Bunker fuels
CaviFlow® Cavitation Technology
Cost and
time savings
time savings
Scalability
Sustainability
Sustainable Bunker Fuels - Solutions through Cavitation Technology
Fuel emulsions - stable, low-emission, ready for use
In the CaviFlow® inline module, RAPTECH cavitation technology produces stable microemulsions for modern bunker fuels in which fossil and biogenic components are evenly distributed. This produces alternative bunker fuels with defined viscosity and density parameters that enable uniform combustion behavior in maritime operations.
In a series of tests with a mixture of HFO and biodiesel and the integrated CaviFlow® cavitation technology, clear optimizations in fuel performance were demonstrated.
The products reduce CO₂, NOₓ and SOₓ emulsions by up to 25 percent and remain phase-stable during transportation and storage. These marine fuels are compatible with existing bunker logistics systems and support decarbonization in shipping without the need to retrofit engines or make changes to the fuel supply.
In a series of tests with a mixture of HFO and biodiesel and the integrated CaviFlow® cavitation technology, clear optimizations in fuel performance were demonstrated.
- The analysis showed a 13.3% decrease in dynamic viscosity at 50 °C, which improves flow properties and makes combustion more efficient
- In addition, daily fuel consumption was reduced by around 4%
- For an MR tanker with a load capacity of around 55,000 DWT, this corresponds to a saving of approximately 1.2 tons of fuel per day
The products reduce CO₂, NOₓ and SOₓ emulsions by up to 25 percent and remain phase-stable during transportation and storage. These marine fuels are compatible with existing bunker logistics systems and support decarbonization in shipping without the need to retrofit engines or make changes to the fuel supply.
Advantages of RAPTECH (bunker) fuel emulsions
Results and parameters
RAPTECH bunker fuels as a sustainable emulsion solution
The low-emission bunker fuels are based on a precise cavitation process that has been successfully validated under real conditions in the RAPTECH pilot plant. Controlled energy inputs create homogeneous emulsions of intermediate fuel oil (IFO), low sulphur fuel oil (LSFO) and biogenic components. This combination ensures stable combustion, adequate viscosity and a suitable flash point.
A test with CaviFlow® cavitation technology reduced the viscosity of an HFO-biodiesel blend by 13.3 % and reduced fuel consumption by 4 %, which corresponds to a saving of around 1.2 tons per day for an MR tanker.
A test with CaviFlow® cavitation technology reduced the viscosity of an HFO-biodiesel blend by 13.3 % and reduced fuel consumption by 4 %, which corresponds to a saving of around 1.2 tons per day for an MR tanker.
| Properties & test methods | HFO 380 | HFO biodiesel |
| Brennwert ( DIN 51900:2023) | 40.598 MJ/kg | 42.396 MJ/kg |
| Density at 15 °C (calculated) | 989.6 kg/m³ | 969.7 kg/m³ |
| Kinematische Viskosität bei 40 °C (DIN EN ISO 3104:2024) | 600 mm²/s (calculated) | 151.3 mm²/s |
| Schwefel (DIN EN ISO 14596:2007) | 1,78% | 1,35% |
| Flammpunkt (DIN EN ISO 2719:2027) | 122 °C | 160 °C |
| Gesamtrückstand (ISO 10307-1:2009) | <0.07% | 0,01% |
| Pourpoint (DIN EN ISO 3016:2019) | 0°C | -21°C |
| Parameter | HFO 380 | HFO biodiesel |
| Preheating temperature | 90 °C | 0 °C |
With an appropriate sulphur content, the products meet the requirements of ISO 8217:2024 and are considered environmentally friendly bunker fuels and distillate fuels. As a high-performance bunker oil and sustainable bunker fuel, they reduce greenhouse gas emissions by up to 25 percent and enable maritime operations with higher energy efficiency and lower environmental impact.
| Parameter | Conventional HFO | VVLSFO | RAPTECH fuel emulsions |
| ISO 8217:2024 Konformität | Yes | Yes |
| Water risk | None | Negligible (≤1%) |
| Greenhouse gas reduction | None | 20-25% |
| Raw material costs | High | Kidney (glycerine/PPO) |
| Engine modifications | None | None |
Saving on fuel costs
Savings on maintenance and lubricants
Energy savings through cleaning agents
Savings in compliance with the CII guidelines
Charter fee
Do you have questions about our innovative fuel emulsions?
