MAN Energy Solutions’ Dual-Fuel Methanol Genset Passes Type Approval Test

MAN Energy Solutions’ 7L21/31 dual-fuel methanol (DF-M) genset passed a type approval test (TAT) at CSSC Marine Power’s production facility in Zhenjiang, China. Following the successful TAT at CMP’s facility, the methanol-fueled genset received approval from major classification societies present during testing.

“Integrating a methanol system into our L21/31 engine has taken around two years, including some 18 months of testing at MAN Energy Solutions facilities,” said Michael Køel Andersen, Head of Testing, MAN Energy Solutions. “Being able to stand here today with an approved engine and concept – despite the tight timeline and R&D development that was demanded – is an important milestone for our business. It also demonstrates that our gensets are agile and ready for the future market.”

Methanol Genset

The new methanol engine design is based on the MAN 21/31 Mk II type, which is part-load optimized with a fuel-oil consumption in the 1–2 MW range and burns heavy fuel oil/distillate and other biofuels in alignment with the ISO 8217:2024 specification. The L21/31 engine has accumulated approximately 3,000 sales over its lifetime.

7L21/31DF-M genset; image credit: MAN Energy Solutions

“We have seen significant growth within the dual-fuel sector and market demand for fuel-flexible engines is strong,” said Hakon Juel Hansen, Manager of Global Promotion and Business Development, MAN Energy Solutions. “Sales of the 21/31DF-M have already reached double digits since its official market launch in 2024, showing that we are capable of providing solutions to power the merchant fleet in what is a period of uncertainty in terms of customer fuel-strategy.”

According to MAN Energy Solutions, the low-cost, port fuel-injection methanol concept makes the new 21/31DF-M medium-speed, small-bore engine suitable for genset and diesel-electric propulsion applications. In a connection to underway projects, the genset is also a matching system for its methanol-fueled, MAN B&W ME-LGIM two-stroke engine.

“This new methanol concept will add to the volume of over 30,000 genset and propulsion engines already provided to industry by our small-bore, four-stroke business unit,” said Hansen. “MAN Energy Solutions has continuously brought engine concepts to the market, supporting the merchant maritime industry on its path to net zero. With this successful TAT, our customers now have another means of supporting their fuel strategy.”

More MAN Energy News

In late January 2025, MAN Energy Solutions achieved a milestone at its Research Center Copenhagen facility, successfully testing and running its ME-LGIA ammonia-powered engine at full, 100% load for the first time. The company installed its proprietary selective catalytic reduction (SCR) system during full-load testing.

According to MAN Energy, its SCR system was operational during all test loads to treat exhaust gases, with supply and safety systems working appropriately. The next phase of testing will optimize performance and low-emissions capabilities, including injection, SCR systems, and control strategies.

The ME-LGIA engine also offers power take-off (PTO) capability: “The ME-LGIA concept is based on the diesel-cycle combustion principle, which makes it eminently suitable for PTO,” said Christian Ludwig, Head of Global Sales & Promotion, Two-Stroke Business, MAN Energy Solutions. “Prior to this round of testing, we simulated PTO on the ammonia engine with very positive results and are happy to see this replicated in real life. We intend to support PTO on the ME-LGIA to the same degree as with the other diesel-cycle engines in our low-speed portfolio.”