Difference of Physical Parameters between Crude Benzene and Benzene

Benzene (C6H6) is one of the most important organic solvents in the chemical industry, and its pure form is widely used in industry and laboratory. In actual production, the raw material is often not perfect benzene, but "crude benzene" containing impurities ". Understanding the differences in physical parameters between the two is of great significance for chemical production, separation and purification, and equipment selection. This paper will analyze the differences between crude benzene and benzene in physical properties, chemical properties and physical and chemical properties in detail, and discuss its application in industry.

Introduction: Background and differences between benzene and crude benzene

benzene is a colorless, odorless, non-toxic vapor solvent, commonly used in organic chemical reactions and industrial production. In actual production, the raw material is often not pure benzene, but "crude benzene" containing some impurities ". These impurities may come from raw material impurities, impurity contamination, or by-products of the production process. Therefore, understanding the differences in physical parameters between crude benzene and pure benzene is of great significance for optimizing the production process and improving the efficiency of equipment.

Chapter 1: Differences in Physical Properties

1. boiling Point

• pure benzene: The boiling point is 80.1°C, which makes it have significant temperature changes during heating and cooling.
• crude benzene: The presence of impurities usually leads to an increase in the boiling point, and some impurities may have a higher boiling point, thereby changing the overall boiling point range. For example, the boiling point of some impurities is higher than 80°C, which may lead to the expansion of the boiling range of crude benzene at atmospheric pressure.

1. Density

• pure benzene: Under standard conditions (20°C,1 atm), the density of pure benzene is 0.8765g/cm³.
• crude benzene: The presence of impurities can significantly affect the density of crude benzene. In general, impurities may cause an increase in density, especially if the impurity itself is relatively dense. For example, the density of some industrial crude benzene may reach 0.88g/cm³ or more.

1. Viscosity

• pure benzene: The kinematic viscosity of pure benzene is about 0.74 cP at 20°C.
• crude benzene: The presence of impurities usually leads to an increase in viscosity, especially when the impurities have a higher viscosity. For example, the viscosity of some crude benzenes may reach 1.0 cP or even higher.

Chapter 2: Differences in Chemical Properties

1. solubility

• pure benzene benzene has excellent solubility, especially in organic solvents, can dissolve almost all substances.
• crude benzene: The presence of impurities may reduce the solubility of crude benzene, especially when some impurities have higher insolubility.

1. Reaction characteristics

• pure benzene benzene has excellent activity in many chemical reactions, such as addition, substitution, elimination and other reactions.
• crude benzene: The presence of impurities may cause some reaction activities to decrease, especially when the impurities have high stability. Therefore, when carrying out a chemical reaction using crude benzene, it is necessary to consider the influence of impurities on the reaction.

Chapter 3: Differences in physical and chemical properties

1. solubility

• pure benzene benzene is slightly soluble in water, but has extremely high solubility in organic solvents.
• crude benzene: The presence of impurities may affect the solubility of crude benzene. For example, certain impurities may have a higher solubility in water, resulting in an increased solubility of crude benzene in water.

1. vapor pressure

• pure benzene: The vapor pressure of pure benzene at atmospheric pressure is about 760 mmHg (at the boiling point of 80.1°C).
• crude benzene: The presence of impurities usually causes the vapor pressure to drop, because impurities increase the surface activity and reduce the vapor pressure.

1. surface tension

• pure benzene the surface tension of pure benzene is about 28.8 mN/m.
• crude benzene: The presence of impurities may cause the surface tension to decrease, especially when certain impurities with higher surface tension are present.

Chapter 4: Differences in Application Areas

1. application of pure benzene

• pure benzene is used as an important solvent and reaction medium in organic chemistry. For example, in benzene ring substitution reactions, addition reactions, etc., the activity and selectivity of pure benzene are key factors.

1. Application of crude benzene

• crude benzene is more common in industrial production, especially when the raw materials are impure or impurities are difficult to remove. For example, in petroleum refining, chemical production, crude benzene is widely used because of its cost-effectiveness and operational flexibility.

Chapter 5: How to deal with crude benzene

because crude benzene contains impurities, its physical and chemical properties are significantly different from pure benzene. This requires special attention in practical applications. For example, when a chemical reaction is carried out, impurities may cause side reactions that affect the efficiency and selectivity of the reaction. Therefore, in the case of using crude benzene, it is generally necessary to remove impurities by a method such as refining or fractionation in order to improve its physical property parameters in a state close to pure benzene.

Conclusion: Problems and Thoughts

in chemical production, the difference between benzene and crude benzene is not only reflected in the physical and chemical properties, but also related to their application scenarios and processing methods. Understanding these differences is important for optimizing production processes and improving equipment efficiency. With the improvement of environmental protection requirements, how to efficiently remove impurities in crude benzene to obtain physical parameters closer to pure benzene has become an important research direction in the field of chemical engineering. In the future, with the progress of technology, the research in this area will be more in-depth, providing more scientific solutions for chemical production.