Moisture Dehydration Solution with Molecular Sieve Desiccant Adsorbents

When it comes to sustainable, clean, and renewable energy sources, Biogas has become increasingly popular due to its potential to transform the energy landscape through the harnessing of the energy potential of organic waste streams. But, the transition from raw waste materials to high-quality biogas is challenging. That’s where renewable energy biogas purification with the PSA / VPSA system comes in.

These remarkable advancements along with the usage of varied molecular sieves, can help transform the renewable energy industry scene. Today let us explore these two bio gas purification processes in detail and understand their differences and similarities.

Know More About Biogas Production and Composition

Biogases are a type of gas formed when organic material, such as food waste or agricultural residues, cattle dung/municipal solid waste, sugarcane press, sewage treatment plant waste, mud, etc., decomposes in an oxygen-deprived environment, like in a compost heap or swampland.

This process is analogous to the recycling process of nature. The composition of bio gas is primarily composed of two components: methane, the positive component that can be used for energy purposes; and carbon dioxide, the harmful component.

Additionally, biogas may contain impurities or fillers, such as hydrogen sulphide, and a small amount of water vapor, which must be removed before it can be used to produce clean energy.

Purification Process: Improving Biogas for Clean Energy

Though biogas is a fantastic well-known and accredited source of renewable energy, it's not always clean for immediate usage as it is produced by the active/anaerobic degradation of organic matter. When biogas is created in a bio gas plant, it contains many impurities and harmful and unnecessary particles/components/impurities that need to be filtered out before use. Thus, the purification process is essential to remove any impurities like moisture, carbon dioxide, hydrogen sulfide, etc.

When the purification process is done using molecular sieves, it can help rid the biogas mixture of different and numerous impurities by capturing them in their selective strainer structures and providing clean and pure methane gas as an end-product.

Molecular sieves can be recruited in processes such as PSA and VPSA to create biogas that is highly purified in nature and prepared to be reconstructed into clean energy ready for use in homes and industrial settings.

Understanding PSA/VPSA Systems

If you're looking for a system to purify your biogas, PSA/VPSA model is the way to go. It's a specially designed gas separation system that uses adsorbent to separate the gas. Adsorbents are like molecular sieves, with a tiny pore on their surface that allows them to selectively adsorb molecules like Co2 and N2 under a certain pressure.

Once it's adsorbed, it's regenerated by being depressurized. These PSA systems use this process to produce the purified methane-enriched gas over and over, repeating the process over and over. The process of biogas purification increases the concentration of methane and decreases the concentration of carbon dioxide in the biogas, resulting in increased calorific value.

The materials used for the adsorbent layer are activated carbon (PC) and zeolite (5a), both of which have been shown in research, to work best at the pressures and compositions tested.

Activated carbon molecular adsorbs mostly CO2 and CH4 and is placed at the bottom of the column for the feed inlet.

Zeolite, on the other hand, adsorbs N2 and carbon molecular and is placed on top of activated carbon. The length of each layer that corresponds to the carbon to zeolite ratio, is a key factor in the PSA/VPSA system.

The adsorption cycle of the pressure swing system is very complicated, as there are many steps in the cycle and interactions between the stages that undergo different operations. The purity of the VPSA system is higher due to the very low process gas flow-rate and the smaller plant size.

Distinguishing PSA / VPAS System: Biogas Cleaning Methods

PSA and VPSA are both biogas cleaning methods, but they differ significantly in terms of the conditions under which they are performed.

Pressure Swing Adsorption/PSA- This method mainly works by varying the pressure in the process. The biogas goes through biogas beds filled with a special material called molecular sieve. The molecular sieve traps the unwanted gases in the biogas. When the molecular sieve is full, the pressure changes, and the unwanted gases are trapped and released. The process is repeated with two biogas beds as a tag team.

Vacuum Pressure Swing Adsorption/VPAS- On the other hand, VPSA uses vacuum power capabilities. When the pressure is minimized/reduced (for example, in a vacuum environment), the sieves collect the particulates or impurities. When they are full, the pressure returns to normal and the particulates are discharged out of the system.

