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Cold Flow Improvers


With global and national regulations becoming increasingly challenging you need additives to meet stringent specifications. Furthermore as a refiner you strive for an optimal use of your valuable raw materials and production facilities. Clariant Refinery Services is dedicated to supply you with tailored products, giving you the greatest possible freedom to design the most efficient fuels.

As a leading provider of cold flow additives for middle-distillates including diesel, home heating oil and biofuels, Clariant Refinery Services offers Middle Distillate Flow Improvers (MDFI) and Wax Anti-Settling Additives (WASA). Based on more than 15 core components we provide tailored solutions to meet your cold flow and wax anti-settling requirements. Our well proven Research and Development track record and the reliable service give you the experience and expertise to address today’s middle distillate problems.

Middle Distillate Flow Improver

Get the DODIFLOW® flow improver you need to meet your most demanding challenges

Refineries are being required to handle a progressively more challenging variety of crudes and permanent process optimization. You need the best Middle Distillate Flow Improver (MDFI) you can find to meet your specific situation. Clariant is a leading supplier of MDFIs with more than 100 different DODIFLOW® flow improver grades. Our experienced experts can help you to find peace of mind for your most difficult challenges.

We provide added value through:

  • Modern terpolymer technology that offers excellent solubility characteristics.
  • Tailored component blending, the base for our customized products.
  • Classic Poly-E/VA-Technology, optimized for best performance in Narrow Boiling Distillates (NBD), Broad Boiling distillates (BBD) and High Final Boiling Point (HiFBP) blends.
  • Improvement in CFPP, PP and SFPP of middle distillates such as diesel and light heating oils.
  • MDFI booster technology as key for treatment of problem blends such as heavy wax drop out, NBD and for depressing CFPP anomalies (CFPP2, ATE).
  • Solutions for special handling requirements e.g. low temperature blending due to the local installation set up.

Together with our Wax Anti-Settling Additives we are able to create Wax Anti-Settling Flow Improvers (WAFIs) customized to specific problems, solving different problems (such as CFPP and sedimentation specifications) within one product.

Our products are in line with industry standards and meet REACH regulations. Required standard approvals can be requested for all individual additives. Those include e.g. "no harms", EPA or Platts listing.

The unique setup of storing and blending our components and products contributes to a secured supply while also providing increased flexibility for new products.

Our technical experts have the industry knowledge to help you to find the best product formulation for your problem with advanced service to improve diesel blending and the refinery's economy.

Wax Anti-Settling Additive

Reduce the buildup of wax layers in vehicle and storage tanks with Dodiwax® wax anti-settling additive.

Clariant DODIWAX® Wax Anti-Settling Additive (WASA) is often used in combination with DODIFLOW® Middle Distillate Flow Improvers (MDFI) in order to improve operability significantly. Wax Anti-Settling Additives prevent crystals from agglomeration and settling of the paraffin crystals at the bottom of the fuel tank.

Using DODIWAX wax dispersants typically allows passage of modern operability tests such as sedimentation tests or LTFT. The combination of DODIWAX and DODIFLOW often lowers MDFI dosage requirements by creating a synergistic improvement of CFPP. The good solubility properties make wax dispersants suitable for terminal on top treatment and multi-component additive blends. The redissolving of paraffin crystals is also improved.

The long history of Clariant allows our experienced experts help you select and design a WASA and MDFI additive system to successfully treat a wide range of diesel fuel grades.

Typical WASA dosage rates lie within the range of 100-300 ppm and must be added at least 10°C above the CP temperature of the middle distillate.

The WASA keeps the paraffin crystals dispersed more effectively when diesel fuel is exposed to temperatures below the cloud point by:

  • Further paraffin crystal size reduction
  • Co-crystallization/nucleation mechanism
  • Comb-Polymer anti-agglomeration effect
  • Electrostatic repulsion

This helps improve vehicle operability and prevents a wax layer from developing on the vehicle tank bottom and will reduce filter cake buildup. The combination of DODIWAX and DODIFLOW also helps to prevent a wax layer forming at the bottom of diesel storage tanks.

Definitions, Measurements and Mechanism

Cold Filter Plugging Point (CFPP)

The Cold Filter Plugging Point was developed as a quick lab test method incorporated into the majority of diesel fuel specifications worldwide. It is designed to provide a more accurate operability prediction than either the simple cloud point or pour point tests. The CFPP test is intended to provide a closer correlation to real diesel vehicle operability within known limits. It describes the temperature at which a defined filter “blocks” or even more precise the temperature where the time that is required to aspirate 20 ml of the fuel sample through a standardized filter exceeds 60 seconds. The CFPP is measured according to EN 116/ASTM 6371/IP 309 (linear method) or EN 16329 (linear method).

CFPP2 and aspiration effects are secondary effects that can occur during CFPP measurements. They mask the real CFPP.

Cloud Point (CP)

The cloud point of a middle distillate is the temperature where upon cooling the first wax crystals appear. The Cloud Point is measured according to EN 23015/ASTM D2500.


