Plastic recycling on floating Platform

Millions of tonnes of plastic end up in the sea every year – because there is no waste disposal in many Countries.
A floating recycling factory could prevent that from happening in the future.


Plastic waste as far as the eye can see. Bags hang in the bushes. Empty coke bottles fill the roadside ditch. In the murky water, tires and canisters are drifting. It looks similarly sad, as here, in Senegal’s capital Dakar, in many developing countries.

Globally, experts estimate, more than 300 million tons of plastics are produced each year. The planet is flooded with plastics. What are people supposed to do? “Without functioning waste disposal systems, they don’t know how and where to get rid of their rubbish,” says Martin Wittmaier, managing director of the Institute for Energy and Circular Economy at the University of Bremen. So the waste ends up in the roadside ditch. If it rains, the stuff is washed across the rivers into the sea. Ten million tonnes enter the oceans every year. Marine mammals suffocate at the plastic. The garbage clogs their digestive system. Microplastics damage the genetic material and hormone balance of marine animals. Even in our food chain, plastic arrived long ago.

That has to change. That is why ambitious Projects have recently been started to deplastify the Sea with gigantic raking, swimming buoys or nets. But all of these initiatives are doomed to failure, Wittmaier says. First, the vast majority of plastic particles are far too small, he said. Second, few swim on the surface. Thirdly, the effort that would have to be put into fishing significant quantities from the sea would be out of all proportion to success.

Environmental expert Martin Wittmaier and shipbuilder Berend Pruin from the Hamburg-based maritime consulting company TECHNOLOG have therefore come up with their own solution: They want to ensure that the garbage does not end up in the sea in the first place. Their Idea: A floating recycling factory cruising off the West African coast, animating people to collect the rubbish. The name: “KuWert.” The Abbreviation stands for plastic recycling.

Recycled Plastic is a commodity in demand which brings good money. “600 to 1000 Euros per tonne,” Says Wittmaier. But only if he is clean and well prepared. “Plastic that has been floating in the sea for years, being maltreated by sunlight, is unusable,” Wittmaier says. To complete the team around Wittmaier and Priun, it still needed a recycling plant expert. So Sven Rausch came on board. He is leading the research and development department at the disposal company Nehlsen in Bremen.

Three project partners, one goal: They want to encourage people on land to turn the plastic into money instead of carelessly throwing it away. The floating recycling factory buys the material from them. On land, numerous jobs would be created for collectors. And more highly skilled jobs on board of the floating factory.

Building such a factory on land makes little sense, the experts say. The flow of recyclables is too low and the political situation often too unstable. The ship covers a much larger area. It regularly calling at the 18 main ports along Africa’s West coast, a region the size of Europe: From Mauritania in the North, down to Ivory Coast. The project also involves specialists from Africa, of course, and they know the conditions on site best.

Such a Factory ship must be large and, if possible, must not waver. “An ordinary hull was therefore out of the question,” explains Christoph Rasewsky, Shipbuilder at TECHNOLOG. The Hamburger ship designers have made a name for themselves with the construction of special purpose ships. In case of the recycling ship they rely on a so-called Semi-diver. The 80 by 130 meter platform, similar to a catamaran, is floating on two gigantic skids. They can be filled with ballast water and lower the ship – then it hardly offers the waves less surface and lies calmly in the sea.

Once built, the on-board factory is little different from one on land: Storage areas, conveyor belts, balers, shredders, sorting, washing facilities, cranes and an extruder to process recycled plastics. In the end, so-called recycled granulate tumbling out of the system. This can then be turned into new plastic products later on.

The Ship can process 64,000 tons a year. This is only a fraction of the total amount that ends up in the sea each year. But Africa’s West coast is just the beginning. Recycling-vessels could just as much cruise ahead of Asia, the South Sea or India. The business model is ultimately the same everywhere: Raw material is purchased for around ten million Euros, the recycled granulate generates about 40 million on the market. It’s the ship’s assets. “The business model works solely through value added. We don’t need huge funding,” Wittmaier says.

The amount of waste, and therefore the potential along Africa’s West coast, is enormous: “Every year plastics with a recycling value of 500 million Euros end up in the roadside ditch,” says Sven Rausch. “Our floating recycling factory offers a win-win-win situation: We create jobs, protect the sea and generate material cycles.”

In order for the ship not to cause more environmental damage during construction and operation than it removes through recycling, the shipbuilding specialists have done a lot of work. They have analyzed the environmental balance of all materials. Just as different types of drive. “With LNG as fuel, we achieve the best result,” Rasewsky sums up. The low-carbon Liquefied Gas is used to power generators, which drive two large PODs. These are large electric motors, which are simultaneously propellers and rudders, making the ship particularly economical and maneuverable.

Plastics that cannot be fed into the recycling process end up in the on-board waste incinerator. “Here, a steam turbine generates on-board electricity for the factory,” Rasewsky says. Solar panels on the hall roof and wind generators could provide additional energy.

The concept of the floating recycling factory promises to solve one of the most pressing problems of our time. The Federal Ministry of Education and Research recognized this and funded the study with 420,000 Euros as part of the “Plastic in the Environment” initiative. Implementing the project would cost around 130 Million Euros. The three project partners are convinced that their course is right. All that is missing is the funding.

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Hans-Jürgen Voigt

Managing Director TECHNOLOG services Gmbh