Drying Of Air And Gases Such As Steam Cracked
Air and gas drying is one of the important processes employed in most industries. Just like regular air, compressed air used in the industries also has the presence of moisture, elements like nitrogen, carbon dioxide and other contaminants. All these can affect the production as well as production processes in the industry. So, they must be removed from the air to achieve quality products and flawless production.
There are compressed air dryers that are used in removing the moisture and water vapour content from the compressed air that is employed in industrial processes. This is done because if there is excess content of water vapour in the air, it can damage the whole system. The water vapour content alone may cause corrosion, blockage of various pieces of equipment, wear and tear of different machine parts etc. To protect the system from all these threats, air and gas drying is necessary.
One of the instances in which air and gas drying is very significant is in steam crackers that are used in petrochemical industries. In ethylene plants, cracked gas drying is one of the important processes. Quality ethylene production can be ensured by employing this technique. Ethylene can be produced as per the specifications and also the formation of hydrates can be prevented to a large extent using the CG dehydration systems.
Steam cracking systems
Steam crackers are used in the petrochemical industries for cracking light naphtha, light hydrocarbons-for instance ethane and propane. They are cracked to form ethylene mainly. This is a process by which unsaturated hydrocarbons are produced by breaking down saturated hydrocarbons. This method is used in the petrochemical industries mainly for producing olefins or lighter alkenes like ethylene, propylene etc.
Ethylene production from naphtha is done using this process. In this process, a liquid carbon feed comes into contact with a solid adsorbent. The byproduct of this process is then cracked in a steam cracker. As a result, hydrocarbon products such as olefins are produced. This process doesn’t involve the use of any catalysts. Not only olefins like ethylene and propylene are produced by this process, but also aromatics like toluene and benzene are produced by this process.
A steam cracker is otherwise known as a cracker, cracking furnace or heater, pyrolysis furnace etc.
Adsorbents used in Cracked gas plants
The formation of hydrocarbon hydrates can cause deadly problems in these plants. To ensure that these problems are avoided to the maximum, dehydration or drying of cracked gas is done. This dehydration is done at a dewpoint equal to or -35 F.
Major desiccants used here are zeolites or molecular beads and activated alumina. This is an improved process for the dehydration of a cracked gas stream that works on thermal energy.
For the separation or removal of contaminants from olefin, a separation technology known as solid bed adsorption is used. Adsorbents like activated alumina and molecular sieves have this excellent capacity to work in reactive environments without any further processes. They can remove any trace of dangerous Impurities to minimum levels. As a result, the plant and its types of equipment can be protected from damage and also optimum performance as well as efficiency of the whole system can be achieved.
The typical process involves steps like, passing the stream that contains water molecules and other impurities via the adsorbent beds to separate all the impurities. This is done at an ambient temperature. At the same time, another bed that was loaded previously with the stream that contained impurities are heated at an extreme temperature ranging between 250 degree Celsius and 290 degree Celsius. This is done to desorb the impurities. After that, this bed is cooled for the next round of adsorption. This process continues again.
This process is of increased significance in today’s ethylene and propylene manufacturing plants for the removal of water and all other impurities. Many industries use applications for the removal of water and other contaminants. Activated alumina and molecular sieves are at the forefront among these widely used applications.
Molecular sieves alone or when combined with alumina have a high adsorption capacity. They help these products to reach all their specifications and at a high quality. Selective gas drying can be achieved by using molecular sieves. They also eliminate the acid particles like carbon dioxide and hydrogen sulphide.
Activated alumina has a very high physical and chemical resistance. Additionally, they have a large number of small pores and tremendous surface area. So, they can adsorb a lot of water. This high water retention capacity and regeneration capacity are the most important facts that make alumina stand out from all other adsorbents.
Sorbead India is a global firm engaged in the manufacturing and distribution of high-quality adsorbents for various applications in several industries. They have made a large number of trusted industrial partners due over a while. They supply high-quality molecular sieves and activated alumina of several sizes and shapes. Customised products and test packets are also offered by this organization.