13 Oct 2021
Reducing carbon emission in cement and concrete industry
The second session of Road to Carbon Zero webinars, with a focus on cement and concrete, finished on 13th Oct, and we received over 700,000 views on the Sina Leju Live platform.
There is an analogy for carbon emissions: China, the United States, and then... Cement. This means that if the cement industry were a country, it would be the world's third largest emitter of greenhouse gases, producing more than 4 billion tons of cement each year, emitting about 8% of the world's total greenhouse gas emissions, and causing more pollution than aviation and merchant shipping combined.
Therefore, in the face of the global carbon neutrality target, cement and concrete industry is worthy of great efforts, attention, and investments.
After Juan Ferriz-Papi introduced that cement is now a very big stumbling block on the road to carbon neutrality, he introduced several materials that can partially replace cement, such as fly ash, slag and kaolin, etc., including the characteristics and the challenges of these materials as cement replacements.
Juan also suggested that we need to think about optimizing processes to improve the way we use these materials and optimize their properties. It is also pointed out that there is a need to study how to develop and standardize the market through standards, certifications and procedures to ensure the quality of materials.
Tongbo Sui introduced the current situation and future prospects of China's low-carbon cement technology. China is a major cement producer in the world, the cement industry is an important basic industry of China's national economy, and cement is also the main composition of modern urban architecture, which makes it even more difficult for the cement industry to achieve carbon neutrality.
For China's current best practice in reducing carbon, there are four main aspects:
Energy efficiency improvement technology
Alternative fuel technology
Clinker substitution technology
Low carbon clinker cement technology
The application and development of this technical route in China's cement industry is the fastest in the world. At present, the average clinker coefficient of China's cement is 0.66, and the calcined clay technology is currently an international hot spot. Furthermore, Prof. Sui Tongbo talked about the development of CCUS technology in the cement industry in China, and suggested that more efforts would be put in place in the future by the sector and the government.
Ling Wang's speech was on the concrete industry. As a big concrete consumer, China's annual output can reach 60% of the world's total output. The content of Wang Ling's speech was very beginner-friendly. She introduced the raw materials of basic concrete, showed the production process of concrete, and gradually introduced four carbon reduction technology approaches of concrete industry:
Optimize the composition and proportion of concrete raw materials to develop green concrete.
Optimize concrete production technology and reduce energy consumption.
Improve concrete durability, prolong service life.
Concrete carbonation being used for carbon capture and utilization.
And she introduced some more advanced technology, such as 3D printing technology, concrete self-repair technology and so on
Ling Wang said that in order to achieve concrete carbon emission reduction, it is necessary to minimize the use of cement in concrete and energy consumption in production, and suggested that concrete carbon emission reduction should be combined with resource conservation and energy conservation, follow the cost-effectiveness principle, and pay special attention to sustainable technology methods.
Seyed Ghaffar introduced his research in concrete 3D printing technology. Seyed said that while 3D printing is no longer uncommon, it is still in its infancy in the field of construction and needs more attention and investment to realize its potential.
In terms of 3D printing technology, more research is done on material science. In order to achieve the goal of sustainable development and circular economy, people are also studying how to recycle aggregate from building waste removal for remanufacturing concrete. Seyed hopes to create added value by integrating waste into building materials.
Seyed presented his team's research on the machine design for concrete printing, as well as the comparison of formulation choices and results to achieve low-carbon goals.