The growing demand for lithium-ion batteries puts pressure on the industry to improve all steps in the product chain, including the heating processes. With electric rotary kilns, lithium refineries could cut CO2 emissions in their heating processes to zero if renewable energy is used, while cathode producers could benefit from lower energy consumption and higher productivity.
The soaring demand for lithium-ion batteries has laid the groundwork for remarkable growth in the battery industry, across the entire production chain. Lithium refineries, as well as cathode and anode producers, are planning new facilities or suiting up to increase production.
However, with the growing demand for lithium-ion technology comes the growing responsibility to evaluate and improve all steps of each process throughout the production chain – to make every one of them as energy efficient and sustainable as possible. That includes the choice of heating solution.
For the calcination process in cathode production Kanthal has traditionally offered silicon carbide elements for roller hearth kilns. But are roller hearth kilns really the best option for this specific heating process? Sachin Pimpalnerkar, Global Product Manager at Kanthal, says no.
“Based on our vast experience from other industries and applications, we’d like to argue that rotary kilns have the potential to improve energy efficiency, temperature uniformity, service life and productivity for cathode manufacturers,” Pimpalnerkar says.
“Just to mention one example, the trays that are needed in roller hearth kilns to carry the cathode precursors consume energy as they absorb the heat, and they also transport heat out of the kiln,” he continues. “With a rotary kiln you only heat the material itself, and hence there is a minimal heat loss associated with carrying the material through the kiln.”
Read more about the comparison here: Rotary kiln vs roller hearth kiln in cathode production
In the lithium refining steps, such as the sulphuric acid roasting process, indirect rotary kilns are already being used, but with gas burners. By replacing gas-fired heating with electric heating in this process, lithium producers stand to make significant cost, efficiency and environmental gains.
“If powered with renewable energy, the entire process releases zero CO2 emissions, while the working environment is not contaminated with CO2, NOx, CO, SOx or noise pollution,” Pimpalnerkar explains.
The efficiency benefits with electric heating compared with gas heating are also significant.
“When heating with gas, you lose a lot of hot air through the exhaust – and lost heat represents inefficiency,” Pimpalnerkar says.
A Proven Technology
According to Pimpalnerkar, there is a general misconception that electric heating is an unproven technology. “It’s important to remember that we aren’t changing the actual process, just the way the heat is put in,” he says. “We do this using our standard heating elements that are already being used in the lithium-ion industry and for which we have extensive references.”
Read more: Switching from gas to electric heating in lithium refineries