Particle technologies are process technologies that produce, use, or separate particles.
For example, pharmaceutical industry produces precise drug formulations based on particle technologies. Activated carbon particles are commonly used in the food industry as an adsorbent to remove impurities, off-flavours, and odours from liquids such as water, beverages, and food ingredients. Chemical industries may use particles as adsorbents to remove certain components in separation processes. One example of separating particles in the chemical industry is the use of cyclones, which employ centrifugal force to separate solid particles from gas or liquid streams based on their particle size and density.
The technologies that produce particles can be divided into solidification, crystallization, and particle modification processes.
We can define solidification as a widely applied process that shapes a melt into a specific form. For instance, a fertilizer melt is...
Soldification
We can define solidification as a widely applied process that shapes a melt into a specific form. For instance, a fertilizer melt is prilled into spherical fertilizer particles to conveniently distribute over the land to grow crops. Another example is the casting of iron into plates or sheets, which are used in construction, automotive body panels, and industrial process equipment. Solidification also includes processes that lead to the formation of amorphous or highly viscous particles which have a non-crystalline structure. Polymer solidification, for instance, involves the cooling or curing of a polymer melt to decrease the viscosity and convert it into a particulate product or a specific shape that is (for a large part) non-crystalline. For solidification processes the emphasis is on the physical characteristics of the shaped product and less on the specific arrangement of atoms or molecules within the solid.
Crystallization is a particle technology that involves the formation of solid particles with a well-defined crystal structure from...
Crystallization
Crystallization is a particle technology that involves the formation of solid particles with a well-defined crystal structure from a solution or melt. It is a widely used technique in various industries, including pharmaceuticals, chemicals, and materials science for purification and separation.
Crystallization selectively forms and grows crystalline particles. By carefully controlling the crystallization conditions, highly pure crystals with specific properties can be obtained from a single crystallization process step. Crystallization is specifically employed to separate or purify substances into a particulate product. The product from a chemical synthesis can for instance be purified by crystallization.
Particle technologies can further be used to intentionally modify particles and their properties. During such a process, particles in the feed...
Particle Modification
Particle technologies can further be used to intentionally modify particles and their properties. During such a process, particles in the feed are transformed to particles with the desired particle properties or functionalities. For instance, milling and grinding processes are employed to reduce the particle size of particulate materials. These techniques involve mechanical forces that break down larger particles into smaller ones. Granulation refers to the process of agglomerating fine particles into larger granules. It is commonly used in chemical industry, where small particles are combined and bound together using binders or additives into larger particles to improve flowability or compressibility.
Another example of particle modification is encapsulation or coating. During the process a thin layer of material is applied onto the surface of particles. This can be done through methods like spray drying, fluidized bed coating, or chemical vapor deposition. Coatings can provide functionalities such as controlled release, improved stability, enhanced compatibility, or modified surface properties of the particles.
Particles can be used in processes to efficiently achieve purified and reaction products. For instance, adsorbent particles...
Particle Use
Particles can be used in processes to efficiently achieve purified and reaction products. For instance, adsorbent particles such as activated carbon, zeolites, and silica gel remove or recover specific substances from gases or liquids. The adsorbent particles possess a high surface area, allowing for increased adsorption capacity. Adsorbent particles can be used in a wide range of processes such as gas purification, water treatment, air pollution control, and adsorption chromatography.
Particles serve as catalysts to accelerate chemical reactions by providing an active surface which reagents quickly react to the preferred reaction product. Catalyst particles play a crucial role in numerous industrial processes, including petroleum refining, chemical synthesis, environmental remediation, and emission control.
Mechanical separations involve the use of physical mechanisms to separate particles based on their size, density...
Particle Separation
Mechanical separations involve the use of physical mechanisms to separate particles based on their size, density, or other physical properties.
For instance filtration is a process that separates solid particles from a fluid (liquid or gas) by passing the mixture through a porous medium, called a filter. The filter retains the solid particles while allowing the fluid to pass through. The choice of filter medium depends on the particle size, desired filtration efficiency, and compatibility with the fluid and particles involved.
Sieving involves the passing of a mixture of particles through a sieve or screen with specific openings or mesh sizes. The smaller particles pass through the sieve, while the larger particles are retained.
Centrifugal forces are used in cyclone separators to separate particles from a gas or liquid stream based on particle size and density. The mixture enters a cylindrical chamber tangentially, creating a swirling motion. Due to the centrifugal force, the heavier particles move toward the outer wall and are collected, while the lighter particles and the gas or liquid continue to the outlet.
