Fertilizer International 518 Jan-Feb 2024
31 January 2024
The future of fertilizer coatings
CONTROLLED-RELEASE FERTILIZERS
The future of fertilizer coatings
New regulatory developments in Europe are focusing attention on eliminating microplastic residues in soils by adopting biodegradable fertilizer coatings. Major technology licensors and engineering companies are also developing new coating technologies for controlled-release fertilizers (CRFs).
MILLIKEN & COMPANY
The EU finally adopts its microplastics regulation: now what?
Introduction
The sustainability of fertilizer coatings, and their sourcing from bio-based natural sources such as vegetable oils, have become priorities for key suppliers such as Arkema (Fertilizer International 500, p24), NAQ Global (Fertilizer International 500, p22) and Novochem (Fertilizer International 516, p40). The industry’s major technology licensors and engineering companies, notably thyssenkrupp and Stamicarbon, have also developed new coating technologies for controlled-release fertilizers (CRFs).
Regulatory developments in Europe, meanwhile, are focusing attention on eliminating plastic residues in soils by adopting biodegradable fertilizer coatings. Leading CRF manufacturer ICL, for example, has recently introduced biodegradable coatings into its controlled-release portfolio (Fertilizer International 510, p24).
A selection of the latest regulatory, technological and product developments in the coated fertilizer market are reviewed.
The arrival of new EU regulation
The European Union (EU) formally adopted a restriction on the use of microplastics in products sold within the region on 25th September 2023, following the recommendation of the European Chemicals Agency (ECHA). This new regulatory action seeks to avoid or reduce the release of microplastics into the environment, regardless of product type. It comes at a time when more businesses and communities are working to increase the ‘circularity’ of plastics consumption and production.
Microplastics can be particularly difficult to dispose of – as, by definition, they are less than 5 millimetres in size and most consumers, therefore, are not even aware they exist. This general lack of awareness means that microplastics could end up in the environment, degrading into smaller and smaller pieces for centuries, if not disposed of or recycled properly.
With the restrictions on microplastics introduced by REACH (Registration, Evaluation, Authorization, and Restriction of Chemicals) regulation 2023/2055 in September, EU companies will have to adhere to industry-specific guidance on how to avoid, remediate or reformulate their products. For the fertilizer industry, this regulation specifically affects fertilizer products that: l Incorporate microplastics as defined below; and l Are not currently governed under REACH EU 2019/1009.
How will this affect fertilizers?
Fertilizers often incorporate microplastics to control the release of their highly water-soluble active ingredients. Microplastics help impart ‘staying power’ and limit the water solubility of fertilizer products by applying a cross-linked polymer – often polyurethane – to their nutrient components. Liquid fertilizer formulations, for example, can incorporate a polymer-based acrylic thickener to enhance their staying power on the ground, while encapsulating solid fertilizer granules within a plastic coating can impart controlled-release characteristics.
A difficult balancing act
Microplastics therefore play an essential role in precision agriculture by helping limit the downstream release of chemicals that could taint the environment. Less desirably, however, the remnants of plastics coating, having partly deteriorated over time to slowly release fertilizer ingredients, are left in the ground and water bodies. The presence of these residual microplastic fragments in the environment can affect animals and humans, as well as countless other organisms that draw nutrients from soil and water.
Striking the right balance between nutrient losses to the environment and microplastic contamination of soil and water is difficult, especially given that controlled-release fertilizer (CRF) technology has not changed much in 50 years. Nonetheless, the introduction of REACH regulation is now providing added urgency and prompting an industry shift. That’s because fertilizer manufacturers, under EU 2023/2055, will have until 2028 to achieve compliance with this microplastic-free regulation. From this date, all products placed on the market will need to adhere to specific requirement. The key takeaways from this regulation are as follows:
- It covers synthetic polymer microparticles. These being defined as: not an unmodified, naturally-occurring polymer; not water-soluble (greater than 2g/L); or not biodegradable.
- Although fertilizer products must be compliant by 17th October 2028, the supplier ingredients that go into these fertilizers will need to be compliant almost a year ahead of the 2028 deadline.
- An interim period is expected, during which end-users may incur increased costs and experience performance gaps, until product innovation catches up with the regulation.
