GREEN CEMENT

Green Cement

Context – Green cement as a sustainable construction material

Concept –

• Green cement is an environmentally friendly product that minimizes the carbon footprint of cement production.

Why is cement manufacturing polluting ?

India’s cement industry contributes 7% of co2 emission as it is heavily relied on coal. Its main challenges are clinker dust, leaks during production and transport, waste during manufacturing , heavy reliance on coal for power. 

• Many attempts have been made to produce green cements and several green cement types have been produced.

• The majority of these are based on technological advances that include energy-efficient, low carbon production methods, new cement formulations, geopolymers, carbon-negative cements, and new concrete products.

• Additionally, green cement production reduces cement intake, and its major raw materials include discarded industrial wastes like blast furnace slag and fly ash.

• Ekkomaxx cement, magnesium oxychloride cement, geopolymer cement, ferrocrete, calcium sulfoaluminate cement, and sequestrated carbon cement are some examples of green cement. Some of these products have been commercialized and used in various projects whereas a number of these cements have not been utilized broadly in construction projects but possess great potential to be used.

• It has been estimated that a single tonne of Portland cement releases approximately six percent of the total man-made carbon emissions, which significantly contributes to the current environmental issues. The usage of green cement can provide an effective solution to such pressing complications. 

• Substituting coal with hydrogen in the cement plant can eliminate CO2 emissions, with hydrogen having six times the calorific value of coal. The cement manufacturer will switch to hydrogen if its adjusted cost, including carbon tax, is equal to or lower than coal costs. There is a demand for green cement, potentially available at a 15% premium.

To make cement manufacturing green focus on 4 areas : 

1. Use alternative fuels like RDF,MSW & Renewable energy, optimise power consumption with AI technologies.

2. Electrifying kilns to reduce emissions, adopting technologies like rotodynamic heaters.

3. Developing eco-friendly cements such as EKKOMAXX & ECOPact, using alternative raw materials and increasing fly ash and pond ash .

4. Improving carbon capture utilization and storage (CCUS) technologies to capture and use CO2 emissions.

Advantages

• Lowers carbon dioxide emission as it does not require as much heat during its production, releasing up to 80% less carbon dioxide. Helps to achieve net zero carbon emission target by 2070.

• Makes use of industrial waste such as fly ash, silica fume, and last furnace that may require several acres of land to dispose of. As a result, it protects land from becoming a dumping ground and ultimately being destroyed.

• Requires less energy since industrial by-products present in green cement, the energy needed in production is greatly reduced. Additionally, it withstands temperature fluctuations and hence decreases costs related to both heating and cooling.

• Long-lasting – Having a low shrinkage rate, green cement tends to be more long-lasting than the traditional cement..