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Low-carbon aviation? Try methane

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12 May, 2024

This post was originally published on Sustainability Matters

In promising news for the aviation industry, researchers from the University of Sydney have developed a chemical process that could create sustainable jet fuel from the methane gas emitted from landfills.

Their research has been published in the Journal of the American Chemical Society.

Methane is a more potent greenhouse gas than carbon dioxide (CO2), trapping far more heat per molecule. According to the International Energy Agency, the concentration of methane in the atmosphere is currently around two and a half times greater than pre-industrial levels and is increasing steadily, with waste emissions and the burning of fossil fuels accounting for a significant proportion.

Australia recently joined the international methane mitigation agreement with the United States, the European Union, Japan and the Republic of Korea.

“Globally, landfills are a major emitter of greenhouse gases, mainly a mixture of CO2 and methane,” said lead author of the study Professor PJ Cullen from the University of Sydney’s School of Chemical and Biomolecular Engineering and Net Zero Initiative. “We have developed a process that would take these gases and convert them into fuels, targeting sectors that are difficult to electrify, like aviation.”

Global landfill emissions are estimated at 10–20 million tonnes of greenhouse gases per year, a value comparable to the emissions of the global energy sector.

Aviation currently accounts for approximately 3% of the world’s emissions. If the research team’s process becomes viable, it could lead to a ‘closed loop’ fuel based on existing emissions, eliminating the need for traditional, unsustainable jet fuels.

“Modern landfill facilities already capture, upgrade and combust their gas emissions for electricity generation; however, our process creates a much more environmentally impactful and commercially valuable product,” Cullen said.

Professor PJ Cullen with Veolia Australia and New Zealand CEO and Net Zero Initiative board member Richard Kirkman next to a Veolia methane well. Image credit: Luisa Low, University of Sydney.

The researchers’ process works by capturing gas in a ‘methane well’ at the landfill site via a shaft-like mechanism, then treating it with plasma.

“The beauty of this is that this simple process captures almost the exact composition that we need for our process,” Cullen said.

Plasma in the lab. Image credit: PJ Cullen, PlasmaLeap Technologies.

“Non-thermal plasma is an electricity-driven technology which can excite gas at both a low temperature and atmospheric pressure. Essentially, what this means is this approach facilitates the conversion of the gas into value-added products by inducing plasma discharge within forming gas bubbles,” Cullen explained.

“The process doesn’t require heat or pressure, meaning it requires less energy, making it highly compatible with renewable energy power sources.”

Cullen and fellow study authors Emma Lovell and Tianqi Zhang are associated with PlasmaLeap Technologies, the supplier of the plasma technology employed to generate plasma bubbles in the study.

Top image caption: Methane wells. Image credit: Luisa Low, University of Sydney.

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Energy Efficiency as an Imperative Climate Strategy

Energy Efficiency as an Imperative Climate Strategy

With mandatory climate statement disclosure rolling out in Australia, businesses need to start reporting on their emissions and sustainability plans for the future. As companies begin assessing the relevant risks and opportunities related to various climate scenarios, energy efficiency presents itself as an immediate climate-strategy with long-term benefits.

Commencing 1 January 2025, businesses that meet two of the three conditions — more than 500 employees, gross assets above $1 billion or $500 million or more in consolidated gross revenue — are required to lodge a climate statement, which discloses their climate-related plans, financial risks and obligations. As part of the gradual roll-out, by 1 July 2027, businesses that meet two of these conditions — more than 100 employees, gross assets above $25 million or exceeding $50 million in consolidated gross revenue — will also be required to report.

This climate statement will need to include the company’s sustainability governance, climate risks and opportunities, including those physical and transition related. They will also need to disclose their Scope 1 and 2 emissions, strategy to decarbonise, and conduct scenario analysis on the short, medium and long term impacts on the business. By the second year of reporting, businesses will also be expected to report on Scope 3 emissions.

Scenario analysis will be based on various assumptions of the state of the climate, one of which includes a possible future where global temperature has increased 2.5°C or more. They will be required to share their climate strategy and steps they are taking long-term in preparation for this scenario.

Common themes within climate strategies will include switching to renewable energy sources, electrifying fleet vehicles, purchasing carbon credits, and carbon capture and storage. Many of these methods look at reducing emissions through the energy source, or targeting the carbon aspect directly; however, climate strategies can also include reducing the amount of energy used. By investing in more energy efficient equipment, sites can maintain production whilst using less energy and producing less emissions.

When increasing energy efficiency and reducing energy consumption first, businesses will see short-term impacts; however, in the long term, they are also improving their foundation for an energy transition. Assuming no other changes, higher energy efficiency can lead to decreased energy demand, allowing for reduced system requirements when specifying and planning for self-generation or energy costs.

To understand what opportunities are available for upgrading to more energy efficient equipment, businesses can start with an energy audit to understand how energy is being consumed across site. Energy audits, like the ABB Energy Appraisal, can provide a roadmap for where and how equipment can be upgraded for the best energy saving potential. An energy audit identifies areas that can be immediately improved with existing equipment on the market, so there is no need to wait for the commercialization or development of more sustainable technology. Going beyond just changing all lights to LEDs, efficiency recommendations may include areas where variable speed drives can be added to control motor speed or upgrading from an IE3 motor to an IE5 ultra-premium efficiency or IE6 hyper-premium efficiency motor to reduce energy losses by 40% or more. This area can often be overlooked on sites as the Minimum Energy Performance Standard (MEPS) in Australia for motors is just IE2.

Mostly used in pumps, compressors, conveyors and fans, motors may seem like a minor part of a site; however, with 45% of the world’s electricity converted into motion by industrial electric motors, there are many opportunities for energy savings. In fact, a recent survey commissioned by ABB IEC Low voltage motors, showed that 92% of surveyed businesses in Australia recognize the important role of electric motors in achieving sustainability targets. In this same survey, participants ranked a reduction in operating cost as a more important driver for investing in energy efficiency than lowering their organization’s emissions. This is because upgrading to newer, more efficient equipment provides benefits beyond just emission reduction. For example, ABB’s Synchronous Reluctance (SynRM) Motors, available in IE5 ultra-premium efficiency or IE6 hyper-premium efficiency, use no rare earth metals or magnets. Running quieter and with bearing temperatures reduced by up to 15°C and winding temperatures by up to 30°, SynRM motors have longer maintenance periods, superior reliability, and contribute to a better operational environment.

Looking ahead, upgrading to an IE5 SynRM motor also provides more visibility into Scope 3 emissions, as SynRM motors meet ABB’s circularity criteria and transparency on environmental impact is provided through Environmental Product Declarations (EPDs).

By requiring companies to disclose their climate information, these new legal requirements are opening the door and facilitating more internal discussions on environmental impact and emission reduction. Whilst mandatory climate reporting is only required of large business entities this year, the progressive roll-out and Scope 3 emission reporting requirements mean that businesses of all sizes in Australia will be impacted by these new requirements. As businesses become more conscious of how sustainability should be integrated into their operations and finances, there is no better time to start investing in energy efficient solutions.

For more information, click here.

Image credit: iStock.com/denizunlusu

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