Among fossil fuels, diesel accounts for a large proportion, especially in the fields of transportation, processing industry and electricity production. Therefore, determining the CO₂ emission factor of diesel not only helps businesses and organizations fulfill their environmental reporting obligations, but also serves as a basis for building a roadmap to reduce emissions, optimize energy costs and enhance brand reputation. So how to determine CO₂ emission factor of diesel? Let's find out more details with GREEN IN in the content below!
What is the CO₂ emission factor of diesel?
According to the IPCC Greenhouse Gas Inventory Guidelines (2006, 2019 Refinement), the default CO₂ emission factor for diesel is 74.1 tCO₂/TJ of energy. This is a commonly used value in national and corporate greenhouse gas inventories, in the absence of a specific locally measured factor.
For business convenience, the CO₂ emission factor of diesel is often converted as follows:
- 1 liter of diesel burned produces about 2,68 kg of CO₂
- 1 kg of diesel burned produces about 3,16 kg of CO₂
These values may vary slightly depending on the chemical composition and energy density of diesel in each country.
When compared to other popular fossil fuels, diesel has an average CO₂ emissions factor, specifically:
- Petrol: ~ 2,31 kg CO₂/liter (lower than diesel).
- Coal (anthracite): ~ 94,6 tCO₂/TJ (higher than diesel).
- Natural gas: ~ 56,1 tCO₂/TJ (lower than diesel).
As such, the CO₂ emission factor for diesel is higher than that of natural gas and petrol, but lower than that of coal. This is the basis for the transport and industrial sectors to consider when choosing fuels, as well as determining the potential for emissions reductions.
Method for calculating CO₂ emissions from diesel
According to the IPCC Greenhouse Gas Inventory Guidelines (2006, 2019 Refinement), the amount of CO₂ emitted from diesel is determined by the formula:
CO₂ emissions (tonnes) = Consumption activity (units)×Emission factor (tCO₂/unit)
In which:
- Operational consumption: amount of diesel used (liters, kg or TJ).
- Emission factor: standard value from IPCC or national factor.
For example, suppose a transport business consumes 1.000 liters of diesel in a year:
- CO₂ emission factor of diesel ≈ 2,68 kg CO₂/liter.
- CO₂ emissions: 1.000×2,68=2.680 kg CO₂≈2,68 tons CO₂.
Thus, just 1.000 liters of diesel emits nearly 3 tons of CO₂ into the atmosphere.
Calculation levels according to IPCC (Tier 1, Tier 2, Tier 3):
- Tier 1: Use the IPCC default emission factor (suitable for national inventories, where detailed data are lacking) to calculate the CO₂ emission factor for diesel
- Tier 2: Apply country or industry specific emission factors that more accurately reflect real-world fuel composition.
- Tier 3: Based on direct measurement data (chemical composition, calorific value, carbon coefficient of consumed diesel). This is the highest level of accuracy but requires more resources and data.
Factors affecting emission factors
Although the IPCC provides a default emission factor for diesel, in practice this can vary depending on fuel properties, engine technology and operating conditions. Some key factors include:
Diesel quality
- Carbon content: Is a factor that directly determines the amount of CO₂ emitted. Diesel oil with a high carbon content has a higher CO₂ emission factor.
- Sulfur content: Does not directly affect CO₂ but affects the combustion process and the formation of other pollutant gases (SO₂, PM). Low sulfur diesel (ULSD – Ultra Low Sulfur Diesel) often provides a “cleaner” combustion process.
Engine technology and combustion efficiency
- New generation engine with electronic fuel injection technology, turbocharger, EGR, SCR help improve combustion efficiency, reduce fuel consumption, thereby reducing CO₂ emissions per unit of work, leading to a decrease in the CO₂ emission factor of diesel oil.
- Old, low-performance engine More fuel consumption, higher CO₂ emissions, even though the emission factor per litre remains the same.
Operating conditions
- Weight: Overloading or underloading a vehicle increases fuel consumption beyond the optimum level.
- Maintenance: Regularly maintained engines (air filter, injectors, lubricating oil) will have better combustion efficiency.
- Environmental conditions: In low temperatures, steep terrain or poor roads, the engine consumes more fuel, increasing the amount of CO₂ emitted per km driven.
Conclusion
It can be seen that the CO₂ emission factor of diesel is not a fixed and unchanging value but is affected by many factors such as fuel quality, engine technology and actual operating conditions. Understanding and analyzing these factors helps businesses, management agencies, and greenhouse gas inventory organizations choose the appropriate emission factor, ensuring accuracy in calculations. At the same time, it opens up opportunities to reduce emissions through the use of cleaner fuels, upgrading engine technology and optimizing operations. This is an important basis for moving towards the goal of sustainable development and reducing greenhouse gas emissions that Vietnam and the world are aiming for.