SOP Production Line
The Mannheim potassium sulfate production line is a typical process for producing potassium sulfate (K2SO4) using the Mannheim process. The process reacts sodium chloride (NaCl) with sulfuric acid (H2SO4) to obtain hydrogen chloride gas and sodium sulfate (Na2SO4), which are then reacted with potassium chloride (KCl) to produce potassium sulfate. The main feature of this process is that no chloride pollution is generated during the production process, and the product contains a low amount of chlorine, which is suitable for crops that are sensitive to chlorine, such as tobacco and grapes.
The specific production process includes several key steps: First, sodium chloride and sulfuric acid react at high temperature to produce hydrogen chloride and sodium sulfate. Subsequently, sodium sulfate reacts with potassium chloride to produce potassium sulfate and sodium chloride. During the whole process, the reaction gas is collected and purified, and potassium sulfate is further purified and processed through steps such as crystallization, centrifugation, and drying to finally obtain potassium sulfate that meets the standards.
The advantages of the Mannheim process for producing potassium sulfate are that it has a low reaction temperature, simpler equipment requirements, and can use by-products in the raw materials to reduce resource waste. This production line is widely used in large-scale industrial production, especially in fertilizer production, and occupies an important position.
WE NOT ONLY PROVIDE RELIABLE PRODUCTS, BUT MORE IMPORTANTLY WE PROVIDE RELIABLE PROCESS DESIGN AND EXPERIMENTATION
Application and improvement of Mannheim process in the production of potassium sulfate (SOP)
Potassium sulfate (SOP) is an important chemical widely used in agriculture, industry and other fields, and is usually produced by the Mannheim process. The process generates potassium sulfate and hydrogen chloride (HCl) by the reaction of potassium chloride (KCl) and sulfuric acid (H2SO4). Although the Mannheim process is widely used in industry, the treatment of its byproduct hydrogen chloride and high energy consumption pose challenges to the process. This article will explore the reaction principle, process flow, advantages and disadvantages of the Mannheim process and its improvement direction, and look forward to its application prospects in modern industry.
Potassium sulfate is an important potash fertilizer. Due to its chlorine-free characteristics, it is particularly suitable for the cultivation of chlorine-sensitive crops such as tobacco, tea and certain fruits. The Mannheim process is a traditional method for producing potassium sulfate, which has high economy and industrial adaptability. However, with the improvement of environmental protection requirements, the high energy consumption and by-product treatment problems in traditional processes have attracted more and more attention. This paper aims to analyze the operating mechanism, advantages and disadvantages of the Mannheim process, and put forward optimization suggestions to achieve more sustainable potassium sulfate production.
Mannheim process overview
The Mannheim process uses potassium chloride (KCl) and sulfuric acid (H₂SO₄) as raw materials to produce potassium sulfate and hydrogen chloride (HCl) through high-temperature reaction. The reaction is mainly divided into the following stages:
- Material pretreatment: Mix potassium chloride and sulfuric acid in a certain proportion to ensure uniform distribution of the raw materials.
- High-temperature reaction: In the Mannheim furnace, the raw materials undergo the main reaction at a temperature of 550–600°C.
- Product separation: Potassium sulfate is collected through cooling and gas-solid separation technology, and the by-product hydrogen chloride gas is collected to prepare hydrochloric acid.
Current application of Mannheim process in potassium sulfate production
PROCESS CHARACTERISTICS
The Mannheim process is popular for its economy and ease of operation, but it also has certain limitations.
Advantages: mature technology, stable process; low investment cost, suitable for small and medium-sized enterprises; wide source of raw materials, easy to purchase.
Disadvantages: high energy consumption due to high temperature operation; improper treatment of by-product hydrogen chloride may cause environmental pollution; insufficient treatment and resource utilization of solid waste.
APPLICATION CASES
Many companies around the world use the Mannheim process to produce potassium sulfate. For example:
A large Chinese chemical company has achieved a steady increase in production capacity by optimizing the raw material ratio and reaction temperature control.
A classic case in Mannheim, Germany, effectively reduced energy consumption and pollution emissions by improving the furnace design and exhaust gas treatment system.
Improvement direction of Mannheim process
IMPROVE REACTION EFFICIENCY
- Optimize reaction conditions: Increase raw material conversion rate by precisely controlling reaction temperature and residence time. Use catalyst to promote reaction rate and reduce energy consumption.
- Improve furnace design: introduce multi-stage heating system to reduce heat loss. Add stirring device to ensure uniform mixing of materials.
