NEUTRAL
A circular product is what makes the business case work. For buyers too.
Het end product of MID MIX® is called Neutral: a white, dry powder of calcium hydroxide en calcium carbonate with stable quality. Neutral is validated for several applications. The sale of Neutral supports the business case for sludge treatments. And the application of Neutral offers competitive advantages to the buyers
WHAT IS NEUTRAL
Hydrated lime. A sustainable alternative with many applications.
Neutral consists mainly of calcium hydroxide (>80% Ca(OH)₂) and calcium carbonate (10–20% CaCO₃): the same substances the construction and lime industries buy and sell daily as a primary raw material. Neutral is validated for multiple applications. Because of its high Ca(OH)₂ content, Neutral also aligns with the REACH registration for calcium hydroxide. The composition of the incoming sludge partly determines Neutral’s specifications. Quality is therefore stable per processed stream, and is established per stream.
A product that can be sold directly for several useful applications. The choice of outlet route(s) is part of the installation design, and that choice partly determines which applications stay open. We go through the pros and cons of the options with you during the plant design. That’s what makes the difference, not just for sustainability and circularity, but above all for the business case.
Ca(OH)₂
calcium hydroxide >80%
Back to basics
Our fallback: replacing primary limestone.
The cement industry uses quarried limestone (calcite) by burning it at about 1.300 °C in the production process. The fuel use already generates CO₂ emissions. Additionally the process also realeases CO₂ that was minerally bound in the limestone itself. Processing Neutral in the same process requires about 900 °C instead of 1.300 °C and releases water vapour instead of CO₂.
For buyers who need to cut their CO₂ footprint, the result is clear: less energy and less process CO₂, for the same chemical function.
Producers get certainty: with a market of large volumes, there’s always a route.
Processing temperature and what’s released
Primary lime from limestone versus Neutral (hydrated lime) in lime burning and clinker production.
1.300 °C
± 900 °C
APPLICATIONS AND VALIDATION
Five applications, each with a significant market.
Replacement for hydrated lime in dry flue gas cleaning
Tested against the customer’s technical and operational specifications; varies per customer.
Replacement for primary hydrated lime in asphalt
Validated against the product requirements of NEN-EN 13.043 (SGS Intron)
Cement replacement in other applications
Soil stabilisation, mortar, plaster. Assessed per application.
Active filler and cement replacement in concrete
Validated against the product requirements of NEN-EN 12.620 (SGS Intron)
Raw material for low-CO₂ cement clinker
Approval per customer, based on technical and operational specifications; the fallback route.
Disclaimer: all quality claims assume suitable input streams. Sludge with higher contaminant levels produces Neutral that may qualify for every application. Even then, there’s a valuable outlet: the clinker route stays available and acts as the safety net that keeps the business case positive.
Not all applications are standardised
Standards exist for concrete, asphalt and other cement applications. Neutral from specific sources meets these standards, confirmed by SGS. For flue gas cleaning and the clinker route, no standardised certification exists: there, Neutral is approved against the customer’s technical and operational specifications. In every case, we also make sure general laws and regulations are met.
Every stream is unique
Every application is assessed per sludge stream: the composition of the incoming sludge partly determines Neutral’s specifications. We test this with our established network of off-take partners. That way, neither the producer nor the buyer of Neutral gets any surprises.
OFF-TAKE AND AVAILABILITY
The off-take is arranged before your line runs.
With our European supply chain partners, we can guarantee that Neutral has an outlet before you invest.
Honest about availability
Neutral is currently available in test quantities. Larger volumes follow with the first full-scale installation, which is now in development and planned for 2027. Buyers testing Neutral in their own application now will be ready to purchase when large volumes become available.
FURTHER DOWN THE CHAIN
The loop can close even further.
After production, Neutral doesn’t only go straight to market. There are also three routes for further processing. In specific cases, these can add even more value.
The routes described below are all at different stages of development and scale-up.
Route 1
Carbonation
Up to 600 kg CO₂ per tonne of Neutral permanently fixed as secondary limestone; relevant for CO₂ pricing.
Route 2a
Dehydration
Neutral is converted back to quicklime using heat; the lime from the process becomes reusable.
Route 2b
Phosphorous recovery
An extension of dehydration: phosphate is separated from the lime.
With these innovations, we’re working to further develop and strengthen the MID MIX concept.
How Neutral forms in the reactor
MID MIX Technology →
Neutral in your application?
Tell us where you’d like to use Neutral. We’ll check together whether the application fits and make a sample available for you to test yourself.
Do you have a sludge stream of your own to treat? Schedule a scan..
A circular solution for sludge treatment with a strong business case.
Contact
Certificerion
SGS Intron
NEN-EN 12.620
NEN-EN 13.043
© 2026 VSGM B.V. · MID MIX® · Neutral