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We have a long and proud history creating and making effective and efficient demulsifier intermediates for oilfield. Our well-known Kemelix™ brand includes a wide range of chemistries, including polyimine derivatives and modified polyols.

Demulsifiers, also known as emulsion breakers, are used to separate crude oil, also known as petroleum, from water. Due to a number of factors involved in the production process, oil and water are liable to mix, creating an emulsion. This is an undesirable situation because when crude oil is refined, the oil should be as dry as possible. Water will damage the refinery, induce corrosion and reduce the efficiency of the crude oil distillation process.

The process by which oil and water emulsions are split is known as demulsification and it can be done in a number of ways.

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Demulsifier sample kit

Are you a bottle tester or looking to test our products on a crude? To help formulators with product selection we offer a test kit containing samples of each of the 20 demulsifiers on the product range. The test kit can be used in field conditions to determine the right product for your production and refinery application. Please contact us to order.

What do we offer for demulsification of crude oil?

To facilitate the economical removal of water from crude oil, we offer Kemelix® demulsifiers that are drawn from a wide range of chemistries, including resin alkoxylates, polyimine derivatives and modified polyols.

When formulated, these products are capable of treating a wide range of emulsions under the most demanding field conditions including short residence times, high turbulence, high solid loadings, low temperature and a high water content.

What types of demulsifiers do we offer?

In oil and water emulsions, the water is stabilised in the crude oil and so the demulsifier must get to the oil and water interface. There are three classes of chemistries that are used to separate oil and water.

  1. Treaters
  2. Droppers
  3. Hybrids.

We also offer desalters, used before refinery processing.


Treaters work by flocculation. Flocculation is the process by which particles are drawn together without coalescing. The water droplets in the emulsion are tiny - sub-micron in size and are collected together and pulled downwards into a water-based layer below the oil and the crude oil is dehydrated above the settling level of the flocculated water droplets. This is noticeable by a brightening of the top oil. Our treaters are typically based on high molecular weight polymeric molecules with hydrophilic ‘tips’ which solvate into the water droplets and facilitate ‘gathering’. Treaters tend to be resin alkoxylates.

Structure of a kemelix treater

Figure 1: Structure of a Kemelix treater


Water droplets within the emulsion have a high interfacial tension and a low surface area. The high surface tension makes them very resistant to merging and this means that within the emulsion they just bounce off each other, like steel balls. Treaters are used to reduce the interfacial tension between the water droplets and allow them to merge together. This is called coalescence. When water droplets coalesce, the singular body of water becomes greater, and drops down, because water is heavier than oil. The emulsion breaks and this produces a layer of water under the oil, which makes it much easier to separate. Droppers tend to be polyol amine ethoxylates.

Method of action by which kemelix droppers work
Figure 2: Method of action which Kemelix droppers work


Hybrids incorporate a balance of molecular design features such that both dropper and treater characteristics are exhibited and the chemistries tend to be polyols or polyol esters. Hybrids reduce the interfacial tension and they also work to flocculate the oil. The exact method of action depends on the crude oil and what is stabilising the water within the crude oil.


What are desalters?

Desalters are used in refinery processing only. When demulsifiers are used to remove oil from water, the water that is left is concentrated brine. The brine consists of calcium, sodium and magnesium ions. Salt corrodes and damages refinery equipment, the distillation column and poisons catalysts. Therefore, lowering the salt content of oil is a key requirement before refining.

How are desalters applied?

Firstly, the crude oil is washed with fresh water to dilute the salt and then demulsifiers are used to separate out the oil and water. Here, the demulsifiers are desalters because they are specifically used to remove brine. Desalters tend to have a much higher RSN number than demulsifiers that are used more generally to remove water.

