What factors should be considered when choosing ethylene glycol
Publish Time: 2024-09-09
The following are factors to consider when choosing ethylene glycol:
Purity-related factors
1. Purpose of use
- Chemical synthesis: If ethylene glycol is used for high-precision chemical synthesis, such as the production of polyester fibers, polyester resins, etc., high-purity ethylene glycol is required. Usually the purity is required to be above 99.5%, because the presence of impurities may affect the progress of chemical reactions, the quality and yield of the products. For example, in the production of polyester fibers, impurities may cause problems such as reduced fiber strength and impure color.
- Antifreeze: When used as antifreeze, the purity requirement for ethylene glycol is relatively low, but it should generally be above 95%. Ethylene glycol with lower purity may contain some impurities that will corrode the metal parts of the cooling system, affecting the service life of the antifreeze and the safety of the cooling system.
2. Impurity impact
- Metal ion impurities: If ethylene glycol contains metal ion impurities such as iron, copper, and calcium, even if the content is very low, it may cause problems in certain specific usage environments. For example, in applications related to the electronics industry, metal ions may affect the performance and reliability of electronic components; in chemical reactions, metal ions may catalyze the occurrence of some side reactions.
- Organic impurities: Organic impurities such as aldehydes and ethers may affect the chemical and physical properties of ethylene glycol. For example, in some odor-sensitive application scenarios, organic impurities may cause odor problems; under high temperatures or specific reaction conditions, organic impurities may participate in the reaction and change the properties of the reaction products.
Physical property factors
1. Boiling point and flash point
- Boiling point: The boiling point of ethylene glycol is about 197.3℃. When used in some high-temperature environments, it is necessary to consider whether its boiling point meets the process requirements. For example, in some high-temperature reaction systems, if the reaction temperature is close to or exceeds the boiling point of ethylene glycol, special pressurization or cooling measures may be required to ensure the stability of ethylene glycol.
- Flash point: The flash point is an important indicator for measuring the flammability of a liquid. The flash point of ethylene glycol is 111.1℃, which is relatively high, which means that it is not easy to burn at room temperature, but it is still necessary to pay attention to fire safety during storage and use, and avoid contact with high-temperature fire sources or strong oxidants.
2. Density and viscosity
- Density: The density of ethylene glycol is about 1.113g/cm³. In some applications that require precise metering or involve fluid mechanics calculations, density is an important parameter. For example, when designing an ethylene glycol delivery pipeline system, parameters such as flow rate and pressure loss need to be calculated based on its density.
- Viscosity: The viscosity of ethylene glycol changes with temperature. At low temperatures, the viscosity of ethylene glycol increases, which may affect its flow properties and heat transfer efficiency in the pipeline. For example, when used as an antifreeze, in winter in cold areas, it is necessary to consider the effect of the viscosity change of ethylene glycol at low temperatures on the circulation of the automobile cooling system.
Safety and environmental protection factors
1. Toxicity
- Ethylene glycol has a certain degree of toxicity. Oral or inhalation of excessive amounts may cause damage to the human body, such as toxic effects on organs such as the kidneys and liver. When using ethylene glycol, appropriate protective measures need to be taken, such as wearing protective gloves and masks to avoid direct contact and inhalation. In some application areas that may come into contact with food and drugs, the use of ethylene glycol must be strictly controlled to ensure compliance with relevant safety standards.
2. Biodegradability
- From an environmental perspective, ethylene glycol has a certain degree of biodegradability, but its degradation rate and degree will vary under different environmental conditions. In some application scenarios with high requirements for environmental impact, such as use near waters that are susceptible to pollution, it is necessary to consider the potential impact of ethylene glycol leakage on the environment and its biodegradability. Try to choose environmentally friendly and easily degradable ethylene glycol products, or take corresponding environmental protection measures to reduce its harm to the environment.
Cost factors
1. Market price fluctuations
- The market price of ethylene glycol will be affected by many factors, such as crude oil prices, market supply and demand, etc. When choosing ethylene glycol, you need to pay attention to market price fluctuations and arrange procurement time reasonably. For example, during a period of falling crude oil prices, the price of ethylene glycol may decrease accordingly, and the reserve volume can be appropriately increased at this time; conversely, when the price rise trend is obvious, the purchase volume can be reasonably controlled according to production needs.
2. Cost-effectiveness
- In addition to paying attention to the price itself, it is also necessary to comprehensively consider factors such as the quality and performance of ethylene glycol to evaluate its cost-effectiveness. For example, although some high-purity ethylene glycol is relatively expensive, it may be a better choice from the perspective of overall production cost and benefit because it can improve product quality and production efficiency; for some application scenarios with low quality requirements, relatively low-priced ethylene glycol products can be selected, but it must be ensured that it meets the basic use requirements to avoid subsequent cost increases due to quality problems.
