The Problem We Solve
Millions of tonnes of sewage sludge, digestate, and industrial organic waste end up in landfills yearly, generating costs and growing regulatory risk. Meanwhile, arable soils lose organic matter and become dependent on synthetic fertilisers that provide nutrients but do not build soil structure or improve its water retention and long-term fertility.
Our Solution
A single-reactor process that takes organic sludge and transforms it into a stable, granulated product rich in NPK + Mg + S and sterile organic matter. The process requires no external heating, which significantly lowers production costs and carbon footprint.
How the Process Works
Substrate preparation
Organic sludge is tested for composition, moisture, bacterial flora, and heavy metals. If heavy metals exceed safe thresholds, they are precipitated before the process begins.
Magnesite blending
Roasted magnesite (MgO content 50–100%, grain size < 1 mm) is added and mixed for 15–30 minutes, creating a reactive mineral matrix. It is the magnesium source that buffers product pH and enriches the blend with MgO.
Acid-stage mineralisation
Phosphoric acid (50–90%) and solid potassium hydroxide are introduced under controlled cooling. The strongly exothermic reaction raises the temperature on its own, with no external heating.
Sulphuric acid concentration
Sulphuric acid (70–100%) is dosed gradually. The temperature peaks below 145 °C, fully hygienising the product and evaporating excess water. Steam is condensed in a closed-loop cooler.
pH adjustment
The cooled product (< 40 °C) is tested. If pH falls between 4.0 and 8.0, the process continues. Below 4.0, micro-doses of magnesite are added until the target range is reached.
Urea enrichment
Urea (5–30%) with a urease inhibitor is blended in. The inhibitor curbs nitrogen loss, keeping amide nitrogen in a form available to crops. The final product is homogenised and ready for granulation.
Product Composition by Substrate
| Substrate | Organic matter | N (amide) | P2O5 | K2O | MgO | SO3 |
|---|---|---|---|---|---|---|
| Municipal sewage sludge | 41.7% | 1.0% | 1.3% | 2.6% | 26.0% | 14.3% |
| Compost | 22.5% | 2.6% | 3.6% | 7.2% | 12.0% | 23.9% |
| Digestate | 42.2% | 1.3% | 1.5% | 2.9% | 23.7% | 18.8% |
| Brewery waste | 38.9% | 1.8% | 0.8% | 1.6% | 25.0% | 21.7% |
| Winery-industry waste | 38.1% | 2.3% | 0.8% | 1.7% | 26.0% | 21.0% |
| Bottom sediments | 42.4% | 1.8% | 2.1% | 4.1% | 22.4% | 27.2% |
Values in w/w% of finished product. Validated across six substrate types at pilot scale.
Main Advantages
Zero External Heating
Exothermic reactions generate all process heat internally, significantly reducing costs and carbon footprint.
Feedstock Flexibility
Accepts sewage sludge, compost, digestate, brewery waste, winery waste, and bottom sediments.
Complete Hygienisation
Sustained temperatures up to 145 °C eliminate pathogens and bacterial contamination.
Balanced Nutrients
Full spectrum of NPK + Mg + S alongside organic matter that builds soil humus and improves water retention.
Closed-Loop Emissions
All steam is condensed and acid aerosols captured. The process meets stringent environmental standards.
Scalable Output
Dry, granulated organic-mineral fertiliser, well matched to the soil profile and rich in essential nutrients.
Who Is This Technology For?
- Wastewater and water utility operators
- Municipal wastewater treatment plants seeking new uses for sludge
- Breweries, distilleries, and wineries turning by-products into revenue
- Agricultural cooperatives wanting locally produced, soil-enriching fertiliser
- Green-technology investors interested in circular-economy projects
Technology Readiness
Technology validated at pilot scale with full chemical characterisation. Covered by an international patent application.
We offer licences to deploy the fertiliser technology and joint development agreements. We support partners in adapting the process to local waste streams and regulatory requirements.