Royal HaskoningDHV launches first UK Kaumera biopolymer plant

Dutch engineering company Royal HaskoningDHV has announced it is to implement a Kaumera biopolymer pilot at a United Utilities site in the UK – the first biopolymer project of this size in the country.

A new market for Royal HaskoningDHV

The installation, due to become operational in early 2025, will also be the first of the company's Kaumera systems in the UK and is a significant step in the previously nascent market for biopolymer recovery from wastewater.

Royal HaskoningDHV's previous permanent installations were located in the Netherlands, and the technology was originally designed to bolt onto the company's Nereda aerobic granular sludge systems, extracting biopolymer from the sludge granules. The UK pilot is set to run for 9-10 months, producing a few tonnes of product per batch.

Both Nereda sludges from the site, and some non-Nereda sludges shipped from other treatment plants will be tested, in order to investigate the produced biopolymer yields from different materials. United Utilities has currently earmarked a site in Blackburn, Lancashire, to locate the technology, although a final decision is still pending as negotiations with site operations are still underway.

Any way that we can recover a higher-value product will be beneficial

With UK utilities increasingly concerned about sludge-to-land as a recycling route, the production of high value products alongside the reduction of sludge volumes is a key driver for technologies like Kaumera. Furthermore, with the advanced thermal conversion (ATC) of sludge being expected to proliferate in the UK in coming years, at a high cost, Kaumera can be used to reduce the volume of sludge to be handled using this route.

"The challenge with recovery of products and/or energy by ATC is that dewatered sludge still typically contains >70 per cent water, and so any thermal processing route will still be relatively costly. Any way that we can recover a higher-value product will be beneficial," explained Royal HaskoningDHV's UK water utilities director Paul Lavender.

"Energy recovery is at the bottom of the value pyramid, whereas recovering valuable products [such as biopolymers] is higher up," he continued.

An industry-wide effort

The pilot will be part of a wider circular economy-focused project that has been mostly funded by an Ofwat Breakthrough Project 2023 award, and also includes a cellulose recovery arm as part of the funding. The combined consortium for the two arms includes United Utilities, South West Water, and Severn Trent, and technology providers Royal HaskoningDHV, Cellvation, and Aqua Minerals.

End-users investigating the uses of the produced product include Yara, Crown Paints, Croda Chemicals and Unilever, and both Glasgow Caledonian University and Cranfield University are supporting the project.

"A big part of the pilot is understanding what a sensible level of downstream refinement would be for the product," outlined Richard Clarke, programme manager (engineering innovation) at United Utilities. "You could get it to a completely white powder, and that could be used in something like paints, or you could take it with little refinement and use it as a biostimulant in agriculture," he continued.

A big part of the pilot is understanding what a sensible level of downstream refinement would be for the product

Clarke also explained that investigating end-of-waste is a key objective – by understanding if the Kaumera can be produced with consistent properties despite variable inputs, and learning which end-markets are receptive to a product made from biosolids.

Achieving end-of-waste status clarifies that a material recycled from a waste product has gone under sufficient processing to compete with those derived from raw materials, and would provide assurances of quality, opening up more markets for the produced biopolymer.

Another efficient reuse route for utilities that is being investigated is utilising the product within the wastewater treatment process itself – as a flocculant, or as a conditioner for sludge thickening/dewatering. This could be a more straightforward avenue as it may not require end-of-waste status. Royal HaskoningDHV has been using the product from previous projects in the Netherlands as a biostimulant – a material that helps promote plant growth in agriculture.

Bringing value in light of regulatory change

Royal HaskoningDHV also sees further benefits to Kaumera for UK utilities. With the Industrial Emissions Directive mandating extra monitoring and reporting for anaerobic digestion (AD) sites into the 2025-2030 AMP8 period (after retrospectively adding sludge AD to the regulation in 2019), the closure of smaller AD plants is expected and more capacity will be required at the larger ones.

The company claims that 25-30 per cent of the organic matter from the sludge would be converted into biopolymers, reducing sludge volumes, and potentially easing the anticipated pressure on capacity at these larger sites.

The remaining waste is also easier to handle: "The extraction process involves heating and pH changes so the reject stream is effectively being hydrolysed, making it very biodegradable. It is then suitable to be sent back to existing sludge treatment assets," continued Lavender.

Fostering offtake market growth

Similar to all emerging recycled products, early-stage market building has been a challenge for wastewater-derived biopolymers. To tackle this, Royal HaskoningDHV and a number of Dutch water companies have recently set up a joint public/private entity.

"The company will act as a market broker, helping the water companies produce the Kaumera product and to find markets for it. It will be more nimble at exploring commercial avenues and accelerating end-of-waste," summarised Lavender.

Centralising the distribution of recycled materials is an increasingly popular model in the water space – with the likes of Aqua Minerals, Ostara and EasyMining following a similar route. The biopolymers market from wastewater treatment has seen accelerated traction in the last year. Paques, another player in the market, saw an injection of €14 million in 2024, showing increased investor confidence in the space. Growth now depends on whether reliable offtake markets are secured.