Spray congealing is an efficient process utilized in the manufacturing industry for the production of solid powders. This innovative technique involves atomization, rapid cooling, and solidification to create uniform and high-quality solid materials.
The spray congealing process begins with the precise atomization of the liquid material. The liquid is heated to a specific temperature and then transformed into fine droplets using a high-pressure nozzle system. This atomization stage ensures that the liquid is converted into small, uniformly-sized droplets, setting the foundation for consistent particle formation.
The atomized droplets are introduced into a controlled environment, typically a temperature-controlled chamber. Within this chamber, the droplets come into contact with a cold gas stream or a cooling medium. The sudden exposure to the cool environment leads to rapid cooling and solidification of the droplets, transforming them into solid particles. The resulting particles exhibit spherical shapes, and uniform sizes.
Spray congealing enables the production of spherical particles with precise and uniform sizes. This uniformity enhances product quality and performance, making spray congealing ideal for applications where consistency is critical.
Our equipment is easy to operate, due to our well defined process operating parameters. Furthermore, the low amount of rotating and intricate parts result in a reliable process, giving the client an overall low operational and maintenance cost.
The process is particularly advantageous for encapsulating sensitive or volatile substances. By solidifying the liquid droplets quickly, spray congealing can protect and preserve the integrity of sensitive components during the manufacturing process.
Spray congealing allows for the incorporation of multiple ingredients into compounded particles, facilitating the creation of composite materials with tailored properties. This flexibility enables the development of advanced materials with enhanced functionalities.
Thanks to a constant stream of technical innovations, such as state-of-the-art air inlet filtration and closed loop operation, emissions can be cut to virtually non existing.
Prills are grains of solid substances formed from molten drops. The result? A free flowing product with low dust and a narrow particle size distribution.
Prills are spherical and naturally resistant to abrasion or damage. Since no additives are necessary in the prilling process, prills of your product are 100% pure.
Thanks to their size and shape, prills have the smallest possible contact surface area and high bulk density. In bulk, prills behave like a fluid which is beneficial for transport, storage and further processing.
This is why prills offer the ideal form of solidification for a wide range of substances and markets.
Looking for more information about the main principles of prilling? Please read the following article: prilling meaning and prill definition.
Prilling is a extremely effective finishing technology and offers you the following advantages over other solidification methods:
Prilling is one of the most economical finishing technologies in the world for large outputs. Compared with other solidification methods such as granulation and pastillation, CAPEX and OPEX will be multiple times lower at increased capacities.
Our equipment is easy to operate, due to our well defined process operating parameters. Furthermore, the low amount of rotating and intricate parts result in a reliable process, giving the client an overall low operational and maintenance cost.
Prilling production is easily scalable within the range of 70 to 110% of the original designed capacity. This makes the prilling production method an extremely flexible option for your total production process. Quickly adapt to changes in the market? With prilling you can.
With the design of our prilling tower and additional equipment, you benefit from a relatively small footprint, compared to other solidification technologies.
The high degree of ‘self-control’ makes it a robust finishing technology with a very stable processing procedure. It can therefore play a vital role in guaranteeing the continuity of your process and quality of your product.
Thanks to a constant stream of technical innovations, such as state-of-the-art air inlet filtration and scrubber technologies, prilling has evolved into a cleaner finishing technology than it has ever been.
Try It With Your Own Product
Wondering if Prilling is suitable for your material? Our specialized R&D team and laboratory offers you the unique opportunity to make a test batch Prills of your product, tailored to your application.
Lab-Scale Feasibility Tests:
Your substance is tested on prillability
Pilot-Scale Production:
If feasible, we produce a batch to simulate industrial performance..
Kreber designs processes and manufactures equipment that use particles or produce a particulate product.
Particles are used and produced in a wide range of processes in chemical, pharmaceutical, chemicals, food, and other industries.
Particles can be used in a separation process as adsorbents to adsorb unwanted compounds and purify a gas stream, or their surface can be used in a reaction process to catalyse selective reactions to synthesize pharmaceuticals.
A particulate fertilizer product allows the convenient distribution over land to let the crops grow while a particulate pharmaceutical product can be administered in the formulation of a tablet to treat a patient.
At Kreber we define particles as small, discrete units of matter. Depending on their use, particles vary significantly in composition, solid structure, size and shape.
