Vateris: a new route to premium SOP

A crossroads moment

Today, the global potassium sulphate (K2SO4 , SOP) market finds itself at an interesting crossroads.

Demand for chloride-free potash fertilizers continues to grow, driven by the expansion of high-value horticulture, precision agriculture and water-soluble fertilizer applications. At the same time, producers face increasing pressure to reduce their carbon emissions, manage energy costs and secure a reliable supply of raw materials.

Against this backdrop, UK technology company Vateris is advancing a new approach to SOP manufacture that addresses several of these challenges simultaneously.

Founded in Nottingham in 2021, Vateris has spent several years developing and scaling-up a novel patented process (Figure 1). This combines gypsum, potassium hydroxide and captured industrial carbon dioxide to produce two valuable products: high-purity SOP fertilizer and a specialist calcium carbonate material for the construction sector.

Although still in the scale-up phase, the company believes its technology has the potential to establish an entirely new production route for SOP, providing the market with an additional source of premium, chloride-free potash, while simultaneously incorporating carbon dioxide into useful products.

Looking beyond conventional production

SOP is produced commercially using a variety of technologies, each with its own advantages and limitations.

The Mannheim process remains the dominant production route globally and has proven itself over many decades. Alternative sources include naturally-occurring sulphate-rich mineral deposits, as well brine-based operations and production based on the glaserite process using sodium sulphate feedstocks, including waste streams.

What Vateris offers is a very different proposition.

Rather than relying on sulphuric acid as the sulphate source, advantageously, the company’s process uses gypsum (calcium sulphate, CaSO4.2H2O) instead. Carbon dioxide captured from industrial emissions is then incorporated into the process, ultimately becoming part of the company’s trademarked calcium carbonate co-product.

The process can consume either mined primary gypsum or secondary by-product sources. The latter includes the large volumes of phosphogypsum (PG) generated by the fertilizer industry during phosphoric acid production – PG being one of the most widely available sulphate-bearing materials in the world.

Vateris calculates that approximately 250 kg of CO2 is permanently sequestrated by their production process (as calcium carbonate ‘GypCarb’ product) for every tonne of SOP produced.

This ability to transform what would otherwise be an industrial emission into a valuable raw material sits at the heart of the company’s technology platform. Indeed, an independent Climate Impact Forecast Validation Study conducted by Impact Forecast concluded that the process has the potential to remove significantly more greenhouse gases than it generates. The study concluded that: “By developing carbon negative vaterite as a supplementary cementitious material that turns concrete into a carbon-absorbing material and producing a fertiliser co-product, the company offers a scalable solution that removes 2.8 times as much greenhouse gases as it emits.”

The result is a production system that addresses two industries with substantial decarbonisation challenges: agriculture and construction.

Quality at the centre

For fertilizer manufacturers, distributors and growers, however, product performance remains the primary consideration. Vateris has therefore placed considerable emphasis on the quality characteristics of its SOP product.

Independent analysis of material produced from the pilot process – carried out by SGS – has shown potassium content exceeding 52% K2O, a sulphur percentage of just above 18% and a chloride concentration well below 0.5%. Impurity levels are also reported to be comfortably within the limits established by the EU’s Fertilising Products Regulation.

The use of potassium hydroxide as the potassium source plays a vital role in this quality profile. Unlike potassium chloride, it introduces no chloride into the process, helping create a highly pure final product.

Vateris has adopted the slogan ‘Purity Redefined’ for its SOP offering, reflecting its aim to deliver a product suitable for the most demanding fertilizer and industrial applications. Purity is particularly valued in the rapidly growing water-soluble fertilizer (WSF) market, where dissolution characteristics and low insoluble content are becoming increasingly important.

Modern fertigation systems – used to deliver dissolved nutrients to crops via drip irrigation – leave little margin for inconsistency. Growers require WSFs that dissolve rapidly and completely, avoiding the filter blockages and irrigation issues that can result from excess insoluble material. Fertilizer blenders likewise demand high-purity SOP products that can be incorporated seamlessly into premium formulations.

