Synhelion and Top Hydrogen Firm Advance Solar Hydrogen
The ETH spin-off Synhelion is working on the commercialization of its solar thermal high-temperature fuels (such as aviation fuel and hydrogen) and has already entered into partnerships with several larger companies that manufacture cement or aviation fuel in order to gradually come closer to its goal of 100% . CO2-neutral fuels by 2030.
The company’s most recent collaboration is with Wood, a world leader in power engineering with a long history of steam reforming natural gas to syngas to produce hydrogen. The 40,000-employee company has now developed a novel technology to use renewable energies instead of fossil fuels to provide the heat required for steam reforming
“We’re going to demonstrate the concept that solar thermal energy can instead be used to power this methane reforming reaction,” said Richard Spiers, Wood Technology Development Director. “Working with Synhelion offers us considerable opportunities in terms of the effectiveness of this energy collection.”
The two companies will test their combined technologies at the DLR solar test facility in Jülich outdoors, with concentrated solar thermal (CST) providing the heat to replace fossil fuels for hydrogen reforming. Wood is testing its new steam reforming technology for the first time.
Synhelion will test its high-temperature CST receiver at 1000 ° C in its first outdoor test “on-sun” and later add a thermal energy storage device. “We’re pretty confident about the performance,” said Lukas Geissbühler, Head of Synhelion Thermal Systems. “Of course, integrating our high-temperature receiver into an outdoor solar field with its changeable weather is more complex than with artificial suns, but we look forward to this challenge.”
If successful, their collaboration would provide a quick route to commercial solar hydrogen at the same low cost as today’s fossil fuel approach. Wood’s traditional steam reforming technology is the market leader in efficiency and is used in more than 120 hydrogen and synthesis gas plants worldwide with a total installed capacity of more than 3.5 million standard cubic meters per hour (Nm3 / h) of hydrogen. So there is a ready global market when this fuel-independent version is tested.
“We estimate that with our solar reforming technology we can drop to 1 euro per kilogram of hydrogen,” explains Geissbühler. With 1 euro to just over 1 USD in USD, this is even lower than the US DOE cost target of 3 USD / kg for the production of green hydrogen.
Green hydrogen technologies
Green (renewable) hydrogen can be produced using either electricity or renewable heat. With electricity, hydrogen (H2) can be split from ultrapure water (H2O) through electrolysis, and if the electricity is 100% renewable, it is green hydrogen.
But using 100% solar heat, an innovative high temperature thermochemical technology that is potentially more efficient is now being innovated by Synhelion and R&D laboratories in Switzerland, Germany, Australia and Japan. By concentrating thousands of “suns” – mirrors that reflect sunlight – on a solar receiver to generate high temperatures of up to 1500 ° C, Synhelion can separate hydrogen from water using redox processes with cerium oxide. This heat-based solar thermochemistry can even split hydrogen from complex liquids such as sulfuric acid (H2SO4).
Synhelion says, however, that the quickest alternative to either green method – electrical or thermal – is to simply use today’s low-cost steam reforming process of methane (CH4), except to replace 900 ° C solar thermal to add the heat for the process deliver. Although it’s not 100% renewable – since methane is still a fossil fuel – solar energy eliminates the other 50% of emissions.
“We are working with Wood to get this solar reforming technology to market faster because they are the absolute reforming experts,” explained Geissbühler, so solar reforming will be the first step in their plans to make solar fuels and hydrogen commercially available in two years’ time.
Solar steam reforming
“Our novel technology is designed to overcome the reliance on combustion as the primary source of thermal energy, and upon successful testing, Wood will commercialize the technology,” said Spiers.
“The company is aware that further increases in efficiency and scalability are extremely important for the introduction of hydrogen as a fuel for the energy transition, and these are the advantages of our innovative technology. The main advantage of coupling to solar thermal energy is the sudden reduction in consumption and the associated emissions. “
100% renewable hydrogen with solar steam reforming
With Synhelion’s solar heat input and Wood’s renewable steam reforming, the heat for steam reforming will be renewable.
“But beyond that, the methane for this steam reforming could come from any source in the future,” Spiers notes. Non-fossil fuel sources for methane include agricultural waste, slaughterhouses, and municipal water treatment.
“If we use methane from a biological source, we can effectively offset 100% of the carbon,” adds Geissbühler.
The two companies have worked together on the project for the past 4 or 5 years. “It became more specific and then we decided to build a large-scale plant together,” says Geissbühler. “We see enormous potential to scale up quickly, so that we can get to market very quickly and at competitive costs with state-of-the-art hydrogen production.”
For the test, the two companies rent the outdoor tower on DLR’s Jülich solar test site with its 80,000 square meter solar field. “We have been working for a few months to develop the R&D facility so that it fits into the existing tower in Germany,” said Spiers. “It was a demanding engineering project for both of them, trying to integrate two technologies into an existing room at the top of a 30-meter-high tower.”
Thermal energy storage is the most cost-effective way to ensure the reliability required for hydrogen production around the clock. Geissbühler explains that they want to use ceramic structures in a one-tank thermocline system for storage. The 250 kW solar receiver from Synhelion is coupled for the first time with the 75 kW reformer from Wood.
“This test unit can be scaled significantly larger than this test,” noted Spiers. The hydrogen industry works in standard cubic meters per hour (Nm3 / h) of hydrogen. “So we usually work on the order of a few thousand to many tens of thousands and have plant capacities of 3,000 to over 200,000 Nm3 / h,” he said, estimating this to be the equivalent of a CST. System between 9MW to 600MW.
There is no such thing as a silver bullet
Since steam reforming requires heat, Wood is also exploring other thermal renewables. “We have various development opportunities that we are examining across our entire hydrogen portfolio,” he commented. “Solar is one of the answers. But the energy transition will not be just one source of energy or one source of hydrogen, there will be countless of them. So we’re looking at a number of technologies, but Synhelion’s solar system looks very promising. “
However, both were skeptical that electrolysis could cut costs enough to compete with the fossil or renewable steam reforming process. “Steam methane reform is currently setting the cost bar,” said Spiers. “The electrolysis organizations cannot exceed a threshold to achieve this round-trip efficiency in order to reduce costs.”
“We can offer such competitive prices because the efficiency of solar thermal is much higher than that of photovoltaics,” says Geissbühler. “The conversion of solar energy into chemical energy in this process is around 30% annually, but if you run PV with electrolysis, you are at 15%.”
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