REDUCE ENERGY CONSUMPTION
- Waste heat recovery: use waste heat generated by reaction for waste heat power generation or preheating raw materials.
- Introduce clean energy: explore the use of clean energy such as natural gas and electric heating to replace traditional coal.
ENVIRONMENTAL PROTECTION
- Resource utilization of by-products: prepare high-purity hydrochloric acid or other chemical products from by-product hydrogen chloride. Develop building material application of potassium sulfate by-product waste residue.
- Waste gas and wastewater treatment: use high-efficiency absorption tower to treat hydrogen chloride tail gas. Strengthen the recovery and harmless treatment of residues in wastewater.
INTELLIGENCE AND AUTOMATION
- Process monitoring system: Use sensors and data analysis technology to achieve real-time monitoring of key parameters such as temperature, pressure, and flow.
- Intelligent optimization: Predict process changes through machine learning models and dynamically adjust production parameters.
Future development trends
With the increasingly stringent environmental regulations and the continuous advancement of technology, the future development of Mannheim process will move towards high efficiency, cleanliness, and intelligence. Specifically include:
- Green process: Comprehensively promote clean production technology to reduce carbon footprint.
- Resource recycling: Build a coupled industrial chain of potassium sulfate production and other chemical products.
- Intelligent manufacturing: Realize automation and intelligence of the entire process to improve production efficiency and quality.
Conclusion
The application of Mannheim process in potassium sulfate production has broad prospects, but it still needs to be further optimized in terms of reaction efficiency, energy consumption, environmental protection and intelligence. By combining the research results of experts with actual production needs and continuously improving the process design and management model, the Mannheim process will better serve potassium sulfate production and related chemical industries.
In addition to having the right equipment and infrastructure, EMCC is uniquely positioned to assist SOP producers from an expertise perspective and has a rich background in the fertilizer industry. EMCC has been at the forefront of developments in conventional and specialty fertilizer production for over 10 years and has become the preferred supplier of testing and development services, custom equipment, and parts and service support to the potash industry. To learn more about the Manheim SOP process or to schedule a test, contact us today!
WE NOT ONLY PROVIDE RELIABLE PRODUCTS, BUT MORE IMPORTANTLY WE PROVIDE RELIABLE PROCESS DESIGN AND EXPERIMENTATION
Potassium Sulfate (SOP): A High-Value Alternative to Potassium Chloride (MOP)
A booming population, combined with many other factors, has put market traction around potassium sulfate (K2SO4) in recent years. Data Bridge Market Research estimates that the potassium sulfate market will exhibit a CAGR of 5.5% between 2017 to 2024, landing at 10,535.84 thousand tons by 2025. Not surprisingly, demand for potassium sulfate processing equipment is also on the rise.
Also known as sulfate of potash, or SOP, potassium sulfate is a premium potash fertilizer with a number of benefits over the more commonly used muriate of potash (MOP).
Benefits of Potassium Sulfate (SOP)
While muriate of potash (also known as potassium chloride) is the most common potash fertilizer, serving as an excellent source of potassium and chloride, it is not appropriate in all settings. As many are discovering, SOP not only improves yield and crop quality, but it also presents a number of advantages:
REDUCED CHLORIDES
Chloride makes up a significant component of MOP. While this is preferable for some crops, it can be damaging to others that are sensitive to chlorides, such as some fruits, vegetables, and nuts. Many chloride-sensitive crops fall into the high-value category, so optimizing quality and yield are especially critical.
Additionally, if MOP is added to soils already rich in chlorides, toxicity can occur. When working with chloride-sensitive crops or chloride-rich soils, SOP provides an optimal solution, as it is substantially lower in chlorides.
ADDED SULFUR
In addition to potassium, potassium sulfate also provides plant-available sulfur. Sulfur deficiencies have become increasingly common in recent years, making products that include the secondary nutrient increasingly desirable.
LOWER SALINITY
Potassium sulfate has a lower salt index than most potash fertilizers, making it the preferred choice when soil salinity is a concern.
SOP Production & Extraction
Potassium sulfate (K2SO4) is not typically found as an existing compound in nature and therefore must be manufactured. There are two main approaches to obtaining SOP:
THE MANNHEIM PROCESS
Traditionally, SOP has been produced by the Mannheim process, in which KCl is reacted with sulfuric acid to yield K2SO4. Although this method does work, it produces the desired compound as a byproduct; the primary product resulting from the process is HCl.
