Article Making hydrogen fuel from waste plastic may whup green version (engineering options)

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Making hydrogen from waste plastic could pay for itself
https://www.eurekalert.org/news-releases/1001547

INTRO: Hydrogen is viewed as a promising alternative to fossil fuel, but the methods used to make it either generate too much carbon dioxide or are too expensive. Rice University researchers have found a way to harvest hydrogen from plastic waste using a low-emissions method that could more than pay for itself.

“In this work, we converted waste plastics ⎯ including mixed waste plastics that don’t have to be sorted by type or washed ⎯ into high-yield hydrogen gas and high-value graphene,” said Kevin Wyss, a Rice doctoral alumnus and lead author on a study published in Advanced Materials. “If the produced graphene is sold at only 5% of current market value ⎯ a 95% off sale! ⎯ clean hydrogen could be produced for free.”

By comparison, ‘green’ hydrogen ⎯ produced using renewable energy sources to split water into its two component elements ⎯ costs roughly $5 for just over two pounds. Though cheaper, most of the nearly 100 million tons of hydrogen used globally in 2022 was derived from fossil fuels, its production generating roughly 12 tons of carbon dioxide per ton of hydrogen... (MORE - details, no ads)

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This a rather 'young' technology..

From: https://onlinelibrary.wiley.com/action/d...uppMat.pdf
Page 18..

The reaction feedstock is processed in batches of 0.5 g.
This requires 25,552 reaction iterations to process
12.97 kg of precursor.

The first problem is that this isn't a continuous process .. zap and scrape the carbon gunk off the sides of the reaction vessel. The most obvious way to remove the carbon would be C + 02 -> CO2 which rather defeats the object of the exercise.
The other problem is that although the amount of plastic waste from 22 million UK households is vast .. per household (mine at least) the actual amount is quite small .. perhaps with the energy content of two small lumps of coal a week. Collecting the equivalent of two small lumps of coal from every household might have some business potential .. but I don't see it as an immediate winner.