With a recent round of investment funding, UP Catalyst (Tallinn, Estonia; www.upcatalyst.com) plans to build a pilot plant for a process that converts waste carbon dioxide into a range of solid carbon materials, such as carbon nanotubes, (CNTs), graphite and carbon black. The pilot plant, anticipated to start up before the end of 2025, will produce about 100 kg/day of solid carbon, a factor of 10 greater than the current pre-pilot production, says Sebastian Pohlmann, chief technology officer at UP Catalyst.
UP Catalyst’s process uses molten carbonate salt to dissolve CO2 from hard-to-abate industrial processes, such as waste incineration. To work effectively, the CO2 must first be purified to above 98% via an amine wash. Once purified, CO2 is pumped into the molten salt, where an electric current is applied across electrodes in the salt. In order to synthesize certain carbon allotropes, a metallic catalyst is also present in the molten salt. The applied current drives an electrolysis reaction where CO2 is split into O2, which is released, and solid carbon, which accumulates on the cathode of the reactor cell, and is mechanically removed.
“By carefully controlling the reaction conditions, including temperature, as well as which catalysts and electrolytes are used, we can dictate the properties of the resulting solid carbon products, and we are aiming for production at price parity for traditional carbon sources,” says Pohlmann.
Among the key engineering challenges UP Catalyst overcame in developing the process is an effective method of introducing the catalyst into the system that avoids having the metals end up in the solid carbon products. Also, the company developed a method for recovering and recycling the molten salt as the reactor cell operates.
There are three general categories for the products made by UP Catalyst’s process: graphite for use in battery electrodes for electric vehicle and stationary storage; CNTs as additives for polymers, paints and cement; and carbon black for paints and coatings.
“The process addresses two growth markets simultaneously,” Pohlmann explains. “We are capturing carbon that would otherwise end up in the atmosphere, and upcycling it to produce solids that fit into a range of performance materials.”
The carbon footprint associated with producing graphite using UP Catalyst’s process is 20 times lower than conventional graphite production, according to UP Catalyst, and emissions for making CNTs are 242 times lower than emissions from the traditional chemical vapor deposition method.