Scientists have found a surprising new ingredient for clean energy: brown seaweed. Researchers at Columbia University in New York and Ewha Womans University in Korea have developed a method to transform seaweed into hydrogen fuel without releasing harmful emissions into the air.
The team published their findings in the journal Nature. They focused on seaweed because it grows incredibly fast and absorbs carbon dioxide from the ocean at remarkable rates. In fact, seaweed captures and stores carbon at seven times the rate of trees and other land plants, making it one of nature's most efficient carbon absorbers.
Unlike crops grown on land, seaweed doesn't need fresh water, fertilizer, or precious farmland. Farmers can harvest it up to six times a year from the ocean, simply letting it grow back. "The carbon sequestration rate of seaweed far surpasses other land based biomass," the researchers noted.
The scientists used a process called alkaline thermal treatment, which heats seaweed with special chemicals to release hydrogen gas. Their tests showed this method produces more hydrogen than traditional approaches currently used in the industry. The process is carbon-neutral, meaning it doesn't add extra carbon dioxide to the atmosphere. It could even become carbon-negative — actually pulling carbon out of the air — if the leftover carbonate materials are stored safely underground.
Green hydrogen is hydrogen made without burning fossil fuels. Right now, most hydrogen comes from natural gas, which releases planet-warming gases during production. Clean hydrogen could replace that dirty hydrogen in factories that make fertilizer, refine oil, and build steel — heavy industries that are difficult to electrify directly.
"This is a very promising result considering a potential learning curve in the development of the biomass ATT technology," the team acknowledged, noting the process is still in early stages. But as the technology improves and costs drop, seaweed could become a significant source of clean fuel for trucks, ships, and factory equipment that need lots of energy but can't run on batteries alone.
The researchers are not alone in pursuing innovative paths to hydrogen. A separate team from Korean universities and the University of California published related work in the journal PNAS, showing that the same treatment process can also pull clean hydrogen from plastic waste — the kind that normally gets buried in landfills or burned. Currently, only 9 percent of plastic waste worldwide gets recycled. Turning that garbage into fuel could kill two environmental problems with one solution.
Together, these studies suggest that seaweed and plastic waste could help build a cleaner energy future — one that doesn't require choosing between powering the economy and protecting the planet.