Innovative process technology for sustainable P recycling

In our PHOS4green procedure, a suspension is produced from the phosphate-containing ash, mineral acid, water (if necessary) and further components, such as further nutrient components or additional phosphate sources. The suspension that is thereby produced is then spray-granulated in a fluidized-bed apparatus, wherein the fertilizer granules form. Here, the preparation of the suspension and thus the reaction of phosphate conversion between the phosphate-containing ashes and the mineral acid are separated from the granulation process.

Based on the nature of the composition of the suspension, the hard-to-dissolve phosphate compound is converted and it is possible to freely determine which end products are then produced.

Thus, we offer an economical, ecological, flexible and simple process for the production of standardized fertilizer granules from phosphorus-containing secondary raw materials such as sewage sludge ash. The resulting fertilizers are high-quality products that are in high demand. These fertilizers can be used in agriculture, forestry and horticulture to adapt the nutrient supply for cultivated crops using existing application technologies.

Our innovative process PHOS4green with tried and tested technology offers you simple and safe entry into the phosphate recovery business.


Conversion of sewage sludge ash into fertilizer is compliant with the federal fertilizer ordinance (DüMV)

With our PHOS4green procedure, we can generate a virtually limitless variety of standardized fertilizer products. This flexibility in terms of the products that can be manufactured ensures long-term profitability in very volatile raw material and product markets. We offer you both the required and extremely flexible procedure and the innovative technology as well.

In just one single production plant, both phosphate fertilizers and various complex fertilizers (NP, PK, NPK) can be manufactured. The only thing you need to do is adjust the recipes. The subsequent spray granulation in the fluidized bed allows the desired granular properties of these different formulations to be set. Our technology is easy and comfortable to control.

The process and the technology can be scaled to meet the desired production capacity or the available volume of sewage sludge ash. You can manufacture a few thousand tons or a hundred thousand tons per year, whatever you need. The end result is, in any case, high-quality, standardized fertilizer granules.

PHOS4green - production of high-quality, standardized fertilizer granules
Glatt plants for the production of high-performance fertilizers from sewage sludge ash.


Exceptional product quality thanks to a special type of granulation

Glatt spray granulation with innovative fluidized bed or spouted bed technology is an optimal process for the manufacture of fertilizer granulates. Granulate construction and subsequent drying can be carried out in a single process step. Glatt process parameters such as capacity, grain size and solubility guarantee the cost effectiveness of your system and quality that is consistent.

The material is continuously mixed in system with a round fluidized bed floor and central discharge. Glatt fluid bed granulators are divided up into several process chambers. In addition to granulation and drying, the cooling of the granulates can also take place here in the same system. For all of our concepts, Glatt guarantees variable and consistent capacities and outstanding product quality.

PHOS4green - spray granulation
Our spray granulation apparatus forms exceptionally round and abrasion-resistant granules for easy and safe handling.


Continuous fluidized bed granulators

The fluidized bed spray granulation is a method for making free-flowing granulate from liquids. It can be used in different applications in various industries, since the product properties can be varied in many ways by setting the process parameters and configurations.

Many industrial applications require the transformation of liquid substances into a stable product form with well-defined properties - and the same is true with our phosphorous recovery process. Spray granulation in the fluidized bed permits liquids, such as suspensions from sewage sludge ash, to be directly made into free-flowing granulate with specific product properties.

For this purpose, the suspension is sprayed into a fluidized bed system. Due to the high heat exchange the water evaporates immediately, and the solids form small particles as starter cores. These are sprayed with other liquids which in turn, after evaporation, form a hard coating around the starter core. This step is continuously repeated in the fluidized bed so that the granulate grows layer by layer like an onion.

Our fertilizer granules are very dense because they have grown in layers, and are thus resistant to abrasion. This is especially important so that no dust forms when handling the fertilizer granules or spreading them on the fields. And yet the solubility is still outstanding. Parameters such as particle size, residual moisture and solids content can be specifically adapted in order to achieve the most varying product properties.

PHOS4green - continuous granulation
Continuous granulation without waste for high, long-term profitability.


High sales revenues exceed the process costs

The evaluation of a procedure's profitability is the key to deciding whether or not to invest. Decisive cost groups are the costs for raw materials, the process costs (investment, operating costs, HR) and, ultimately, the sales proceeds.

Sewage sludge ash is used in the raw materials, which, according to the current market situation, generates a purchase price that is likely to increase in the future. Inexpensive residues can also be used in our process as nutrient components. Lower your total raw material costs with PHOS4green!

The PHOS4green process does not use expensive, often multi-stage extraction and separation techniques, as is common with other phosphate recycling methods. In addition, there is no waste which costs money to dispose of. Take advantage of the moderate process costs offered by PHOS4green! A crucial point for any recycling process is whether the products being produced are in demand and at what price they can be placed on the market. There is considerable uncertainty in many P recycling processes as no standard products currently exist on the market which can be used to make a reliable calculation. The monetary value of the nutrient gives no indication here because there are no well-defined soil and plant specific nutrient compositions. Therefore, these recyclates are generally considered to be waste products in the market with a correspondingly low value.

If phosphoric acid is produced in recycling processes instead, then the process is very complex. Expensive chemicals are needed and the waste generates significant disposal costs. This results in production costs for the phosphoric acid which lie far above the current market prices.

Create sustainable, profitable end products.

PHOS4green is our solution for your investment decision!

PHOS4green - calculation
We will be happy to support you in calculating your individual cost structure at your location.


Proven technology on an industrial scale

For our process, we rely on our tried-and-tested technology involving fluidized bed spray granulation. We combine this with an upstream process step to convert the insoluble phosphates from the ashes into readily-available nutrients for plants.

Dissolution processes are standard procedures in the chemical industry for the production of innumerable products. The technology required for this is available for every imaginable material on an industrial scale. For our first process step, we use this tried-and-tested technology.

As a pioneer in fluidized bed technology, we have more than 60 years of experience in leading-edge solutions for developing, refining and manufacturing granulates. As a manufacturer of plants, we have been creating plants for decades, focusing on our spray granulation - all over the world.

Therefore no technology development is needed to implement our PHOS4green process. The process can be implemented immediately on an industrial scale at any location. The intermediate steps of scaling up from the laboratory, which are often necessary in other phosphorus recycling processes, together with the corresponding development risks, are eliminated.

Benefit from a technology that's available on an industrial scale!

PHOS4green - phosphorus recovery
Fluid bed technology for phosphorus recovery on an industrial scale