Beyond Zero Emissions launched their latest book "Rethinking Cement" at NeW Space @ University of Newcastle.
Making cement is responsible for 8% of all global emissions (more than all the cars in the world). Modernising cement is achievable and affordable, and Rethinking Cement shows how Australia can lead the world with zero carbon cement.
Approximately 110 people came along to find out how we can change cement making to achieve zero emissions in the industry within 10 years using already commercialised technologies.
The first stage of cement making is to transform limestone (calcium carbonate – CaCO3) into lime (CaO), the process of which releases carbon dioxide (CO2) as a waste product. Over half of cement-related emissions are due to this chemical process. A further third of the emissions is from heating required for this process. The remaining emissions are from mechanical actions such as grinding the product.
The report lists five strategies that can get Australia to a zero carbon cement industry in 10 years, and potentially to negative carbon emissions!
Geopolymer cement can be produced without the need for Limestone and is produced without releasing carbon dioxide. Furthermore, it can utilise waste products fly-ash and blast furnace slag. There is over 400 million tonnes of fly-ash from coal powered thermal power stations. The first strategy is to source 50% of cement production from geopolymer cement.
Regular cement can also be blended with other materials, such as fly ash, and slag, reducing its carbon intensity. The second strategy is for the remaining 50% of cement to be blended up to 70% with this replacement material.
The third strategy involves using Mineral Carbonation. Mineral carbonation is a “carbon capture and utilisation” process where waste carbon dioxide is diverted, captured and chemically sealed within a mineral such as magnesium carbonate. This utilises magnesium silicate, found in serpentine, of which Australia has large deposits.
The fourth strategy involves using less cement by designing buildings and other structures to use concrete more efficiently, utilising high strength cement, and replacing concrete with timber such as high tensile laminate.
The fifth strategy gets us to negative emissions with Carbon Negative Cements. Although early days, the development of magnesium-based cements would have the ability absorb carbon dioxide, and therefore have negative emissions.
Newcastle’s own Dr Bonnie McBain was the MC for the night. Speakers included Vanessa Petrie CEO BZE, Jordie Bates, Michael Lord BZE Project Director, Marcus Dawe CEO Mineral Carbonation International, and David Sparkes, Newcastle President of Engineers Australia. Following the speakers, a lively Q&A session ensued with Michael Lord, Marcus Dawe, David Sparkes, who were joined by Bernard Hockings (who built a house with zero carbon blocks) and Alan Morrison CEO Ultrafloor.
The Tom Farrell Institute teamed with Engineers Australia, Mineral Carbonation International and Housing Industry Australia to support the launch in Newcastle of Rethinking Cement.
The development of Rethinking Cement was funded in part through a crowdfunding campaign in memory of Jenn Bates. Jen Bates was the Newcastle coordinator for BZE, and was tragically killed in 2016. The book Rethinking Cement is dedicated to the memory of Jennifer Bates.