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Waste heat recovery technology from Orcan Energy on energy efficient tanker for the first time

Image of the two oil and chemical tankers from Donsötank, which will be commissioned in 2021. With the help of an efficency PACK each, the waste heat from the thermal oil and HT water system of the engines are to be used to generate electricity.


Munich, 5 October 2020 – The CleanTech company Orcan Energy, leading manufacturer of waste heat recovery solutions, will be supplying its technology to the Swedish tanker operator Donsötank. The family-owned company, with a fleet of five existing tankers, has set a goal for itself to become a leader when it comes to environmental issues. In order to achieve that Donsötank is fitting its two new 22,000-tonne deadweight tonnage tankers for oil and chemical products with the newest and most environmentally-friendly technologies. Orcan Energy supplies the waste heat recovery systems that convert waste heat into electricity to reduce strain on the environment.

The new tankers, designed by the Swedish designer FKAB, are currently being built at Wuhu Shipyard Co. Ltd in China and will be delivered in 2021. Aside from waste heat recovery, Donsötank opted for a low-resistance hull design and the use of the low-emission fuel LNG to reduce environmental impact. Using LNG as a primary fuel is made possible by the 10V31 dual fuel main engine from Wärtsilä.

After the recovered waste heat is partially used for several heating purposes, the remaining part will be used to generate electricity by means of the Orcan technology. Orcan Energy’s efficiency PACK is a waste heat recovery system that is based on an ORC (Organic Rankine Cycle). The efficiency PACK uses waste heat from the thermal oil system and the jacket cooling water to produce electricity, thereby recovering waste heat from both the main engine and the auxiliary engines. In order to do that a heat exchanger transfers waste heat from the thermal oil circuit to the ORC. The HT water is being routed through the efficiency PACKs directly. Here, the refrigerant is evaporated – a non-toxic, non-flammable hydrocarbon – and routed to the expansion machine as superheated vapour. The highly pressurised refrigerant is expanded, thereby driving the expansion machine. The rotational energy is used to drive a generator that produces electricity.

One of the main advantages of the expansion machine inside the system is that it’s very well suited for fluctuating amounts of waste heat, meaning that it retains its efficiency. The efficiency PACK will provide well over 80 kW of additional electrical net power to the ship’s grid while discharging, because of the energy-intensive inerting operations. And also at sea the waste heat recovery system contributes significantly to the on-board electricity demand by feeding back more than 70 kW into the grid.

The efficiency PACKs result in a CO2 reduction of 295 tonnes and fuel savings of around 100 tonnes per vessel. In other words: for both tankers combined the efficiency PACK will save the equivalent of approximately 5,000 gas tanks for cars or the electricity consumption of over 300 German three-person households every year.

Ingvar Lorensson, managing director at Donsötank, explains the choice for this technology: „This generation of tanker is designed with a focus on the energy efficiency from the beginning. To recover the waste heat and convert it to electricity is one step to minimize the emissions. We came in contact with Orcan Energy in an early stage and their solution fits perfectly into our vessels.”

The installation of the efficiency PACKs was supported by the Swedish Environmental Protection Agency. Their Klimatklivet (Climate Leap) initiative aims to reduce emissions that affect the climate by making local investments for the greatest possible climate gain.


About Donsötank

Donsötank is a family-owned company, registered in 1953. Donsötank owns and operates five oil and chemical tankers in additional to the two newbuildings that will be delivered during 2021.