7 Key Benefits/Value of Using PSA/VPSA Systems

Here are some of the top advantages of biogas:

• The use of these systems eliminates impurities such as carbon monoxide, hydrogen sulphide, and moisture to produce pure and high-quality biogas.
• It also utilizes less energy consumption when compared to other available traditional cleaning methods, so it's a great option if you're looking for an affordable alternative.
• The PSA/VPSA system’s design can be molded to fit smaller facilities, and is suitable for a wide range of applications.
• These systems are highly scalable, depending on the biogas production volume, and can be redesigned to fit different project sizes as per your industry requirements.
• The cycle of PSA /VPSA makes it possible to run on a continual basis, guaranteeing a consistent flow of clean biogas, and relatively low maintenance levels.
• With cleaner biogas, there are fewer carbon emissions and fewer pollutants in the air, which helps with environmental sustainability.
• It can be built in a variety of ways, including modular units/bed configurations/layouts, so you can easily add more units and make changes as needed.

With the increase in the advantages of biogas combined with the help of systems like PSA and VPSA, we're turning biogas into a cleaner and more powerful energy source. Make sure to use the best-quality, selective filters, molecular sieves for your needs, that can capture impurities, to make sure the process is efficient and useful.

Zeolite powder has proficiently made a mark as a commercial adsorbent, ion exchanger, and catalyst, that contains microscopic pores used to latch onto unwanted molecules/moisture. It is a go-to adsorbent for purifying liquids and gases, removing contaminants like heavy metals and odors.  Unexpectedly, the same porosity also serves as catalyst sites for enhancing chemical processes in petrochemical, agriculture, refining, and wastewater treatment industries.

For these and so many other applications, you should definitely consider buying this amazing adsorbent from only the best zeolite powder suppliers in India. Let us learn about this molecular sieve in detail and its benefits and uses.

Understanding Zeolite Powder/Molecular Sieve

Zeolites have an exceptional molecular architecture and a defining feature of a complex porous framework reminiscent of a molecular labyrinth, making them the most appealing alternatives for industrial applications due to their unique characteristics.

Molecular sieves are considered a subset of zeolites, which are custom-made sieves on a molecular scale. They are available in a spectrum of sizes, and specifically made to selectively capture different molecules depending on their unique structures and chemical attributes.

These materials are used in numerous varied industries and applications, from separating molecules in petrochemical processes, VOC reduction, to enabling environmentally friendly detergents.

Exploring The Properties of Zeolite Molecular Sieves

Zeolite molecular sieves possess a wide array of properties, centered around their exceptional porous nature. A typical zeolite's framework structure is created by secondary structures created by primary tetrahedra. Here are some of the key properties of Zeolite, that you should know.

- Pore size distribution: Materials such as zeo lite molecular sieves have microscopic pores/holes with varying diameters. According to their size, these pores can be used to segregate molecules. Larger molecules cannot fit through the perforations, but smaller ones can, thus catering to a wide variety of applications. Zeolite molecular sieves can be used to separate and purify various chemicals efficiently.

- Highly porous structure: They have a porous structure, that allows them to have large surface areas. Because of the complex structure of the channels and chambers, the surface area is large enough for molecules to stick to. This increases the adsorption efficiency and allows them to absorb large quantities of target molecules. They are used for a wide range of catalytic applications.

- Selective charge distribution: Furthermore, due to the pore geometry of zeolite molecules and charge distribution, they are highly selective for adsorption. This means that zeolite molecules with small differences in polarity and size can be separated with precision when compared to the other traditional methods. They can help catalyze isomerization, alkylation, and epoxidation.

Because zeolite molecules are highly adsorptive, they are able to adsorb molecules in favorable conditions and release them in unfavorable conditions. This responsiveness plays an important role in a variety of applications, such as gas separation and catalytic cracking.

