The global mining industry has demonstrated its commitment to cut greenhouse gas (GHG) emissions in support of the Paris Agreement, with many major mining companies announcing decarbonization targets over the past 18 months. This increased focus on GHG emission reduction has accelerated the implementation of Liebherr’s existing low carbon systems and triggered future projects to offer completely fossil fuel free mining equipment options. Liebherr Mining’s strategy will mainly focus on machine operation, as studies show that accounts for more than 90% of GHG emissions over the lifecycle of equipment.
The Liebherr Group’s in-house core competencies include electrification, batteries, internal combustion engines, injection systems and alternative renewable fuels. Building from this experience, the company’s Zero Emission Program has clear targets and a roadmap to achieve low carbon solutions for the full range of off-highway trucks and excavators in 2022, and fossil fuel free solutions for most applications by 2030. Modularization, along with an energy type agnostic approach to drivetrains, are key elements in easing the transition for customers with the possibility to retrofit modules.
2022 low-carbon technology
Liebherr Mining is finalizing initiatives to achieve its 2022 target for low carbon emission solutions across its complete digging and hauling range. That includes the Trolley Assist System for Liebherr haul trucks. The system is an effective first step on the road to zero emission mine sites of the future. Using an overhead pantograph or trolley bars to connect an electric-drive system to the electrical network, the Trolley Assist System reportedly will increase truck fleet productivity or reduce fleet size, while maintaining yearly production when compared with standard trucks. A significant reduction of diesel fuel consumption and CO2 emissions is also made possible with the Trolley Assist System. However, this of course depends on the percentage of renewable energy content in the grid-supplied power.
Liebherr is currently operating 39 T 284 trucks fitted with the Trolley Assist System at two different sites, as well as 100 ton trucks and a fleet of T 236 trucks running on a 5 km trolley line in Austria — the longest in the world.
The Liebherr Group has over 30 years of experience in electric-driven machines for earthmoving, material handling and mining applications, including Liebherr Mining units ranging from 130 to 800 tons. Thanks to 70% of parts commonality with diesel versions, including structural components and hydraulic systems, Liebherr also offers complete retrofit options for existing machines.
To offer better machine mobility and safety for the workforce on site, Liebherr has developed a cable reel option for all electric drive excavators either in backhoe or face shovel. The cable reel is completely autonomous and has a capacity up to 300 m depending on the excavator type. Further, Liebherr proposes an operational concept for excavators with cable reel in backhoe applications, particularly in double benching operations.
Liebherr is continuously improving and upgrading its standard machines to enable the transition to emission reductions. Liebherr Power Efficiency (LPE) is the most recent built-in technology upgrade making this productivity and sustainability contribution.
Starting with Generation 7, all Liebherr mining excavators will be equipped with Liebherr Power Efficiency (LPE) as standard. This specific engine and hydraulic management system reduces fuel consumption by up to 20%. The system:
• Adapts piloting processes according to operator requirements.
• Electronically controls pressure and oil flow.
• Increases efficiency of the control valves and the new Liebherr pumps.
• Has a fully integrated engine control system.
• Reduces hydraulic losses and load profile of the engine for increased component lifetime.
• Reduces energy consumption without impact on the machine performance.
Based on R&D advances, Liebherr is able to provide size-equivalent machinery with higher production rates and less fuel consumption. In fact, the combination of LPE together with the improved productivity of the R 9600 excavator has shown 29% less fuel consumption per ton of produced material over a one-year production study, compared to its predecessor, the R 996B. Expressed in fuel efficiency, tons per liter, this corresponds to a 40% better use of fuel.
These outstanding efficiencies are said to allow Liebherr excavators to set new benchmarks in their respective classes and are important enablers for any kind of future drive train, as they significantly reduce the effort for cable handling or refueling and storage of alternative fuels.
Pathway to zero emission
As second step, Liebherr’s goal is to offer completely fossil fuel free mining equipment for hauling, digging, and dozing by 2030. This development will take into consideration the GHG emissions over equipment’s full lifecycle, as well as the overall well-to-wheel energy ecosystem. The company is also taking into account the operational mining process conditions that influence the choice of energy.
Liebherr will develop three drivetrain options to achieve near zero emissions for its off-highway trucks: battery power module, internal combustion engines powered by renewable fuels, and hydrogen fuel cell-battery power module.
Research and development for internal combustion engines operating with renewable-based alternative fuels is progressing within the Liebherr Group, with Hydrogenated Vegetable Oil (HVO) as an approved fuel for machines powered by Liebherr engines as a first step. Hydrogen combustion engines are also currently being tested in Liebherr’s factory in Switzerland. The methanol combustion process has been developed for large displacement engines and is ready to move towards serial engine industrialization based on market demand. Additionally, the ammonia combustion process is under investigation, with high potential in the use of ammonia for heavy mobile, high energy demanding machines and gensets.
Liebherr mining excavators and dozers will also both have the option to be powered by internal combustion engines running on alternative fuels, along with the existing electric drive version for excavators.
To achieve near zero emissions for mining dozers and excavators, it is also crucial to employ the most efficient drive system to reduce fuel consumption. The Liebherr hydrostatic drive system already achieves up to 20% improved fuel efficiency compared to competitive mechanical products. Despite this, company engineers are currently in the process of comparing efficiency of an electric drive on a dozer prototype with hydrostatic drive efficiency. Given Liebherr’s expertise in both hydrostatic and electric ac drive systems, the company is in an excellent position to choose the most appropriate option for the best drive system for near zero emissions.
Liebherr is also partnering with industry experts for their Zero Emission Program. ABB, a leader in power and automation technologies, develops state-of-the-art technology and equipment for overall electrification of mine sites, including a focus on trolley assist infrastructure deployment. ENGIE, the global reference in renewable hydrogen, low-carbon energy, and services, will jointly with Liebherr evaluate the different renewable energy solutions, in particular renewable hydrogen and hydrogen-derived fuels, for loading, hauling, and dozing processes. This cooperation ensures that an integrated well-to-wheel approach is basis to define the best solutions for the mining industry.
With concept studies nearly finalized for trolley-battery hybrid, and ammonia and methanol for internal combustion engines, Liebherr expects to undertake field validation from 2024 to 2026, followed by the integration of proven fossil fuel free solutions from 2026 to 2030 into the entire range of mining machines.
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Filed Under: Mobile Hydraulics - EV Engineering, Vehicle Control Unit