Periodic Reporting for period 1 - ALGWAS-BIOR (Sustainable Valorization Of The Algae Industry Waste-Stream Within An Advanced Clean Technologies-Based Integrated Biorefinery Concept)
Reporting period: 2021-01-21 to 2024-01-20
The objective of the ALGWAS-BIOR project is to demonstrate the feasibility of transforming the food industry waste stream into high-value biobased products by utilizing the concept of biorefining based on emerging green technologies. The project is designed to promote green processes in sustainable food processing by reusing and valorizing the waste stream into value-added, marketable products. It aims to enhance the sustainability of integrated cascade biorefineries.
The ALGWAS-BIOR project proposes to implement efficient and sustainable processes for large-scale production of bioactive molecules for a wide range of applications, including food ingredients, biobased materials, food packaging, pharmaceuticals, cosmetics, and the chemical industry. It also aims to investigate and optimize the relationship between operating procedures and the structure, functionalities, and mechanisms related to the industrial waste stream´s hydrolysis, bioconversion, and catalytic nanosizing of the
Subcritical water, also known as pressurized hot water, was the principal green technology used in the design of the biorefining process. This technology was supplemented with other technologies, including ultrasounds, high-pressure homogenization, high-pressure microfluidization, and green nanotechnologies. The targeted bioproducts, including agar, polyphenols, proteins, cellulose, and nanocelluloses, were efficiently obtained through a cascade integrated green processing supported by sustainable technology and green chemistry. By valorizing these bioproducts present in the food industry waste stream, which have the advantage of being biologically active molecules, the project significantly contributes to reducing total CO2 emissions in the food manufacturing and supply chain.
The ALGWAS-BIOR project proposes to implement efficient and sustainable processes for large-scale production of bioactive molecules for a wide range of applications, including food ingredients, biobased materials, food packaging, pharmaceuticals, cosmetics, and the chemical industry. It also aims to investigate and optimize the relationship between operating procedures and the structure, functionalities, and mechanisms related to the industrial waste stream´s hydrolysis, bioconversion, and catalytic nanosizing of the
Subcritical water, also known as pressurized hot water, was the principal green technology used in the design of the biorefining process. This technology was supplemented with other technologies, including ultrasounds, high-pressure homogenization, high-pressure microfluidization, and green nanotechnologies. The targeted bioproducts, including agar, polyphenols, proteins, cellulose, and nanocelluloses, were efficiently obtained through a cascade integrated green processing supported by sustainable technology and green chemistry. By valorizing these bioproducts present in the food industry waste stream, which have the advantage of being biologically active molecules, the project significantly contributes to reducing total CO2 emissions in the food manufacturing and supply chain.
Among existing green technologies, subcritical water was utilized as the primary tool for valorizing the algae industry waste stream. Using optimization principles, the key operating parameters to achieve maximum efficiency and reproducibility were systematically evaluated and refined. The primary focus was on extracting residual crude agar from the algae industry waste stream by varying key operating conditions such as temperature, pressure, extraction time, and the ratio of algae to water.
The use of subcritical water hydrolysis reduced the environmental impact by substituting hazardous chemicals with water. It is widely available, cost-effective, recyclable, and capable of significantly reducing downstream processing costs by eliminating harmful organic solvents from the final product. Optimizing the cascade biorefining concept indirectly considered the impact of water at subcritical conditions on product yield, properties, texture, and purity, while also minimizing environmental impact.
Conducting pilot-scale experiments was crucial to validating the feasibility and performance of the optimized process under real-world conditions. This approach enabled the monitoring of key performance indicators (KPIs) such as product yield, energy consumption, and process stability.
The ALGWAS-BIOR project has primarily identified potential environmentally friendly substitutes for hazardous chemicals, with a preference given to water as the most environmentally benign solvent. By promoting conditions that minimize water usage in subcritical formulations by increasing solid-to-liquid ratios up to 10%, higher extraction efficiency was ensured. Statistical analysis also confirmed a negative relationship between the severity factor (time and temperature-dependent) and the agar gel texture parameters. Under optimal recovery conditions, the recovered agar exhibited typical texture characteristics, with desirable parameters, such as hardness, adhesiveness, cohesiveness, springiness, and gumminess.
Mild extraction conditions enabled the recovery of the majority of residual agar without significantly affecting other functional molecules such as lignocellulose, proteins, antioxidants, polyphenols, and minerals. In the context of circular economy and industrial symbiosis, two concepts promoted by the ALGWAS-BIOR project, subcritical water extraction selectively targets molecules, facilitating a full cascade biorefining process of algae waste.
The sustainable applications of the recovered agar have been investigated with the design of bilayered composite films made of a first layer of agar/chitosan and a second layer of citric acid-crosslinked agar/polyvinyl alcohol (PVA) using an efficient layer-by-layer casting technique.
Additionally, various high-pressure processing technologies in combination, including subcritical water, high-pressure homogenizers, and high-pressure microfluidizers, have been explored in green nanotechnology. Their synergistic action has significantly improved conversion efficiency in terms of cost, energy efficiency, and thermal stability of products.
The ALGWAS-BIOR project has established a process and engineering design through the comprehensive development of process flow diagrams (PFDs) and piping and instrumentation diagrams (P&IDs).