The Varied Applications of Zeolite

• Molecular sieve, or zeolite, play a pivotal role in the petrochemical and refining industries. They are pretty essential ingredients in the process of hydrocarbon separation, allowing for the production of cleaner products and increasing the efficiency of refining operations.
• Zeolites uses are found in environmental applications to remove pollutants from air/water. These sieves act as efficient air purifiers, capturing varied pollutants such as VOCs and nitrogen oxides to reduce the adverse effects on the environment. In water treatment applications, these sieves selectively remove heavy metals & contaminants and even radioactive ions from water sources.
• Under the influence of zeolite molecules, gas separation is highly efficient. Zeolite molecules are well-suited for sorting some very specific gases out of complex mixtures. This is a skill that is highly sought after by the natural gas and the hydrogen industry. By allowing efficient separation and storage of gas, zeolite powder molecules contribute to energy sustainability.
• If you're in the catalysis business, you've probably heard of zeolite molecules that act as catalysts. Their pores provide a tiny space for chemical reactions to take place, that help with the catalysing process. This is really important when it comes to making chemicals and plastics, as well as in emissions control systems in automobile catalysts.

These remarkable properties of zeolite powder as a purifier and catalyst are revolutionizing industries for a better and more sustainable goal. That’s why you should consider buying from a trusted zeolite manufacturer.

Molecular sieve adsorbents are useful because they can hold a lot of molecules, choose the ones they want, last long, and can be reused. Mainly made up of 3-D structures of Alumina oxide and Silicon Dioxide, molecular sieves can be used for removing contaminants, moisture, air, or unsuitable molecules from different substances.

Types of Molecular Sieve Adsorbents

Molecular Sieve 3A

Molecular Sieve 3A is a potassium-infused form of zeolite A, having a pore size of 3 angstroms. It can adsorb water and molecules sized less than 3 angstroms, Therefore, it can be used to suck water out of both liquids and gases, like methanol, ethanol, natural gas, refrigerants, and air. You can reuse Molecular Sieve 3A after heating it to 250 º C to get rid of any leftover moisture.

Sorbead India provides the largest molecular sieve range available in India, manufactured in a dry environment and controlled conditions in beads, pellets, and powder forms.

Molecular Sieve 4A

Meet Molecular Sieve 4A, a sodium form of zeolite A, having a pore size of 4 angstroms. Therefore, it can adsorb water and other molecules equal to or smaller than 4 angstroms, like oxygen, nitrogen, and carbon dioxide, and suck moisture out of air, solvents, and pharmaceuticals products.

Molecular sieve 4A can also be used to purify and separate liquids and gases, such as argon, krypton, xenon, hydrogen, and oxygen. If you want to regenerate Molecular Sieve 4A, heat it to temperatures between 250f to 450f

Molecular Sieve 5A

Next up, the formidable Molecular Sieve 5A with a pore size of 5 angstroms. It is a calcium form of alkali alumina silicate and is the most suitable for Pressure Swing Adsorption.

Molecular Sieve 5A can capture a variety of molecules, ranging from water and carbon dioxide to alcohols, mercaptans, and hydrocarbons. It is mostly used for paraffin separation, removing moisture and hydrocarbon from SF6 refrigerant, and for the Pressure Swing Adsorption process of oxygen or hydrogen.

Molecular Sieve 13X

Molecular Sieve 13X has a 10 Angstrom pore size, which is bigger than the 3A, 4A, and 5A variants. Therefore, it filters out any molecules larger than the kinetic pore diameter of 10 Angstrom. It adsorbs water, carbon dioxide, alcohol, aromatics, and hydrocarbons, along with purifying liquids and gases like air, natural gas, oxygen, and nitrogen.

Molecular Sieve 13X can be reused after heating it at a temperature of 260-320 degrees, and then cooling it to room temperature. Pressure swing adsorption is another method to regenerate the molecular sieve 13X, or purging the sieve in a pure medium liquid or gas would also do the trick.

Carbon Molecular Sieve

The Carbon Molecular Sieve, crafted from carbonized organic polymers, flaunts its adaptability with variable pore sizes and high attraction to oxygen and carbon molecules. With a high Nitrogen Yield, it is highly useful for all PSA Nitrogen Systems – quickly separating oxygen from compressed air and leaving behind nitrogen. It has a unique ability to adsorb hydrogen, methane, and carbon monoxide based on their kinetic diameters.

