Eastman will deploy thermal batteries at its second chemical recycling plant in the United States. The chemical manufacturer announced in March it chose its existing site at Longview, Texas, for the new PET depolymerisation facility.
The project will receive up to $375 million in Bipartisan Infrastructure Bill and Inflation Reduction Act funding from the US Department of Energy. The Longview site was chosen, in part, because it provides enough space for on-site renewable energy.
Now, Eastman has announced it will pair solar energy with brick heat batteries that can provide continuous heat of up to 1500 C from such intermittent clean energy sources.
The company is partnering with California-based Rondo Energy, a Bill Gates-funded startup which has developed Rondo Heat Batteries (RHB) to decarbonise the industrial sector.
By powering its PET depolymerisation process with low- or zero-carbon heat, Eastman’s recycled materials will have up to 90% fewer greenhouse gas emissions than materials produced with fossil feedstocks. PepsiCo has already signed a contract to use Eastman Renew materials from the Longview facility to create more sustainable packaging with a much lower carbon footprint.
Rondo Heat Batteries (RHB) are modular units containing thousands of tons of brick and coils of metal, similarly to kitchen toasters. The so-called ‘brick toasters’ store high-temperature heat as its been done for centuries with bricks.
When power is available from the sun or the wind, electrical heaters glow brightly and warm the bricks around them. The bricks then store energy for hours or days with less than 1% loss per day. When heat is needed for industrial operation, air flows through the brick stack and is superheated to over 1000 C. Automated controls adjust heating to the desired temperature at the outlet.
The RHB systems can store more than 1 MWh of power per square meter, a high level of density that preserves area use at industrial facilities. Rondo Energy says a single RHB300 unit could eliminate more than 40,000 tons of carbon emissions per year – equivalent to the carbon offset created by about 8,700 electric vehicles. The units are reportedly fully automatic, can deliver heat on demand for 24 hours a day at constant temperatures, and have a lifespan of over 40 years.
“This can be a true game changer for providing low- or zero-carbon power for industrial processes,” said Neil Brown, an Eastman engineer. “Anywhere there are great needs for process heat — and Eastman uses a lot of heat to power our processes — thermal batteries can be a solution because you’re able to store heat for so long with so little loss. Another plus of building this new facility at an existing site is that if we run into challenges as we’re integrating the new thermal technology, we have backup steam and power systems in place to allow continued operations.”
The Longview plant will have capacity to process about 110,000 tonnes of plastic waste annually.
The investment is expected to create more than 200 jobs, as well as about 1,000 temporary construction jobs. Eastman currently employs more than 1,500 in Longview.