Vateris believes its recrystallisation process can deliver both strong chemical specifications and the physical performance required by these increasingly demanding applications.

Addressing supply chain challenges

The planned market entry by Vateris also looks timely.

Its arrival comes at a time of growing discussion about SOP’s long-term supply security and its production economics. Energy costs, for example, remain a major consideration across Europe.

At the same time, sulphur and sulphuric acid markets are currently experiencing extreme market tightness and price volatility, creating additional uncertainty for producers that rely on these feedstocks. Notably, the sulphur price has exceeded $1,000/t at times this year.

The fact that Vateris, by utilising gypsum as its sulphate source, is not exposed to sulphur and sulphuric acid supply shortages and pricing provides a competitive advantage.

Its technology also operates at ambient temperature, unlike the high-temperature reaction conditions associated with conventional SOP technologies such as the Mannheim process. This should offer meaningful energy advantages as the technology scales up.

Importantly, Vateris is not positioning itself as a replacement for existing production routes. Instead, the company sees itself as an additional provider of SOP, via its patented technology, at a time when demand for premium low-chloride fertilizers continues to expand.

Currently, global SOP demand is growing at around 2-3% annually, with some higher-value, water-soluble market segments expanding even faster. As a result, many industry observers expect additional SOP production capacity will be necessary over the coming decade.

Making commercial scale-up a reality

Like many successful industrial technology ventures, Vateris’ journey has progressed through a series of carefully managed development stages.

The company’s pilot facility in Nottingham is already producing representative SOP material for customer evaluation and application testing. Current pilot capacity is around 50 kg per day, providing sufficient volumes for qualification programmes with prospective partners and off-takers.

The next milestone is the construction of a demonstration plant, currently targeted for 2027. This facility is expected to produce up to two tonnes per day of SOP, creating the opportunity for broader market testing and early commercial sales.

This demonstration phase is needed to provide prospective customers with the confidence that comes from operating at a meaningful industrial scale – generating the performance data necessary for larger commercial projects.

Looking further ahead, Vateris plans to commission its first full-scale commercial production plant during 2028-2029. Initial SOP design capacity is expected to be approximately 50,000 tonnes per annum, with further expansion anticipated thereafter.

Over the longer term, the company sees a pathway to production volumes of up to 300,000 tonnes of SOP annually by 2033 through multiple plant operations and potential licensing partnerships.

“An essential success factor in our scale-up is partnerships with established manufacturers. We’re already exploring joint industrial development with our strategic investor Holcim, for example. As we enter our next phase, we’re seeking that same relationship with a major fertilizer industry player,” Jeremie Rombaut, Chief Commercial Officer, Vateris.

Building strategic partnerships

One notable aspect of the Vateris story is the calibre of industrial partners already involved.

The company has attracted investment and support from major players in the construction materials sector, including Holcim, reflecting confidence in the potential of its calcium carbonate co-product.

There is also growing interest from the fertilizer industry. In this sector, Vateris is actively seeking strategic relationships spanning product offtake, supply chain collaboration, industrial co-location opportunities and investment partnerships. Several fertilizer sector offtake agreements have already been signed, with other discussions ongoing.

The company believes these partnerships will play a key role in accelerating commercial deployment of its SOP technology, while ensuring that future production capacity aligns closely with market requirements.

An innovative technology worth watching

The fertilizer industry has never lacked innovation. Yet very few new SOP production platforms have emerged with the potential to operate at significant scale.

That fact alone makes Vateris an interesting company to watch.

Its combination of readily available feedstocks, carbon utilisation, ambient-temperature processing and the production of a high-purity SOP product offers a distinctive addition to the industry’s technology portfolio.

Clearly, much work remains to be done. Demonstration plants must perform, commercial economics must be proven at scale and long-term partnerships must be secured.

But, if the company succeeds in translating promising pilot plant results into industrial reality, the market will gain something increasingly valuable: a new source of premium SOP that combines product quality, supply chain resilience and a significantly lower carbon footprint.

For a fertilizer sector tasked with feeding a growing population – while reducing its environmental impact – that is a proposition likely to attract considerable attention in the years ahead.