Dehydration or drying of gases is a significant process involved in most industries. Water molecules and moisture content should be eliminated from the gaseous streams, mainly in the petrochemical industries and chemical plants. Processes like pressure swing adsorption and thermal swing adsorption are mainly used in the drying of gases. They employ regenerative methods wherein adsorption and desorption takes place continuously so that the adsorbent can be used for drying without any interruptions.
Air and gas drying is necessary because water molecules or moisture content, as well as all other undesirable contaminants, should be removed from industrial gases to prevent problems like corrosion and oxidation, damage caused to the pieces of equipment, blockage or plugs formed in the pipelines etc. They can also lead to the slowdown of the whole system and even result in a shutdown.
Adsorbents-mainly activated alumina balls and molecular sieves or zeolites are used in the drying of Catalytic Reforming Recycles Gases & Synthesis Gases.
Catalytic reforming involves the conversion of naphtha formed from crude oil via distillation into reformates having high octane presence. Paraffins or hydrocarbons with a low-octane presence are converted into isoparaffins and naphthene. Then they are converted into aromatic hydrocarbons with high octane presence through partial dehydrogenation. As a result of this dehydrogenation, a high quantity of byproducts- hydrogen gas is formed. Then this hydrogen gas is refined via hydrocracking. On the other side, hydrogenolysis- another reaction takes place. As a result of this side reaction, light hydrocarbons including methane, ethane, propane, butane etc., are formed.
Reformates are the blending stocks for gasoline. Further, they are also a source of production of chemicals like benzene, toluene, xylene etc.
Industries use catalytic steam reforming processes to produce hydrogen, natural gas, ammonia, methanol etc.
Synthesis gas is a product of dry reforming otherwise known as carbon dioxide reforming. It’s a combination of carbon monoxide and hydrogen. With the help of noble metal catalysts such as Ni or its alloys, carbon dioxide reacts with hydrocarbons like methane to form synthesis gas.
These gases were produced via the traditional process named steam reforming reaction aka coal gasification. But today, due to the increased concerns regarding global warming, steam is replaced with carbon dioxide as the reactant.
In many industries, synthesis gas production is a core process. Its mainly produced from natural gas or coal. The source depends on the availability and cost. Synthesis gas is mainly needed in methanol synthesis, ammonia synthesis etc. The steam reforming process for the production of synthesis gas from natural gas is highly endothermic. This conventional process involved a high amount of heat whereas the new auto thermal reforming process that is available nowadays doesn’t involve that much heat.
Electricity generation is one of the important functions of synthesis gas. This is a combustible gas that can be employed as a fuel as well. They can be produced from different processes such as partial oxidation, dry reforming, steam reforming etc. It's an important intermediate that’s used in the manufacture of ammonia, methanol, hydrogen etc.
Activated alumina & molecular sieves for air and gas drying
Activated alumina balls and molecular sieves or zeolites can be used to dry gases with a relatively high amount of water vapour. Due to factors like high adsorption capacity, its excellent regeneration power, physical and thermal resistance etc, they are very popular and are employed in most industrial air-drying practices. Low cost and high efficiency are two other features that make them stand out from other adsorbents.
As a surface phenomenon, adsorption can take place only by using adsorbents with tremendous surface area. It’s the process by which the solute molecules are accumulated at the surface of the adsorbent. There is a direct relation between the surface area of the adsorbent and the adsorption capacity. When compared to non-polar molecules, polar molecules have more chances of adsorption.
The pores of adsorbents (activated alumina and molecular sieves ) are optimized in such a way that they can absorb a high amount of moisture. Activated alumina will remain dry even when they are saturated with water.
Sorbead India is an International distributor of adsorbents and desiccants. They supply high-quality products like silica gel, activated alumina and zeolites or molecular sieves for various industries.
Activated alumina or aluminium hydroxides of grades AD-101 (SORB-I) & ALSORB-F are available here. They are capable of adsorbing a higher amount of water than other adsorbents including molecular sieves. In sorbead, molecular sieves of various types and sizes including 3A, 4A, 5A, 13X, carbon molecular sieves and molecular sieve powder are available. Adsorbents in the form of granules, beads and pellets, dust are all available here. Only high-quality products are supplied by Sorbead India. They take customized orders as well.