Reducing CO2 emissions

BOC is partnering with Alcoa World Alumina Australia and CSBP, a Wesfarmers subsidiary, in a 15-year contract that is set to be the biggest in Australia using waste carbon dioxide (CO2).

BOC's CO2 treatment process will be used in Alcoa's carbonation project, which will consume between 180 and 220 tonnes of waste stream CO2 per day.

The CO2 is consumed when it is added to Alcoa's bauxite residue, a refining waste product, and reduces the alkalinity (pH) levels of the material. This lower pH level will open several doors for the re-use of the material and reduce the environmental risks associated with its long-term storage.

Alcoa is already operating a successful carbonation pilot plant at Kwinana. Under the new agreement, CO2 will now be captured, processed and delivered by BOC from chemical and fertiliser manufacturer CSBP's waste stream. It will be on a much larger scale and at reduced cost to Alcoa than previous arrangements.

BOC is installing the infrastructure and supplying the operating expertise necessary to provide downstream processing of the raw CO2 provided by CSBP for supply to Alcoa. Project development and construction is underway, and Alcoa plans to begin receiving carbon dioxide from BOC (using raw CSBP CO2 as feed stock) by the end of 2006.