bore MAN B&W engines account for most NOx solutions (37%). Additionally, exhaust gas recirculation (EGR) accounts for 724 versus 1,292 SCR solutions.

Furthermore, the company reported that some 67 engines were equipped with EcoEGR, representing about 9% of all EGR solutions. EcoEGR is a tuning method that lowers fuel consumption by recirculating a small amount of exhaust gas while operating in Tier II.

EGR prevents the formation of NOx by controlling the combustion process, while selective catalytic reduction (SCR) uses a catalyst and an additive to remove the NOx generated by the combustion process as an after-treatment process.

MAN has long experience with EGR technology and reported its first order in 2011, while its own in-housedeveloped SCR-HP (-High Pressure) won its first order in January 2019. This features a drastically reduced reactorsize, compared to rival systems, to which MAN Energy Solutions has been providing system approval since 2014.

Methanol-fuelled, MAN B&W LGIM engines have a special feature as explained by Kjeld Aabo – Director of New Technologies – MAN Energy Solutions, last year: “Through the use of water emulsion in the methanol, we are able to reach Tier III levels in methanol fuel-mode, completely removing the need for a dedicated NOx-abatement technology. Our introduction of this on our G50-LGIM engine gains us highly valuable service experience – especially in the methanol-carrier segment – while we see a very clear demand for full Tier III-compliance across all fuel types outside this segment by means of EGR.”

Since the first studies into EGR started with MAN Energy Solutions in 2004 and in-service tests were initiated from 2009 both the technology and its use has changed significantly. What at the outset was targeted solely as a measure to comply with IMO NOx emissions requirements, has turned out to become a cornerstone in modern engine design and optimisation, says Lars T. Danielsen, Promotion Manager, Two-Stroke Promotion & Customer Support - MAN Energy Solutions.

First developed purely as a high pressure application for high sulphur HFO, the technology has since then matured and been applied on both high and low sulphur engines, dual fuel engines as high pressure EGR, while R&D efforts and inservice tests have also been conducted as low pressure EGR.

Current versions utilize the high pressure configuration, with its superior response to engine load transients and black smoke prevention, and comes in both the standard tuning for NOx Tier3 compliance configuration as well as the EcoEGR configuration, which provides fuel and emission reductions in both Tier 2 and Tier 3 operation modes.

“Providing compliance for close to 1,200 engines, and increased efficiency for more than 160 EcoEGR tunings and 250 ME-GA engines, MAN Energy Solutions and its licensees offer a wide range of system suppliers for the water treatment system (WTS),” says Danielsen. “Depending on fuel sulphur content the WTS will be tailored to the specific needs, spreading from a fully high sulphur HFO compatible system to the Otto Cycle methane fuelled ME-GA configuration which offers the latest generation 3 system where all water handling system components are incorporated onto the engine, providing superior hull integration and minimum engine footprint.”

In March 2023, MAN received orders from Hyundai Samho Heavy Industries and HJ Shipbuilding & Construction for MAN B&W G80ME-LGIM dual-fuel engines in connection with the construction of 9 × 9,000 teu container vessels for HMM Co. The engines, which are capable of operation on green methanol and conventional fuel-oil, represent the first order for the G80 bore size and will feature MAN’s EGR systems.

Shipping has come a long way in a short period of time when it comes to the uptake of new fuels. MAN Energy Solutions is proud to have brought three technologies – in the form of EGR, and low- and high-pressure SCR variants –to market so that owners and ship designers can select what best fits their individual project.