Mitsui Mining & Smelting Finds CO2 Reduction Method by Rare Earth

Mitsui Mining & Smelting developed a new technology to decrease carbon dioxide (CO2) emission by using rare earth as conversion agent. CO2 is converted to CO by cerium based agent, which is reduced by hydrogen. Mitsui Mining & Smelting expects this technology can decrease steel plants’ CO2 emission by 8%, utilizing hydrogen and heat generated from coke ovens.

The method needs to reduce cerium based agent by hydrogen under high temperature. This reduced agent and additional heat can convert CO2 to CO. Temperatures are key know-how. The used agent can be recycled by hydrogen again. Mitsui Mining & Smelting’s R&D official said the firm succeeded in 97% conversion from CO2 to CO.

This method requires large quantity of hydrogen, heat and CO2. Thus the technology seems suitable for steel plants where much hydrogen, heat and CO2 are generated.

The official explained the method realizes 8% reduction of Japanese steel plants’ CO2 emission, which is estimated at 200 million metric tonnes per year. Converted CO can be utilized at blast furnaces or chemical makers. In the case to decrease CO2 emission by 8%, required agent volume is as small as several ten tonnes.

If the method is adopted to steel plants, development of converting reactor is also necessary. Converting reactor is equipment to convert CO2 to CO with cerium based agent. Mitsui Mining & Smelting aims to commercialize the technology through cooperative R&D with integrated steel makers and engineering makers.