The federal government and operators promise to convert the liquid gas terminals in Germany for more climate-friendly energy sources such as ammonia or hydrogen. However, that is not so easy. A feasibility study by the Fraunhofer Institute shows what an immense and expensive challenge this represents.
Expensive and complex: the liquid gas terminals currently being built on the German coast are to be converted later for more climate-friendly energy sources such as ammonia or hydrogen – according to the plan. But such a conversion would be less easy than is often suggested, as a study has now revealed.
Bad investments can therefore only be avoided if certain adjustments are planned now. And even then, great uncertainties remain.
For a long time, liquid gas was considered too expensive, too complex and too harmful to the climate to be competitive. However, in view of the war in Ukraine and the suspension of deliveries from Russia, newly built LNG terminals and floating storage and regasification units should now create new opportunities for supplying liquid gas.
The cooled and compressed methane gas is pumped into these terminals by tankers, turned back into gaseous form and fed into the gas network.
But what if, in the course of the energy transition, natural gas is no longer needed at some point? As early as 2045, the German energy supply is to be managed without fossil fuels, which could turn the LNG terminals into industrial ruins worth billions. In order to prevent this, the plans of the government and operators envisage that the LNG terminals will also store and process more climate-friendly fuels such as ammonia (NH 3 ) and liquid hydrogen in the future.
In a study, Matia Riemer and her colleagues from the Fraunhofer Institute for Systems and Innovation Research (ISI) have now examined whether this is possible, what costs are incurred and what problems can arise with this reallocation. To do this, they evaluated the current state of research based on the specialist literature and conducted surveys of experts from industry and science.
The result is only partially positive: “It is currently unclear whether the terminals, with their high investment costs, can continue to be used in the future,” explains Riemer. Because a flexible change from one energy source to another is not feasible without technical and structural adjustments. Instead, the conversion of the LNG plants for ammonia or liquid hydrogen sometimes requires considerable conversions – and that can be expensive.
The construction of permanent LNG terminals therefore harbors the risk of bad investments or a fossil “lock-in” – the compulsion to continue using the terminals for the fossil fuel methane for economic reasons. In addition, some technologies required for the storage, processing and transport of ammonia or liquid hydrogen have hardly been researched and are at best implemented on a small scale.
The main problem: Ammonia and liquid hydrogen make different technical demands on systems and transport than liquid gas. Ammonia has a higher boiling point than LNG and therefore requires less thermal insulation. However, it is corrosive and toxic. Liquid hydrogen, on the other hand, has an even lower boiling point than LNG and therefore requires better thermal insulation. It can also cause material embrittlement and has a high risk of explosion.
In concrete terms, this means that the storage tanks in the terminals in particular must be planned and constructed from the outset in such a way that they can be converted as easily as possible for ammonia or hydrogen. “If this is already taken into account in the design phase of the LNG terminal, 50 to 70 percent of the investment costs could be retained through continued use,” say Riemer and her colleagues.
Among other things, this could be achieved if, instead of the usual steels, a stainless steel that is suitable for the extremely low temperatures of liquid hydrogen and is resistant to embrittlement is used for the tanks. In the case of a planned conversion to ammonia, the tanks would have to be made of particularly corrosion-resistant steel alloys. What these are, however, has not yet been fully researched.
Another problem is the further processing and transport of the fuels: “There is currently no pipeline network for ammonia in Germany and road transport is not feasible on a larger scale because ammonia is classified as dangerous goods,” the researchers state. If the ammonia is to be further processed into hydrogen, appropriate cracking systems are also required, which split the hydrogen out of the molecule.
However, such plants for ammonia cracking are expensive, consume large amounts of electricity and have hardly been tested on an industrial scale. This could mean that the use of ammonia as an energy source in Germany is too unprofitable.
In the case of liquid hydrogen, it would in principle be possible to transport it via tanker truck or to discharge it in gaseous form via existing natural gas pipelines. With the latter, however, increased losses occur due to escaping gas. In addition, there has been little practical experience with terminals for liquid hydrogen or hydrogen distribution on a large industrial scale. Only in Kobe, Japan, does a small prototype of an import terminal already exist, as the team reports.
If a conversion of LNG terminals is to work, the technical infrastructure required for subsequent steps must therefore be included in advance. “For example, nearby industrial parks can contribute to the exchange of valuable energy waste streams or offer distribution infrastructures such as pipelines, which can be an important criterion,” explains co-author Florian Schreiner from Fraunhofer ISI. Cheap and climate-neutral power sources also play an important role in profitability.
“In order to keep this risk low, a concept for converting the LNG terminals to other energy sources should be drawn up during the planning phase and taken into account when selecting materials and locations,” recommends Riemer. Bringing together industry, infrastructure developers, science, politics and other stakeholders is therefore essential. (Conversion of LNG Terminals for Liquid Hydrogen or Ammonia, Report 2022 (PDF))
Source: Fraunhofer Institute for Systems and Innovation Research (ISI)
This article was written by Nadja Podbregar
The original of this article “Many questions still unanswered: conversion of the LNG terminals involves high risks” comes from scinexx.
