Carbon Capture and Utilization (CCU) Technology: The Next Trend for the Cement Industry

Rony

Moderator
Carbon dioxide emissions involved in cement production are a serious issue for cement manufacturers and cement companies.

This issue has become more severe in the last few years because of the increasing demand for cement and raw materials like limestone being the major source of these harmful emissions.

However, advancements in tools and technology are paving the way for a significant reduction of carbon dioxide emissions. The modern carbon capture and utilization (CCU) approach is a reliable and effective method to reduce emissions. CCU is based on the mineralization of components derived from concrete.

CCU is typically defined as a set of tools and technologies used in capturing and using carbon dioxide as a carbon feedstock to make products like fuels, chemicals, and cement without using fossil fuels.



Industrial Application of CCU​

The concept of CCU depends on concrete recycling that involves fines rich in cement paste to be separated from the rest of the components like sand and aggregate.

Once the fines are fully separated, they are carbonated to produce a new material that can be used to produce composite elements. After properly processing and treating all elements, carbonated recycled concrete paste (RCP) will possess the same properties as fly ash in composite cement.

The basic working principle of CCU and mineral carbonation is that the hydraulic cement components and the hydration products can react with the carbon dioxide in a humid environment. Carbonation of the RCP makes it possible to isolate the carbon dioxide released by limestone calcination.

Overall, the entire carbonation process can be completed between a few minutes to a few hours at a suitable temperature and pressure. It is also possible to use carbon dioxide in a minimum concentration of gas like the exhaust gases of the cement plant. Once the cement paste is carbonated, it will produce calcium carbonate and amorphous gel.

The amorphous gel has a very quick reaction, leading to the formation of compressive strength. As a result, this material can also be used as additional cementitious material to reduce the amount of cement clinker in the cement.


Components Required for CCU​

CCU requires two main inputs:

a. Carbon Dioxide​

Carbon dioxide is emitted from almost all kinds of industries like power, chemical, cement, steel, and biological processes. Such sources can be used to capture and use carbon dioxide in CCU at this stage. However, in the long run, carbon dioxide can also be extracted directly from the atmosphere.

b. Energy​

Energy is required to operate the tools and technologies that will convert carbon dioxide into fuels and chemicals. This energy can be obtained in the form of heat, solar radiation, or electricity to power the entire CCU process.

Ideally, energy should be obtained from renewable sources or a source with the least environmental footprint. Moreover, technologies that convert carbon dioxide into mineral materials require a very small amount of energy input because the chemical reaction generates heat naturally. Water is also needed to produce fuels and chemicals.

Water for the production of fuels and chemicals is also required.



Benefits of CCU​

Using RCP for cement production has two main benefits:

  1. It reduces the amount of carbon dioxide being produced in the carbonation process.
  2. It can be utilized in composite cement.
  3. CCU-derived fuels can transform the transportation sector by reducing the net carbon dioxide emissions because it is easier to use them in the current engines.
  4. CCU can also be highly useful in the transition of energy systems by providing an alternate way of storing and transporting renewable electricity in the form of liquid or gaseous fuels.
As a result of these two major applications, the overall carbon dioxide emissions during cement production can be significantly reduced.

It can play an integral role in the circular economy and preservation of natural resources because the components derived from demolished concrete can easily be recycled and used in new concrete manufacturing processes.


Takeaways​

All in all, CCU is becoming vital to reach global climate goals and the development of a circular carbon economy by providing sustainable solutions in the cement industry.

Therefore, it is a huge opportunity for the world to mitigate the effects of climate change, transform the construction industry, and make energy transition much more eco-friendly.

Cement manufacturers and cement suppliers should definitely start adopting CCU on a large scale to bring much-needed sustainability to the construction industry and provide reliable solutions to eco-conscious consumers.
 
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