Combustion Efficiency Calculator

| Added in Chemistry

What is Combustion Efficiency?

Combustion efficiency is a measure of how completely fuel is burned in a combustion process. It is calculated based on the ratio of carbon dioxide (CO₂) to the sum of carbon dioxide and carbon monoxide (CO) in the flue gas. Higher efficiency indicates more complete combustion, less wasted fuel, and lower emissions of harmful pollutants.

Formula

The combustion efficiency formula is:

$$E = \frac{\text{CO₂}}{\text{CO₂} + \text{CO}} \times 100$$

The result is expressed as a percentage.

Where:

  • E = Combustion efficiency (%)
  • CO₂ = Concentration of carbon dioxide in flue gas (ppmv)
  • CO = Concentration of carbon monoxide in flue gas (ppmv)

How to Calculate

  1. Measure the concentration of CO₂ in the flue gas (in ppmv)
  2. Measure the concentration of CO in the flue gas (in ppmv)
  3. Add the two concentrations together
  4. Divide the CO₂ concentration by the total
  5. Multiply by 100 to get the percentage

Calculation Example

Given:

  • CO₂ concentration = 14 ppmv
  • CO concentration = 3 ppmv

Calculation:

$$E = \frac{14}{14 + 3} \times 100 = \frac{14}{17} \times 100 = 82.35$$

The combustion efficiency is 82.35%.

Applications

  • Boiler and furnace optimization: Adjust air-fuel ratios for maximum efficiency
  • Emissions monitoring: Ensure compliance with environmental regulations
  • Energy audits: Identify opportunities to reduce fuel consumption
  • Industrial processes: Optimize combustion in kilns, incinerators, and other equipment
  • HVAC systems: Maintain efficient operation of heating equipment

Factors Affecting Combustion Efficiency

  • Air-fuel ratio: Too much or too little air reduces efficiency
  • Fuel quality: Moisture content and composition affect combustion
  • Temperature: Higher temperatures generally promote complete combustion
  • Mixing: Proper mixing of fuel and air is essential
  • Residence time: Sufficient time must be allowed for complete combustion

Improving Combustion Efficiency

  1. Optimize the air-fuel ratio
  2. Ensure proper maintenance of burners and combustion equipment
  3. Preheat combustion air when possible
  4. Use high-quality, consistent fuel
  5. Monitor and adjust combustion regularly
  6. Minimize excess air while maintaining complete combustion

Frequently Asked Questions

Combustion efficiency measures how completely fuel is burned. Higher efficiency means more carbon is converted to CO2 rather than incomplete combustion products like CO.

Carbon monoxide is a product of incomplete combustion. More CO means fuel energy is being wasted and harmful emissions are being released.

Well-tuned systems typically achieve 95-99% combustion efficiency. Below 90% usually indicates problems with air-fuel ratio or equipment condition.

Optimize air-fuel ratio, maintain clean burners, preheat combustion air, use high-quality fuel, and ensure proper equipment maintenance.