A Japanese town is recycling used adult nappies. They are turning them into small pellets that can be used as fuel.

Local authorities are collecting the soiled nappies – which traditionally went for waste incineration – from retirement homes and converting them into two-inch long pellets which are then burned to heat the water in the town of Houki’s public baths.

The rapid increase in nappy waste allied to the cost of upgrading the town’s incinerators led to a decision to convert one incinerator to recycle the nappies and help reduce the cost of heating water using natural gas in public baths

With a rapidly ageing population, Japan has more adults who use nappies for incontinence than babies, creating almost 1.5 million tonnes of waste per year.

It is predicted that this number will rise by 23pc by 2030, when the over-65 demographic will make up a third of the population.

“When you think about it, it is a difficult and big problem,” said Kosuke Kawai, a senior researcher at the National Institute for Environmental Studies.

“Japan and other developed countries will face similar problems in the future.”

In the westerly town of Houki, waste from nappies alone makes up about 10pc of its rubbish.

Because they are made from cotton and plastic, they swell by up to four times their original size once used, requiring large amounts of energy to incinerate them.

This leads to excess carbon emissions and high fuel costs for local authorities.

However, if the used nappies are separated from other forms of waste, it is possible to turn them into fuel pellets.

The nappies are sterilised and fermented for 24 hours, meaning their volume is reduced by a third.

The fluffy remnants are then turned into two-inch long pellets which can be burned.

The fuel source does produce some carbon emissions but the Japanese government has calculated they are less polluting than coal or oil.

Houki is not the only town experimenting with nappy waste.

Several others in Japan are also exploring the possibility that they can be converted into a material that can be used in cement.

Telegraph Media Group Limited [2021]