Discarded cigarette butts—the next high-performing hydrogen storage material?

November 1, 2017, University of Nottingham
Discarded cigarette butts—the next high-performing hydrogen storage material?
Credit: University of Nottingham

Discarded cigarette butts are a major waste disposal and environmental pollution hazard. But chemists at the University of Nottingham have discovered that cigarette butt-derived carbons have ultra-high surface area and unprecedented hydrogen storage capacity.

The research was carried out by Robert Mokaya, Professor of Materials Chemistry, and Troy Scott Blankenship, an undergraduate project student, in the School of Chemistry and has been published in the academic journal Energy and Environmental Science.

Professor Mokaya said: "We have utilised cigarette butt waste as starting material to prepare energy materials that offer unprecedented hydrogen storage properties. This may not only address an intractable environmental pollution problem – – but also offers new insights into converting a major waste product into very attractive hydrogen storage materials."

Hydrogen is attractive as a fuel because whether it is burned to produce heat or reacted with air in a fuel cell to produce electricity, the only by-product is water.

Solving a major waste disposal problem

Every year nearly six trillion cigarettes are smoked worldwide. This generates more than 800,000 metric tons of cigarette butts. Apart from causing unsightly litter, cigarette butts contain contaminants such as toxic heavy metals which can leach into waterways potentially causing harm to both humans and wildlife.

Cigarette butts – used - are a lingering pollution hazard because they mainly contain cellulose acetate which is non-biodegradable. However, the cellulose acetate makes them an attractive starting material for valorisation to porous carbons. Such valorization is in line with the current trend to move away from coal-based carbonaceous precursors to biomass-derived or waste-based starting materials for porous synthesis.

Turning waste into fuels or energy sources

Hydrothermal carbonisation, a process that requires only water and heat, of discarded cigarette butts yields a carbon product called hydrochar. The research team found that when the hydrochar is activated it generates oxygen rich porous carbons that have very high surface area.

Professor Mokaya said: "We show that activated carbons derived from cigarette butts or filters, via sequential benign hydrothermal carbonisation and activation, are super porous with ultra-high surface area and exhibit unprecedentedly high hydrogen storage capacity. This work not only raises the interesting question of whether valorisation can solve the intractable cigarette butt problem but also offers porous carbons that attain new levels of hydrogen for porous materials in general."

As part of the drive towards the 'Hydrogen Economy', in which is used as a low-carbon energy source, this technique could be developed to replace, for example, gasoline as a transport fuel or natural gas as a heating fuel.

This publication is part of the team's ongoing search for sustainable carbons with optimized properties as energy including for .

Explore further: How to pave over our big butt problem

More information: Troy Scott Blankenship et al. Cigarette butt-derived carbons have ultra-high surface area and unprecedented hydrogen storage capacity, Energy Environ. Sci. (2017). DOI: 10.1039/C7EE02616A

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14 comments

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MR166
not rated yet Nov 01, 2017
"Professor Mokaya said: "We have utilised cigarette butt waste as starting material to prepare energy materials that offer unprecedented hydrogen storage properties. This may not only address an intractable environmental pollution problem – cigarette butts – but also offers new insights into converting a major waste product into very attractive hydrogen storage materials.""

This is an demonstration of what to say when someone asks "Where exactly did all that grant money go?"!
MR166
1 / 5 (1) Nov 01, 2017
It is obvious to me that the research has no merits on it's own and must be linked to some sort of recycling effort in order to appear to be beneficial.
MR166
1 / 5 (1) Nov 01, 2017
If the paper just stated that cellulose acetate could be turned into a H2 storage media I would not be at all critical.
dnatwork
5 / 5 (1) Nov 01, 2017
If the paper just stated that cellulose acetate could be turned into a H2 storage media I would not be at all critical.


You are always about cost. It would cost money and materials and energy to produce fresh cellulose acetate. This study takes something that has already been paid for and discarded by a consumer and reuses it, saving both the initial production costs and the costs of disposal, to produce a product that is much more valuable than the original. That's at least a triple win. How could you possibly object, based on your own principles?
MR166
not rated yet Nov 01, 2017
DNA do you really think that it will cost nothing to collect, transport and process all of those used cigarette filters?

