Carbon Capture and Utilisation (CCU) ( UPSC Prelims)

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News Context

The Department of Science and Technology (DST) recently unveiled a pioneering R&D Roadmap designed to help India achieve its Net Zero Targets through Carbon Capture, Utilization, and Storage (CCUS).

About Carbon Capture and Utilisation (CCU)

     ○ A collection of technologies designed to capture and utilize carbon as a feedstock for producing vital products like fuels and chemicals, which are mainly sourced from fossil resources.
  ● Carbon Capture:  
        ○ From industrial sources (e.g., cement plants) or energy sources (e.g., biomass power plants): Technologies such as membranes, solvent absorption, or adsorption are used to separate CO₂ from flue gases.
    ● Direct Air Capture (DAC): Ambient air is processed through a gas trapping system where CO₂ is extracted from the air for use or storage.  
  ● Carbon Utilisation: After being captured, CO₂ can be used through two primary methods: Direct Utilisation and CO₂-to-Products.  

Carbon Dioxide Utilization Pathways Direct Utilisation

Enhanced Oil Recovery (EOR) involves injecting CO₂ into oil and gas reservoirs to enhance extraction.
 Food & Healthcare: High-purity CO₂ is utilized in food processing and medical applications.
 Industrial Uses: CO₂ serves as a solvent in processes like dry cleaning, acts as a heat transfer fluid, and is used as a welding gas, among other applications.
 Chemicals: CO₂ is employed in the production of urea, plastics such as polycarbonates, and in microbiological conversions.
 CO₂-to-Products: Fuels: CO₂ can be converted into methanol or further processed into gasoline and diesel through Fischer-Tropsch synthesis.
 Mineral Carbonates: CO₂ reacts with calcium or magnesium to create building materials, such as cement.

Ocean-based CCUS

• The process includes capturing CO2 from different sources and storing it in seawater or deep-sea sediments.
 • Key Techniques
    o Ocean Alkalinity Enhancement (OAE): Increases CO2 absorption by introducing pulverized minerals (such as Lime) or by electrochemically enhancing rock weathering.
    o Ocean Fertilisation: Encourages the growth of phytoplankton by adding micronutrients like phosphorus and nitrogen, aiding in deep-ocean carbon storage.
    o Other: Includes Biological Carbon Capture and the enhancement of Blue Carbon Sinks such as mangroves.