A.P. Moller - Mærsk, Wallenius Wilhelmsen, BMW Group, H&M Group, Levi Strauss & Co. and Marks & Spencer are teaming up to explore LEO—a blend of lignin and ethanol—that could be part of the future solution for sustainable shipping.

Around 80% of the goods you use every day are delivered to you by sea. Sea shipping accounts for 2-3% of global CO₂ emissions, a proportion that is set to increase as global trade continues to grow at a sluggish but steady pace. As such, this industry has an urgent need to reduce its environmental impact.

Mærsk and Wallenius Wilhelmsen have teamed up with the University of Copenhagen and major customers including BMW Group, H&M Group, Levi Strauss & Co. and Marks & Spencer to form the LEO Coalition, which will explore the environmental and commercial viability of LEO fuel for shipping.

The marine sector has very different fuel requirements than automotive or aviation.

Shipping requires bespoke low-carbon fuel solutions which can make the leap from the laboratory to the global shipping fleet. Initiatives such as the LEO Coalition are an important catalyst in this process.

—Søren Toft, Mærsk Chief Operating Officer

Lignin is a structural bio-polymer which contributes to the rigidity of plants. Lignin is isolated in large quantities as a byproduct of lignocellulosic ethanol and pulp and paper mills. Currently, it is often incinerated to produce steam and electricity.

Neither lignin nor ethanol separately are currently major biofuel options for the shipping industry. In a report for IEA Bioenergy, two University of Copenhagen researchers noted that:

Commercial production of bioethanol is almost twice as much as biodiesel, with the majority of the fuel used for automotive transportation. Bioethanol has a lower cetane number and lower energy content than biodiesel, though its use reduces the emissions and carbon footprint of shipping operations. The advancement of new multifuel diesel engine technologies can potentially open the marine fuel market for bioethanol, but it will be decades before these technologies can be found in a larger number of the vessels.

As for lignin, the team said:

The production of marine biofuels can potentially be integrated into a biorefinery focused on bioethanol production from e.g. pulp & paper processing or 2nd generation lignocellulosics, where the residual lignin waste can serve as a feedstock for further fuel upgrading. Hybrid technology refers to the production of fuels by both biochemical (fermentation of carbohydrates) and thermochemical (thermal upgrading of lignin) processes. While bioethanol is not a drop-in fuel, the residual lignin can be converted to a drop-in fuel via thermal treatments such as gasification or solvolysis. During these thermochemical processes, the residual lignin is converted to fluid intermediates (gas or oil) which are then catalytically upgraded to hydrocarbon fuels, thereby upgrading low-value lignin to a transportable liquid bunker fuel.

They also observed that Progression Industry in the Netherlands has been collaborating with Mærsk to develop a lignin-based marine fuel—CyclOx—since 2012. CyclOx is a diesel fuel made by mixing cyclohexanone with diesel. Cyclohexanone delays the diesel combustion process, thus allowing the diesel to mix better with oxygen so that less NOx and soot are emitted during combustion. This means that a higher combustion temperature can be permitted in the engine, in turn reducing NO_x.

Once blended with diesel, cyclohexanone also decreases soot emissions. CyclOx fuel has the potential to be produced by extracting oxygenates via depolymerization of lignin, thus making it a second-generation biofuel.

However, researchers at the University of Copenhagen have also been working on a novel and simple noncatalytic process to directly liquefy lignin rich solid residual from second generation bioethanol production by solvolysis with ethanol to produce a bio-oil without the need for exhaustive deoxygenation. The process does not require addition of catalyst or a reducing agent such as hydrogen.

The oxygen content is lowered to <10 wt % (corresponding to an HHV of 36 MJ/kg) and the bio-oil is stable and acid free (verified by NMR), and due to the use of sulfur-free lignin rich residual as feedstock, the resulting oil product is equally sulfur-free.

Our customers’ ambitions on sustainability are increasing rapidly, and we applaud this development. Clearly, LEO would be a great step forward for supply chain sustainability, and it has the potential to be a viable solution for today’s fleet, and not just a future vision.

—Craig Jasienski, Wallenius Wilhelmsen CEO

Sea transport logistics plays an important role for the BMW Group´s vehicle production and distribution processes all over the world. As the company fosters sustainability along the entire value chain the participation at the LEO project is a valuable commitment.

Copenhagen University is currently running the laboratory-scale development of this potential marine fuel. The project aims to move into phase II—testing the fuel on actual vessel engines—in the second quarter of 2020. Following a successful phase II, phase III will begin: the scaling up of LEO fuel production.

Resources

• Chia-wen Carmen Hsieh, and Claus Felby, University of Copenhagen “Biofuels for the marine shipping sector” IEA Bioenergy report

• Joachim B. Nielsen, Anders Jensen, Line R. Madsen, Flemming H. Larsen, Claus Felby, and Anker D. Jensen (2017) “Noncatalytic Direct Liquefaction of Biorefinery Lignin by Ethanol” Energy & Fuels 31 (7), 7223-7233 doi: 10.1021/acs.energyfuels.7b00968