Particle sizes range from nanoscale particles consisting of a few molecules or atoms to microparticles observable with a microscope, and larger particles visible to the naked eye. A particle size distribution (PSD) gives information on the collection of particle sizes in the product. The particle size distribution of fertilizer prills determines for instance how easy the product can be distributed over the land and how fast the product dissolves when coming into contact with water.
Particles usually are solids which have a crystal structure with a very specific arrangement of molecules or atoms in them. For instance, table salt, sugar and the fertilizer urea are such crystalline solid particles. Sometimes particles benefit from an amorphous structure, such as amorphous silica which can be employed in rubber, plastics, coatings, and paints to enhance properties such as reinforcement, viscosity control, and improved scratch resistance. Also, highly viscous liquid such as long chain polymers can form particles. For pharmaceutical particles the solid structure strongly impacts on particle product properties such as dissolution behaviour, bioavailability, and shelf life.
Specific compositions within the particle can be beneficial for the particle product application. Particles consisting of a mixture of fertilizers can have the optimal nitrogen and sulfur composition for specific crops. In the food, pharmaceutical and fine chemical industries high levels of purity are desired. For instance, impurities from side reactions during the synthesis of an active pharmaceutical ingredient could lead to unwanted additional biological activity of the administered drug if these impurities end up in the final particulate product.
The particle shape can be vital for the flow and storage properties of a product. A single crystal particle often has a very distinct shape with flat surfaces, such as the cubic crystal particles of industrially produced table salt.
Kreber is a Dutch family-owned company that has been located at the Europoort Rotterdam since 1902. It is there, in this industrial epicenter, that we have been specializing in prilling for the past 50 years. Over that time, we have refined this technology down to the most minute details, and our equipment is optimized to take full advantage of every innovation.
With an impressive track record we are able to prill a variety of chemical substances such as several fertilizers (Urea, AN, ANP, CAN), Bisphenol-A, Sulphur and various customized applications.
Particularly when it comes to technology, standing still always means falling behind. In order to continue innovating the prilling process, our prilling solutions and prilling equipment and other particle processes we have our own in-house RD&I team.
Thanks to innovative facilities such as the Kreber Prilling Laboratory and the Kreber Pilot Facility, our RD&I team is able to take the prilling technology and customer solutions to the very next level. One of the major developments is the Vibro prilling. Adding a vibration to the melt has proven to result in more uniform prills with a defined narrow prill size distribution.
Kon. Wilhelminahaven ZZ 25
3134 KG Vlaardingen
Port Number 651
The Netherlands
info@kreber.nl
+31 10 248 02 22
Kreber specializes in particle technologies,
specializing in both particle formation and the
utilization of particles in various applications.
With a strong focus on innovation and research, we offer comprehensive process development options to optimize particle-based solutions. Through application of the vast experience of our research team and the utilization of our manufacturing plant, we provide tailored opportunities to enhance and streamline particle-related processes.
The key areas of process development at Kreber lies in particle technologies. Our research team works closely with clients to explore novel methods of particle formation, refining existing techniques, and tailoring particle characteristics to meet specific application requirements. By leveraging our expertise, clients can achieve improved functionality and enhanced performance in their particle-based solutions.
Additionally, Kreber operates a machine factory allowing us unique manufacturing capabilities. This facility enables us to design and build specialized testing equipment tailored to our clients’ unique needs. Whether it’s small scale proof of concept research or a scale up experiment proving the process on a larger scale, Kreber can design, build and test new concepts and ideas with dedicated build equipment. Collaborating with our research team, clients can utilize these tools to optimize their particle-based processes, validate product performance, and ensure consistent results.
By capitalizing on the expertise of our research team and the capabilities of our machine factory, clients/you can harness the power of innovative particle formation techniques, specialized testing equipment, and scalable manufacturing processes. Together, we can unlock new possibilities and drive the advancement of particle technologies across various industries.
High-end product quality, high production capacity, low energy consumption and minimal downtime.
An overview of our full package for a prilled solidification section.
Inside the Kreber Prilling Tower, droplets are sprayed in a counter-current stream of the cooling medium to solidify the prills.
When the prills have been formed and solidified, the Kreber Prill Scraper collects them in a slotted hole in the tower bottom.
When the solidified and cooled prills are collected at the bottom of the tower, they need to be offloaded for packaging or further processing.
Prills are most often cooled in ambient air. Certain products can require an inert atmosphere, for safety reasons or because they react with oxygen.
At Kreber, our aim is to consistently provide a safe and optimized prilling process. To this end, we have developed several special options.
