Is this the best way to produce cheap hydrogen?

By Irina Slav for Oilprice.com

When the European Union recently announced large-scale hydrogen production plans as part of its green energy future, many in the solar, wind, and natural gas industry rejoiced. But there is also an emerging avenue for hydrogen production and its rubbish. Literally.

Hydrogen has already established itself as an inseparable part of the energy world of tomorrow when emissions will, hopefully, be minimal of not completely absent. Yet not all hydrogen is created equal: most of the hydrogen produced in the world today—as much as 95 percent—is produced from natural gas, which compromises its “clean” credentials. The rest is produced through electrolysis, using solar and wind power.

While it is theoretically possible to gradually phase out the so-called blue hydrogen, which is the one produced from natural gas, it may well be quite an expensive option. But how about using feedstock that has a negative cost? This is what companies utilizing waste-to-hydrogen technologies are doing.

The reason waste as a feedstock for hydrogen production has a negative cost is pretty straightforward: municipalities are happy to pay someone to take away their trash from the landfills and put it to good use. Sometimes solar and wind electricity also turn negative in terms of cost, when there is overproduction, but these are temporary occurrences and by no means something that could be relied on to ensure the low cost of green hydrogen.

How does the waste-to-hydrogen process work? Well, there are different approaches. One, used by scientists from India’s Institute of Chemical Technology, involves grinding food waste, filtering the larger particles, and feeding it into something called an anaerobic digester, where bacteria break down the waste into gases, with hydrogen featuring highly in the mix. 

Another approach, used by a California startup called Ways2H, also involves processing the waste—including plastics—into small particles. These are then filtered to remove inert materials and fed into a gasification vessel in the company of ceramic beads heated to as much as 1,000 degrees Celsius (1,832 F). The heat turns the waste into methane, hydrogen, carbon monoxide, and carbon dioxide. Then the gases pass through a reforming vessel, where steam breaks down the methane into more hydrogen as well as carbon oxides.

A third approach, utilized by another hydrogen company, SGH2 Energy, takes the thermal process a step further, using plasma torches to break down the waste, which leaves out the production of ash and, according to the company, results in the purest hydrogen possible, as required for use in vehicle fuel cells.

“We can do it cheaper because our fuel is free, in exchange for offering disposal services at no cost to generators. And we can run the plant year-round while electrolysis depends on availability of solar and wind,” the CEO of SGH2, Robert Do, told Arlene Caridis from GreenBiz recently.

There may be more ways to produce hydrogen from waste on the horizon. Hydrogen could make an excellent solution to the world’s unclean energy problem, but its production is still quite expensive if it is to be completely green rather than blue. The negative cost of the feedstock is therefore an advantage for waste-to-hydrogen technologies, as is the fact that the gasification installations can run non-stop, unlike solar or wind-powered electrolyzers. And these processes could eliminate more CO2 than electrolysis.

The EU has stated that hydrogen will have a leading part to play in decarbonizing transport and manufacturing. It has plans to build at least 40 GW of electrolysis capacity by 2030, with 6 GW of these to be up and running by 2024. This is a clear indication that hydrogen as a fuel has a promising future ahead. It might be smart for not just the EU, but for anyone on the decarbonization path.

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