Optimise alumina processing temperature at Yarwun refinery (Revoked)

Optimise alumina processing temperature at Yarwun refinery (ERF123378) was an industrial energy efficiency project located at the Rio Tinto Yarwun Alumina Refinery, approximately 10km northwest of Gladstone in Central Queensland. Registered in September 2018, the project was designed to reduce emissions within the heavy industrial facility but was voluntarily revoked in December 2022. The project area is situated within a major industrial precinct, bordered by grazing lands and coastal scrub, with the Mount Larcom range visible to the west.

The project operated under the Industrial Electricity and Fuel Efficiency methodology. This framework credits activities that improve the energy efficiency of industrial equipment, such as upgrading control systems, replacing boilers, or optimizing processing temperatures to reduce fuel or electricity consumption per unit of output. Unlike land-based carbon farming, this methodology focuses purely on engineering and operational improvements in a facility setting.

Environmentally, the Gladstone region experiences a sub-tropical climate characterized by summer-dominant rainfall, averaging approximately 880mm annually. While the refinery site itself sits on highly modified industrial land and fill, the surrounding region is characterized by texture contrast soils (chromosols and sodosols) and coastal clay loams. Low-lying areas near the facility are mapped for potential acid sulfate soils, a common feature of the coastal flats in this region.

A key operational note is that the Yarwun refinery utilizes "high temperature tube digestion" technology (operating around 280°C) to refine bauxite. The project likely targeted the optimization of these digestion temperatures to minimize steam generation requirements from coal or gas boilers. The revocation in 2022 coincides with Rio Tinto's shift toward more aggressive decarbonization strategies, such as the "Yarwun Hydrogen Calcination Pilot" (announced 2021/2022), suggesting the project was superseded by broader facility-wide transition plans or the Safeguard Mechanism reforms.