Alumina Limited

Emissions

The processes required to refine alumina from bauxite ore and to smelt aluminium from alumina require significant amounts of energy. If the energy is sourced from the consumption of fossil fuels such as fuel oil, coal and electricity generated from coal fired power stations, it follows that such production results in significant emission levels.

The climate change debate has caused  governments, the scientific community and increasingly the general populous tofocus on production and management of GHG emissions and theie potential impacts on the environment.. Globally, governments have responded by committing to GHG reductions and this has resulted in legislative changes in the form of taxes on carbon production or the introduction of emission trading schemes to accelerate innovation to reduce emission or stimulate increased reliance on cleaner or renewable energy sources. AWAC’s GHG emissions present sustainability and business challenges for the AWAC joint venture. Our focus and importantly, that of operating partner Alcoa is on decreasing GHG intensity by:

  • increasing energy efficiency through process and technology improvements
  • investigating alternative energy sources from low or no carbon based generation,  (renewable options to meet large volume energy requirements are limited in many regions)
  • advancing technological solutions for GHG abatement. 
  • increasing energy efficiency through process and technology improvements
  • investigating alternative energy sources from low or no carbon based generation,  (renewable options to meet large volume energy requirements are limited in many regions)
  • advancing technological solutions for GHG abatement. 

A major challenge is balancing the need to ensure energy security with energy diversification. Currently base-load electricity supply at AWAC’s Portland aluminium smelter in the Australian state of Victoria depends on the guarantee of long-term energy supply contracts. This reliance on secure contracted energy supply effectively reduces the opportunities to switch energy sources. This is especially relevant in Victoria where base load delivery of electricity is almost exclusively dependant on coal fired power stations. Despite these hurdles, Alcoa continue to pursue opportunities to reduce the carbon intensity of the electricity AWAC purchases. 

Strategy

Alcoa, as manager/operator of the AWAC’s facilities employ a climate change strategy that consists of five key components – emissions reductions, strategic energy decisions, stakeholder and policy engagement, product advantage and climate adaption.

For AWAC;

  • emission reductions includes process improvements for example, shared initiatives to reduce the emission of perfluorocarbons at the Portland smelter.  
  • strategic energy decisions include, where practical, seeking cleaner energy sources as a means of reducing GHG emissions. Approximately 135,000 tonnes of CO2 emissions have been avoided at AWAC’s San Ciprian alumina refinery in Spain by transitioning from a reliance on fuel oil as the major source of energy to natural gas.
  • climate change policies and attitudes continue to evolve and engagement with governments, non-governmental organisations, not-for-profit organisations, community groups and other relevant stakeholders on climate change issues is a key platform in AWAC’s strategy
  • Alcoa educate policymakers and customers of the light weighting and other benefits of aluminium and aluminium based materials in reducing or avoiding GHG emission compared to other competing materials
  • climate adaption means trying to assess the potential impact of changing weather patterns on AWAC’s global mining operations, water management and supply chain efficiencies.

Achievements

Since 1990 AWAC's Victorian smelters have achieved a direct emissions reduction of 65% per tonne of aluminium produced and the alumina refineries in Western Australia have achieved a direct emissions reduction of over 21% per tonne of alumina.

The Pinjarra alumina refinery in Western Australia has two onsite gas-fired cogeneration power plants. These co-generation plants operate on natural gas, a transitional fuel that is cleaner than the alternative coal generated power plants, operating at 75 per cent energy efficiency compared to 30 – 50 per cent for other power plants in Western Australia. Energy generated by these plants is estimated to save approximately 450,000 metric tonnes of greenhouse gas emissions annually compared to a similar-sized coal-fired plant. In addition, the cogeneration plants reduce the refinery emissions by 270,000 tonnes per year through more efficient steam generation. 

 

Results and goals

In 2015 AWAC's total (on a full facility basis) absolute greenhouse gas emissions from AWAC’s declined by approximately 17.8% to 15.2 million tonnes from 18.5 million tonnes of CO2 registered in 2014. Almost two thirds the reduction in absolute GHG compared to 2014 is absence of emissions associated with the Point Henry aluminium smelter that closed in August 2014. Point Henry was a significant emitter of GHG due to its reliance on imported electricity produced by coal fired power stations. This is notably reflected in the reduction of Scope 2 (Indirect) in table below for Scope 2 (Indirect) emissions that fell from 8.1 million tonnes of CO2 in 2014 to 6.2 million tonnes in 2015.

Other contributors to the reduction in absolute GHG emissions in 2015 compared to the 2014 result were:

  • the sale in December 2014 of the Clarendon alumina refinery in Jamaica
  • curtailment of production in the second half of 2015 at the Paranam refinery in Suriname
  • the closure in August of 2014 of the Point Henry aluminium in Victoria, Australia
  • completion of the transition from fuel oil to natural gas at the San Ciprian alumina refinery located in Spain that enabled a reduction of its greenhouse gases, cutting CO2 by 30 percent and eliminating SO2 emissions.

Performance on a CO2 intensity basis (metric tons of CO2e per tonne of production) demonstrates a substantial improvement over the past ten years with intensity dropping by 11.7 per cent for the smelting operations and 14.3 per cent for the global alumina refinery portfolio.

In early 2012, Alcoa revised their total (direct and indirect) carbon dioxide intensity targets as a result of exceeding the original 2020 target of a 20 per cent reduction from a 2005 baseline. The revised targets are a 30 per cent improvement in carbon dioxide intensity by 2020 and a 35 per cent improvement by 2030.

Greenhouse gas emissions
AWAC Full Facility of tonnes of CO2 equivalents.
 20152014201320122011
Direct (Scope 1) 8,986,055  10,330,772 10,535,150 10,510,813 10,745,735
Indirect (Scope 2)  6,180,774  8,123,143* 9,645,096 9,995,224 9,953,062
 
 
Total 15,166,829  18,453,915 20,180,246 20,506,037 20,698,797

* The reduction in Scope 2 (indirect) emissions is due to the closure of the Pt. Henry aluminium smelter in August 2014. Pt. Henry consumed electricity imported from both the electricitiy grid and AWAC's Anglesea power station. Both sources of electricity are derived from coal fired power stations.

Scope 1 (direct GHG) emissions are those released directly by AWACs’ sites through energy sources such as natural gas. Scope 2 or indirect emissions are those from power stations predominantly electricity that supply energy to AWAC’s sites and also associated with the generation of steam at the co-generation facilities located at the Pinjarra refinery.

Emissions calculation methodology

The Greenhouse Gas Protocol: A Corporate Accounting and Reporting Standard (Revised Edition), Australia - National Greenhouse and Energy Reporting Act, Brazil GHG Protocol Programme and The Climate Registry: General Reporting Protocol. Emission per source calculated by applying WRI Calculation Tool