Periodic Reporting for period 1 - ELLIPSE (EFFICIENT AND NOVEL WASTE STREAMS CO-PROCESSING TO OBTAIN BIO-BASED SOLUTIONS FOR PACKAGING AND AGRICULTURAL SECTORS)
Reporting period: 2023-05-01 to 2024-10-31
The main objective of ELLIPSE is the valorisation of two heterogeneous waste streams produced in significant amounts in Europe (13,8 MTon/year of paper sludge and 53,9 slaughterhouse waste MTon/year) to produce cost-efficient PHBV for agricultural and personal care applications, by the coprocessing with other organic wastes such as sludge from the dairy industry and glycerol from the biodiesel industry. During the project, PHBV is formulated in materials which are then transformed in packaging (paper coating and rigid packaging) and agricultural applications (mulching film and coated fertilizers), where its characteristics (biodegradability, higher elasticity and better processability than PHB) make it a perfect substitute for traditional fossil plastics, thus reducing the environmental impact.
The following objectives are addressed during the project:
• To apply effective pre-treatments for heterogeneous paper and slaughterhouse waste.
• To improve the yield of VFA production in acidogenic fermentation.
• To obtain PHBV copolymers through efficient and sustainable processes.
• To recover nutrients (nitrogen and phosphorous) to be used as bio-based fertilizers.
• To produce prototypes for personal care and agricultural applications.
• To validate enzymatic and chemical recycling to recover monomers that will be reincorporated into the production process.
The following objectives are addressed during the project:
• To apply effective pre-treatments for heterogeneous paper and slaughterhouse waste.
• To improve the yield of VFA production in acidogenic fermentation.
• To obtain PHBV copolymers through efficient and sustainable processes.
• To recover nutrients (nitrogen and phosphorous) to be used as bio-based fertilizers.
• To produce prototypes for personal care and agricultural applications.
• To validate enzymatic and chemical recycling to recover monomers that will be reincorporated into the production process.
This comprehensive work has advanced the optimization of VFA production, PHA synthesis, nutrient recovery, and environmental sustainability:
Characterization and Pretreatment: 14 residues from the pulp and paper industry, along with slaughterhouse waste, glycerol, and dairy sludge, were characterized. Physical and chemical pretreatments were tested, with alkaline pH (10) yielding higher volatile fatty acid (VFA) concentrations. Codigestion trials demonstrated optimal VFA production at a 4:1 substrate-to-inoculum ratio, achieving up to 20 g/L of VFAs.
Fermentation and Process Optimization: Semi-continuous processes showed improved VFA production. Fe(0) nanoparticles did not significantly impact results. VFA concentration was improved using membrane filtration and reverse osmosis.
Reactor Operations: A 1 m³ reactor and pilot systems were successfully operated, with VFA concentrations of 5–6 g/L achieved.
Bacterial Strain Screening: Two strains were identified as optimal for polyhydroxyalkanoate (PHA) production, showing robustness and high productivity in bioreactors. Biopolymers produced complied with specifications for further applications.
Innovative Fertilizers and Algal Cultivation: PHAs were used in fertilizer coatings with tunable release kinetics. A hybrid microalgae cultivation system achieved significant nutrient recovery and biomass production, making algal biomass suitable for agricultural applications.
Digestate Treatment and Nutrient Recovery: Digestate was processed via mechanical separation, ultrafiltration, and reverse osmosis, optimizing nutrient recovery and reducing energy consumption. Ammonium sulfate was recovered and utilized in trials.
Process Modelling and Life Cycle Assessment (LCA): Process modelling for VFA production was conducted, analyzing cost, energy use, and environmental impact. LCA identified electricity consumption as the primary contributor to environmental impacts. Social LCA highlighted tailored stakeholder engagement strategies.
Characterization and Pretreatment: 14 residues from the pulp and paper industry, along with slaughterhouse waste, glycerol, and dairy sludge, were characterized. Physical and chemical pretreatments were tested, with alkaline pH (10) yielding higher volatile fatty acid (VFA) concentrations. Codigestion trials demonstrated optimal VFA production at a 4:1 substrate-to-inoculum ratio, achieving up to 20 g/L of VFAs.
Fermentation and Process Optimization: Semi-continuous processes showed improved VFA production. Fe(0) nanoparticles did not significantly impact results. VFA concentration was improved using membrane filtration and reverse osmosis.
Reactor Operations: A 1 m³ reactor and pilot systems were successfully operated, with VFA concentrations of 5–6 g/L achieved.
Bacterial Strain Screening: Two strains were identified as optimal for polyhydroxyalkanoate (PHA) production, showing robustness and high productivity in bioreactors. Biopolymers produced complied with specifications for further applications.
Innovative Fertilizers and Algal Cultivation: PHAs were used in fertilizer coatings with tunable release kinetics. A hybrid microalgae cultivation system achieved significant nutrient recovery and biomass production, making algal biomass suitable for agricultural applications.
Digestate Treatment and Nutrient Recovery: Digestate was processed via mechanical separation, ultrafiltration, and reverse osmosis, optimizing nutrient recovery and reducing energy consumption. Ammonium sulfate was recovered and utilized in trials.
Process Modelling and Life Cycle Assessment (LCA): Process modelling for VFA production was conducted, analyzing cost, energy use, and environmental impact. LCA identified electricity consumption as the primary contributor to environmental impacts. Social LCA highlighted tailored stakeholder engagement strategies.
Anaerobic Digestion for VFA Production: A semi-continuous process with a 4:1 S/I ratio and pH 10 produced up to 20 g/L of VFAs from bellygrass and glycerol (1:1). A 30 L anaerobic membrane bioreactor (AnMBR) is enhancing VFA yield and quality by combining acidogenic fermentation and membrane separation.
Pilot Plant Operations: A 1 m³ anaerobic digestion plant for pulp and paper waste has been operational at BEST GmbH since 2004, and another at Green Generation is conducting trials with bellygrass and glycerol.
Biopolymer Production: Two robust bacterial strains were isolated, capable of converting VFAs into PHBV with HV content exceeding 10%, meeting mechanical property standards. Fed-batch fermentation achieved high cell density and polymer accumulation.
Fertilizer Encapsulation: Fertilizers were successfully encapsulated using extrusion compounding and coating, utilizing ammonium sulfate recovered from digestate.
Nutrient Recovery and Algal Cultivation: A hybrid microalgae cultivation system achieved nutrient reductions of 85% in nitrogen, 92% in phosphorus, and 85% in COD. Nutrient recovery via ultrafiltration and reverse osmosis achieved high yields and efficient water recovery.
Pilot Plant Operations: A 1 m³ anaerobic digestion plant for pulp and paper waste has been operational at BEST GmbH since 2004, and another at Green Generation is conducting trials with bellygrass and glycerol.
Biopolymer Production: Two robust bacterial strains were isolated, capable of converting VFAs into PHBV with HV content exceeding 10%, meeting mechanical property standards. Fed-batch fermentation achieved high cell density and polymer accumulation.
Fertilizer Encapsulation: Fertilizers were successfully encapsulated using extrusion compounding and coating, utilizing ammonium sulfate recovered from digestate.
Nutrient Recovery and Algal Cultivation: A hybrid microalgae cultivation system achieved nutrient reductions of 85% in nitrogen, 92% in phosphorus, and 85% in COD. Nutrient recovery via ultrafiltration and reverse osmosis achieved high yields and efficient water recovery.