In its just released Climate Change Report 2020, Rio Tinto outlines in some depth its strategies and pathways to achieve a low carbon future across all its operations aligned with the Paris Agreement, both to its initial 2030 targets to reduce absolute emissions by 15% and emissions intensity by 30% relative to its 2018 baseline, but also its net zero target for 2050 and beyond.
A big part of this relates to mobile diesel which is Rio Tinto’s third highest GHG emission source at approximately 16% of total emissions. In the Pilbara, emissions are mostly related to the natural gas used to generate power for the mines and processing plants, and from the diesel consumed by the mining and rail fleet. There Rio says it will continue to develop low-emission alternatives for mobile fuel use in haul, load and rail. Diesel for trucks and electricity are the main sources of emissions in Rio’s copper business and here also the company is advancing alternative fuels truck trials.
But what exactly are the alternatives is Rio Tinto looking at for its mobile fleets? The report says it has completed analysis and concept modelling of emissions sources and energy needs of its fleet and has identified and prioritised zero emissions pathways: “We are working to accelerate development of, and to de-risk, the required technology for switching to clean energy sources. We are doing this through industry collaborations such as ICMM’s Innovation for Cleaner Safer Vehicles (ICSV) and direct engagement with our suppliers and other partners.”
Specifically, for the first time Rio states that its “preferred technology pathway is the most energy efficient and targets full battery electric fleet with dynamic or fast charging technology to maintain fleet productivity.” It adds: “Technical challenges with this pathway involve creating flexibility in the infrastructure so it can adapt to changing haul roads and the limitations on battery charge rates. An alternative pathway builds off the battery electric technology but replaces the dynamic or fast charging technology with the less energy efficient hydrogen cycle (electrolysis and fuel cells)” – this is a reference to potential use of FCEV hybrids. “Technical challenges with this pathway involve storing and transporting hydrogen and dealing with transient power requirements that are typical in mining.”
Rio Tinto’s Centres of Excellence are working with the product groups to investigate emissions abatement technology use cases. Under the Surface Mining Centre of Excellence projects include:
- Pilbara electric haul truck collaboration
- Battery electric tender collaboration
- Battery/fuel-cell electric 40-100 t trucks
- Engagement with power service providers on batteries and charging
- Ongoing discussions with vehicle and engine manufacturers to investigate the substitution of diesel with renewable fuels and compressed natural gas in vehicles
- Analysis of alternate rail technology including battery electric locomotives
