Crude oil demulsifier: technical principles, application scenarios and latest research progress
I. Introduction
In the oil industry, emulsion problems are often encountered during the extraction, transportation and processing of crude oil. Emulsion is a mixture of oil and water, which usually forms a stable dispersion system due to the presence of natural emulsifiers. This stable emulsion brings many challenges to the treatment of crude oil, such as increased energy consumption, reduced equipment efficiency, and affected product quality. Therefore, crude oil demulsifiers came into being and became one of the key technologies to solve these problems. This article will deeply explore the technical principles, application scenarios and latest research progress of crude oil demulsifiers, and analyze in detail different types of demulsifiers, including phenolic resin polyether, polyacrylate, polyoxyethylene glycol, alkoxylated resin and diepoxide.
II. Technical principles of crude oil demulsifiers
(1) Interfacial activity
One of the core futions of crude oil demulsifiers is to destroy the stability of emulsions by reducing the tension at the oil-water interface. The stability of emulsions mainly depends on the high interfacial tension at the oil-water interface, which makes it difficult for water droplets and oil droplets to merge. The surfactant component in the demulsifier can be adsorbed on the oil-water interface, reducing the interfacial tension, making it easier for water droplets and oil droplets to aggregate and merge. For example, the nonionic surfactant in some demulsifiers can form a thin film on the oil-water interface, which can effectively reduce the interfacial tension and promote the coalescence of water droplets.
(2) Charge neutralization
The water droplets in the emulsion usually carry a negative charge, and the electrostatic repulsion between these charges makes it difficult for the water droplets to merge. Demulsifiers neutralize these charges and destroy the electrostatic repulsion between water droplets, thereby promoting the coalescence of water droplets. For example, cationic demulsifie can adsorb on the surface of water droplets, neutralize the negative charge on the surface of water droplets, weaken the electrostatic repulsion between water droplets, and promote the coalescence and sedimentation of water droplets.
(3) Wetting and penetration
Demulsifiers can also dissolve natural emulsifiers such as colloids and asphaltene adsorbed on the oil-water interface through wetting and penetration. These natural emulsifiers are important factors in the stability of emulsions. Their presence hinders the coalescence of water droplets and oil droplets. Demulsifiers can penetrate into these natural emulsifiers and dissolve them, thereby destroying the stability of the emulsion. For example, the alcohol components in some demulsifiers can penetrate into the emulsifier molecules and dissolve them, making the emulsion unstable.
(4) Bridging flocculation
Demulsifier molecules can also connect water droplets together through bridging to form larger water droplets for easier sedimentation. This bridging effect is similar to the effect of flocculants, which increases the sedimentation rate of water droplets by forming larger water droplets, thereby achieving oil-water separation. For example, the polymer components in some demulsifiers can connect water droplets together through bridging to form larger water droplets, which promotes the sedimentation of water droplets.
III. Classification and characteristics of crude oil demulsifiers
(1) Phenolic resin polyethers
Phenolic resin polyethers are a type of demulsifier with high molecular weight and multifunctional groups, which are widely used in treating crude oil emulsions with high water content. Its main characteristics include:
High interfacial activity: It can significantly reduce the oil-water interfacial tension and promote the coalescence of water droplets.
Good thermal stability: It can still maintain efficient demulsification performance under high temperature conditions.
Strong adaptability: It is suitable for various types of crude oil emulsions, especially for high acid value crude oil.
(2) Polyacrylate
Polyacrylate demulsifier is a class of high molecular polymers with excellent performance, with the following characteristics:
Efficient demulsification ability: It can achieve oil-water separation in a relatively short time, and is particularly suitable for treating complex emulsions.
Good chemical stability: It can maintain a stable demulsification effect in acidic, alkaline and neutral environments.
Environmentally friendly: It is easy to biodegrade and has little impact on the environment.
(3) Polyoxyalkylene glycol
Polyoxyalkylene glycol demulsifier is a class of high molecular polymers based on ethylene glycol, with the following characteristics:
Low toxicity: It is safe and harmless to the environment and operators.
Good wettability: It can effectively penetrate into the emulsion and dissolve natural emulsifiers.