This process consists of first carrying out an exothermic reaction between potassium chloride (KCl) and sulfuric acid (H2SO4), and then an endothermic reaction between potassium chloride (KCl) and potassium bisulfate (KHSO4) to produce HCl and K2SO4.¹
The resulting K2SO4 is cooled in a rotary cooler and may then be further finished into the desired product form.
While the Mannheim process is still in use, it has largely given way to an alternative method: extraction from natural complex salts.
Complex Salt Processing
Naturally existing complex salts can also provide a source of potassium sulfate. Here, potassium- and sulfate-bearing minerals are altered to remove byproducts, leaving potassium sulfate behind. This process is highly complex and contributes to the high cost of SOP.
A high-level overview of the process could be described as ore preparation and flotation, conversion to and leaching of schoenite, and finally, moisture reduction in a rotary dryer. This process may differ depending on the complex salt being treated.
Langbeinite, in particular, is a well known source of SOP that has gained popularity in recent years. This nutrient-rich mineral compounds (K2Mg2(SO4)3) can be modified to remove magnesium and obtain SOP, or it can be used as a potash fertilizer itself; in addition to potash and sulfur, langbeinite provides a source of secondary nutrient magnesium. For this reason, it is also known as sulfate of potash-magnesia, or SOPM. Kainite and carpathian polymineral ores are other common complex salts from which SOP is commonly derived.
Polyhalite, an evaporite mineral, is a similar source of SOP and magnesium. The mineral has been gaining interest in recent years, but is currently produced in only small quantities.
Forms of SOP
Potassium sulfate is like most potash fertilizers, in that it can be processed into a variety of different particle sizes and forms to meet various market needs; it is typically available in the form of powder, compaction granules, or round pellets/granules.
POWDERED POTASSIUM SULFATE
While powdered potassium sulfate provides fast nutrient delivery, it can be difficult to handle and transport, and often becomes windblown upon application. For this reason, it is often desirable to agglomerate SOP into one of the forms below.
COMPACTION GRANULES
Compaction granules are produced using a roll compactor, in which potassium sulfate is pressed into a sheet and then broken up into the desired size granules. This method makes the potassium sulfate much easier to handle with significantly reduced dust, but has jagged edges that are prone to breaking off into dust.
ROUND GRANULE
Spherical potassium sulfate granules are produced via a non-pressure agglomeration technique referred to as pelletizing. This is typically carried out on a disc pelletizer preceded by a pin mixer.
The granules produced in this process are of the highest quality, offering the least amount of dust and typically the greatest amount of flowability.
Potassium Sulfate Process Development
Feasibility testing is an important aspect of developing a potassium sulfate fertilizer. Batch- and pilot-scale tests such as those conducted in the EMCC Innovation Center are used to gather process data and determine the best set of parameters to produce a product with the desired specifications from the unique source of material. Both roll compaction and pelletizing, along with drying can be evaluated.
A variety of particle characteristics can be measured and adjusted during testing to produce an agglomerate to exacting specifications. Target particle characteristics often include:
- Amount of
- attrition/degradation
- Bulk density
- Compression
- Crush strength
- Flowability
- Green/wet strength
- Moisture content
- Particle size analysis
- Physical characteristics
- Solubility
Conclusion
Potassium sulfate is a premium potash fertilizer offering a number of benefits over other potash fertilizers, including low chlorides, added sulfur, and reduced salinity. Produced through two primary approaches, SOP can be processed into powdered, granular, or spherical pellets. Testing is a critical component in the development of an SOP process, helping to gather process data necessary for scale-up.
With an extensive history in the fertilizer industry, EMCC is a leader in custom equipment and systems for both traditional and novel fertilizer production, offering rotary dryers, coolers, disc pelletizers, and more. In addition to our custom equipment, we can provide comprehensive testing services at batch and pilot scale for the granulation of potassium sulfate into a product of desired specifications. For more information on our potassium sulfate capabilities, contact us today!
WE NOT ONLY PROVIDE RELIABLE PRODUCTS, BUT MORE IMPORTANTLY WE PROVIDE RELIABLE PROCESS DESIGN AND EXPERIMENTATION
Testing Essential in Developing a Potassium Sulfate (SOP) Fertilizer Granulation Plant
The potassium sulfate (SOP) fertilizer market is continuing on a growth trajectory and is anticipated to see a CAGR of 5.16% between 2020 and 2027. The alternative to potassium chloride (MOP) has gained a foothold in agriculture as a premium product for high-value and chloride-sensitive crops, as well as a source of sulfur.
