In the petroleum industry, the choice of demulsifier is crucial. Demulsifiers are chemicals used to destroy emulsions and are mainly used in the development and processing of mineral resources such as crude oil, petroleum, natural gas, and coal. Excellent demulsifiers can effectively reduce the interfacial tension of the emulsion and separate the components in the emulsion, thus improving production efficiency and product quality.
For different types of petroleum products, different demulsifiers need to be selected. Here are some examples of demulsifier choices:
Oil-in-water crude oil demulsifier
Oil-in-water crude oil is a common emulsion, mainly composed of water, oil and emulsifier. In order to break this emulsion, a demulsifier needs to be selected that can reduce the interfacial tension. The specific selection steps are as follows:
(1) Analyze the composition of the emulsion and determine whether the demulsifier acts on the water phase or the oil phase; (2) Select an appropriate demulsifier so that it has a lipophilic and hydrophilic balance value that competes with the emulsifier; (3) Optimize the dosage and action time of demulsifier to achieve the best demulsification effect.
Petroleum based demulsifier
Petroleum matrix refers to the part of crude oil other than the light distillates. During the processing, asphaltene, colloid and other components in the matrix easily form emulsions. In order to reduce production costs and improve product quality, it is necessary to choose an efficient and environmentally friendly demulsifier. The specific selection steps are as follows:
(1) Analyze the chemical composition of the matrix and determine the target of the demulsifier; (2) Select an appropriate demulsifier so that it can produce a demulsification effect for specific components; (3) Optimize the dosage and action time of the demulsifier, To achieve the best demulsification effect.
Natural gas hydrate demulsifier
Natural gas hydrate is a new type of energy resource, formed from natural gas and water under certain conditions. During the mining and processing of natural gas hydrates, emulsions are easily formed. In order to improve mining and processing efficiency, a highly targeted demulsifier needs to be selected. The specific selection steps are as follows:
(1) Analyze the composition of natural gas hydrate and determine the target of the demulsifier; (2) Select an appropriate demulsifier so that it can produce demulsification effect on the unique components of natural gas hydrate; (3) Optimize the dosage of demulsifier Dosage and action time to achieve the best demulsification effect.
For different petroleum products, the solutions are as follows:
Crude oil: Crude oil demulsifier mainly destroys the stable state of oil-water emulsion, causing water droplets to coalesce and settle, and then separate from crude oil. When using, the composition and properties of crude oil and the adaptability of the demulsifier should be fully considered to select the best variety and concentration of demulsifier.
Gasoline: Gasoline demulsifiers mainly work at the oil-water interface to reduce the tension at the oil-water interface, allowing water droplets to coalesce and settle as quickly as possible. At the same time, the demulsifier should also have anti-oxidation, anti-corrosion and other properties to adapt to the chemical environment of gasoline.
Diesel: Diesel demulsifier is similar to gasoline demulsifier. It should also have the function of reducing the interfacial tension of oil and water and promoting the coalescence of water droplets. In addition, considering the wide operating temperature range of diesel, the demulsifier should also have good high and low temperature resistance.
Lubricating oil: Lubricating oil demulsifiers need to have good polarity and adaptability, and can effectively remove moisture and impurities in the oil without negatively affecting the lubricating oil itself. In addition, considering the wide operating temperature range of lubricating oil, the demulsifier should also have good high and low temperature resistance.
In the petroleum industry, demulsifiers are widely used in processes such as crude oil dehydration and desalination, natural gas dehydration and desulfurization. If the emulsion produced during these processes is not destroyed in time, it will affect the normal operation of the equipment and the quality of the product. At present, commonly used demulsifiers mainly include surfactants, polymers and polymer esters.
Surfactant demulsifiers have good interfacial activity and can reduce the interfacial tension of the emulsion, thereby destroying the emulsion system. The advantage of this type of demulsifier is that it is easy to use and effective, but the disadvantage is that the dosage is large and the cost is high.
Polymer demulsifiers mainly use the adsorption effect of polymers to render the emulsifier ineffective. The advantages of this type of demulsifier are less dosage and lower cost, but the disadvantage is that the effect is slower.
Polymer ester demulsifiers have good properties such as high temperature resistance, acid and alkali resistance, and are suitable for a variety of emulsification systems. The advantage of this type of demulsifier is that it has a wide range of applications, but the disadvantage is that its effect is average.
When selecting a demulsifier, it is necessary to comprehensively consider the characteristics, problems and solutions of different petroleum products. First of all, it is necessary to clarify the nature and use of petroleum products in order to select a demulsifier with corresponding adaptability. Secondly, it is necessary to understand the production process and usage environment of the product in order to choose a demulsifier with better stability and safety. Finally, the optimal variety and concentration of demulsifier should be determined based on experimental results and application experience.