Green extraction is one of the promising innovation themes that could strongly contribute to sustainable growth of the French economy especially in perfume, cosmetic, food ingerdients, fine chemicals and pharmaceutical industries. Extraction is one of the key technologies of the process industry, often requiring up to 50% of investments in a new plant and more than 70% of total process energy used. Existing extraction technologies have considerable technological and scientific bottlenecks to overcome : (1) to drastically (up to 75%) reduce energy consumption of extraction processes ; (2) to meet the more and more stringent legal requirements on emissions by discovering alternatives to  petroleum solvents; (3) for cost reduction and increased quality as well as functionality to stay competitive on a global basis. This project will resolve these barriers not only at a scientific level, but also at technology, basic hardware, and development levels.

Green extraction of natural products: concepts, principles, and applications. Its place between "green chemistry” and “Green processing”. Its position in the global chain "from plant to molecule" with crushing and drying, solid / liquid extraction, distillation, separation, purification and organic synthesis. Development of extraction processes "solvent free" using clean processes such as microwave involving new thermal phenomena that can intensify mass transfer phenomena. Understanding Fick and Darcy laws allows other applications such as “microwave hydrodiffusion and gravity”, process patented and commercialized. The agrosolvents as an alternative to petroleum solvents in the extraction of natural products. Understanding the solubility parameters will anticipate REACH over potential elimination of petroleum solvents such as: hexane, dichloromethane ... Study of degradation pathways of molecules extracted from natural products.

Definition of Green Extraction

A general definition of green chemistry is the invention, design and application of chemical products and processes to reduce or to eliminate the use and generation of hazardous substances. In relation to green extraction of natural products, this definition can be modified as follows: “Green Extraction is based on the discovery and design of extraction processes which will reduce energy consumption, allows use of alternative solvents and renewable natural products, and ensure a safe and high quality extract/product”.

Three major solutions have been identified to design and demonstrate green extraction on laboratory and industrial scale to approach an optimal consumption of raw materials, solvents and energy: (1) improving and optimisation of existing processes; (2) using non-dedicated equipment; and (3) innovation in processes and procedures but also in discovering alternative solvents.

The Six Principles of Green Extraction

The listing of the “six principles of Green Extraction of Natural Products” should be viewed for industry and scientists as a direction to establish an innovative and green label, charter and standard, and as a reflection to innovate not only in process but in all aspects of solid-liquid extraction (Figure 1). The principles have been identified and described not as rules but more as innovative examples to follow, discovered by scientists and successfully applied by industry.

Principle 1: Innovation by selection of varieties and use of renewable plant resources.

Principle 2: Use of alternative solvents and principally water or agro-solvents.

Principle 3: Reduce energy consumption by energy recovery and using innovative technologies.

Principle 4: Production of co-products instead of waste to include the bio- and agro-refining industry.

Principle 5: Reduce unit operations and favour safe, robust and controlled processes.

Principle 6: Aim for a non denatured and biodegradable extract without contaminants.

The Green Research Axes are structured as follows:

• Define eco-extraction and find its place between "green" chemistry, "intensified" processes and "sustainable" development
• Development of "clean" extraction processes using innovative technologies, microwaves and ultrasound, involving original phenomena that can intensify material or heat transfer phenomena.
• Substitute alternative solvents for petroleum solvents, both in terms of efficiency and chemical degradation, selectivity and environmental impact.
• Understand and model extraction. Development of a prediction tool (solute/solvent interactions) for a given raw material and target molecule, assigning them a solvent and an optimum process.

Origin, definition and principles of Eco Extraction

In 2010, discussions, led by working groups composed of researchers and professionals in the field of natural product extraction, made it possible to define eco-extraction and its principles. A very general definition has been adopted: "Eco-Extraction is based on the discovery and design of extraction processes that reduce energy consumption, but also the use of alternative solvents to eliminate petroleum solvents and a renewable and innovative plant resource".

These workshops made it possible to list expectations but also to consider future visions, in a context of sustainable development, both at the level of producers of plant raw materials and industrial processors or formulators of finished products or academic and institutional researchers. The main conclusion of these working groups was to identify a key concept: "eco-extract" that directly affects consumers far beyond eco-extraction. Work is being carried out on the reflection of a specific "eco-extract" label but also on the assessment of its environmental impact using Life Cycle Assessment.

The Team

Maryline Abert-Vian (MC HDR), Farid Chemat (PR), Anne-Sylvie Fabiano-Tixier (MC HDR), Emmanuel Petitcolas (AI), Sandrine Périno (MC HDR), Karine Ruiz-Roble (IE)

PhD students :  Ombéline Claux, Christian Cravotto, Léo Lajoie, Sarah Madji, Amandine Rousset

Post-doc, contract : Catherine Caillet, Pierre Daniel, Nazifa Faqeryar, Boutheina Khadhraoui, Jean-Baptiste Mazzitelli

Collaborations in France

UMR UNS/CNRS 6001, Université de Nice, LBE INRA Narbonne

Collaborations (International)

Université de Pharmacie, Turin (Italie)