CLEAN AT SEA

Motorists in Germany know the problem: if you have a car that emits a high level of toxic pollutants, there are many city centers you can no longer drive through. Only more environmentally friendly motor vehicles may do so unhindered. What many people do not know is that what applies to car drivers also applies to sea captains. Tightened environmental requirements in more and more ocean regions are forcing shipping companies to refit their ships with environmentally friendly drives or install a filter system.

In a pilot project, Wessels Reederei GmbH & Co. KG in Haren is taking a completely new approach: it is the world’s first shipping company to retrofit a container ship with a modern, environmentally friendly liquefied gas drive. Support bearings made of Lignostone® cryogenic play a central role. Of course, they, too, come from Haren – from Röchling.

When the Wessels shipping company’s container ship Wes Amelie returns to sea after its refit, it will be powered by what is known as a dual-fuel concept – a drive that can, as required, run on two fuels, either liquefied natural gas (or LNG) or on conventional marine diesel.

The reason for the pilot project is tighter environmental regulations. The International Maritime Organization has issued new exhaust gas emission regulations for emission-controlled areas (ECAs). ECAs are shipping areas, such as the North Sea and the Baltic Sea, where special environmental guidelines apply. Ships that want to travel there must, in future, be fitted with a low-emission drive, such as a modern, environmentally friendly LNG drive. Ships powered by heavy oil are no longer allowed to travel in these areas nor enter certain harbors. The pollution from ship exhaust fumes is a health hazard and contaminates the water. For example, the waste gas nitrogen oxide causes extreme algal growth in the Baltic Sea.

Fast and Reliable
Shipping companies must refit their fleets and have new ships built with drives that meet the new requirements. There are two particularly important points here. One is that the ships need to be converted quickly to minimize downtimes and revenue losses. The second is that the new LNG drives must be reliable, safe and efficient. So, to convert the Wes Amelie to the new technology, marine engineers with a lot of expertise are in demand. The engineering is being carried out by TGE Gas Engineering GmbH from Bonn.

Thermally Insulated LNG Fuel Tank
One special challenge is the fuel tank in which the liquefied gas is stored. Liquefied gas is natural gas, which liquefies when cooled to minus 164°C. The engineers must therefore permanently thermally insulate the 500 m3 tank from the ship’s structure because if the tank heats up, the energy required to cool the liquefied gas would increase. Conversely, a cold exchange would cause the ship’s structure to freeze. For this permanent thermal insulation, the engineers use special support bearings made from the laminated densified wood Lignostone® cryogenic made by Röchling. These prevent heat exchange between the tank and the adjoining ship’s structure.

Reliable insulation in demand: LNG fuel tanks of modern LNG drives have to be permanently insulated from the ship’s structure.

For modern LNG drives: The laminated densified wood Lignostone® cryogenic ensures the required insulation.

Lignostone® cryogenic is a laminated densified wood made from beechwood veneers (fagus sylvatica), which are joined together with thermosetting synthetic resins under pressure and heat. “The result is a special properties profile that is especially suited to the thermal insulation of LNG,” explains Rainer Sanders, General Manager Sales Composites. The material unites excellent thermal insulation with an outstanding temperature resistance between minus 196°C and plus 90°C, together with high mechanical strength. “This enables Lignostone® cryogenic to reliably insulate the LNG fuel tank, thereby contributing to the reliability of the new drive,” sums up Sanders.

Proven Worldwide
The Lignostone® used in the pilot project is a material that has already proved its worth in international shipping for decades. Lignostone® cryogenic is used worldwide for cryogenic insulation in large tankers that transport liquefied gas. The laminated densified wood insulates storage tanks, measuring up to 180,000 m³, from the ship’s hull and is approved for shipping by many reputable classification societies, such as GL, BV and ABS. More than 100 gas tankers have been fitted out with this material in the last three years.
“With this experience Lignostone® cryogenic offers the best properties for the thermal insulation of LNG fuel tanks and assists the development of new, efficient and environmentally friendly ship drives,” says Rainer Sanders.

 
 

Rainer Sanders
Röchling Industrial
General Manager Sales Composites
Phone: +49 5934 701­-332
rainer.sanders@roechling­-plastics.com

Photos © Reederei Wessels, Röchling