By Rich Piellisch, HHP Insight

Liquefied natural gas quality – and the standards and practices to maintain it – will be increasingly important as the fuel is embraced for ships, as much of the world’s LNG has a methane content that precludes its use in many common engines.

That was the word from Stuart MacDonald of the LNG new markets team at Shell, speaking at the Poli-techs conference hosted by Clean Fuels Consulting in Brussels late last month.

Natural gas quality, MacDonald said, “varies significantly depending on where it is sourced.” MN (methane number) is consistently high in North America, for example, from 90 to 95, but ranges from 67 to 91 in Europe (heavily dependent on the Middle East and Africa) and 69 to 87 in Asia, (also dependent on Middle East supply).

Tolerant Engines Are Important

“The greatest overall production levels are seen at lower methane numbers,” MacDonald said.

Engine specifications vary too, he said. An engine with a minimum MN specification of 80 can use just 38 per cent of global natural gas supply, while an MN of 70 makes more than 90 per cent of world gas acceptable.

Thus, “a wider tolerance to gas quality by engines across different sectors promotes market growth through greater supply availability.”

“Choosing an engine technology which matches local supply of LNG is crucial for near-term market development,” MacDonald said.

Engine tests for Shell’s new dedicated-LNG powered barges for the Rhine, he said, confirm performance at even the lowest methane numbers. The new vessels have 400-horsepower SGI-16 CGM Scania engines from Sandfirden Technics (HHP Insight, September 18).

Tramp Trade Post-2030

MacDonald’s CFC Poli-techs presentation was titled Gas Quality: Leadership as a Driver for LNG in Transport Markets.

Also speaking at CFC Poli-techs in Brussels, “LNG can offer a compelling value proposition,” said Shell Shipping LNG4T Marine Project Manager Andy Alderson. Market adoption has already started with ferries, service vessels and inland waterway craft, he said, likewise noting that Shell has launched the first of its two 100-per-cent LNG-powered barges (HHPI, March 20).

The market will progress between 2015 and 2020/2025 to short-sea intraregional shippers and cruise ships, especially within emission control areas (ECAs), Alderson said, before spreading to long-haul vessels calling at fixed ports and finally, post-2030, to the tramp trade once an extensive port LNG bunkering infrastructure is established.

Standards, Standards, Standards

Alderson gave a run down on the complicated regulatory situation facing LNG developers, noting that Shell is working with organizations including the IMO (the International Maritime Organization), SIGTTO (the Society of International Gas Tanker and Terminal Operators), and CCNR (the Central Commission for the Navigation of the Rhine).

Items under discussion include machinery shut-down principles, bunkering with passengers onboard, and training and accreditation, Alderson said.

He noted that Shell operates some 1,800 vessels worldwide, and expects about a quarter of them to be using LNG fuel by 2025.

Alderson’s CFC Poli-techs presentation was titled The Unchartered Sea Ahead for LNG Ship & Fuelling Regulations.

This article is reprinted with permission from HHP Insight, available at HHP Insight offers first-to-market, original content on natural gas for high horsepower applications in the marine, mining, rail, and energy exploration and production sectors.