- In certain instances, REACH regulation EU 2019/1009 on fertilizer standards can take precedence over the new EU 2023/2055 regulation. Where this is the case, the guidance is to continue to follow REACH EU 2019/1009 as the appropriate standard.
Not just a European challenge
For European players, 2028 is not that far away, especially considering that products will need to be market-ready by 2027. While expectations of change may appear to be on the far horizon for companies not invested in EU markets, it is worth noting that the Canadian and Australian parliaments are expected to enact similar legislation within a few years, with more countries potentially following suit within the decade. At the same time, products sold into a microplastic-regulated market such as the EU must follow regional guidelines, regardless of where the fertilizer manufacturer is based.
Practically, this means that if you are not formulating compliant fertilizer products, or actively investigating microplastic-free or reformulated products, now is the time to do so. It can be daunting to know where to start, but here are three things to consider:
1. Adhering to REACH regulation EU 2023/2055 doesn’t necessarily mean developing polymer-free fertilizer, as the regulation does outline exemptions. This means your product could still contain polymer coating elements if they are: naturally occurring, water-soluble (greater than 2g/L), or biodegradable under an accepted test method.
2. Regulation EU 2023/2055, by governing the use of microplastics, will have an impact on how manufacturers develop inert or inactive components like coatings or colorants. This change does not, however, generally affect the active ingredients of fertilizers, as these are governed by REACH EU 2019/1009 in many cases.
3. The difficulty with this regulation is that it directly impacts the controlled-release fertilizer technology currently used in the global marketplace. As things stand today, existing CRF technology cannot meet REACH EU 2023/2055 while still matching prevailing performance expectations and current market costs. This regulation will therefore force a major shift in the fertilizer industry – one that will be accompanied by interim performance shortcomings and, potentially, increased costs. Change is, however, part of the very nature of business. So breakthroughs in collaborative innovation are expected to solve these issues eventually.
Summing up
The move away from microplastics will, ultimately, deliver significant sustainability advantages. The ECHA estimates that, of the 145,000 tonnes of microplastics used across all EU industries, nearly 42,000 tonnes end up in the environment. Fertilizer companies should therefore have a vested and growing interest in embracing new and novel approaches that will enhance the economy.
Whatever the underlying motives, this new EU microplastic regulation should encourage the fertilizer industry to rise to the challenge and harness the innovation that will ensure compliance and bring about a more sustainable future.
About the author
Wade Holcombe is TS&D Team Lead for agriculture within Milliken’s Chemical Business. He and his team develop and refine Milliken solutions for seed treatments, crop protection and fertilizers.
THYSSENKRUPP
Sustainable and future-proof coating technologies
Introduction
Increasingly, the fertilizer industry needs to meet new, more stringent environmental obligations and respond to calls from society for greater sustainability. In Europe, these demands are exemplified by the EU’s Green Deal – although similar pressures apply in other regions.
To prepare the fertilizer industry for these future needs, thyssenkrupp Fertilizer Technology (tkFT) and thyssenkrupp Uhde have developed controlled-release fertilizers to meet upcoming European and worldwide demand for products with better nitrogen use efficiency.
Controlled-release fertilizers (CRFs)
The conventional application of commodity fertilizers to crops typically results in big nutrient losses. These can reach 70 percent or more for some nitrogen fertilizers such as urea. Such losses are directly responsible for the nitrate pollution of groundwater and soils in countries where intensive agriculture and fertilization is practiced, such as those in Western Europe.
Consequently, legislators in some regions have reacted by introducing restrictions that limit both the amount of applied fertilizers and the number of applications allowed during the growing period. Additionally, the use of so-called stabilised fertilizers (SFs) is also being mandated to cut nutrient losses.
Having recognised this trend, thyssenkrupp Uhde, as a leading engineering, procurement and construction (EPC) contractor for ammonia and urea plants, has been working to develop SFs and controlled-release fertilizers (CRFs) together with their associated production processes. One successful outcome has been the development of innovative polymer coated urea (PCU) products (Fertilizer International 503, p26). These special types of CRF use biologically degradable polymers such as polylactic acid (PLA) to coat urea granules (Figure 1).
These polymers decompose in soil without producing environmentally harmful substances and can be produced from renewable resources. This ensures that the whole production and crop application process is sustainable.
