Ortho-Xylene (o-Xylene), identified by CAS 95-47-6, is an aromatic hydrocarbon that forms the basis for numerous critical industrial chemicals. NINGBO INNO PHARMCHEM CO., LTD. offers insights into its fundamental chemistry, properties, and production methods, which are essential for understanding its extensive applications.

Chemical Structure and Properties:

o-Xylene is an isomer of xylene, meaning it shares the same molecular formula (C8H10) but differs in the arrangement of its two methyl groups on the benzene ring. In o-Xylene, these methyl groups are attached to adjacent carbon atoms (positions 1 and 2), giving it the IUPAC name 1,2-Dimethylbenzene. This specific structural arrangement influences its physical and chemical characteristics:

  • Appearance: o-Xylene is a colorless, flammable liquid with a characteristic sweet, aromatic odor.
  • Physical Properties: It has a boiling point of approximately 144.4 °C (291.9 °F) and a melting point of around -25.2 °C (-13.4 °F). Its density is about 0.88 g/cm³, making it less dense than water, and it is largely insoluble in water but miscible with most organic solvents.
  • Reactivity: The methyl groups on the benzene ring are reactive and can undergo various chemical transformations, including oxidation and halogenation. Its primary industrial importance stems from its susceptibility to oxidation, yielding phthalic anhydride. The aromatic ring itself can also undergo electrophilic substitution reactions.

Production Pathways:

The industrial production of o-Xylene primarily involves two main sources:

  1. Petroleum Refining: o-Xylene is a component of the BTX (Benzene, Toluene, Xylenes) aromatic fraction obtained from catalytic reforming of petroleum naphtha. The mixed xylenes stream then undergoes separation processes, often employing precision distillation or selective adsorption techniques, to isolate the o-Xylene isomer. This is currently the predominant method for industrial-scale production.
  2. Coal Tar Distillation: Historically, o-Xylene was also obtained from coal tar distillation. While this method is less common now for large-scale production, it remains a source for certain niche applications.

The separation of xylene isomers is crucial because each isomer has distinct applications. For instance, while o-Xylene is primarily used for phthalic anhydride, p-Xylene is essential for producing terephthalic acid used in PET plastics. The efficiency of these separation processes directly impacts the purity and cost of the final o-Xylene product.

NINGBO INNO PHARMCHEM CO., LTD. ensures that the o-Xylene we supply adheres to strict quality standards, reflecting its critical role in advanced chemical manufacturing. Understanding the chemistry and production of o-Xylene allows our partners to better utilize its capabilities in their respective industries.