Molecular Sieve Powder

Activated molecular sieve powder is a form of 3A and 4A molecular sieve that is utilized for a variety of specialized adsorbent purposes like scavenging the moisture evolved during formulation of 1 K, 2 K or 3 K Epoxy Resin , Paints or Polyurethane Systems  and balancing the basic chemicals in paint. Sorbead India provides pure molecular sieve powder with high adsorption quality and efficacy.

Advantages Of Molecular Sieve Adsorbents

Molecular sieve adsorbents are widely utilized to achieve molecular separation based on size.

• High adsorption capacity: These adsorbents can remove large quantities of water/moisture and polar molecules from liquids or gases, thus boosting the purity and quality of the product.

• Stability and resistance: Molecular sieve adsorbents resist challenging conditions, including high temperatures, pressures, and exposure to contaminants. As a result, they are highly durable and optimal in performance.

• Regeneration: Molecular sieve adsorbents can be reused. You just have to apply heat or gas and wait for the adsorbed molecules to be removed.

The Pressure Swing Adsorption (PSA) procedure is a popular regeneration procedure, where one molecular sieve bed is dehydrated, and the other is regenerated under a vacuum. The resultant water from one bed is mixed with the vapors from the other bed, turned into liquid, and then pumped out.

How To Choose The Right Molecular Sieve Adsorbent?

Choosing the right type of molecular sieve adsorbent for your needs can be challenging, but here are some tips or recommendations to help you:

You must note the size and shape of the molecules you want to remove or keep. Different kinds of molecular sieve adsorbents have different pore sizes, ranging from 3 to 10 angstroms.

Think about how much and how well the molecular sieve adsorbent can hold and let go of molecules. For example, if you want to make compressed air dry, you should use a molecular sieve, which can hold more molecules than activated alumina, and can make the air very dry at low moisture levels.

Test the strength of the molecular sieve adsorbent in terms of handling high heat, pressure, and dirt. You should pick the kind that can survive the situation of your need without fault.

Production of ammonia NH3 is integral to chemical synthesis as it is used widely as a fertilizer for agricultural use, as a primary component in pharmaceuticals, and in the manufacture of various chemicals. For the synthesis of ammonia, there is a reaction between hydrogen gases and these gases need purification and drying so that there is optimal product quality and efficiency.

The purification and drying of the synthesis of gas that is used in NH3 production is very important for a host of reasons. The presence of moisture content in the gas could lead to corrosion. This could cause damage to the catalyst that is used in the ammonia synthesis reaction. The catalyst can face a reaction from water molecules that could impact its lifespan by reducing it and also lead to its deactivation. Due to this, the removal of moisture from the gas is required so that the usage can be prolonged by the improvement of the effectiveness of the catalysts.

The synthesis gas can have impurities like compounds of sulfur, hydrocarbons, and carbon dioxide and these have a negative impact on the performance of the catalyst. Such impurities serve to deactivate and poison the catalyst. This leads to a natural reduction in the efficiency of the same and a lowering in the production rates of ammonia. These impurities can lead to side reactions that are unwanted and these would lead to the formation of by-products that are not desired. The purification of this synthesis gas through the removal of impurities would ensure higher yield and product quality. Thus, the synthesis gas purification is required and this is done through 13x molecular sieves.

Molecular sieve for gas drying is used as there are highly effective as adsorbents and thus, used in the process of purification as well as gas drying. Due to their structure, there is selective adsorption of the specific molecules possible. Due to the porous nature of the 13x molecular sieves moisture and impurities can be trapped from the gases and this makes them ideal for the synthesis gas purification.  Molecular sieves function on the principle of exclusion by size since the pores have a precise size. This allows smaller molecules to gain entry and be adsorbed while larger molecules would be excluded effectively. Thus, molecular sieves for natural gas drying are preferred as there is a higher rate of efficiency that allows the removal of impurities and moisture from the synthesis of the gas.

Synthesis gas purification and drying uses a particular type of molecular sieve which are 13x molecular sieves. These sieves are ideal for the adsorption of molecules like water, sulfur compounds, hydrocarbons, and water. The 13X molecular sieves have a higher capacity for the adsorption of impurities and moisture. This leads to the effective purification of the particular synthesis gas. Furthermore, these molecules can be selectively adsorbed while nitrogen and hydrogen gases are allowed to pass through so that the components that are required from the synthesis gas are effectively retained.

