MAN Energy Solutions says China’s Stage II – commonly known as the C2-emission standard (GB15097 regulation) – due to enter into force in July 2021 will drive demand for its L21/31 engine.
The new legislation will primarily apply to inland waterways, coastal areas and most rivers, covering domestic bulk carriers, feeder containers, oil tankers, passenger Ro-Ros and government vessels. The company expects the introduction of C2 to grow sales of its small-bore, four-stroke MAN L21/31 engine type as a result.
Directive limits relate not just to NOx and hydrocarbons (HC) but also to particulate matter (PM), which MAN Energy Solutions noted is ‘attracting increased focus from the maritime industry’. The limits are said to be particularly challenging for type 2 marine engines with single-cylinder displacements of under 15 litres, and an overall power output of <2,000 kW.
‘As soon as C2 came on the horizon, we realised it was an excellent opportunity for our MAN L21/31 engine, whose compactness, low fuel-oil consumption and power rating make it particularly suited to this segment,’ said Finn Fjeldhøj, Head of Small-Bore, Four-Stroke Engineering, MAN Energy Solutions.
According to Fjeldhøj, extensive testing has shown that the engine complies with C2 particulate-matter limits without needing a particulate filter, while an SCR system will be required to meet NOx requirements.
‘In practice, such an SCR system will be sparingly employed to optimise engine efficiency and limit after-treatment operational expenses,’ said Fjeldhøj. ‘We are confident that this practical solution will win favour in vessels sailing Chinese inland-waterways.’
MAN Energy Solutions says the L21/31 can fulfil classification requirements as both controllable-pitch-propeller (CPP) propulsion and genset applications. Based on recent research, the company is already capable of pursuing the engine’s official emission certificates from the China Classification Society but continues to develop more advanced solutions with its licensees to further reduce the environmental impact of the engine, as well as customers’ operational costs.