Technologies to reduce WA greenhouse gas emissions

By SHANNON BEATTIE

The clean energy transition has been described as our “greatest challenge” at a workshop hosted by the Australian Academy of Science at Curtin University in October.

AgZero2030 chair Simon Wallwork joined Emeritus Professor Stephen Powles, WA chair of the Academy, as well as Academy Fellows, leading researchers, policymakers, and representatives from the private sector to discuss technologies to reduce WA’s emissions toward zero. 

The event aimed to inspire positive change and offer valuable insights into achieving carbon neutrality, with speakers discussing current developments and innovative solutions in the field.

The workshop was opened by Darren West, Parliamentary Secretary to the Environment Minister, who emphasised the urgency of the clean energy transition and highlighted the State Government's Sectoral Emissions Reduction Strategy, which involves collaboration with businesses and investments in green technologies like battery technology.

A wide range of speakers covered a vast variety of topics, which have been summarised below.

Professor Malcom McCulloch – ARC Laureate Fellow

China is now the largest emitter globally, contributing 30 per cent of total emissions, while India's emissions are rapidly increasing.

Land and oceans serve as significant CO2 sinks, and the emission gradient between the northern and southern hemispheres is expanding.

The global carbon cycle currently appears stable, with a consistent land-to-ocean CO2 ratio, though approximately 44pc of total emissions remain in the atmosphere.

Notably, Australia's Black Summer bushfires emitted double the country's annual emissions, while COVID-19 induced a temporary reduction in emissions.

Recent observations signal concern, as Earth's average temperature surpasses historical records, with land warming twice as fast as the ocean, heightening fire risks, especially in the Arctic where the tundra warms at an accelerated rate.

Professor Kliti Grice – ARC Laureate Fellow, Curtin University

A study on the deep-time climate changes spanning 600 million years identified five major extinction events, and these historical events, such as the Triassic Extinction, offer insights into current global warming.

For instance, the early Triassic period, characterised by temperatures six degrees hotter than today and the absence of ice caps, is not unique and has occurred at other times.

The Paleocene-Eocene epoch, marked by a thermal maximum 56-66 million years ago, experienced a slower temperature change compared to the current rate, driven by increased CO2 levels and methane release from marine gas hydrate reservoirs, leading to a significant extinction event.

Despite varied causes of past climate changes, such as meteorite impacts or tectonic movements, these historical events provide a basis for comparing and understanding the impact of contemporary global warming.

Dr Linda Stalker – Senior Principal Research Scientist, CSIRO

Carbon capture and storage (CCS) encompasses two types: industrial capture and direct air capture, playing a crucial role in achieving the carbon neutral 2050 goals by swiftly mitigating substantial CO2 levels.

As the cost of direct air capture (ACCUS) rises, it becomes a stronger rationale for embracing CCS, aided by the federal government's safeguard mechanism.

Despite Australia's considerable potential for CCS at 227 gigatonnes of CO2 equivalent, challenges arise from the mismatch between emission sources and suitable geological sinks, emphasising the necessity to cluster CCS projects for shared facilities among emitters. Currently, various industries in Australia are actively exploring CCS, with numerous feasibility studies in progress.

David Fallon – General Manager Energy Transition, Chevron Australia

The Gorgen has two gas fields with a high reservoir of CO2 content in two gas fields (14-16pc of methane), which needs to be extracted.

The Gorgen CCS project aims to capture the 99pc pure CO2, process it to dry it, increase the pressure and store it two kilometres below the surface where it reacts with aquifer and rock to become carbonates.

It is the world's largest CCS operation at 1.6 million tonnes of CO2 equivalent per annum, which is below the 4mt capacity.

Challenges include effective pressure management due to water co-produced during CO2 injection, necessitating the introduction of a temporary filtration system to handle impurities.

The project has sequestered a total of 8mt of CO2 to date, emphasising that CCS is just one tool among many for achieving a low-carbon economy, with a cost of abatement estimated at around $30 per tonne of CO2.

Cameron Remeljej – Head of Carbon Capture and Sequestration, Woodside Energy

Woodside aims to achieve a low-cost, lower-carbon portfolio by focusing on scope one and two emissions through operational changes and the utilization of offsets.

Their goal is to reach net zero by 2050 or earlier, involving a planned $5 billion investment in decarbonization by 2030.

To meet the 2030 targets, Woodside employs offsets, including the purchase of ACCUS and engagement in carbon projects like a reafforestation initiative with biodiverse plantings over more than 2000 hectares.

The company is actively involved in four CCS projects, repurposing gas fields to store CO2 in old wells, leveraging knowledge of extracted gas volumes to estimate CO2 storage capacity.

However, as of now, Woodside lacks specific plans to reduce scope three emissions, which constitute a significant portion of their overall emissions.

 Professor Richard Harper – Murdoch University

The focus on agriculture centres on emission reduction strategies, emphasising the importance of preserving forests and decreasing methane and nitrous oxide emissions.

Efforts include altering savanna burning techniques to minimize carbon loss and increasing carbon stocks in soils and trees through improved management practices.

While highlighting the carbon offsetting potential in locations like Wickepin with trees contributing seven to nine tonnes per hectare of CO2 equivalent per annum, the need to replace fossil fuel emissions with bioenergy and timber products was emphasised.

Despite a solid legislative framework for carbon credits in Australia, concerns were raised about the insufficient land area to achieve net-zero targets, prompting a call for rigorous examination and public disclosure of carbon yields from registered projects.

Professor David Blair – Emeritus Professor, The University of Western Australia

It is essential to educate children about climate change, emphasising the urgency as it is already a predetermined reality.

The focus should be on integrating technology and creating opportunities to empower children with knowledge, ideally before reaching year 10, as interest in science tends to decline thereafter.

The call is for a modernised approach to science education to address the growing issue of "climate anxiety," with a suggested shift in narrative from doom and gloom to framing climate change as an "adventure story."

Professor Craig Buckley – Deputy Director of the Fuels and Energy Technology Institute

The Hydrogen Storage Research Group, comprising a team of 30 individuals, focuses on hydrogen, an abundant element constituting 75pc of known gases.

Despite being lightweight and having an ignition point ten times lower than methane, hydrogen can be as safe as other fossil fuels.

It offers an export opportunity, and existing gas infrastructures can be adapted for hydrogen production, making it attractive to the gas industry.

While hydrogen can be produced from renewable energy and used in internal combustion engines, its poor energy density compared to petrol makes compression necessary for use, posing challenges for export.

Research is exploring solid-state hydride form due to its export potential, allowing it to be transported as a powder and converted back to hydrogen at the destination by adding water.

Richard Macoun - Future Battery Industries Cooperative Research Centre

The potential for a thriving battery industry in Australia is a focal point for the CRC, given the critical role of energy storage, especially with the variability of renewable energy.

Western Australia is the third-largest contributor to emissions in Australia, primarily from resources, utilities, and manufacturing, has key sectors such as LNG, alumina, and mining as major emitters.

The alumina industry is pursuing a decarbonisation roadmap based on renewable energy sources, while the mining sector is adopting a "batteries first" approach with a specific CRC project on electrifying mines.

The transition to sustainable energy with storage capability is crucial, with economic considerations driving the integration of renewable energy in new projects.

Despite lithium-ion batteries being the current leading option, there's a need for alternative resources due to limited lithium availability.

While battery production costs are decreasing with economies of scale, enabling widespread energy storage requires incentive programs, demonstration initiatives, and workforce development, necessitating government leadership.

Full-scale recycling in the battery industry is expected to take at least a decade to achieve significant impact.