Zeolites

Zeolite is a crystalline aluminosilicate found naturally in the sedimentary rocks can be synthesized artificially under controlled conditions. These microporous materials, often referred to as “molecular sieves,” play a crucial role in various industrial, environmental, and scientific applications. 

In 1756, the mineralogist Baron Axel Fredrik Crönsted discovered the Stilbite. Under fast heating conditions this mineral seemed to be boiling due to its water loss. Crönsted named it “zeolite”, from greek word “zeo”, meaning “to boil” and “lithos” meaning “stone”.

Zeolites are composed of a three-dimensional framework of aluminum, silicon, and oxygen atoms, arranged in a regular pattern. The framework contains channels and cavities of uniform size, creating a porous structure with precise dimensions. The unique arrangement of atoms gives zeolites their exceptional properties, such as high surface area, thermal stability, and ion-exchange capacity. These minerals form through the crystallization of volcanic ash or other silica-rich materials over geological timescales. The specific conditions under which zeolites are formed result in a wide variety of zeolite structures, each with its own set of properties.

The most common framework types include faujasite, mordenite, and clinoptilolite, each with specific pore sizes and geometries.

Zeolites as Catalyst

One of the most significant properties of zeolites is their catalytic activity. The porous structure of zeolites allows for the selective adsorption of molecules, making them ideal catalysts in various chemical reactions. The uniform pore size of zeolites can act as a molecular sieve, selectively allowing certain molecules to enter and react within their confined spaces.

Molecular Sieves

Our Zeolite molecular sieves possess unique properties that facilitate various applications. They excel in liquid separation/purification (solvents, hydrocarbons, etc.), gas separation/purification (natural gas, air, etc.), moisture control, and chemical processes. Depending on the pore size, these molecular sieves fall into different available types such as 3A, 4A, and 5A, each with unique properties such as high adsorption capacity, thermal strength, compressive strength, and durability.

Zeolite molecular sieves, also known as 3A molecular sieves, are a specific type of crystalline aluminosilicate. These molecular sieves possess a regular micro pore structure with a pore size of about 3 angstroms (Å), making them highly effective for adsorption processes. They selectively adsorb molecules with diameters smaller than 3Å. These molecular sieves have a high adsorption capacity, compressive strength, durability, and a high adsorption flux.

Membrane

Our Zeolite membranes, crafted from robust crystalline aluminosilicate materials, distinguish themselves with exceptional chemical and thermal stability, along with high selectivity. They enable precise separation of liquid mixtures (paraffin isomers, xylene isomers, etc.), Gas/Hydrocarbons separation (biogas, natural gas, and CO2 capture), and water desalination, utilizing molecular sieving, diffusion, and adsorption mechanisms. The zeolite membrane system offers a straightforward continuous process with reduced energy consumption and a smaller footprint.

Zeolite membranes are an emerging market attractive segment in solvent dehydration, and water desalination, CO2 capture due its good selectivity and high flux improvement. The main mechanisms for separation by zeolite membranes are molecular sieving, diffusion, and adsorption. Molecular sieving involves the rejection of any molecules of a size greater than the pore size of the membrane.

Potential uses include:-

  • Oil & Gas Industry: separation of p-xylene from o-xylene,
  • Renewable Fuels Industry: separation of ethanol/butanol and separation of water in biofuel production, 
  • Heating, Ventilation and Air Conditioning Industry: separation of Oxygen and Nitrogen from Air.
  • Biogas Plant upgradation: Methane gas purification from biogas with impurities such as H2S and CO, CO2 removal