Green Power-to-X debut

SYNTHETIC NATURAL GAS MAKES ITS COMMERCIAL DEBUT

On a sunny autumn afternoon near the north German coast on Wednesday, 29 October 2021, a select audience gathered to watch the bunkering of a test cargo of 20 tons of LNG onto a 1,036 teu capacity container vessel

Yet the bunkering event itself represented a signifi cant event. The fuel bunkered was synthetic natural gas (SNG) generated from 100% renewable electricity, and the event marked the fi rst time that such a fuel had been used in commercial shipping.

Retrofi tting as key to emissions reduction

The vessel selected for the first bunkering of SNG was ElbBLUE. The 1,036 teu container feeder, which is owned by German shipowner Elbdeich Reederei and operated by charterer Unifeeder, is an example of a successful conversion to dual-fuel operation. When its four-stroke main engine was converted to a MAN 51/60DF unit in 2017, it was the first such conversion of its type globally.

The event was also attended by Stefan Eefting, Senior Vice President and Head of MAN PrimeServ, Augsburg, who stressed that engine retrofits to operate on synthetic fuels would have a crucial role to play in reducing or even eliminating future emissions.

The vessel sailed to St. Petersburg in Russia, where the performance of the vessel would be monitored by a team of engineers from MAN PrimeServ, MAN Energy Solutions’ aftersales division.

The arrival of Power-to-X

While the event focused on the technical achievement of bunkering SNG, the greater implication was that it marked the arrival of green synthetic natural gas (SNG) into the fuel mix for commercial shipping.

The quantity of fuel supplied may have been comparatively limited, and the fuel was supplied at a price that was significantly above other alternative fuels, such as LBG. However, the fact that synthetic natural gas (SNG) produced in Lower Saxony from renewable electricity has been bunkered represents a key milestone.

It was also fitting that the first bunkering of green SNG should occur in Germany, given the importance of German researchers in the history of synthetic fuel production research. The importance of figures such as Friedrich Bergius, as well as Franz Fischer and Hans Tropsch, live on in their eponymous processes.

As Wayne Jones OBE, Chief Sales Officer, MAN Energy Solutions told The Motorship during a tour of the vessel, the bunkering demonstrated that the technology required for Power-to-X to work was both developed and available.

Mr. Uwe Lauber, CEO of MAN Energy Solutions, took a broader view of the challenge of introducing SNG into the marine fuel chain. “SNG is not available in the quantities required by the shipping industry at the moment, so there is a chicken and egg aspect to the discussion”, Dr. Lauber said, adding that “I’m quite sure that the [expansion of renewable

Credit: MAN ES 8 The ElbBLUE

became the fi rst vessel to be bunkered with green SNG bunkering on 29 September 2021

8 The 20t stem of

SNG was produced from renewable electricity at kiwi AG’s plant in Lower Saxony (pictured).

Credit: Audi AG

energy sources to produce green hydrogen] would come. Because there is no alternative to decarbonisation.”

Dr. Lauber also noted that the development of viable commercial business cases for synthetic fuels relied on the introduction of “an appropriate CO2 price”, as well as technical advances in electrolyser production.

Dr. Lauber also noted that the introduction of CO2 from Carbon Capture, Use and Storage schemes would also lower the GHG emissions generated by supplying synthetic natural gas. MAN Energy Solutions was a partner in the current Northern Lights CCUS project, which also involved HeidelburgCement’s Swedish subsidiary, as well as DNV, Equinor and a number of other participants.

Political environment

According to local observers, the inconclusive result of the German parliamentary election in September 2021 is likely to result in the creation of the country’s first three-party governing coalition, with either the Christian Democrats or Social Democrats forming a majority with the Liberals and Green parties. Energy policy and attitudes towards natural gas and hydrogen in particular are just two of the areas where the Liberals and Greens have divergent attitudes.