Efficient separation: Efficient oil-water separation can be achieved at a relatively low temperature.
(4) Alkoxylated resin
Alkoxylated resin demulsifiers are prepared by alkoxylation reaction and have the following characteristics:
High selectivity: can be optimized for specific types of emulsions to improve demulsification efficiency.
Good dispersibility: evenly dispersed in crude oil to ensure uniform action of the demulsifier.
Strong adaptability: suitable for a variety of operating conditions, including different temperatures and pressures.
(5) Diepoxide
Diepoxide demulsifiers are a new type of polymer compound with the following characteristics:
High efficiency demulsification: can achieve oil-water separation in a very short time, especially suitable for emergency treatment.
Versatility: in addition to the demulsification function, it also has certain antiseptic and bactericidal effects.
Environmentally friendly: easy to degrade in treated wastewater and harmless to the environment.
IV. Application scenarios of crude oil demulsifiers
(1) Crude oil extraction
During the crude oil extraction process, stable emulsions are often formed in the oil wells. These emulsions not only reduce the production of the oil wells, but also increase the difficulty of subsequent treatment. Demulsifiers can reduce the stability of the emulsions and achieve oil-water separation, thereby increasing the production of the oil wells. For example, in an oil field in Bohai Sea, a new type of polyamine demulsifier was applied. The demulsifier was prepared by a specific chemical synthesis method and can effectively reduce the water content of the exported crude oil to less than 0.5%, and shorten the static dehydration time of crude oil from more than 120 hours to less than 48 hours.
(2) Crude oil transportation
During the crude oil transportation process, due to factors such as pipeline friction and temperature changes, the water and oil in the crude oil are prone to emulsification. This emulsification phenomenon not only increases the energy consumption of the pipeline, but may also cause pipeline blockage and corrosion. The application of demulsifiers can help crude oil maintain a stable oil-water separation state during transportation and prevent pipeline blockage and corrosion. For example, in long-distance oil pipelines, the use of demulsifiers can effectively reduce the water content in crude oil, reduce friction in the pipeline, and improve transportation efficiency.
(3) Crude oil processing
In the refining and petrochemical links, the application of crude oil demulsifiers helps to improve the processing efficiency and product quality of crude oil. Through the action of demulsifiers, the water in crude oil can be effectively removed, reducing energy consumption and pollution in subsequent processing. For example, in a certain refinery, a new type of demulsifier was used. This demulsifier can achieve rapid demulsification at a lower temperature, effectively reducing the water content in crude oil and improving refining efficiency.
V. Latest research progress on crude oil demulsifiers
(1) Hyperbranched polymer demulsifiers
In recent years, research on hyperbranched polymer demulsifiers has made significant progress. Hyperbranched polymers have a special three-dimensional topological structure and can achieve efficient demulsification at a lower temperature. For example, Professor Mi Yuanzhu's research group reported a hyperbranched polymer demulsifier based on crude oil emulsion in "Separation and Purification Technology". This demulsifier can achieve a demulsification efficiency of nearly 100% at a temperature of 45°C and exhibits good demulsification performance in a wide pH range (4-12). This hyperbranched polymer demulsifier not only has efficient demulsification ability, but also has good environmental friendliness and can be quickly degraded in treated wastewater.
(2) New polyamine demulsifiers
New polyamine demulsifiers are also one of the research hotspots in recent years. Polyamine demulsifiers are prepared by a specific chemical synthesis method and have high efficiency in demulsification and good stability. For example, a new type of polyamine demulsifier was applied in an oil field in Bohai Sea. The demulsifier can effectively reduce the water content of the exported crude oil to less than 0.5% and shorten the dehydration time of crude oil from more than 120 hours to less than 48 hours. This new type of polyamine demulsifier not only improves the processing efficiency of crude oil, but also reduces production costs.
(3) Multifunctional demulsifier
With the continuous advancement of technology, the research on multifunctional demulsifiers has also made significant progress. Multifunctional demulsifiers not only have high efficiency in demulsification, but also have other functions, such as corrosion protection and sterilization. For example, a research team has developed a multifunctional demulsifier that integrates demulsification, corrosion protection and sterilization. This demulsifier can not only reduce the water content of crude oil, but also effectively prevent pipeline corrosion and microbial growth, thereby improving the safety and efficiency of crude oil transportation and processing.
