Gasification vs Incineration: Key Waste Management Decisions

Waste management is a big challenge for cities. Landfill space is running out, and greenhouse gas emissions are a problem. This article compares gasification and incineration. We look at how they work, their environmental impact, costs, and best uses.

How Gasification and Incineration Work

Gasification turns waste into gas with little oxygen. It happens at 600-1400°C and makes syngas (CO, H2, CO2). Incineration burns waste completely with lots of oxygen at 850-1200°C. Key differences:

• Gasification needs smaller, more even waste pieces
• Incineration makes more ash (25-35% vs 5-15%)
• Gasification plants are smaller (50-300 tons/day vs 300-3000 tons/day)

Environmental Impact

Gasification is usually better for the environment:

• Less greenhouse gas: 0.3-0.7 tons CO2 per ton of waste vs 0.5-1.2 tons
• Less water used (30-50% less)
• Smaller land needed (40% less space)
• Less noise (10-15 dB quieter)

Cost Comparison

Costs depend on plant size and waste type:

• Building cost: $2000-4000 per ton daily for gasification vs $3000-5000 for incineration
• Gasification can sell syngas ($50-80 per ton) and biochar ($20-50 per ton)
• Incineration is cheaper for large plants (over 500 tons/day)

Choosing the Right Method

Consider these factors when choosing:

• Waste type: Gasification works best with over 60% organic material
• Energy needs: Gasification stores

  Gasification vs Incineration: Key Differences in Waste Management

  
  

  How These Technologies Work

  Gasification and incineration handle waste differently. Gasification heats waste at 600-1400°C with limited oxygen. This creates syngas (40% CO, 30% H2, 15% CO2) that can be stored and used later. Incineration burns waste completely at 850-1200°C with extra oxygen, making heat and ash immediately.

  Main technical differences:
  • Gasification needs uniform waste sizes, while incineration can handle mixed trash
  • Gasification makes tar as a byproduct that needs treatment
  • Incineration produces more ash (25-35% of input) than gasification (5-15%)
  • Gasification uses less oxygen (0.2-0.5 ratio) than incineration (1.5-2.0)

  
  

  Environmental Impact Comparison

  Data shows gasification has several environmental advantages:

  Factor	Gasification	Incineration
  CO2 per ton waste	0.3-0.7 tons	0.5-1.2 tons
  Dioxin control	Under 0.1ngTEQ/Nm³	Needs active carbon
  Water use	30-50% less	Higher

  Gasification also locks 95% of heavy metals in glass-like slag and needs 40% less land.

  
  

  Cost and Practical Considerations

  Building a gasification plant costs $2000-4000 per daily ton capacity, compared to $3000-5000 for incineration. But gasification has higher maintenance costs (15-20% more).

  When to choose each technology:
  • Gasification works best for:
    • Smaller operations (under 200 tons/day)
    • Waste with over 60% organic material
    • Places needing energy storage
  • Incineration suits:
    • Large cities (over 500 tons/day)
    • Areas with district heating systems
    • Mature waste streams

  New plasma gasification technology may change these choices in coming years.