The use of subcritical water hydrolysis reduced the environmental impact by substituting hazardous chemicals with water. It is widely available, cost-effective, recyclable, and capable of significantly reducing downstream processing costs by eliminating harmful organic solvents from the final product. Optimizing the cascade biorefining concept indirectly considered the impact of water at subcritical conditions on product yield, properties, texture, and purity, while also minimizing environmental impact.
Conducting pilot-scale experiments was crucial to validating the feasibility and performance of the optimized process under real-world conditions. This approach enabled the monitoring of key performance indicators (KPIs) such as product yield, energy consumption, and process stability.
The ALGWAS-BIOR project has primarily identified potential environmentally friendly substitutes for hazardous chemicals, with a preference given to water as the most environmentally benign solvent. By promoting conditions that minimize water usage in subcritical formulations by increasing solid-to-liquid ratios up to 10%, higher extraction efficiency was ensured. Statistical analysis also confirmed a negative relationship between the severity factor (time and temperature-dependent) and the agar gel texture parameters. Under optimal recovery conditions, the recovered agar exhibited typical texture characteristics, with desirable parameters, such as hardness, adhesiveness, cohesiveness, springiness, and gumminess.
Mild extraction conditions enabled the recovery of the majority of residual agar without significantly affecting other functional molecules such as lignocellulose, proteins, antioxidants, polyphenols, and minerals. In the context of circular economy and industrial symbiosis, two concepts promoted by the ALGWAS-BIOR project, subcritical water extraction selectively targets molecules, facilitating a full cascade biorefining process of algae waste.
The sustainable applications of the recovered agar have been investigated with the design of bilayered composite films made of a first layer of agar/chitosan and a second layer of citric acid-crosslinked agar/polyvinyl alcohol (PVA) using an efficient layer-by-layer casting technique.
Additionally, various high-pressure processing technologies in combination, including subcritical water, high-pressure homogenizers, and high-pressure microfluidizers, have been explored in green nanotechnology. Their synergistic action has significantly improved conversion efficiency in terms of cost, energy efficiency, and thermal stability of products.
The ALGWAS-BIOR project has established a process and engineering design through the comprehensive development of process flow diagrams (PFDs) and piping and instrumentation diagrams (P&IDs).
The ALGWAS-BIOR project provided significant advancements in the design and implementation of sustainable manufacturing solutions based on the use of green technologies. Among the green technologies used, subcritical water was the primary method for the sequential isolation of value-added compounds and ingredients for a wide range of applications, including the food industry, sustainable food packaging, the cosmetic sector, material sciences, the pharmaceutical industry, functional food, and nutraceuticals. These compounds, which included residual agar, proteins, polyphenols, and molecules with antioxidant potentials, are biologically active and possess interesting technological functionalities.
Subcritical water processing, was complemented by distinct high-pressure technologies such as high-pressure homogenization and microfluidization, to develop a viable integrated biorefining concept. In addition to the operating temperature, adjusting process parameters in subcritical water not only allowed a selective and complete recovery of the residual phycocolloid but also conferred on it a wide range of physicochemical properties and gel textures. Simultaneously, the primary extraction of the hydrocolloids under mild conditions improved the cascading mechanism of the biorefining and drastically improved the recovery of a high yield of functional intermediate compounds. The incorporation of green nanotechnology resulted in the valorization of the fiber-rich residue at the end of the extraction route. Testing the use of maleic acid as an eco-catalyst, recoverable and reusable at the end of the process in place of strong mineral acids in green nanotechnology allowed for the completion of the valorization process. Integrated processes led to the production of value-added cellulose nanocrystals and cellulose nanofibrils with higher thermal stability. Progress has been made in the establishment of process-properties relationships, allowing for the assessment of the physicochemical and structural changes towards high-pressure chemical treatments and physical conversion. Scaling up the subcritical water process using a pilot-scale automated continuous reactor represents a breakthrough that allowed for the validation of the designed biorefining process connected to food industry waste stream sustainable management and a closed-loop bioeconomy.
Subcritical water processing, was complemented by distinct high-pressure technologies such as high-pressure homogenization and microfluidization, to develop a viable integrated biorefining concept. In addition to the operating temperature, adjusting process parameters in subcritical water not only allowed a selective and complete recovery of the residual phycocolloid but also conferred on it a wide range of physicochemical properties and gel textures. Simultaneously, the primary extraction of the hydrocolloids under mild conditions improved the cascading mechanism of the biorefining and drastically improved the recovery of a high yield of functional intermediate compounds. The incorporation of green nanotechnology resulted in the valorization of the fiber-rich residue at the end of the extraction route. Testing the use of maleic acid as an eco-catalyst, recoverable and reusable at the end of the process in place of strong mineral acids in green nanotechnology allowed for the completion of the valorization process. Integrated processes led to the production of value-added cellulose nanocrystals and cellulose nanofibrils with higher thermal stability. Progress has been made in the establishment of process-properties relationships, allowing for the assessment of the physicochemical and structural changes towards high-pressure chemical treatments and physical conversion. Scaling up the subcritical water process using a pilot-scale automated continuous reactor represents a breakthrough that allowed for the validation of the designed biorefining process connected to food industry waste stream sustainable management and a closed-loop bioeconomy.