Our experts in the fields of chemistry and process engineering will provide you with competent advice on all aspects of using our sustainable RAPTECH (bunker) fuels in your plant.
-100%
Addition of
Additives
-25%
Reduction
from emissions
- RAPTECH CaviFlow® technology uses controlled hydrodynamic cavitation to efficiently produce stable fuel emulsions by finely dispersing and homogenizing difficult-to-mix components such as heavy fuel oil, biodiesel and optionally water
This highly effective homogenization and mixing process - naturally with a flexibly adjustable ratio - forms the basis for stable emulsions. Optionally based on renewable and alternative energy sources. The result is low-emission, consumption-optimized, alternative fuels, ideal for use in shipping and industrial energy generation.
CaviFlow® cavitation technology is suitable for:
- Emulsions with heavy fuel oil (HFO)
- Combinations of HSFO, VLFO and ULSFO
- Biodiesel as a renewable energy source
- Bioethanol for industrial use
- Pyrolysis oil from recycled plastics (WPPO)
- Hydrogenated vegetable oil (HVO)
- Glycerine-based fuel solutions
- Water-in-fuel emulsion systems
- Qualitative upgrading of heavy fuels
- Cavitation-based fuel reforming
- Optimization of atomization properties
- Demand-oriented use of additives
Conformity with ISO 8217:2014
(Specification for bunker fuels)
(Specification for bunker fuels)
CaviFlow® modules
Efficient bunker fuel emulsification with CaviFlow® inline technology
The RAPTECH CaviFlow® inline modules enable energy-efficient processing of modern bunker fuels by introducing controlled cavitation directly into existing lines. We use standardized threads and flange connections to integrate the systems into bunker fuel plants without any modifications. The compact design allows operation with variable viscosity and ensures stable flow conditions for bio-based fuel emulsions.
Depending on the application and volume flow, variants from 6 m³/h to 100 m³/h flow rate are available for processing bunker fuels:
All modules are control-compatible with common PLC platforms and transmit process data in real time. The smooth interior design reduces maintenance and ensures long-term high availability, providing engineers and purchasers with predictable efficiency and scalability in bunker fuel applications.
Depending on the application and volume flow, variants from 6 m³/h to 100 m³/h flow rate are available for processing bunker fuels:
- Plug & Play solution
- Immediate use
- Low-maintenance technology
- Low investment costs
- Scalable flow rates
- 6 m³/h to 100 m³/h
All modules are control-compatible with common PLC platforms and transmit process data in real time. The smooth interior design reduces maintenance and ensures long-term high availability, providing engineers and purchasers with predictable efficiency and scalability in bunker fuel applications.
Technology and research highlights
Lower emissions and ISO 8217-compliant
Optimized combustion of bunker fuel through homogenized emulsions
RAPTECH cavitation technology optimizes the homogenization of modern bunker fuels and marine fuels by using the CaviFlow® inline module to convert liquid mixtures into stable microemulsions. This marine fuel structure promotes uniform combustion, increases the energy efficiency and enables constant quality parameters for viscosity, density and particle distribution.
With a sulphur limit value for a marine fuel below 1.35 percent, it meets the requirements of the IMO regulation (International Maritime Organization) and supports operators in emission control areas (ECA). The results serve as a resilient alternative bunker fuel that utilizes existing marine fuel supply systems and creates the technical basis for a measurably reduced environmental impact.
- The result is a reduction in emissions of up to 25 %
With a sulphur limit value for a marine fuel below 1.35 percent, it meets the requirements of the IMO regulation (International Maritime Organization) and supports operators in emission control areas (ECA). The results serve as a resilient alternative bunker fuel that utilizes existing marine fuel supply systems and creates the technical basis for a measurably reduced environmental impact.
Convert to fuel emulsions now - with CaviFlow® Plug & Play modules
Increase the efficiency and sustainability of your system: CaviFlow® inline mixers integrate state-of-the-art cavitation technology directly into your fuel system - ready to connect, low-maintenance and scalable. Ideal for fuel emulsions without conversion measures.
- Send us a short message. We look forward to hearing more about your projects.
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Frequently asked questions on the topic: Bunker fuel
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