Particles have a wide range of applications, from pharmaceuticals to fertilizers. An application works best if the particles have the preferred structure, purity, size and shape. Kreber particle technologies are optimized to produce the particulate product with the right particle properties. Let us help you to develop the optimized technology for your particles.
Kreber designs, constructs, and supports
high-quality particle process technologies
for industries all over the world.
The approach that can improve the fertilizers nitrogen use efficiency and counteract nitrogen pollution of the earth.
At the turn of the twentieth century, humanity was confronted with its biggest challenge up until that point: a global food crisis and subsequent mass starvation that loomed over the world. The global consumption of nitrogen compounds, be it in the form of nitrogen fertilizers or explosives, threatened to surpass its natural supply, in the form of natural niter and guano deposits. This challenge was solved by Fritz Haber and Carl Bosch with their novel process, which was capable of capturing atmospheric dinitrogen with hydrogen at high temperatures and pressures. Through this process, humanity became able to nourish the crops they were growing with the nutrient it needed the most: reactive nitrogen. In his Nobel lecture in 1920, Haber himself predicted that in the near future his process would be needed to produce millions of metric tons of fixed nitrogen [1]. He turned out to be right, as the world today produces over 100 Tg of nitrogen [2].
What Haber could not have foreseen was the environmental impact of fertilizer that the mass consumption of such a high amount of nitrogen compounds would have. As of now, the world is facing the opposite of the challenge it did at the end of the nineteenth century: battling the effects of nitrogen pollution on earth. However, this time there seems to be no one-stop solution to this looming crisis, and global collaboration is needed to change the way the world produces and consumes nitrogen-based fertilizers globally.
Kreber is active in particle engineering, a science that can help address the future challenges of reducing nitrogen pollution from fertilizers and therefore fertilizer pollution. This article will reflect on the possible ways particle engineering can improve the shaping and production of nitrogen fertilizers, and how that can help in overcoming the harmful effects of this global challenge.
While the application of nitrogen-based fertilizers is still vital to sustaining the current population, the surplus of nitrogen leaking into the environment is leading to numerous concerning developments. The current method of using and producing nitrogen fertilizers has led to reductions in biodiversity and the acceleration of climate change through the production of nitrous oxide, mainly driven by an imbalance in the nitrogen cycle, as shown in Figure 1. The global challenge the world is currently facing can be described as the problem of maximizing the net positive outcomes of all available nitrogen fertilizers.
As suggested by Houlton et al, making the most of these benefits lies in the development of the following five strategic imperatives [3].
Nitrogen use efficiency is defined as the nitrogen that will end up absorbed into the crops over the total nitrogen applied in the form of fertilizers.
Counter-intuitively, research has shown that over the last century, efficiency has actually decreased from 60% down to approximately 46% [3]. Efficiency improvement can be achieved by focusing on the 4R’s of good nutrient stewardship: Right source, Right rate, Right time, Right place [4].
The ‘right source’ means that the fertilizer type or nutrient content is matched to the specific needs of the crop to which it will be applied, while the ‘right rate’ focuses on the ideal amount of nutrients that is tailored to the crops’ exact needs. The ‘right time’ or timing means that the relevant nutrients are made available at the ideal moment that the crop needs them. Finally, the ‘right place’ or placement means that the nutrient is placed where the crop can easily consume it.
While there is an abundance of affordable nitrogen fertilizers in wealthier nations, there are still countries with only limited access to them. Improved accessibility will increase resilience to negative weather effects and lower the likelihood of worldwide famine, as long as the nitrogen is applied in an efficient and low-polluting manner.
In order to reduce the unwanted effects of nitrogen pollution, leaked nitrogen can be removed from the environment by either agro-ecological or technological methods. These two removal methods also bring with them the possibility of potentially recycling the nitrogen and increasing nitrogen use efficiency, thus lowering the environmental impact of fertilizer in the long run.
At a governmental, industrial, social and individual level, spillage and overbuying both lead to the fact that approximately a quarter of all food is wasted along its lifecycle, rendering a significant quantity of applied nitrogen fertilizer unused in terms of nutrition.
Lastly, dietary choices have consequences for both the environment and individual health. For instance, approximately 10% of all nitrogen used for the production of cow feed for beef production is lost in the process. Lifecycle analysis and consumer education will be required to guide consumers to a smaller footprint.
One method of overcoming these challenges lies in the field of particle engineering. Particle engineering is the science of altering or forming solids into a desired shape, size distribution or composition, and is also concerned with other aspects of the particle’s morphology and surface characteristics. This type of engineering is mainly applied in the fields of pharmaceuticals, food, cosmetics, and paints, where the morphology of particles is handled with the utmost care.
