It's a somewhat ominous-sounding sentence, but the comparison isn't as grim as it seems: "The operations slightly evoke the factory scenes from Soylent Green, the 1973 dystopian thriller in which nutrition wafers are made from human remains." So write Motoko Rich and Makiko Inoue for the New York Times in describing a recycling plant in Houki, Japan, that turns used adult diapers into fuel pellets. In this case, those pellets fuel a boiler that heats the water of the town's public baths (the paper talks to a visitor to the public bathhouse who wasn't grossed out to learn this). It's not exactly a quirky one-off, at least in terms of trying to figure out what to do with adult diaper waste. Thanks to an aging population, Japan's elderly use more diapers than its babies do.
In Houki, about 10% of all trash is made up of diapers, and in Japan, almost all trash is incinerated, which pumps emissions into the atmosphere. Houki opted to convert one of its two incinerators into the diaper recycling plant, and the Times explains the benefit won't just be environmental. "Because diapers contain so much cotton pulp and plastic, and swell to four times their original weight after soiling, they require much more fuel to burn than other sources of waste," Rich and Makiko write; that translates into hefty bills. It's not as easy as just building the plant though: Used diapers have to be separated from the rest of the trash, which households in Houki don't do. But the town is home to the Daisen Rehabilitation Hospital, which separately bags the 400 pounds of used diapers it produces a day; these are collected and brought to the recycling plant. (Read the full story.)