Operability refers to the cold operating performance of a given fuel, meaning that a vehicle will operate satisfactorily down to a certain temperature until eventually the engine fails to run smoothly. When the engine will no longer run, due to extreme plugging of the fuel filter or even fuel solidification, the so called operability limit has been reached.

Vehicle field operability, as we might call it, is dependent on four important factors:

  • Weather conditions (rate of cooling and lowest temperature reached)
  • Vehicle construction (protected or exposed fuel lining/fuel filter)
  • Diesel cold flow performance
  • Length of time the vehicle is standing exposed to the cold conditions

Operability can best be tested at All Weather Chassis Dynamometer-test sites (AWCD) or alternatively in the less costly Rig-tests. In the Rig-test, just the cold flow critical parts of the engine (filter, injection pump, tank, fuel lining) are arranged in a cold box. The fuel to be tested is filled into the tank and the system cooled down repeatedly until the critical temperature is determined, whereupon filter blockage occurs. The injection pump is driven by an electric engine.

CFI - Mode of Action

The development of Clariant flow improvers is based on profound understanding of fuel characteristics and the molecular interaction of specially designed polymers with the various types of paraffins found in diesel. Also, all aspects of a successful application, even under challenging conditions, play an important role. Clariant flow improvers efficiently interact with paraffins when they begin to drop out, thereby limiting crystal growth to an uncritical size and keeping them well dispersed within the fuel. The formation of interlocking platelet-like space-filling agglomerates that are prone to form sediments is prevented. The fuel, so treated, remains fluid and filterability to temperatures way below the original pour point temperature.

Flow improving additives do not alter the cloud point or the rate of precipitation of wax as the fuel is cooled down. The additive improves the low temperature operability just by changing physical properties of the fuel. The need for kerosene is reduced and this valuable component can be released to the jet fuel pool, creating additional value to this particular refinery stream.

Diesel Fuels and Heating Oil

Diesel fuels and heating oil contain lower molecular weight paraffins with carbon numbers up to approximately C30. Fuels within this range can differ significantly in cold flow properties. Diesel cuts coming from Coal to Liquid or Gas to Liquid procedures show higher pour points than diesel coming from crude distillation. Some high waxy crudes lead to diesel cuts with high pour points. Pipeline specifications and local requirements may require the use of PPDs for such diesel fuels. All these different middle distillates require PPD which are optimized to the individual paraffine distribution. Clariant is specialized to develop these tailored PPD, aiming to use PPD in most economic injection rates. Whatever your challenge, we have the expertise and experience to help you meet it. Our experts are on hand to develop innovative solutions just for you.

International Standard for Cold Flow Improver Determination

EN 116

Diesel and domestic heating fuels- Determination of cold filter plugging point - Stepwise cooling bath method

ASTM D6371

Standard Test Method for Cold Filter Plugging Point of Diesel and Heating Fuels

IP 309

Diesel and domestic heating fuels - Determination of cold filter plugging point

EN 16329

Diesel and domestic heating fuels - Determination of cold filter plugging point - Linear cooling bath method

IP 419

Simulated Filter Plugging Point [SFPP]

EN 23015

Petroleum products; determination of cloud point

ASTM D2500b

Standard Test Method for Cloud Point of Petroleum Products and Liquid Fuels

ASTM D7689

Standard Test Method for Cloud Point of Petroleum Products (Mini Method)

DGMK 663

Evaluation of the filtration behavior of Diesel fuels

IP 387

Determination of filter blocking tendency

EN 590

Automotive fuels – Diesel - Requirements and test methods

DIN 516031

Liquid fuels - Fuel oils – Part 1: Fuel oils EL, minimum requirements

EN 15940

Automotive fuels - Paraffinic diesel fuel from synthesis or hydro treatment - Requirements and test methods


There are many different types of biodiesel on the market. Some contain fatty acid methyl esters made by trans-esterification of vegetable oils, cooking oils or animal fats with an alcohol producing fatty acid esters while others are hydrocarbon based, e.g. produced in process similar to Fischer-Tropsch. Biodiesel is mainly used in standard diesel engines as blend or as pure fuel. Blends of biodiesel and conventional hydrocarbon-based diesel are labeled with a B-factor in most cases. Pour Point Depressants are used for higher B-contents (e.g. bio content > 20%) or when handling the pure substances, e.g. before blending or when transporting or storing pure biodiesel. B100 (pure biodiesel) is also used in some engines but needs pour point and cloud point modifications. Clariant has developed specially designed biodiesel PPD’s, such as DODIFLOW 5603.

Clariant Product Portfolio

Clariant is able to provide you with different solutions depending on your individual requirements. We are offering different product lines, ranging from our DODIFLOW® and DODIWAX® Performance Line, where you can pick your additive according to your need. The Superior Line includes our well known tailored product solutions that match the right service to meet the customer’s needs and support the application.

Product Line
Standard offerings
Tailored Solutions
Onsite – Service
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If your fuel or applications require more customized formulations to meet or overachieve specific targets, then we can offer products from the DODIFLOW® High-End Line.

To see the full range of products from our Performance Line or to get a deeper insight in our offerings, please reach out to the contact person listed below.

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