Hydrodynamic disintegration for feedstock valorization - enhancing methane production and sustainable nutrient recovery in agricultural biogas plants.

This study investigates the impact of hydrodynamic disintegration (HD) on the valorization of diverse organic feedstocks for agricultural biogas plants. The study included a comprehensive evaluation of the effects of HD on various agricultural and industrial by-products, including cattle and swine slurry, distillery residue, maize silage, sugar beet pulp (in both loose and pelletized forms), and fruit residues. Disintegration tests were conducted under identical energy density conditions (35-210 kJ/L) to assess changes in the release of organic and nutrient compounds, and the impact on anaerobic digestion performance (BMP tests). HD significantly enhanced the solubilization of organic matter, nitrogen, and phosphorus for several substrates, particularly sugar beet pulp and maize silage. In contrast, increases in soluble organic compounds were relatively modest for cattle and swine slurry. The effect of HD on methane yield was substrate and energy density-dependent: for cattle slurry, low-energy HD (10-35 kJ/L) increased methane potential by 4.1-6.8%, whereas for swine slurry, HD reduced methane yield by up to 30% for higher energy densities (140 kJ/L). Importantly, HD accelerated anaerobic digestion, shortening digestion time by approximately 3 days for cattle slurry and up to 8 days for swine slurry at 140 kJ/L. These findings highlight the need to optimize HD parameters based on substrate characteristics and intended valorization goals (energy production vs. nutrient recovery). HD represents a promising technology for enhancing both renewable energy generation and nutrient recovery in sustainable agriculture; however, optimization of the disintegration process is critical to maximizing benefits while avoiding potential negative effects on biogas plant performance.