​Combined Fuel Treatment – FID Reducer and FID Improver

Retain More Fuel. Improve Its Combustion.

Fuel efficiency starts before the engine. Combustible fuel can be lost with separator sludge, while poor fuel condition at injection can reduce combustion efficiency.


The FID Reducer and FID Improver address these two stages. The Reducer conditions fuel before separation to retain more usable fuel. The Improver conditions fuel near the engine to improve combustion stability and reduce fuel consumption.

Combined fuel treatment diagram showing the FID Reducer before the separator and the FID Improver before the engine.

Two treatment points with different objectives: retain usable fuel before separation and improve fuel condition before combustion. Simplified installation overview.

Stage One — Retain Usable Fuel

The FID Reducer breaks down combustible agglomerates before the fuel enters the separator. More usable fuel remains in the fuel stream, while inorganic contaminants remain available for removal by the separator.


Typical sludge reduction is 50–80%, depending on fuel condition and separator operation. Less sludge reduces waste handling and disposal requirements.

Stage Two — Improve Combustion

Fuel components can re-agglomerate as fuel moves through storage and the supply system. The FID Improver provides treatment close to the point of use, improving fuel consistency before injection.


This supports better atomization and combustion stability, reduces soot and smoke formation, and helps lower fuel consumption.

Why Treat Fuel at Two Points?

The separator and engine perform different tasks. Treatment before separation is intended to reduce combustible fuel losses to sludge. Treatment near the engine is intended to improve the fuel condition presented to the injection system.


The two units are therefore selected for their own operating flows and installation positions. A combined installation addresses both objectives, while each system can also operate independently.

Illustration of fuel agglomeration and mechanical conditioning at different treatment stages.

Operational Benefits

Before the separator: Typically 50–80% less sludge generation and reduced loss of usable fuel

Before a four-stroke engine: Reported HFO fuel savings of approximately 1–1.5%

Before a two-stroke engine: Reported HFO fuel savings of approximately 2–2.5%

Fuel handling and combustion: Reduced agglomerate-related fouling, soot and smoke

Optional Water-Fuel Emulsion

For suitable engine applications, the FID Injector introduces controlled quantities of water to produce a water-fuel emulsion. This can provide additional reductions in NOx and particulate emissions.


The choice between homogenization alone and water-fuel emulsification depends on the engine, its injection and control strategy, and the operating objective. The Injector arrangement is assessed as part of the complete fuel system.

Plan Your Combined Fuel Treatment Installation

Send us your separator details, engine information, fuel types and fuel-system drawing. We will help assess the treatment points, required capacities and expected operational benefits.


The systems can be installed together or introduced in stages, according to your priorities and installation schedule.