Xylene

WHAT IS XYLENE?

Xylene is a solvent mixture consisting of three isomers: ortho, meta, and para-xylene. It plays a crucial role in the chemical and manufacturing industries.

Xylene is a clear, colorless liquid with a pleasant aromatic odor.

It is soluble in alcohol, ether, vegetable oils, and most other solvents but is almost insoluble in water.

CHARACTERISTIC PROPERTIES OF XYLENE

Physical and Chemical Properties

• State: Liquid
• Color: Clear, colorless
• Characteristic odor: Aromatic
• Vapor pressure (mm Hg) at standard temperature and pressure: 8
• Vapor density (Air = 1) at standard temperature and pressure: 3.7
• Water solubility: 0.02% (at 25°C)
• Density (kg/m³): 870 (at 15°C)
• Molecular weight: 106
• Boiling point (°C): 139 – 141
• Autoignition temperature (°C): 500
• Evaporation rate: 0.8

XYLENE PRODUCTION

In nature, xylene is only found in crude oil at varying concentrations, depending on the oil source and its geological formation period.

However, extracting xylene from natural sources is not economically efficient. In industrial applications, xylene is mainly produced from petroleum through processes such as:

• Catalytic Reforming using Pt, Re
• Steam Cracking or Thermal Cracking of Gasoline
• Cyclar Process for hydrocarbon conversion

APPLICATIONS OF XYLENE

• Paint Industry: Xylene is used as a solvent for surface coatings due to its slower evaporation rate compared to toluene and its good solubility. It is widely used in enamel coatings and paint production.
• Pesticide Manufacturing: Used as a carrier in pesticide production.
• Adhesive Production: Utilized in the manufacturing of rubber adhesives.
• Dilution Solvent: Xylene is used for thinning paints and inks in cases requiring slower drying. It serves as an alternative to toluene due to its superior solubility and slower evaporation.
• Cleaning Agent: Xylene is used for cleaning metal surfaces and semiconductor materials.
• Plastic Production:
  • p-Xylene is a key precursor for terephthalic acid and dimethyl terephthalate, both of which are used in producing polyethylene terephthalate (PET) plastic bottles and polyester fabric.
  • o-Xylene is an essential precursor for phthalic anhydride.

SAFETY AND STORAGE PRECAUTIONS FOR XYLENE

• Avoid exposure to heat sources, flames, strong oxidizing agents, nitric and sulfuric acids, halogens, or molten sulfur.
• Store in specialized containers in a dry, cool, well-ventilated area with sealed lids.
• Use proper grounding techniques during transportation and storage.
• Protect chemical containers from impact, heat sources, sparks, and strong oxidizing agents.
• Do not pressurize, cut, heat, or weld used chemical containers. Do not reuse empty containers without thorough cleaning.
• Keep out of reach of children and away from residential areas.