AlumiNEXT™ is driving the transition of alumina refineries to net-zero CO₂ emissions by addressing both transitional low-carbon solutions for the short and medium term and transformational net-zero technologies for the long term.

The project aims to develop and demonstrate steam recovery technologies, including thermal vapour recompression (TVR) and mechanical vapour recompression (MVR), to improve efficiency and reliability. Preliminary assessments suggest these approaches can make net-zero alumina production economically viable, with competitive costs compared to natural gas when carbon impacts are considered.

The project focuses on:

1. Achieving net-zero steam generation and recovery within the Bayer Process (refining bauxite ore to produce alumina) to improve the sustainability and efficiency of alumina production. This involves optimising existing processes and integrating innovative technologies to reduce emissions.
2. Decarbonising the energy-intensive calcination process, the final heating step in alumina production, where hydrated alumina (aluminium hydroxide) is heated to very high temperatures to remove chemically bound water, converting it into pure alumina (aluminium oxide). This research component will develop strategies to significantly lower calcination’s carbon footprint.

These two project components are further divided into research areas that address specific challenges and opportunities, ensuring that AlumiNEXT™ systematically tackles barriers to decarbonisation.

• 1.3 Low-carbon high-temperature alumina calcination
• 1.4 Low-carbon heat for the hydrometallurgical process component of alumina refining

• Storage of variable renewable energy and capture of waste heat for steam production
• Hydrogen or electric calcination assessment

• Cost-benefit analyses for steam generation methods across diverse plant and country scenarios.
• CO₂ reduction and levelised cost of alumina production assessed for current process configurations.
• Case studies demonstrating benefits of optimised systems.
• Evaluations of benefits and challenges of waste heat recovery.
• Cost and performance models incorporating system scale, temperature, working fluids and renewable energy inputs.
• Cost and performance models for processes using alternative heat transfer media, optimised for economic and operational feasibility.
• Enhanced process efficiency and sustainability through novel media integration.
• Strategies to retrofit existing calciners with electrification methods for improved operational stability.
• Assessed thermal energy storage (TES) integration to stabilise alumina calcination under fluctuating energy supplies.
• Designs for preliminary lab-scale net-zero alumina calciners.
• Experimental data for alumina particle behaviour in net-zero reactor conditions to optimise scaling.
• Insights into alumina product properties for improved reactor designs.
• Insights into fluid dynamics, heat transfer and reactor operation to support industrial scale-up.
• Improved understanding of particle behaviour for agglomeration and steam recovery for MVR.
• Assessments of durability, corrosion, wear resistance and thermal stress management in new calciner designs.
• Evaluations of feasibility and reactor design for a two-stage calcination process to enhance efficiency.
• Preliminary designs integrating waste heat recovery for net-zero calcination processes.
• Analyses of benefits and challenges of waste heat recovery.
• Cost and performance models for waste heat systems incorporating renewable energy inputs.

• Electrification of the calcination process, including the use of thermal storage, to significantly reduce CO₂ emissions.
• Development of alternative calcination methods, such as hydrogen and solar thermal, to provide
  low-carbon heat.
• Continuous steam generation with low or zero emissions.
• Recovery and reuse of waste heat from the calcination process to support the Bayer Process.
• Advanced steam integration designs to enable recovery of steam and waste heat lost during production.
• Understanding of how to retrofit and adapt existing plant designs and equipment to minimise disruption and reduce costs.
• De-risking high-TRL technologies for immediate retrofitting to reduce emissions in current refineries.
• Advancing novel technologies for next-generation refineries to achieve a step-change in efficiency, emissions reductions and cost savings.
• Development of process models and components tailored to specific refinery needs, ensuring the integration of low-carbon heat sources and efficient steam-recovery designs.
• Improved resilience and future-proofing of energy infrastructure to meet the evolving needs of heavy industry by incorporating scenarios and technology developments into predicting future energy supply and demand trends.

• Lee L, Ingenhoven P, Saw WL, Nathan GJ. The techno-economics of transmitting heat at high temperatures in insulated pipes over large distances. Applied Energy. 2024; Vol. 358, 122634.

RP1.013 Alumina refineries’ next-generation transition (AlumiNEXT™) Project