【国际燃气联盟IGU】2024年低碳气体技术详解报告_20页_9mb

Summary of "Introduction to Low Carbon Gas Technologies"

Core Content

This document provides an overview of low-carbon and renewable gas technologies, emphasizing their role in decarbonising the global energy system and supporting the transition to net-zero emissions. It outlines three main areas: Decarbonisation, Diversification, and Innovation, with a focus on technologies that can reduce greenhouse gas (GHG) emissions while leveraging existing natural gas infrastructure.

Main Low Carbon Gas Technologies

1. Decarbonisation

• Biomethane production through anaerobic digestion

  • Process: Organic matter (e.g., food waste, manure, sewage sludge) is broken down by bacteria in the absence of oxygen, producing biogas (rich in methane).
  • Biogas can be upgraded to biomethane, which can replace natural gas in the grid.
  • It is considered carbon-neutral as it captures methane from organic waste and converts it into fuel, preventing its release into the atmosphere.
  • Efficiency depends on the source material.

• Pyrogasification

  • A thermochemical process that converts dry biomass and solid recovered fuels (SRF) into syngas.
  • Syngas is rich in CO, H₂, CO₂, and CH₄ and requires purification.
  • Higher temperatures (800–1500°C) are used, with challenges in pollutant removal and catalyst costs.

• Hydrothermal gasification

  • Converts wet or liquid organic waste into syngas under high pressure and temperature.
  • Syngas can be purified to produce clean CH₄ or H₂, or converted into chemicals.
  • Methane content can reach 50–60% with catalytic conversion, and up to 90% when H₂ is co-injected.
  • H₂ concentration in syngas can reach 50–75%.

• E-methane

  • Produced by combining CO or CO₂ with H₂ using methanation.
  • CO₂ can be sourced from biogenic or industrial processes, or captured from the atmosphere.
  • E-methane can be used in existing natural gas infrastructure.

• Solar photocatalytic processes

  • Mimics natural photosynthesis using solar energy and photocatalysts (e.g., semiconductors).
  • Produces H₂ and O₂ through water splitting, either via photocatalysed (PC), photo-electrochemical (PEC), or PV-EC methods.
  • Reduces reliance on electricity and biomass, avoiding GHG emissions.

2. Diversification

• Hydrogen production technologies
  • Methane reformation: Produces blue hydrogen by reforming methane and capturing CO₂.
  • Water electrolysis: Produces green (renewable) or pink (nuclear) hydrogen using electricity.
  • Thermal gasification: Converts solid organic matter into syngas, which is then processed into H₂.
  • Methane pyrolysis: Produces H₂ and solid carbon from methane without CO₂ emissions.
  • Biological production: Uses fermentation or biophotolysis to generate H₂ from organic matter.
  • Geological extraction: Two types:
    • Natural hydrogen ("white" hydrogen): Generated through water-rock reactions (e.g., serpentinisation) and stored underground.
    • Water injection induced hydrogen ("orange" hydrogen): Involves injecting CO₂-saturated water into iron-rich formations, producing H₂ and sequestering CO₂.

3. Innovation

• The gas industry must innovate to meet climate targets and ensure energy security.
• Investment in decarbonising technologies (e.g., CCS, CCU, renewable gas, hydrogen) is essential.
• Policy support, access to financing, and infrastructure development are critical for scaling up these technologies.
• Innovation in the gas sector can drive down supply chain emissions and support the transition to sustainable energy.

Key Information

• Over 140 countries have committed to carbon neutrality by mid-century.
• Low-carbon gas technologies are vital for overcoming the intermittency of renewable energy and supporting energy transition.
• Existing gas infrastructure can be leveraged for cost-effective deployment of these technologies.
• Hydrogen is expected to play a significant role in energy systems, with several emerging production methods.
• The efficiency and scalability of these technologies are key to achieving global climate goals.
• Methane pyrolysis and solar photocatalytic processes are promising for low-emission hydrogen production.
• Geological extraction methods, such as "white" and "orange" hydrogen, offer new avenues for hydrogen production while sequestering CO₂.

Conclusion

The document highlights the importance of low-carbon gas technologies in achieving global decarbonisation goals. It outlines a variety of methods to produce biomethane, hydrogen, and other renewable gases, each with its own advantages and challenges. The integration of these technologies with existing infrastructure and the need for innovation, investment, and policy support are central to their successful deployment and the transition to a sustainable energy future.