With the use of 13X molecular sieves for the synthesis gas drying and purification of NH3. This helps in the maintenance of the catalyst’s integrity and activity and this results in an improvement of the ammonia production rates as well as the quality of the product. Through the effective removal of moisture as well as impurities these 13X molecular sieves are able to play a vital role in the optimization of the efficiency and the performance of the process of ammonia synthesis. 

13X Molecular Sieves for Gas Drying and Purification

The properties of 13X molecular sieves make them perfect for the process of synthesis gas purification. The pore size being larger is able to aid in the adsorption of carbon molecules as well as sulfur compounds which are larger. There is a higher adsorption capacity for impurities and moisture in comparison to the molecular sieves of smaller-pore size. Due to this 13X molecular sieves are able to effectively remove contaminants of various types from the synthesis gas. Furthermore, these are cost-effective as even after the 13X molecular sieves lose some of their effectiveness with repeated adsorption, they still can be regenerated through the process of heating. Thus, it is possible to repeat the purification and drying process post the regeneration of the 13X molecular sieve bed.

13X molecular sieves play an important role as the purification and drying of NH3 synthesis gas is required so that there is a higher quality of ammonia gas produced with the best possible efficiency. When ammonia is synthesized nitrogen, hydrogen, and ammonia react together but these gases that are used in the process also have impurities like carbon dioxide and moisture which need to be removed. It is important to remove these impurities as water vapor or moisture could lead to damage to the catalyst that is used in the synthesis reaction of ammonia due to corrosion. It is important to remove the impurities during the synthesis gas purification. For example, water vapor can lead to damage due to corrosion. Through the removal of moisture, the activity as well as the integrity of the catalyst are retained and this impacts the production rate and the quality of the ammonia product. CO2 also is an impurity present that can either poison or lead to the deactivation of the catalyst. Its presence leads to a reduction in the efficiency of the catalyst as well as a lowering in the ammonia production rates. There could be undesired side reactions when carbon dioxide is present due to the formation of certain by-products. With its removal, there is a higher quality of ammonia production.

Apart from all these other advantages, 13X molecular sieves have a long lifespan as well as durability. Due to this, it is possible to use them for longer while at the same time reducing the need for replacement frequency. This impacts the cost element. They are versatile and so offer a wide range of applications that are not only limited to the process of gas drying and purification. Applications for the same are found in various industries from petrochemical refining to air separation, natural gas purifications, and also the dehydration of organic liquids.

For the fertilizer industry, ammonia is a key component in the fertilizer production of ammonia nitrate and urea. With the use of 13X molecular sieves, the drying, as well as purification of the NH3 synthesis gas, is made possible. The removal of impurities and moisture is done to improve the quality and efficiency of the production of ammonia and this leads to high-quality fertilizers. Ammonia is also used in the production of chemicals and so 13X molecular sieves are required for the purity of the synthesis gas so that impurities do not affect the product’s quality or lead to unnecessary chemical reactions. Ammonia is used as a feedstock in the petrochemical industry and thus, the removal of impurities is integral there as well so that catalysts purity is maintained and there is optimal efficiency in terms of ht production. Thus, though the use of 13X molecular sieves is efficient and cost-effective in the long run, it is at the same time qualitative as the product quality improves as does the efficiency and productivity. 

In the petrochemical industry when it comes to the production of synthetic fibers, plastics, and similar materials, a vital process is steam cracking through which important chemicals like propylene and ethylene are produced. In steam cracking, there is the thermal decomposition of ethane, propane, or naphtha (basically hydrocarbon feedstock). This is done at high temperatures for the production of lighter hydrocarbons. However, as a by-product of this process, carbon dioxide is produced. This is not desired as there are several issues that this causes like possible reactions with ethylene. Such reactions cause the formation of unwanted byproducts. Another reason CO2 removal is required is that there could be corrosion caused to equipment or deactivation of the catalyst apart from other types of operational challenges. Due to this, the use of a molecular sieve for CO2 removal is required.