One common way in which fertilizer producers bring potassium sulfate to market is in a granular form produced through the wet granulation process. And as the number of producers looking to granulate their potassium sulfate (SOP) continues to rise, feasibility testing and process development services are in ever-higher demand; producers are discovering that this novel source of potash requires thorough testing and development to bring a successful SOP granulation operation online.
Here’s a look at why testing is so important when it comes to granulating SOP fertilizers, and how producers are utilizing the EMCC Innovation Center to develop their commercial-scale operations.
Why Wet Granulation for SOP?
Wet granulation, also known as agitation agglomeration, pelletizing, or tumble-growth agglomeration, is just one way to produce an SOP fertilizer product. SOP may also go to market in the form of powder, crystals, or compaction granules. So why wet granulation?
Wet granulation produces a rounded fertilizer granule, which has numerous benefits over other forms of SOP, including reduced dust, improved flowability and spreading, enhanced coating potential, and more. All of these qualities make a fertilizer produced via wet granulation considered a premium product. But one of the biggest reasons for choosing this type of granulation is that it gives producers a much greater ability to control particle characteristics.
As part of producing a premium product, many producers are looking to control particle characteristics to manage the look, handling, and performance qualities of their product; wet granulation enables this.
Potassium sulfate granules produced via wet granulation in the EMCC Innovation Center
Why Potassium Sulfate (SOP) Granulation Testing is So Critical
Feasibility testing and process development are often recommended when it comes to granulating materials, but testing is especially important for potassium sulfate for several reasons.
A NOVEL FERTILIZER
First and foremost, despite not being a newly discovered material, interest in using SOP as a fertilizer is fairly new. Compared to mature fertilizers such as MOP, DAP, or NPK, the production of potassium sulfate as a fertilizer product is not quite as well established.
While significant work around the properties of SOP and its behavior in a process setting has been carried out, there is still much work to be done. Testing gives producers the opportunity to establish a baseline of data around their material, determine basic process parameters, and bring to light any potential challenges the material may present in a commercial-scale setting. Testing is therefore vital to designing a commercial-scale plant that reliably operates at its rated capacity and yields product of the desired quality.
TO ESTABLISH PROCESS PARAMETERS
Testing is also necessary to gather process data such as feed rates, retention times, equipment speed, binder spray locations, temperature profiles (in the case of drying), and much more. Ultimately, testing reveals the “recipe” of process variables necessary to produce a product that meets quality expectations and process criteria.
VARIATION IN SOP SOURCES
Granulating SOP is further complicated by the multiple avenues through which it can be produced. Each approach, and variation of approach, as well as the starting material inputs, can yield different characteristics in the final SOP. This might include variations in:
- Particle size distribution
- Chemical composition
- Bulk density
- Moisture content
- Hardness
- Rheology
- And more…
This diversity makes each source of SOP unique, further necessitating testing to establish baseline and advanced process data.
TO ASSESS DIFFERENT BINDERS
Binder selection is a critical aspect of the granulation process. With various binders available, producers must select a binder that not only facilitates granule formation and growth, but that also provides the desired characteristics in the finished product.
Binders can also be selected to impart nutritive value or other beneficial qualities to the product. Testing therefore is vital to determine which binder provides the best fit based on process and product goals.
A sample of SOP granules is evaluated during testing in the EMCC Innovation Center
SOP Granulation Testing Capabilities
The EMCC Innovation Center offers several options for testing SOP granulation. In broad terms, the Innovation Center can:
- Confirm feasibility
- Show proof of concept
- Establish proof of product
- Illustrate proof of process
When testing on a continuous basis, the Innovation Center is also able to provide producers with information on process stability, bottlenecks, power requirements, and even emissions.
Depending on what stage a project is in, what is known about the material, and what the project goals are, testing can be conducted at batch or pilot scale, on a single piece of equipment or as a continuous process loop with drying and recycle. Key equipment available for testing includes:
- Rotary Drum Granulator
- Coating Drum
- Disc Pelletizers
- Rotary Dryer
- Various support equipment (feeding, conveying, etc.)
In addition to having the right equipment and infrastructure, the Innovation Center is uniquely positioned to assist SOP producers from an expertise point of view as well, with an extensive background in the fertilizer industry. EMCC has been on the front lines of both traditional and specialty fertilizer production development and has become a preferred provider to the potash industry for testing and development services, custom equipment, and parts and service support.
Conclusion
As SOP gains more market share, the importance of feasibility testing and process development services will continue to grow as producers work to establish standards for the product, and explore specialty formulations and treatments.
