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Researchers Turn Waste Toilet Paper into Electricity Source

ByTimothy James DimacaliNOVA NextNOVA Next

A team of Dutch scientists is working to address the world’s energy problems from the bottom up, in a manner of speaking.

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In fact, it’s a solution that’s been right under our noses all along. Researchers from the University of the Netherlands and the University of Amsterdam are looking into the possibility of using waste toilet paper (WTP) as a source of electricity.

“People usually prefer not to think about it at all,” the researchers said in their study.

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But lead researcher Els van der Roest says that the basic technologies are already in place to turn this waste into a valuable resource.

Used toilet paper may just be the fuel of the future, say Dutch researchers.

“In Scandinavian countries [for example,] waste toilet paper is already sieved out of the sewage system. And the gasification and cleaning equipment is currently being installed in Alkmaar, the Netherlands,” she said.

Her co-researcher, Dr. Gadi Rothenberg, agrees.

“I think [our work] will be relevant to those cities and communities that already pay someone to clean the processed WTP from their sewage installation filters. This happens in most western European countries,” he said in an email interview.

In 2010 alone, some 27,000 trees’ worth of toilet paper was either flushed or dumped into landfills every day, according to World Watch.

And in 2016, over 142 million consumers polled in the US admitted to using as much as an entire roll of tissue every other day, according to Experian researchers.

With so much material to work with, the Dutch researchers saw a golden opportunity: up to 80 percent of dry toilet paper is made of combustible cellulose—a prime candidate for fuel, if it can be processed efficiently.

“It is a rich source of carbon [and] is continuously available in the developed world regardless of country and season,” the researchers noted.

Van der Roest and her team devised a two-stage process in which waste toilet paper is collected and gasified before being introduced into a fuel cell.

Similar to a battery, a fuel cell relies on chemical reactions to directly produce electricity.

The gases are then introduced into a fuel cell, where chemical reactions convert the gases into electricity.

The system converts up to 57% of waste paper into into energy, according to the researchers, which is comparable to the output of existing natural gas power plants.

The system also has the added benefit of helping minimize the carbon footprint of power generation, since it would be tapping otherwise unutilized biological waste.

“The electricity from WTP could displace electricity from fossil sources such as coal and gas. Upon taking into account that WTP originates from biomass, the CO 2 emissions would be comparable to those of electricity from renewable sources,” the researchers said.

Some things still need to be worked out, though: fuel cell technology is still expensive, making the system economically unfeasible at least for now.

The researchers expressed optimism, however, that the cost will go down as the technology matures.

“Given that the solid-oxide fuel cell market is still developing, strong learning-by-doing and economies-of-scale effects are expected. This could result in a decrease in the levelized cost of electricity on the longer term,” the researchers concluded.

So how soon will it be before we see a toilet paper-powered electric plant? It’s mostly a matter of political will, according to Rothenberg.

“The hurdles are like the ones for any new process: building the first installation is risky and expensive, and municipalities are typically risk-averse,” he explained.

But there’s also one surprising problem that may arise from the widespread use of this system: Should WTP power technology take off, we can likely expect used toilet paper to gain in value.

“Currently, the fuel costs are negative (because we use waste as a raw material), yet this could change if the value of WTP would increase as a result of this process,” the researchers said.

Which gives a whole new meaning to the phrase, “flushing money down the toilet.”

Photo credit: Elya / Wikimedia Commons (CC BY-SA 3.0)

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