There's a lot of plastic in the water.
But sifting small pieces of plastic out of the largest bodies of water on the planet is a major challenge.
Already, machines exist that can sift plastic particles out of salt water and convert them into their base hydrocarbons — the building blocks of fuel. But those machines are generally too big and unwieldy do deploy where they can be the most useful: in the oceans themselves.
A new project, presented at the most recent meeting of the American Chemical Society, aims to do just that.
Claudia Rocha/American Chemical SocietyJames Holm, a sailor, and Swaminathan Ramesh, a chemist, developed a mobile reactor, small enough to fit on a boat, that can injest ocean plastic and salt water all day and churn out usable diesel fuel. The process is continuous, efficient, and scalable, meaning it can be adjusted to fit any sized ship and work without constant stops and starts. It's also fast enough that the diesel it produces could theoretically be used on the boat carrying it during the voyage.
Of course, though the project was created with the goal of improving the environment in mind, it has at least one built-in environmental drawback: Converting all the billions of pounds of ocean plastic into a hydrocarbon fuel, then burning that fuel, would likely add a non-trivial amount of carbon to the atmosphere.
The first major test of the reactor will take place in Santa Cruz, California, where it will convert plastics into diesel for the local government to power city vehicles. Whether similar reactors will actually be deployed out on the water in any large-scale way remains to be seen.