Biodegradable pha-based controlled-release fertiliser coatings

Overview

Biodegradable PHA-based coatings offer a revolutionary solution for controlled-release fertilisers, significantly enhancing nutrient use efficiency (NUE) in agriculture. By leveraging the water barrier properties of Polyhydroxyalkanoates (PHAs), these coatings ensure a prolonged release of nutrients, reducing the frequency of fertiliser application and minimizing environmental impact. This technology is ideal for eco-friendly agricultural practices, promoting sustainability.

Technical specifications

Coating Methods:

• Green Solvent Spray Coating: Utilizes PHA dissolved in eco-friendly solvents, applied to urea granules via spray coating in a fluidised bed. Produces thin coatings (~5wt%) with nutrient release extending beyond 50 days.
• Reactive Layer Coating (RLC): Forms PHA-based polyurethane coatings by reacting PHA polyols with isocyanates on fertiliser beds, offering a solvent-free alternative.

Development Focus:

• Optimization of PHA type, solvent choice, and fluidised bed parameters
• Investigation of PHA polyol chain length, isocyanate type, and layering strategies
• Exploration of dual-function biopolymer layering to adjust release and biodegradation rates

Technology readiness level

Currently at TRL 4, this technology has demonstrated feasibility in laboratory settings with preliminary successful tests. The project aims to further validate through extended water release testing and cost analysis over a 12-month period, supported by sponsored research partnerships.