How we can help in finding the right demulsifier

Crude oils are a complex blend of molecules and different well sites at different times can produce vastly different crude oils with different degrees of emulsification. Also, solids within the oil, such as salt or scale can act as emulsion stabilisers. Finding the right chemistry can be a complex task. Bottle testing is the industry standard method for the analysis of demulsifiers for crude oils. We offer a demulsifiers kit containing all of our demulsifiers. Please contact us to request a demulsifier kit. We can also advise on the correct application of our range of demulsifiers, including crude oil analysis and relative solubility number.

What makes our demulsifiers different?

Our Kemelix® demulsifiers and emulsion breakers offer excellent demulsification properties at low addition rates, with a very sharp oil/water interface. Kemelix products are also excellent at treating heavy crude oils. We also offer specific BTEX free, green demulsifiers. 

Green demulsifiers

Operators are constantly striving to improve produced water quality. To do this they must employ effective demulsifiers which deliver drier oil, a sharper interface and cleaner water. However, environmental legislation is driving pressure to improve sustainability of ingredients and protect wildlife whilst still delivering oil within specification.

In response to these challenging requirements, we have developed a range of demulsifiers which help our customers create high-performing formulations that have minimal environmental impact, do not require special permissions and that do not have any substitution warnings. Key features and benefits of the three Kemelix grades can be found in the table below.

Feature Benefit 
BTEX-Free Ingredients
Enable finished products to meet stringent regulations, and with reduced environmental impact
Excellent environmental profile
Enable finished products to meet stringent regulations, and with reduced environmental impact
Effective at low inclusion levels
Reduction in cost of demulsifier formulation
High speed of action Suitable for separation vessels with shorter residence times
High degree of demulsification
Reduced residual water in crude oil
High clarity water phase
Reduction in cost of subsequent water treatment steps
High quality interface
Easy separation of water from crude

Relative solubility number 

What is relative solubility number (RSN)?

The RSN of a demulsifier is a measure of its solubility properties. The RSN test method determines the hydrophile-lipophile balance of the demulsifier under test by means of a water titration. The RSN is the volume of water (in millilitres) necessary to produce a persistent turbidity in the given solvent system. We have developed a novel method for determining the RSN of a demulsifier. This method offers substantial reductions in the risks to health, safety and the environment that was inherent in historic tests.

What is the test method for determining the relative solubility number?

Historic tests typically involved hazardous solutions of benzene and 1,4-dioxane. Our novel method utilises a solution of dimethylisosorbide (75%), butyl diglycol (20%) and xylene (5%), a much safer and environmentally friendly test method with the results generated being directly comparable to those generated by the historical method.

Interpreting RSN values

All values quoted are determined with a solvent stripped demulsifier.
  • Products with an RSN < 13 are insoluble in water
  • Products with an RSN 13-17 are water dispersible
  • Products with an RSN > 17 are soluble in water.

How does knowing the RSN number help when formulating?

Final demulsifier formulations contain several demulsifier components and all of our demulsifiers are suitable to be blended. Often final demulsifier formulations have an RSN between 8 and 15 and the synergistic effects of blends between our different demulsifiers chemistries offer performance benefits to using single components.

Brochure: Demulsifiers

Offshore oil rig and operating vessel where flow assurance and demulsifiers are key to operations
2.2 MB

Presentation: Green demulsifiers

676.1 KB

Marketing sheet: Understanding interfacial properties of demulsifiers

284.4 KB

Data sheet: Green demulsifiers

197.3 KB

Kemelix™ demulsifiers

 Kemelix™, efficient and effective demulsifier intermediates with reduced environmental impact for the oil and gas industry. 

View our Kemelix brand here

Recommended products

Kemelix™ 3697X

An ester chosen for its environmental profile and suitability for demulsifier formulations. It can act as both a dropper and a treater to collect and coalesce water droplets and release free water.

Kemelix™ 3702X

An ester chosen for its environmental profile and suitability for demulsifier formulations. It can act as both a dropper and a treater to collect and coalesce water droplets and release free water.

We can find a solution for your needs.