Inert-gas generators for tankers are a mature technology, but incremental changes are still taking place
The teaming up of Finnish maritime services and products provider Wärtsilä with SAACKE, a German-based specialist in combustion systems for seagoing vessels, was big news in the largely inert, inert-gas sector. Central to the agreement is a co-operation regarding safety, in particular with regard to inert-gas systems and gas combustion units. The agreement covers SAACKE’s boilers, exhaust gas economisers, and air-cooled gas combustion units, as well as Wärtsilä’s inert-gas systems and combined inert gas and gas combustion units. Wärtsilä will also make its flue gas system available to SAACKE, making it possible for a single delivery of a boiler and flue gas system.
SAACKE director of marine systems Peter Breidenich said: “Our agreement with Wärtsilä extends our long-standing co-operation to a strategic partnership. This will deliver value to our customers and will improve the market position for both companies.”
Wärtsilä Gas Solutions product line manager for inert-gas systems Geir Hellum said: “We are very excited at the potential benefits this agreement offers, both to the two companies and to their customers. We are confident that by working closely together, we can improve performance for all of us.”
The joint offering targets the LNG carrier and LPG carrier markets, which are expected to remain strong in the near future. For Wärtsilä, the agreement encourages an increased focus on gas systems, while for SAACKE it adds the ability to deliver boilers and inert-gas systems as a single integrated package for tankers.
The Finnish-German strategic alliance faces another big player in the inert-gas generator market, Alfa Laval. The Danish company has just completed a two-year assessment of its new Automatic Fuel Efficiency Module (AFEM), which is a new modification for reducing the fuel consumption of Alfa Laval Smit Combustion inert-gas systems. It does so by ensuring the inert gas that keeps cargo safe during offloading is only generated in the exact amounts required.
In a two-year pilot project, the AFEM allowed Italian shipping company Navigazione Montanari S.p.A. to achieve an average fuel savings of 30%. Based in Fano on the Adriatic Sea, Navigazione Montanari owns and manages a fleet of 21 tankers. It operates worldwide, with a particular concentration throughout the Mediterranean region. In recent years, Navigazione Montanari has been focused on improving environmental standards, especially with regard to minimising CO2 production and fuel waste.
Valle di Navarra, a 40,000 DWT product carrier built in 2002, was selected as the test vessel for the project. The ship primarily sails in the Mediterranean, with gasoil and gasoline cargo. Compared to similar vessels with Smit Combustion systems, Valle di Navarra discharges frequently – up to three times per week – which provided Alfa Laval with ample statistical information on the AFEM’s performance and reliability.
“A failed module could prevent cargo from being discharged, meaning expensive delays in port”
Data collection was one reason that Alfa Laval decided on a particularly long pilot programme, but guaranteeing the cargo’s safety and reliable availability was even more crucial.
“The AFEM modification is part of the inert gas generator’s combustion control circuitry,” said Alfa Laval Inert Gas Systems manager customer support Mart Blankert. “A failed module could prevent cargo from being discharged, meaning expensive delays in port. Working with potentially volatile cargo, we took our time with the pilot to ensure that everything functioned as intended.”
Navigazione Montanari’s technical director, Alessandro Federico added: “The AFEM was designed with capabilities for full override in case of any such problems. Although you expect some issues with any pilot project, we’re glad to say that we never lost a minute of commercial operation with the AFEM.”
Mr Federico also pointed out the close co-operation Navigazione Montanari had with Alfa Laval during the pilot. Alfa Laval’s engineers provided responsive assistance and support to ensure the AFEM performed properly and that the inert-gas system only produced the necessary amount of inert-gas during offloading. This made it possible to greatly reduce the operational expenses related to inert-gas production aboard Valle di Navarra.
“With the AFEM installed, the inert-gas generator capacity is constantly adjusted,” explained Mr Federico. “Purging can never be fully eliminated or avoided in practice, but an optimum setting is maintained. We can see most of the fuel savings at lower discharge rates, where they can be up to 30%.”
For vessels with Smit Combustion systems already installed, the AFEM is available as a retrofit installed and commissioned by a trained Alfa Laval service engineer. For new inert-gas systems, the AFEM will be available as an added option at the time of the original installation.
The retrofit installation option raises the issue of how inert-gas suppliers have fared so far during the Covid-19 pandemic. Alfa Laval’s vice president business unit gas systems, head of inert-gas systems Erik Haveman said that due to the company’s global set-up there has been very little disruption.
The company has also opened a new production facility in Qingdao, China, which Mr Haveman described as state-of-the-art. It is also on the doorstep of the shipyards in China. Shipyards often present owners with an inert-gas generator supplier, one whose installation the yard is familiar with, but the equipment is likely to be used unchanged on the vessel for 30 years. Owners also have a preference, and that too, is often down to familiarity.
Upgrades and retrofit installations in the inert-gas generation sector are quite rare – the equipment is expected to last the lifetime of the vessel. But the pressure to meet decarbonisation and GHG targets has an influence, as in the development of the AFEM system.