Final answer:
Filter driers such as Activated Alumina and Molecular Sieve are used in HVAC systems to remove moisture and contaminants. Activated alumina is created from the reaction involving sodium aluminate, while molecular sieves are made from sodium aluminosilicate and are very effective due to their regular pore structure.
Step-by-step explanation:
The types of filter driers you've mentioned, such as Activated Alumina (Aluminum Oxide) and Molecular Sieve (Sodium/potassium Aluminum Silicate), are crucial components in refrigeration and air conditioning systems. They are used to absorb moisture and other contaminants.
Activated alumina is produced by the dehydration of aluminum hydroxide. In a reaction, the aluminum hydroxide is precipitated from a solution containing sodium aluminate by the addition of acid:
Na[Al(OH)4](aq) + H3O+ (aq) → Al(OH)3 (s) + Na+ (aq) + 2H2O(l)
The precipitated aluminum hydroxide is then removed by filtration and heated, forming aluminum oxide (Al2O3), an essential component of activated alumina.
On the other hand, molecular sieves often utilize materials like sodium aluminosilicate. These are synthetic zeolites with a regular pore structure that traps the molecules of a specific size and shape, making them very effective at drying refrigerants.
It is important to note that the introduction of various sodium compounds, such as sodium carbonate and sodium silicate, has significantly impacted various industries, from cleaning agents to glass manufacturing, due to their properties and the environmental factors involved.