Patented process as a cost-effective alternative to electrolysis

The course to success of Siqens began with special methanol fuel cells. Then came the electrochemical hydrogen separation (EHS) in addition, based on the self-developed HT-PEM-FC stacks. With their help, hydrogen can be separated from natural gas or waste gases from industry and waste incineration with a high degree of purity. The manufacturer also sees EHS in combination with its own fuel cells as a solution to the last mile problem.

Whether in the South American jungle or at an altitude of 3,000 meters in the Swiss mountains, in a research station in the Antarctic or at a border post in northern Scandinavia – in all these places HT-PEM fuel cells from Siquens are in use, which supply electricity for radio and measuring stations or cameras, as Thomas Klaue, managing director of the company founded as a startup in Munich in 2012, states.

The special methanol fuel cells are also, however, in less exotic places: For example, they serve in the lighting of German highway construction sites or aviation obstruction lighting of wind parks. The “Ecoport” FC systems consist of fuel cell stacks with a high-temperature polymer electrolyte membrane (HT-PEM) and a reformer. “In the reformer, pure hydrogen is obtained from methanol,” according to engineer and doctor of business administration Klaue. “This hydrogen then passes through the HT-PEM fuel cell. Our system works with industrial methanol, however, at a fraction of the cost compared to high-purity methanol.”

These systems therefore differ significantly from direct methanol fuel cells (DMFCs), in which a liquid methanol-water mixture is passed through the FC. For that, the methanol has to be as pure as for medical purposes, which is correspondingly expensive, explains Klaue, who has been CEO of Siqens since the end of 2019. The efficiency and power range of DMFCs are comparatively low, and they do not tolerate low temperatures well. Other indirect methanol fuel cells with PEM and reformer are available in both the low and high temperature range, but these would require manufacturer-specific methanol-water mixtures with lower energy density, according to Klaue. With a consumption of 0.6 liters per kilowatt-hour of electricity, Siqens is the market leader in efficiency. The Ecoports, according to Klaue “our bread and butter business,” have a peak electrical output of 800 or 1,500 watts (continuous operation: 500 or 1,000 watts).

FC as a replacement for diesel generators
Methanol, which has long been used in industry, like other liquid fuels, can be transported and stored cost-effectively. Because of this, (methanol) fuel cells are particularly suitable for areas without a connection to an electricity grid and where an uninterruptible power supply must be guaranteed, for example in the emergency power supply for critical infrastructure. Up to now, this function has mostly been performed by diesel generators, but these will little by little be replaced by fuel cells in the future – and not only because of their significantly lower CO₂ emissions: They also work more quietly and are free of particulate matter and nitrogen oxides.

Ecoport 800

Demand for the patented systems, with which the southern German company has been on the market since 2019, is rising. For example, agencies, companies and operators of telecommunications systems are interested in the methanol fuel cells from Siqens, which according to Klaue are robust and reliable and can also be used far away from civilization. This applies to all climate zones, from minus 20 to plus 50 degrees Celsius. What’s more, the operating costs are around 75 percent lower than those of diesel generators. This year, the Munich-based company, which employs around 30 people, expects to sell several hundred of its HT-PEM fuel cell systems.

That the need to use hydrogen and fuel cell technologies for reasons of climate protection is increasing is beyond question today. The Siqens CEO stressed however: “We are convinced that the hydrogen economy will only be a success with price-competitive solutions, especially when it comes to last-mile distribution.”

FC as a replacement for diesel generators
In addition to fuel cells, the company has been offering a very special technical solution for producing pure hydrogen since 2022: electrochemical hydrogen separation (EHS). In this patented process, the feed gas flows through an HT-PEM stack, which is also used in the Ecoport, states Klaue. “The stack with the MEAs is comparable to a sieve that, under tension, is only permeable to the hydrogen molecules that have been reduced to protons on the anode side. On the cathode side, the protons get the electrons back. The product is highly pure hydrogen.” With this method, hydrogen can be separated, purified and processed from very different media. This can be natural gas or exhaust gas that is produced in industrial processes or from waste incineration. The hydrogen can also be obtained from natural reservoirs such as natural gas deposits.

And because methanol is a good hydrogen carrier, the EHS system can also avoid the last mile problem: From the methanol transported via the natural gas network, hydrogen is produced directly on site at the consumer’s premises CO₂-free. “In 10 liters of methanol, approximately one kilogram of hydrogen is chemically bound,” calculates Thomas Klaue. This is more than in a standard 70-kilogram compressed gas cylinder that contains 50 liters of hydrogen compressed to 200 bar. The yield with that is only 0.8 kilograms. Instead of transporting hydrogen in bundles of heavy steel bottles or in pressure tanks by trailer, as was previously the case, a lot of money can be saved through the employment of methanol fuel cells.

Transport and storage costs currently make up the largest percentage of the hydrogen price. “This is even more true if the deployment location can only be reached by helicopter,” added Klaue. “The ratio of transport weight to useful H₂ weight is for methanol ten to one versus one hundred to one for compressed gas cylinders.”

1 kg hydrogen for less than two euros
During EHS, likewise to water electrolysis, electricity is used. However, the energy requirement is significantly lower: Per kilogram of hydrogen, only three to five kilowatt hours of electricity would be needed; so around ten percent of the electricity required for electrolysis. “This produces hydrogen in fuel cell quality at a price of less than two euros per kilogram,” states Klaue. The technology is flexible, scalable and can be adapted to a wide range of gases. Such a system, which only takes up an area of one to two square meters depending on its capacity, can be connected directly to the gas network.

The EHS process could produce a good 100 kilograms of hydrogen per day with three stacks, which is enough for an H₂ refueling station, according to Thomas Klaue. The modular design also allows several tonnes per day to meet the needs of an industrial company. “Electrochemical hydrogen separation is definitely an attractive alternative to other H₂ technologies, as it consumes comparatively little energy and has a high selectivity for hydrogen,” according to the CEO.

Following an initial pilot project in Australia, there is now a second one in Germany: In the Unterfranken city of Haßfurt, hydrogen is being obtained from the natural gas grid using EHS. The municipal utilities of the city are known as pioneers, because they have been relying on renewable energies since the 1990s: photovoltaics, wind power and biogas from farmers in the region. Since 2016, they have had an electrolyzer to generate hydrogen from surplus wind power.

Now, with the help of EHS technology from Siqens, they are tapping into the municipal gas grid as a source of hydrogen. This is done in cooperation with the Helmholtz-Institut Erlangen-Nürnberg and the Institut für Energietechnik of the university Ostbayerische Technische Hochschule Amberg-Weiden. The hydrogen separated from the natural gas is compressed and stored and, as needed, converted into electricity via a fuel cell.

As many gas network operators want to add green hydrogen to their natural gas in the future, such solutions for separating and processing climate-neutral gas could soon become more significant. “By separating the gases using EHS at the point of consumption, the end customer can be supplied directly with high-purity ‘green’ hydrogen,” says Thomas Klaue. In other words, hydrogen of the quality required for industrial processes or fuel cell vehicles. For this reason, Klaue also argues vehemently in favor of maintaining the gas grids.

In February of this year, he publicly appealed to the German economy ministry to reconsider the dismantling plans; for cost reasons alone. “In addition, the planned H₂ core grid will not be able to supply the entire country with green energy for a long time without great effort,” he says. However, because the nationwide gas network is largely suitable for hydrogen, the infrastructure should be used for the future transportation of green hydrogen, to supply industry and communities with climate-friendly energy.