Yes I am all about cost and how cost affects the viability of every new process or invention.
dnatwork
not rated yet Nov 01, 2017
What does it cost to dispose of trillions of these things full of toxic chemicals? I'm pretty sure there is no one willing to pay extra for that. But people will pay for a hydrogen storage medium. This would get you the raw materials more cheaply (because it's already being thrown away) and keep the toxins our of landfills and waterways.

How to collect and sort them? Add a penny per filter deposit to the price, just like with soda bottles. That's $2 per carton. People would save up their butts and turn them back in, already separated from all other trash.

It still results in a low to no-cost resource for the storage medium. You're just recycling the money of the person who buys the cigarette. If they don't choose to collect the deposit (as I never do for my juice bottles because 20 cents a week is not worth the trouble), that's their problem. Someone will find it worthwhile.
IronhorseA
5 / 5 (1) Nov 01, 2017
"Yes I am all about cost and how cost affects the viability of every new process or invention."

Everything costs. However you reach a point where the time and energy you spend trying to save time and energy (and costs) costs you more time and energy (and money) than what you actually save.
Whydening Gyre
5 / 5 (1) Nov 01, 2017
I remember basic training...
We would occasionally stop for five minutes to catch your breath and "smoke one if ya got one."
If ya didn't have one, your required activity was to pick UP the butts left laying around by previous smoke breakers.
There was a lot of 'em...
To this day I am still a cigaret butt Nazi, in that when I go outside to have a smoke (at a hotel, for example), I pick up all the butts left laying on the ground (BY THE ASHTRAYS, fer Chrissakes!) and throw them away properly. I ALWAYS snuff my butts out and put them in a proper receptacle.
It's one of my biggest gripes (and for others, I'm sure) about smokers.
Go figure...
Anyway, the cost is nothing, other than a second or two.
MR166
4 / 5 (2) Nov 01, 2017
WG I realize that it costs nothing to put your cigarette butts in an ashtray. It is the cost of getting them to a central location for processing in meaningful quantities that is in question. If this process is worthwhile it is a 99.999% certainty that virgin materials would be more energy efficient, thus less costly, than recycled material.
barakn
not rated yet Nov 02, 2017
Some recycling isn't worth it (glass, for example), but cigarette butts have something going for them. They are collected separately from the rest of the trash because of the danger of setting the trash on fire. It's hard to convince humans to sort recyclables, but they do sort out cigarette butts automatically. The containers (ashtrays) are often outside and thus easy to collect from.
MR166
not rated yet Nov 02, 2017
Barakn I hope for the sake of humanity that your above post was sarcasm.
Whydening Gyre
not rated yet Nov 02, 2017
...
The containers (ashtrays) are often outside and thus easy to collect from.

With 2 butts in the ashtray and a thousand on the ground around it.
This proves that a majority of smokers THINK they're Michael Jordan - but aren't...
And...
Really good point, MR...
Eikka
not rated yet Nov 04, 2017
It would cost money and materials and energy to produce fresh cellulose acetate. This study takes something that has already been paid for and discarded by a consumer and reuses it, saving both the initial production costs and the costs of disposal, to produce a product that is much more valuable than the original. That's at least a triple win.


You're overlooking the big white elephant in the room: do you suppose we want people smoking cigarettes in the first place? The cigarette butts are "free", but carry at tremendous cost.

If we are to produce this material in large volumes, we can't be relying on a raw material that is essentially a byproduct of people getting themselves lung cancer.

I join with MR166 with the point that the recycling argument is a red herring to provide "added value" to an invention that probably doesn't stand on its own merits alone - perhaps it's not even very good at storing hydrogen - but the writers needed to "sell" it somehow.

Eikka
not rated yet Nov 04, 2017
Indeed, the record setting hydrogen capacity is obtained at -196 C which is less than practical by about 216 degrees.

What does it cost to dispose of trillions of these things full of toxic chemicals?


Probably not very much, as they are burned for energy with the rest of the non-compostable waste.

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