VI. Selection and application skills of crude oil demulsifiers
(1) Demulsifier selectivity
Selecting a suitable demulsifier requires consideration of many factors, including the type of crude oil, the properties of the emulsion, and operating conditions. Different types of crude oil emulsions require different types of demulsifiers. For example, phenolic resin polyether demulsifiers are suitable for high acid crude oil, while polyacrylate demulsifiers are more suitable for handling complex emulsions. In addition, the selection of demulsifiers also needs to consider factors such as the acidity and alkalinity of the emulsion, temperature, and pressure. For example, some demulsifiers work better under acidic conditions, while others work better under alkaline conditions.
(2) Optimization of operating conditions
The effect of demulsifiers is affected by operating conditions such as temperature and pressure. For example, polyoxyethylene glycol demulsifiers can achieve rapid demulsification at lower temperatures, while some alkoxylated resin demulsifiers require higher temperatures to achieve the best effect. In addition, operating conditions such as pressure and stirring speed will also affect the effect of demulsifiers. For example, at higher pressures, demulsifiers diffuse faster and can act more effectively on emulsions. Therefore, when using demulsifiers, it is necessary to optimize according to the specific operating conditions to ensure the best effect of the demulsifier.
(3) Environmental friendliness
When selecting demulsifiers, their impact on the environment must also be considered. An ideal demulsifier should have low toxicity and be easily degraded in the treated wastewater. For example, diepoxide demulsifiers can be degraded in the treated wastewater in a short time and have little impact on the environment. In addition, the amount of demulsifier used also needs to be optimized to reduce the burden on the environment. For example, by optimizing the formula and use method of the demulsifier, the amount of demulsifier used can be reduced while improving the demulsification effect.
VII. Conclusion
Crude oil demulsifiers play a vital role in the petroleum industry. Their efficient demulsification performance helps to improve the processing efficiency and product quality of crude oil. With the continuous advancement of chemical technology, the research and development and application of new demulsifiers will bring more possibilities to the petroleum industry. At the same time, the rational selection and use of demulsifiers can not only improve production efficiency, but also reduce the impact on the environment and contribute to sustainable development. In the future, with the further development of technology, crude oil demulsifiers will play a more important role in the petroleum industry and provide strong support for the efficient and environmentally friendly development of the petroleum industry.
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UNPChemicals' Demulsifiers
General Information | Function | Application | |||||
Product | Description | Dehydrati-ng agent | Drying agent | Wetting effect | Oil-in-water demulsifier | Waste oil demulsifier | Desalting agent |
DEMET A-21 | Alkoxylated resin | • | – | – | • | • | – |
Alkoxylated resin | • | – | – | • | – | • | |
DEMET B-11 | Alkoxylated resin | – | • | – | • | – | – |
DEMET B-127 | Alkoxylated resin | – | • | – | • | – | – |
DEMET C-163 | Alkoxylated resin | • | – | – | • | – | – |
Alkoxylated resin | • | – | • | • | – | Optimal | |
DEMET C-232 | Alkoxylated resin | • | – | – | • | – | • |
DEMET I-9010 | Diepoxides | – | • | – | • | • | • |
DEMET I-9026 | Diepoxides | – | • | – | • | • | • |
DEMET I-9030 | Polyacrylate | • | – | – | – | – | – |
DEMET I-9037 | Polyacrylate | • | – | – | • | • | – |
DEMET I-9045 | Alkoxyamine | • | – | • | • | • | • |
DEMET L-3134 | Alkoxylated resin | – | • | – | • | – | • |
DEMET M-9510 | Polyacrylate | • | – | – | • | • | • |
DEMET G-62 | Polyoxyalkylene glycol | • | •* | – | • | • | • |
DEMET G-3172 | Alkoxylated resin | • | – | – | • | – | – |
DEMET G-482 | Polyethylene glycol | • | •* | – | • | – | • |