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Chemical, 2017-02-27, 10:11 AM

From an industrial by-product to a high-quality fertilizer: New process from thyssenkrupp permits low-cost granulation of ammonium sulfate

  • thyssenkrupp presents new plant type at Nitrogen + Syngas in London
  • Greater cost efficiency compared with conventional processes

thyssenkrupp Industrial Solutions, the plant engineering division of the German technology group, is presenting a new process for the cost-efficient production of granular ammonium sulfate at the “Nitrogen + Syngas” conference in London this week. The new plant type produces a valuable sulfur-containing nitrogen fertilizer in granular form from the byproduct ammonium sulfate solution. The process offers fertilizer manufacturers major advantages: firstly, much greater cost efficiency compared with conventional processes producing granular ammonium sulfate from ammonia and sulfuric acid, and secondly improved spreading and mixing properties compared with crystalline products.

“Demand for granular ammonium sulfate exists all over the world,” explains Dr. Jens Mathiak from thyssenkrupp Industrial Solutions, who developed the new process together with his team. “We want to give fertilizer manufacturers the opportunity to convert byproducts into high-quality nitrogen fertilizers, which command premium prices compared with standard products in crystalline form. The many advantages of the granular form andthe high profit margin are two major reasons to choose the thyssenkrupp ammonium sulfate process.”

Innovative technology converts by-products into valuable fertilizers

The new patented thyssenkrupp process combines the advantages of high-value granularfertilizer with cost-efficient production. The process starts with ammonium sulfate solution, an industrial by-product occurring mainly in the production of caprolactam and in coalburning furnaces. Ammonium sulfate is mixed with an additive in a specific ratio. The additive results in greatly reduced dust formation during granulation and high crushing strength in the end product.

In a second step the liquid mixture is sprayed into a fluidized bed granulator and processed into solid granules. The product from the granulator is taken to a screen. Oversize pieces are crushed and returned to the granulator together with undersize particles. Then the product is conveyed to a storage facility. The granules are round and very hard and therefore very resistant to impacts and abrasion.

Through the simultaneous supply of sulfur and nitrogen, ammonium sulfate permits strong crop growth and high yield levels. It guarantees long-lasting nutrient supply and promotes the availability of micronutrients in the soil such as manganese, boron and iron. Ammonium sulfate is currently mostly sold in the form of crystals, which are difficult to incorporate into granulated fertilizer blends. Conventional granulation plants are not able to process ammonium sulfate solutions. Instead they require comparatively high-priced ammonia and sulfuric acid as starting materials.

High demand promises excellent sales opportunities

Following successful lab and bench-scale tests, thyssenkrupp built a pilot plant in 2016 with an initial production capacity of 500 kg per hour. “Here too all the tests have been successful so we can now scale up the process to industrial scale with capacities between five and 20 metric tons per hour,” explains Dr. Mathiak. “Fertilizer manufacturers worldwide will be able to benefit from greater cost efficiency. Granular ammonium sulfate is currently made by very few manufacturers so demand is high and there are great sales opportunities, also in niche markets.”

About thyssenkrupp Industrial Solutions:

The Industrial Solutions business area of thyssenkrupp is a leading partner for the engineering, construction and service of industrial plants and systems. Based on more than 200 years of experience we supply tailored, turnkey plants and components for customers in the chemical, fertilizer, cement, mining and steel industries. As a system partner to the automotive, aerospace and naval sectors we develop highly specialized solutions to meet the individual requirements of our customers. Around 19,000 employees at over 70 locations form a global network with a technology portfolio that guarantees maximum productivity and cost-efficiency.

The Fertilizer & Syngas Technologies business unit has more than 90 years’ experience in the engineering, procurement, construction and service of fertilizer plants. Based on a unique combination of engineering experience, project management expertise and leading, eco-friendly technologies, we develop tailored solutions that enable fertilizer manufacturers around the world to enhance their efficiency and competitiveness.

Twitter: @thyssenkrupp_en

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The ammonium sulfate granules produced are round and very hard and therefore very resistant to impacts and abrasion (©thyssenkrupp Industrial Solutions).
The ammonium sulfate granules produced are round and very hard and therefore very resistant to impacts and abrasion (©thyssenkrupp Industrial Solutions).
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