These types of CRFs make nutrients available over the entire growing period. They are also more efficient as they supply nutrients in the exact quantities required by crops. This provides the option to:
- Either increase crop yields by up to 10 percent for the same amount of fertilizer
- Apply less fertilizer to achieve the same yield.
The production of CRFs can be integrated within an existing ammonia-urea production complex, or set up as a standalone plant, and can be realised for a wide range of production capacities. To minimise nutrient losses and increase nutrient use efficiency, the same coating technology can also be successfully applied to other fertilizer types, including potash-, phosphateand sulphurcontaining fertilizers.
STAMICARBON
Coated fertilizers get smart
Introduction
With fertilizers playing an increasing role in food production, the application of urea remains essential if crop yields are to increase. Yet urea typically has a low nutrient use efficiency due to the loss of nitrogen, which is either volatilised into air as ammonia and N2O, or lost to surface and ground water as nitrates. These environmental losses have adverse effects, ranging from air pollution and fine dust, to elevated levels of nitrates in drinking water, and the eutrophication of surface water bodies.
The switch to smart fertilizers
Fertilizers are traditionally applied several times during the growing season to ensure that plant nutrient needs of crops are continuously met from planting through to harvest. It is common practice in Europe, for example, to apply fertilizers in three split applications. The first application fulfils between 40-50 percent of total crop demand. The second, applied several weeks later, meets 20-30 percent of demand, while a third and final application, several weeks before harvest, boosts the nutritional value of the crop.
However, the need to keep sufficient nutrients available throughout the growing season can mean these are quickly lost to the environment, as farmers tend to oversupply fertilizers to maximise their yields. The losses associated with this excessive fertilizer use often result in poor overall nutrient use efficiency.
Smart fertilizers, in contrast, behave very differently. These products are able to unlock and release nutrients to closely match the nutrient demands of the crop. In this way, nutrient release is attuned to crop needs, creating a perfect balance between nutrient supply and plant uptake, so preventing nutrient losses to the environment. Ideally, nutrient use efficiency is optimised by adjusting the nutrient release curve of the fertilizer so it corresponds exactly with the nutrient demand curve of the crop.
The smart solution: polymer coated urea
Controlled-release urea can be classed as a true ‘smart fertilizer’. It is produced by encasing the urea granule within a polymer coating. This acts like a membrane, sealing the urea from the surrounding soil environment. Over time, urea’s hygroscopic nature naturally attracts and draws in water through this membrane, where it dissolves part of the urea. A driving force then develops due to the high nitrogen concentration inside the membrane relative to the low concentration outside. As a consequence, nitrogen dissolved in water permeates outwards through the membrane into the soil, ready to be absorbed through the root system of the plant in an efficient and controlled manner (Figure 1).
This creates an almost perfect balance between crop needs and fertilizer supply, as nutrient release through the membrane is temperature dependent, and also depends on water availability. As a result, losses to the environment, whether to air or water, are prevented and maximum nutrient use efficiency is achieved.
PurActive™ technology
US-based Pursell Agri-Tech has developed a novel technology, registered as PurActive™ , for the production of polymer coated controlled-release fertilizers (CRFs). This new approach, by combining a novel polymer type with innovative coating technology, provides an economic solution to smart fertilizer production.
Stamicarbon, the nitrogen technology licensor of Maire engineering group, has taken a 20 percent stake in Pursell AgriTech. The mutually beneficial collaboration joins up Stamicarbon’s global network and technological capability with Pursell AgriTech’s leading expertise in coated fertilizers. This will enable both companies to pursue promising CRF market opportunities worldwide. Stamicarbon’s technology package called Controlled-Release Fertilizer Design™ is being offered to the market as a full ‘lump sum turn key’ project option.
At the heart of the Controlled-Release Fertilizer Design™ package is a modular coating plant. Its relatively low investment cost and a compact layout allows these coating plants to be easily constructed near to end-user markets.
Currently, the first commercial Controlled-Release Fertilizer Design™ reference plant operates on a 24 hours, five days a week basis in Sylacauga, Alabama. This first-of-its-kind US plant has the capacity to produce up to 100,000 t/a of controlled-release fertilizer and is operated by Stamicarbon’s partner Pursell Agri-Tech.
