Marine Marchande
SLCE, firm believers in reverse osmosis

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SLCE, firm believers in reverse osmosis

Marine Marchande
Construction Navale

Although SLCE has remained relatively unknown, this Lorient-based company has been steering a steady course through the straits of naval subcontracting since 1989. Today, it ranks highly in reverse osmosis (RO), a technique that is widely used, among other applications, for producing fresh water. Each year, more and more SLCE units are to be found aboard ships and ashore.

 

SLCE's Caudan facility, near Lorient (© SLCE)

SLCE's Caudan facility, near Lorient (© SLCE)

 

“The basic idea dates back to the 18th century, when Abbé Nollet discovered that he could produce fresh water by filtering salt water through the lining of a sheep’s stomach,” says Patrick Riot, one of the two founders (with Gilles Cury) of SLCE Watermakers. Salt can be eliminated from seawater by forcing it through reverse osmosis membranes under pressure. Although the technology itself is simple, it was not widely used or developed commercially until the 1980s. Even then, RO was slow to replace distillation boilers, the traditional method of choice at sea.

Luxury yachts, fishing boats and warships

The founders, however, had always believed in the technique’s potential. When Patrick Riot and Gilles Gury left the SMDO group in the mid-1980s, they decided to continue studying the prototypes they had previously worked on. “An experiment had been conducted some time before on Houat Island off the south coast of Brittany. We decided to improve the principle, primarily by changing the composition and arrangement of the membranes by making them flat. We wanted to design a system that could be mass produced.” The first machine produced 100 litres/hour and was exhibited at the Paris Boat Show. “Because this level of production was a good fit, we initially targeted the luxury yacht niche market. Within a year, we had made contact with all the leading boatyards in France.”

The two SLCE founders soon turned their attention to the fishing industry, where fresh water is essential to keep the ice-making machines well supplied. “The fishing sector is not an obvious market, particularly when trying to sell an innovative product which flies in the face of traditional methods. We had to prove the equipment’s reliability, its ability to withstand tough conditions and its added value.” Piriou was the first boatyard to order an RO unit to top up the 20 tonnes of fresh water that a trawler under construction would normally sail with. The machine was compact, and passed muster. “Word of mouth resulted in other boatyards approaching us and new orders. We installed our equipment on Saupiquet tuna boats, a large boat called Joseph Roty 2, but also on smaller ones.” Throughout the 1990s, the fishing industry was SLCE’s main market.

 

RO plant aboard FREMM frigate Aquitaine (© SLCE)

RO plant aboard FREMM frigate Aquitaine (© SLCE)

 

Once the fishing industry had demonstrated how robust the technology is and shipyards became more familiar with the process and its benefits — not least increased endurance — naval shipbuilders also took interest. “We began with patrol boats for the French customs and coastguard agencies in 1991, followed by public service patrol boats built for the French Navy by CMN.” Contracts followed thick and fast: patrol boats Jonquille and Jasmin built by Couach; retrofits for the French P400 fleet; the Siroco landing platform dock; French naval research vessel Beautemps-Beaupré which left the STX shipyard in 1996; the frigate Jean de Vienne; the Mistral-class LHDs; the FREMM frigates; the Charles de Gaulle aircraft carrier as well as B2M- and BSAH-type support vessels now being built by Piriou; Bayunah-class corvettes for the United Arab Emirates Navy built by CMN, and other vessels destined for international clients. “To date we have installed close to 150 RO units producing 15 to 750 m3/day on French navy vessels and almost the same number on vessels for other countries including Abu Dhabi, Algeria, Belgium, Egypt, Gabon, Indonesia, Kuwait, Mauritania, Morocco, New Zealand, Poland, Saudi Arabia, Singapore  and Thailand.

 

Barge for Morocco built by Damen (© SLCE)

Barge for Morocco built by Damen (© SLCE)

 

Cruise ships and oil & gas

ROs for naval vessels currently represent 20% of SLCE’s workload. “One-quarter of our revenue to date comes from cruise ships. We are now working with STX Saint-Nazaire on the MSC Preziosa and the Europa 2, and also plan to supply units for RCCL’s Edge-class ships, among other clients. Overall, our workload is really diversified.” Through its association with STX, SLCE is delivering two RO plants — each producing 1,350 m3of fresh water a day and 50 of demineralized water —for the AIDA Cruises ships built by Japan’s Mitsubishi Heavy Industries. “We also supply the oil and gas sector with RO units for platforms and ships all over the world. Other markets include service and auxiliary vessels, commercial shipping and the fishing industry.”

 

RO plant for an AIDA Cruises ship ready to send to shipbuilder MHI (© SLCE)

RO plant for an AIDA Cruises ship ready to send to shipbuilder MHI (© SLCE)

 

Land-based plants

Since 2000, SLCE has been developing a range of RO equipment specifically for land-based plants. “These were initially developed to serve remote holiday resorts and areas with unreliable reticulated water supplies. Military bases have found them useful too. We have also installed our RO units on islands with inadequate supplies of fresh water.” In one experiment on Île de Sein, in Brittany, a distillation boiler with an energy consumption of 75 kWh/m3 was replaced by an RO and recuperator plant that consumes just 3 kWh/m3. “Instead of burning 25 litres of fuel oil to produce each cubic metre of fresh water, the facility now requires just 1 litre.”

 

RO plant on Île de Sein, Brittany  

RO plant on Île de Sein, Brittany  (© SLCE)

 

Towards cleaner energy

To keep up with market demand, SLCE has grown to a staff of 28. The company sees innovation as a top priority, and endeavours to make each new model more efficient than the last by integrating improved energy recovery devices such as turbochargers into the upstream portion of the process and heat exchangers known as recuperators into the downstream portion. These measures reduce the energy used to produce potable water. “We constantly strive to advance the technology by testing new membrane materials, optimising mechanical and electrical details and training RO maintenance staff.”

With a range comprising RO units producing 30 litres/hour to those with a capacity of 1,500 tonnes/day for ships and 2,000 tonnes/day for land-based stations, SLCE plans to further expand its international client base. “International customers, mainly in Asia and northern Europe, account for 75% of our sales. As in the past, the way forward is to develop products that meet customers’ needs.”

Written by Caroline Britz, translated by Steve Dyson and Allison Wright.