The manufacturing methods of electrolysis, plasmolysis, and methanation, according to the Institute for Ecological Economic Research, are beneficial for cities not only ecologically but also occasionally economically.
Cities might recycle waste materials from businesses and sewage treatment facilities to create sustainable gas utilizing clean energy. Studies conducted by the Institute for Ecological Economy Research (IW) support this. Urban gas production would have obvious ecological and economic benefits and could complement gas imports, even though cities can only meet a small portion of their gas needs this way. The UMAS study, which was supported by the Federal Ministry for Economic Affairs and Climate Protection, uses Berlin as an example to demonstrate this, according to the researchers.
Currently, natural gas accounts for about 25% of the primary energy used in Germany. Elisa Dunkelberg, an energy expert at the IW, asserts that moving away from natural gas is necessary for Germany to soon become carbon neutral as well as for greater supply security.
“To do this, it’s critical to minimize the use of gas in industry, energy generation, and heating. Green hydrogen and synthetic methane should be employed in places where gas cannot be replaced in the future.
The research project UMAS, directed by the Berliner Erdgasspeicher GmbH, looked into how much gas may be produced in Berlin and which processes produce a disproportionately high amount of CO 2 compared to natural gas storage. Conclusion: It would be beneficial for the environment if urban gas production using renewable electricity.
because waste products can be used. since the waste heat produced may be utilized especially effectively, the transit routes and losses are minimal, and This technique also functions as a “power-to-gas” storage technology for the urban energy transition because gas can be stored more effectively than electricity. This is required to account for the shifting demand as well as the so-called “dark doldrums,” during which no wind or solar energy is available. According to the report, there are already viable options for producing hydrogen in cities. The scientists claim that additional investigation and development are required to generate methane on-site.
Sewage treatment facilities may provide the greenest hydrogen.
The so-called wastewater plasmolysis process used in sewage treatment facilities is regarded by researchers as being very affordable and environmentally beneficial. This ground-breaking method, created by the Graforce corporation, separates hydrogen from the ammonium present in sewage water using renewable electricity.
According to Dunkelberg, the procedure presents a huge chance to lower the sewage treatment plants’ harmful nitrous oxide emissions while simultaneously producing inexpensive hydrogen. Although there are sewage treatment facilities in every city, the potential is limited.
Additionally, wastewater from specific industrial sectors, such as biogas plants, flue gas cleaning, and paper recycling, may be acceptable for the procedure. It is predicted that wastewater plasmolysis can meet up to 5% of Berlin’s anticipated hydrogen consumption if all of these potentials are utilized.
“Water is split into hydrogen and oxygen during electrolysis, but plasmolysis is more effective and uses less electricity. As a result, the prices are roughly half as low and can compete with imported hydrogen, “Janis Bergmann, an energy economist at the IW, adds.
However, from an ecological standpoint, the electrolysis process also outperforms natural gas, particularly if the waste heat generated is utilized and fed, for instance, into the city’s district heating network. Urban areas typically have greater production costs than breezy regions like the North and Baltic Seas, nevertheless.
However, it will likely also be essential to create hydrogen in less productive places in order to meet the objectives of the climate policy. Dunkelberg advises cities to maximize their regional potential for plasma and electrolysis of wastewater.
Industry exhaust gases used to produce methane for urban use
The gas grid can already accept hydrogen. ten percent in the now, and twenty percent in the future. However, in the future, locally generated hydrogen might also find its way into pipelines and power plants that were made especially for it. Alternatively, you may use it to generate methane. Urban gas production from methane in cities provides benefits, even if using the hydrogen directly is significantly more energy efficient. Methane is a fuel that can be used without any limitations in the current infrastructure and is simple to store.
Here, the upcycling idea also applies. Carbon dioxide is the main ingredient needed in the creation of methane, along with hydrogen and energy. a waste product that comes from biogas facilities and is also found in other places, like the exhaust from cement manufacturers and waste incinerators. Dunkelberg claims that the CO 2 that had previously just escaped could now be captured, mechanized, and so employed once more for energy. “Of course, when the methane is burned, the carbon is released once more. It, therefore, is not a carbon sink. However, if renewable electricity is used for production, our estimates indicate that methane can be created without impacting the climate.
Further investigation would be required to determine the extent to which Berlin and other cities might independently cover their methane and hydrogen demands, as well as the capital required. In any event, the researchers insist that urban gas production be taken into account in conceptions for the urban energy transition.
