Phenolic resins used as raw materials for carbon molecular sieves due to several reasons:

High Carbon Yield:

Phenolic resins have a high carbon content, which is essential for the formation of carbon molecular sieves. The high carbon yield allows for the production of molecular sieves with a high surface area and pore volume, which are crucial for their separation performance.

Low Cost

Phenolic resins relatively inexpensive compared to other carbon precursors, such as pitch or activated carbon. This cost-effectiveness makes them an attractive option for large-scale production of carbon molecular sieves.

Easy Processing:

Phenolic resins easily molded into various shapes and sizes, making them suitable for the fabrication of complex structures in molecular sieve manufacturing. Additionally, the curing process of phenolic resins is straightforward and achieved at moderate temperatures and pressures.

Good Mechanical Properties:

Carbon molecular sieves made from phenolic resins exhibit excellent mechanical strength and durability, which are important for their long-term stability and resistance to wear and tear during operation.

Wide Temperature Resistance:

Phenolic resin-based carbon molecular sieves have a wide operating temperature range, making them suitable for use in various industrial applications where temperature fluctuations may occur.

Reproducibility:

The use of phenolic resins as raw materials for carbon molecular sieve allows for consistent and reproducible product quality, which is essential for meeting the stringent requirements of industrial separation processes. 

In summary, phenolic resins are favored as raw materials for carbon molecular sieve due to their high carbon yield, low cost, ease of processing, good mechanical properties, wide temperature resistance, and reproducibility. These factors contribute to the overall performance and reliability of carbon molecular sieves in various separation applications.