As such, the bunkering ceremony occurred at a time of intense scrutiny of the decarbonisation agenda in Germany. The event was also attended by senior politicians from Hamburg and Schleswig-Holstein, as well as Germany's national maritime coordinator.

The Motorship notes that the scope of a German federal funding programme for eco-friendly propulsion systems on inland ships was extended to include funding for conventional diesel engine replacements or upgrades earlier in 2021.

Environmental case for SNG and P-to-X

The early adoption of green SNG into the LNG fuel mix would offer significant environmental advantages. Compared with

Copyright: The Motorship

conventional HSFO, SNG offers an 80% reduction in GHG emissions as measured on a well-to-wake basis in CO2 equivalent terms.

This reflects the slightly different content of SNG compared with LNG, as described in ‘What is green SNG’ below.

Mr. Pengg-Buehrlen of kiwi AG added that the Life Cycle Analysis (LCA) for SNG had not yet been concluded, and that was expected to be one of the outcomes from the trial. However, the use of captured CO2, the lower methane number, as well as the absence of upstream emissions, was likely to lead to a clear advantage for SNG in CO2e terms.

A full comparative analysis of SNG as measured against conventional LNG had not yet been completed. Timm Niebergall, Shortsea Director Unifeeder, noted that one of the objectives of the test of the new fuel on board the ElbBLUE was an accurate measurement of the environmental emissions.

8 Dr Uwe Lauber,

CEO, and Wayne Jones OBE, Chief Sales Offi cer of MAN Energy Solutions during a tour of ElbBLUE’s engine room

What is green SNG

Green Power-to-X technologies refer to the conversion of renewable electricity into fuels that can be easily stored and transported. The approach has begun to attract considerable attention in recent years, as it represents a potential solution to the problem of reducing greenhouse gas emissions from so-called diffi cult to abate sectors, such as shipping, aviation and heavy goods vehicles.

The approach used in Brunsbüttel used synthetic fuel generated from 100% renewable energy via H2 production through water electrolysis, and subsequent methanation into synthetic natural gas. As a result, the SNG lowers the carbon dioxide (CO2) footprint of the fuels produced, while producing a fuel that is compatible with existing infrastructure for fuel distribution and bunkering.

The liquefied SNG was produced in a power-to-gas facility in Werlte, Germany, owned by kiwi AG. Originally built on behalf of automaker Audi, the facility has a 6MW electrolyser capacity, based on 3 x 2MW 2012-vintage atmospheric alkaline electrolysers. The electrolysers themselves are robust, and have a "respectable" 65% efficiency level, Hermann Pengg-Buehrlen, CEO of kiwi AG told The Motorship.

The CO2 required for the methanation step is supplied from captured CO2, with further reductions in the upstream GHG emission footprint, while the energy required for the production process was generated from 100% renewable energy sources.

Quality of SNG

The SNG produced by kiwi AG’s hydrogenation process is stable in quality. The gas was successfully used by former owner Audi AG in a pilot programme for passenger vehicles.

While the gas produced by the plant is consistent in quality, it has a slightly lower methane number than conventional LNG, as the SNG does not include some of the other alkanes seen in conventional LNG (such as butane, propane and ethane), PenggBuehrlen noted. SNG also contains lower quantities carbon monoxide and sulphur, although slightly higher levels of CO2 introduces a requirement for a scrubber alongside the liquefaction step.

Economics of SNG production

The cost of the SNG, which was supplied on a commercial basis, is expected to fall as SNG production proceeds along the experience curve. Larger and more efficient electrolyser installations are expected to contribute to the reduction in costs, owing to the weight of electrolyser costs in SNG production. Underlying electricity costs remain a key determinant of production costs: locations with plentiful supplies of low cost, renewable electricity, are expected to emerge as potential production centres.

Mr. Pengg-Buehrlen also noted that new developments, such as the recent introduction of a liquefaction unit developed by kiwi AG in mid 2021, was also expected to contribute to reduce the cost of producing SNG compared with conventional LNG.