Previously, smaller scale coating plants capable of economically producing smart fertilizers for broad acre agriculture have simply not been available. However, the introduction of the Controlled-Release Fertilizer Design™ concept provides fertilizer producers and distributors with the ability to bring a new range of ‘smart’ products that improve crop fertilization to market. These act in one of two ways: either increasing crop yields at the same fertilizer application rate or achieving the same yields at a reduced rate. More generally, the wider adoption of CRFs helps reduce negative pressures on the environment by cutting nutrient losses to air and water.
Positive field trial results
Field trials conducted with polymer coated controlled-release urea (PCU 2.0) in different cropping systems, such as field corn, sweet corn and potatoes, have all shown that significant increases in nutrient use efficiency are achievable. A single application of controlled-release urea provides 5-10 percent higher yields, against a split application of conventional fertilizers, when applied at the same overall application rate. Alternatively, controlled-release urea provides similar crop yields when applied at 75-85 percent of the total application rate of conventional fertilizers.
Financial analysis also shows that targeting a higher yield at the same application rate permits a price premium of $150-800/t (depending on crop) for controlled-release urea, versus standard urea, whereas targeting a lower application rate for the same yield permits a premium of $60-110/t. These calculations exclude the additional labour and fuel savings provided by the single application of CRFs.
Overall, crop fertilization with CRFs offers the following benefits:
- Both ammonia volatilisation and nitrate leaching losses are negligible
- Steadily releases nutrients over the whole 3-4 month growing season
- Makes nearly all of the nutrients supplied available to the crop
- Reduces costs through a single application in the spring that eliminates the need for a summer side dress.
Stamicarbon’s Vision 2030
By improving the nutrient use efficiency (NUE) of fertilizers, Stamicarbon’s Controlled-Release Fertilizer Design™ package will help deliver one of the two goals set out in its ‘Vision 2030’ innovation agenda. The agenda’s other goal is to reduce the emissions and energy consumption of fertilizer plants. Stamicarbon is aiming to achieve both goals by focusing on three specific areas:
- Making fertilizers more effective and efficient by increasing their NUE
- Shift to the sustainable production of nitrogen-based fertilizers from renewable feedstocks using renewable energy
- Rolling out the digitalisation of fertilizer plants to improve their energy consumption and reduce emissions.
ICL
New biodegradable coating technology
ICL has developed a new generation of biodegradable coatings for its controlledrelease fertilizer (CRF) portfolio (Fertilizer International 510, p24). The new coating technology is designed to meet the requirements of the new EU fertilising products regulation (2019/1009) and reduce the environmental footprint of CRFs. It will also help Europe’s farmers comply with the EU’s Green Deal policy.
This patented innovation, named eqo.x, coats nitrogen fertilizer granules applied to field grown crops. The technology has already been fully tested in the field – and shown excellent results in terms of ease of production, nutrient use efficiency, and reducing volatilisation and leaching losses.
According to ICL, eqo.x is one of the most important innovations and technological launches since CRFs were first introduced to the market decades ago.
“We see this as a huge step forward in the use of enhanced efficiency fertilizers for the agricultural market,” comments Ronald Clemens, ICLs Global Marketing & Portfolio Manager CRF. “The biodegradable release technology will be able to reduce all kinds of nutrient losses, and combines this with all the known advantages of CRFs, such as reduced application frequency and application rates.”
Clemens explains how the new biodegradable coating functions (Figure 1):
“Eqo.x works similar to our existing coatings. The soil temperature affects the speed of release in a similar way to E-Max coatings. That makes it easy for the farmer to use the new product, as neither the application or the performance will change.
“The new technology offers an improvement in release patterns, making CRFs with eqo.x technology even more reliable and predictable than before. And after the longevity ends, the coating shells will degrade even faster to CO2 and water, leaving no trace behind.”
Wide ranging trials with eqo.x technology have all shown an increase in nutrient use efficiency, says Clemens:
“We have tested the release specifications in the lab under various temperature regimes, in water and in soil as well as under practical circumstances. In all those conditions, the nutrient use efficiency was significantly increased, giving better results than growers practice – in terms of yield, number of applications or application rates.”
ICL has already introduced eqo.x technology to the market in its Agrocote and Agromaster CRF formulations.