Prilling, the core technology of Kreber, is a method of particle engineering for spherical solids in the range of approximately 0.5 to 3 mm, as shown in Figure 2. In-depth particle engineering can have an effect on several physical aspects of spherical solids, such as:
For instance, in milk powder production – which is achieved by spray-drying – particle engineering is widely used with regards to dissolution behavior. For the consumers, food powder dissolution has a direct impact on their perception of the overall product quality. By altering the size, shape, and porosity – whilst maintaining the important flavor characteristics – solubility is greatly increased. Before particle engineering was applied in the production of milk powder, adding the finished product to water would result in the powder floating on the top of the liquid. The powdered milks of today readily fall to the bottom of the water, resulting in a fast-dissolving powder.
In terms of the five solution directions discussed in the previous section, the science of particle engineering can play a role in improving the efficiency of nitrogen usage. More specifically, when applied to the 4R’s, it helps to improve the right time and right place solutions.
For the first solution (the right time), the timing of consistent nitrogen release can be coupled, among other variables, to the dissolving rate of the nitrogen source. Nitrogen release is achieved either by water dissolving the nitrogen or by bacterial life-transforming the fertilizers’ nitrogen into nitrites that are essential to the crop. The available surface area can be adjusted through particle engineering by ensuring a specific particle size or porosity, or by applying a coating or encapsulating the nitrogen source.
Currently, particle engineering solutions are already being explored in order to achieve a controlled release rate. For instance, ammonium nitrate in its more porous low-density form has an accessible surface area that is approximately five times greater than ammonium nitrate in its high-density form [5]. As the surface area can be coupled to the dissolving rate, a dissolution rate decrease of up to five times can be achieved when porosity is minimized. Subsequently, when the high-density form of ammonium nitrate is encapsulated, the nitrogen release rate can be altered even further. In urea fertilizers, the application of coating urea prills with slowly dissolvable sulfur or a polymer has led to a clearly slower release rate, with the added benefit of sulfur as an additional nutrient for the crops.
In pharmaceutical applications, when the control rate is of the utmost importance, encapsulation is the most common approach. There, a carrier melt is used in which the active compound is suspended. The melt is subsequently either spray-chilled or prilled in order to arrive at a solid material with the active compound encapsulated. The carrier melt dissolution characteristics, coupled with the active compound concentration and compound size relative to the final product, can be altered accordingly to accurately obtain the desired release rate of the active compound. A similar type of process can be explored for nitrogen fertilizers as well, where either urea or ammonium nitrate powder can be suspended in a wax or other slowly dissolving, bio-friendly compound, in order to gain control of the release characteristics.
As for the second solution, the right place, it is important that the nutrients are delivered at the place where the crops need them. Currently, consistent particle size is of importance for the traditional mechanical method of distributing fertilizers over farmland.
Newer methods of fertilizer distribution have shown the potential of using liquid fertilizers in bulk to obtain better control of the dose uniformity over the crop fields. This liquid fertilizer would consist of either slurries (solids suspended in a liquid) or a solution of nutrients in an environmentally friendly liquid. The liquid nature of these nitrogen fertilizers means that the nutrient can be sprayed evenly over the land, leading to a high degree of control over the dosage per square meter and therefore over the placement of the nutrients.
The way slurries or solutions are created will yield a need for different and more flexible technological designs for applications with nitrogen fertilizers. When directly supplied to the crops, the nitrogen release rate needs to match the needs of the crop and the land it grows upon. When used to create a liquid fertilizer, however, where the solid will be dissolved or suspended in a liquid, the particle size has to be much smaller to be able to accurately dose and quickly dissolve the fertilizer in the carrier liquid.
Fighting the pollution effects of nitrogen fertilizer use, while still having the means to help feed all of humanity is a truly daunting challenge now, just as it was in the late 1800s. This time, however, it is not an option to wait for a singular, brilliant solution such as the Haber-Bosch process. Industry-wide joint initiatives are essential, coupled with a level of decisiveness from governments all over the world to tackle these problems. Smarter ways of offering nitrogen fertilizers to crops is one of the main issues on which a better method has to be found to increase the nitrogen use efficiency, while also reducing the fertilizers’ environmental impact. In that light, particle engineering can prove to be a piece of the puzzle, which has to be solved together.
Toon Nieboer has been researching the prilling process for years. In addition to publishing various articles about this subject, he is a frequent speaker at conventions.