With unmatched experience and comprehensive testing capabilities, the EMCC Innovation Center provides the ideal environment for testing SOP wet granulation at every stage from batch to continuous pilot scale. For more information, or to schedule a test, contact us today!
WE NOT ONLY PROVIDE RELIABLE PRODUCTS, BUT MORE IMPORTANTLY WE PROVIDE RELIABLE PROCESS DESIGN AND EXPERIMENTATION
Recommendations for Drying Potassium Sulfate (SOP) Fertilizer
The burgeoning potassium sulfate (SOP) fertilizer market is not just pushing demand for the increasingly popular alternative to potassium chloride (MOP); it’s also calling for more of the equipment needed to process the compound into a market-ready product, especially when it comes to drying – a critical step in both initial extraction and fertilizer production.
Rotary dryers continue to be the industry standard for processing potash. As the market continues to pick up, those looking to develop an SOP drying line should keep the following considerations in mind for success.
The Role of Drying in SOP Fertilizer Production
Drying plays an essential role in bringing a potassium sulfate fertilizer to market in two ways:
DRYING RAW SOP
First, drying is often employed during the initial mining process used to extract the compound from complex salts.
In this setting, drying prepares the material for use as a feedstock in downstream processes.
DRYING FINISHED SOP FERTILIZER
Second, drying is an essential finishing step in the pelletizing/wet granulation process – a technique commonly used to transform the potassium-bearing compound into a premium fertilizer product.
Challenges With Drying SOP
Although SOP is similar to MOP, the two potassium compounds are not identical. This, combined with the fact that SOP processing is not nearly as well established as MOP processing, necessitates a customized approach to drying the material.
For these reasons, EMCC recommends those beginning their entry into the SOP market do two things:
WORK WITH A QUALIFIED DRYING EXPERT
Drying any novel material requires a high level of expertise to achieve the desired result without infringing on product quality.
This is especially true when it comes to potash materials, as they often present some unique challenges that will need to be addressed through the dryer design. In this setting, expertise is invaluable to expediting the road to commercialization and designing a dryer that will perform efficiently and reliably for the long term.
Further, experience is also helpful in minimizing potash dryer emissions, a growing effort in the industry.
EMCC Potash Dryer Shipping
TEST SOP DRYING
As a high-value alternative to MOP, meeting the physical and chemical product specifications expected by the market is paramount. SOP producers must develop a process that can reliably and efficiently produce a feedstock or fertilizer product with the exact specifications their customers demand.
Moisture content plays an especially important role in meeting expected quality, as it has an influence on several aspects of the product. If a fertilizer product is under dried, for example, producers not only risk higher transportation costs, but also potential mold growth and caking or spoiled product. In contrast, if the product is over dried, product color can be affected and the product may be more prone to attrition and dust.
Since SOP is fairly new to the market, dryer feasibility testing and process development play an integral role in scale-up.
Testing in a facility such as the EMCC Innovation Center offers customers the opportunity to confirm feasibility, as well as work out process variables and gather the data necessary for scale-up. The following data points are refined during testing in the Innovation Center to identify the unique combination of parameters that will allow the producer to reach the precise moisture content and quality they’re looking for:
- Dryer temperature
- Retention/Residence time
- Drum slope
- Drum speed (RPMs)
- Air volume
- Feed rate
- Feedstock characteristics
In addition to dryer testing, testing is also available for SOP granulation.
Conclusion
Drying is an essential step in bringing SOP to market as a fertilizer product, and for this, potash producers rely on rotary dryers. Because SOP is a novel material and behaves differently from MOP, EMCC recommends producers work with a drying expert and thoroughly test their drying process.
EMCC is the potash industry’s preferred supplier for custom rotary dryers and coolers. All EMCC dryers are designed around the specific source of material to be dried, with comprehensive testing available in our Innovation Center. We also offer an extensive parts and service program for keeping potash dryers running their best. For more information on our potash dryers and services, contact us today!
WHY CHOOSE EMCC AS YOUR PARTNER?
Shanghai Exceed Industry Co., Ltd (China EMCC) is a manufacturing enterprise specializing in high-tech fertilizer machinery. For many years, we have devoted to producing inorganic and organic fertilizers granulator equipments. By consistently creating values for our customers around the world, we have become one of the leading suppliers in global agricultural fertilizers industry. With China EMCC, you may get comprehensive services of consulting, design, equipment, installation, training, emergency assistance, field assistance, spare parts and routine maintenance to save fertilizer plants cost.
