Clean diesel cuts CO2 emissions by 90 percent

The term “clean diesel” refers to technologies, fuels and systems designed to reduce harmful emissions from conventional diesel engines, particularly those of particulate matter (PM), nitrogen oxides (NOx) and other pollutants. This doesn't mean that diesel engines are completely emissions-free, but they do meet more stringent standards.

When we talk about clean diesel, we are referring to different types of diesel that, however, have in common a significant reduction in the substances present in traditional diesel.

• Conventional diesel contains sulfur, which contributes to the formation of particulate matter and sulfur oxides.
• Il low-sulfur diesel o ultra-low sulfur diesel (ULSD) contains less than 10 ppm sulfur, reducing harmful emissions.
• Il biodiesel It is produced from vegetable oils or animal fats and can be blended with conventional diesel.

The most developed form of clean diesel is found in the acronym HVO, Hydrotreated Vegetable Oil.: is A renewable fuel obtained from agricultural waste or used oils. As a drop-in fuel (often compatible with existing engines without modification), it offers a high cetane number, ensuring cleaner combustion and a reduction of up to 90% in CO2 emissions compared to traditional diesel. Thanks to its sulfur-free nature and chemical structure, it significantly reduces the formation of soot and carbon deposits in the engine, particularly in the injectors and diesel particulate filter (DPF).

The real star of the moment, in the field of clean diesel, is theHVO (Hydrotreated Vegetable Oil).

• It is a diesel produced by used oils, animal fats and waste
• It is chemically almost identical to fossil diesel
• Works in existing engines without modification (“drop-in fuel”)

Vantaggi chiave:

• up to 90% less CO₂
• less particulate matter and NOx
• cleaner combustion and less residue

It's the only solution already immediately usable on a large scale, without changing cars or infrastructure. The only limit is the availability of raw materials (oil and waste).

European standards  Euro 6 (cars) and Euro VI (trucks and buses) impose very low limits for NOx (nitrogen oxides) and PM (particulate matter).

• These engines combine different technologies to “clean” exhaust gases.

The technology enables clean diesel to greatly reduce polluting exhaust emissions, both smoke and harmful emissions.

1. Diesel Particulate Filter (DPF)
   • Treats particulate matter (PM) by trapping it in the filter.
   • Periodically the filter is regenerates by burning the accumulated particulate matter at high temperatures.
2. Selective Catalytic Reduction (SCR)
   • System that reduces nitrogen oxides (NOx) by transforming them into nitrogen (N₂) and water (H₂O).
   • Use a urea-based additive (AdBlue) injected into the exhaust gases.
3. EGR – Exhaust Gas Recirculation
   • Reintroduce some of the exhaust gases into the engine to lower the combustion temperature and reduce the formation of NOx.
4. Advanced fuel injection
   • System common rail e multiple injection they improve combustion, reducing both smoke and harmful emissions.

The new frontier

New technologies aim to produce diesel fuel from:

• recycled plastic
• municipal waste
• advanced biomass

In this way, in addition to the environmental benefits deriving from the type of fuel, waste and refuse to be disposed of are also reduced.

Another frontier is synthetic diesel produced with renewable energy.

How does it work:

• if you use green hydrogen + CO₂ captured
• a synthetic liquid fuel similar to diesel is created

Pro:

• virtually carbon neutral
• compatible with current engines

Against:

• still very expensive
• limited production

It is seen as a strategic solution for aviation, heavy transport and fleets.