A 300 kW CraftEngine can supply 1,650 MWh electricity and reduce 800 tonnes of CO2 emissions annually by using engine cooling water only.

Shipping + waste heat recovery=less fuel and CO2 emissions

What can the shipping companies do to lower their CO2 emissions? Mattias, who attended the Sulphur Cap 2020 Conference in Amsterdam in April, shares his takeaways from the event and outlines some of the options available to the industry.

In April, the International Maritime Organization (IMO) gave shipping nations its biggest challenge yet: to reduce the sulphur content in ship fuel from 3.5 down to 0.5 % by 2020, and eliminate all CO2 emissions by 2050. Needless to say, it will be an expensive undertaking for shipping companies to reach those targets. So, what choices do they have and what’s the cheapest route? 

The Paris Agreement: the shipping industry gets onboard

CO2 emissions from the shipping industry totals 3 % of global emissions (around 45 billion tonnes of CO2) and various studies project shipping’s GHG emissions to grow if tough measures are not taken. For example, the 3rd IMO GHG study foresees an increase of shipping's GHG emissions from 50 up to 250 % by 2050. The 1.5 °C global warming scenario, agreed to in Paris under the UN’s Framework Convention on Climate Change, would however require complete decarbonization of the shipping industry between 2035 and 2050. If shipping emissions peak early or already start to decline, the transition can take longer. However, if it peaks at a later stage, a steeper decline of shipping's CO2 emissions would be needed, with a reduction to zero by 2035. Decarbonization of shipping by 2035 is one of the proposals currently discussed.

The average life of a ship is about 25 years, which makes it vital to start improving current ships and not just new ones. Even if all shipowners would order zero-emission vessels starting today, there would still be a considerable share of vessels that would not reach the emission targets. While sulphur can be removed through gas treatment, GHG emissions is a much harder challenge to crack. 

Recovering waste heat from the ship engines or changing to a more environmentally friendly fuel are some ways to significantly reduce emissions. 

The first challenge: the 2020 sulphur cap 

To limit the emissions of sulphur, shipping companies will have to either install new exhaust gas treatment systems such as scrubbers and filters or start using a cleaner fuel (e.g. marine gas oil). 

Applying a gas treatment system is costly and will require a rebuild of the main component of the catalyst and instalment of new systems that have a delivery time of up to five years. The other option of using a cleaner fuel also comes at a price; it is estimated that this measure will increase operational costs by 50 %. That said, ship operators are most likely to go with this last option, which means they’ll look for ways to reduce their fuel consumption to keep the costs down.

One way to keep the costs down is by turning a vessel’s waste heat into electricity. Waste heat recovery is a smart investment as it tackles both goals at the same time – less fuel means less emissions. 

Viking Heat Engines has developed a heat engine specially designed for waste heat recovery that can easily be installed onboard ships. It’s called the CraftEngine and allows ship operators to use up to 5 % less fuel across all operating conditions without affecting the performance of the engines in any negative way. The CraftEngine can turn exhaust gas, jacket water and scavenge air, or a combination of all three, into electricity.

By implementing the CraftEngine, big sea vessels with 55 MW engines can save EUR 700,000 and 800 tonnes CO2 per year and smaller vessels such as car ferries with 23 MW engines can save EUR 350,000 and 400 tonnes CO2 per year.

Putting the CraftEngine into a global perspective, it has the potential to reduce 45 million tonnes COper year, which is about the same amount as Norway's total annual CO2 emissions. 

This blog post has been written by Mattias Nilsson, Development Engineer at Viking Heat Engines Germany. You can reach Mattias at mattias.nilsson@vikingheatengines.com.

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