The 5A molecular sieve is used for CO2 removal as it has an affinity towards carbon dioxide due to the selective nature of its properties. This molecular sieve for steam cracking is used because when the cracked gas stream is passed through the 5A molecular sieve bed, the CO2 molecules are the ones that are adsorbed. Other gases like propylene and ethylene, on the other hand, are allowed to pass through. Thus, there is efficient CO2 removal with minimal waste. Of course, the capacity of adsorption can be affected by various factors like pressure, the concentration of the CO2 gas as well as temperature. These molecular sieves are preferred for gas generation because they are effective as well as cost-efficient due to their regenerative capacities. Through the application of heat or the reduction of pressure, the CO2 molecules on the adsorbent can be released and thus, the 5A molecular sieve can be reused for removing CO3 from steam-cracked gas.

The Importance of CO2 Removal from Steam-cracked Gas

CO2 as discussed previously is a component that is commonly found in steam-cracked gas as it is produced during the process of steam cracking that takes place in the petrochemical industry. Though not exactly harmful there are negative effects of the presence of CO2 based on its physical properties. Being acidic when it is dissolved in the water it forms carbonic acid. Due to this, when moisture or water is present the carbonic acid formed could lead to the corrosion of pipelines and equipment. Such corrosion leads to the weakening of infrastructure that causes failures, leaks, and inevitably replacement or costly maintenance.

Apart from corrosion, another problem area is the fouling of heat exchangers and other process equipment. The reaction of CO2 with other gas stream components leads to the formation of solid deposits and scale. These can adhere to the surface of the equipment. The heat transfer efficiency thus, is hampered which in turn leads to drops in pressure. Such equipment would need eventual replacement despite the increased frequency of cleaning. CO2 removal is also required because of the negative effects it has on the quality and purity of a product. This holds especially true for separation processes and catalytic reactions. When CO2 reacts with catalysts it reduces the effectiveness of the latter and this reduces the yield as well as the quality of the product. Thus, the efficiency of the separation process is hampered, and obtaining a pure product becomes more challenging.

How 5A Molecular Sieves Work

The basic principle behind the working of 5A molecular sieve for CO2 removal is in the selective adsorption of molecules on the basis of polarity and size. The pores have uniform size and shape and are able to selectively let molecules up to a certain size enter and adhere while they simultaneously exclude molecules that are larger. This same principle comes into play in the case of molecular sieve for steam cracking where the CO2 molecules are trapped from the gas mixture due to their comparatively small size.

It is the properties of 5A molecular sieve that make them so ideal for the gas separation process. Their pore size for instance is 5 angstroms and thus, larger molecules of oxygen and nitrogen are able to pass through undeterred while the smaller molecules of CO2 are trapped due to the molecular filter that operates on pore size. The high adsorption capacity also serves to increase efficiency while the selectivity ensures minimal adsorption of other components from the gas stream. Furthermore, since they are regenerative 5A molecular sieves are a cost-effective option. The process of regeneration also is simple as either the application of heat or the reduction of pressure can cause the trapped CO2 molecules to desorb.

The Benefits of Using 5A Molecular Sieve for CO2 Removal

Some of the prime benefits of using molecular sieves for steam cracking have already been gone through in terms of their selectivity and cost-effectiveness due to regeneration. They are also found to be energy efficient as compared to other techniques for CO2 removal. While some techniques require more energy expended for the capture of CO2 and the regeneration of the molecular sieves, the absorption and desorption processes that have been discussed above run on comparatively lower energy consumption. This helps in the reduction of operational costs.

Apart from the cost and effectiveness, 5A molecular sieves are a scalable adsorption technology that finds applications in various gas flow volumes and rates. Also, they are industry versatile, for instance, they are used in flue gas treatment as well as natural gas purification apart from the petrochemical industry. On an environmental level since there are no chemicals used in this process of CO2 removal it does not affect the environment or human health. The regeneration process too does not require additional chemicals or reagents. As far as stability is concerned, it exhibits good stability in the long term and durability as well. This reduces replacement and maintenance-related costs. All these factors make the use of 5A molecular sieves for CO2 removal ideal for the long run while at the same time providing quality output at a cost-effective rate.