Biomass comes from renewable organic matter (plants, trees, agricultural residues, organic waste) that renews itself over a period of months or years. Fossil fuels come from ancient organisms that have been transformed over millions of years. The use of biomass can be more sustainable: it contributes to a shorter carbon cycle, whereas fossil fuels release carbon that has been stored for millions of years.

Carbon is the basis of all living molecules (sugars, lipids, proteins, etc.). In industry, this carbon serves as a building block for manufacturing products such as fuels, plastics and materials. This is also why petroleum, which is very rich in carbon of ancient biological origin, has served as the basis for the modern chemical industry.

The carbon in petroleum has been stored in the ground for millions of years: when we use it, we release ‘new’ CO₂ into the atmosphere, which adds to the existing stock. Conversely, plants contain carbon that has recently been captured from the air and which, through photosynthesis, enables them to produce molecules such as sugars and amino acids, which are the building blocks of proteins and lipids. When these molecules are used, the carbon is re-emitted, but it remains in a short cycle: absorption by plants → transformation → emission → re-absorption, and the cycle can begin again.

Thus, by replacing fossil resources with renewable biological resources, we can reduce the carbon footprint of materials and energy while preserving the balance of the carbon cycle.

Biotechnology uses living organisms or their components (enzymes, cells, etc.) to create or transform products. It draws on many disciplines such as biochemistry, genetics, molecular biology and microbiology.

It has been used by humankind for a long time: the fermentation of bread, wine, beer and yoghurt is already a form of biotechnology. What has changed today is that we have a much better understanding of how living organisms work, particularly thanks to genetics. Scientists can control microorganisms to perform specific tasks or improve their performance. Biotechnology enables the development of cleaner and more energy-efficient industrial processes.

It is used in many sectors:

• Food: production of lactose-free milk, improvement of food texture, etc.
• Health: production of antibiotics (penicillin from the fungus Penicillium), insulin produced by modified bacteria, vaccines, cell therapy, etc.
• Environment: wastewater treatment, soil decontamination, etc.
• Agriculture: genetically modified plants to be disease resistant, etc.
• Industry: paper manufacturing, production of bio-detergents, manufacture of molecules for fine chemicals, etc.
• Energy: production of bioethanol from microalgae grown in bioreactors or from lignocellulosic biomass, etc.

The main techniques used in the various fields include:

• Fermentation: use of microorganisms to transform substrates into useful products.
• Animal, plant or microbial cell cultures.
• Genetic engineering: modification of genetic material to add, remove or modify genes.
• Enzymatic processes: using enzymes to catalyse reactions.

They are found in textiles, building materials (wood, plant-based insulation), packaging, certain bioplastics (bottles, car parts), cosmetics, paints, household products, pharmaceuticals and biofuels.

Bio-based products, also known as bioproducts, are derived from materials of biological origin, but this does not guarantee that they are biodegradable. Unlike raw organic materials such as peelings, these products have undergone chemical transformations that can prevent their natural degradation. Their biodegradability depends on their chemical composition and how they are manufactured.

A bioplastic such as PLA (polylactic acid) is biodegradable under industrial conditions (controlled temperature and humidity). Other plastics, such as bio-based PET, are made from biomass but have the same structure as conventional PET and do not degrade naturally.

It should be noted that biodegradability does not necessarily depend on whether a product is petroleum-based or bio-based. A product can be derived from petroleum and still be easily broken down by microorganisms if its chemical structure allows it. Conversely, a product can be natural and take several years to degrade (e.g. wood or natural rubber).

These are therefore two distinct concepts: ‘bio-based’ refers to the origin of the product, while ‘biodegradable’ refers to the end of the product's life.

Yes, biofuels emit greenhouse gases when burned. However, their impact can be reduced by the fact that the plants used for biofuels have captured CO₂ during their growth. Thus, over their entire life cycle, emissions are offset by carbon absorption: this is known as ‘net zero emissions’.

However, the carbon footprint also depends on production practices. If the biomass comes from deforestation or requires high energy consumption, the carbon footprint can be as bad as, or even worse than, that of fossil fuels. It is therefore necessary to take into account the entire life cycle, from production to use.

Yes, biomass for the manufacture of bio-based products can compete with other uses: food production, forest management, water availability and biodiversity conservation. To avoid these conflicts of use, it is important to prioritise sustainable resources, such as inedible agricultural residues, non-food crops and organic waste, and to establish a clear regulatory framework.

In France, the National Biomass Mobilisation Strategy (2018) established an order of priority for the use of biomass:

• food (first for humans, then for animals),
• biofertilisation (i.e. returning crop residues to the soil to maintain fertility),
• the manufacture of bio-based materials and products,
• energy production (gas, heat, electricity).

This order aims to ensure the responsible use of biological resources and promote a sustainable bioeconomy.

For a bio-based product to be sustainable, it must be assessed throughout its entire life cycle: from biomass production to manufacturing, use and end of life (reuse, recycling, composting or biodegradation).

Several points to bear in mind:

• The method of biomass production: Agricultural practices may require inputs (fertilisers, pesticides) that deplete the soil, pollute the water and harm biodiversity. They also consume water and energy, sometimes fossil fuels, which can increase the carbon footprint.
• Impacts related to land use change: Changing the use of land from one type to another (forest, agricultural land, grassland, etc.) can affect greenhouse gas emissions and biodiversity. There are two types of change:
  • Direct changes: for example, a forest is cleared to plant maize for bioethanol production → release of carbon stored in the soil and vegetation, loss of biodiversity. The impact can also be positive if degraded land is converted to cultivated land.
  • Indirect changes: the production of a crop for a new use displaces food production elsewhere, causing agricultural expansion onto other land and therefore new emissions.
• Manufacturing processes: Optimising energy and water use, limiting the use of toxic products, limiting waste or recovering co-products, etc.
• End of product life: The end of life must be considered from the design stage onwards in order to reduce impacts and minimise waste.
• Socio-economic impacts: Excessive demand for biomass can lead to competition with food and increase the price of certain agricultural raw materials. In addition, the development of the bio-based products sector has an impact on the region through the creation of industrial facilities, waste production and local nuisances, but it also enables the development of new non-relocatable jobs and provides additional income for farmers.

In summary, for a bio-based product to be sustainable, it requires a well-managed renewable resource, an optimised transformation process and a controlled end of life.

There are several definitions that have evolved over time, but a simple definition can be given: the bioeconomy refers to all activities that produce, use or valorise biological resources (plants, microorganisms, organic waste) to create goods and services, in a sustainable and circular manner.

It is developing mainly at local and regional level, in order to use nearby resources, reduce the carbon footprint associated with transport and create local supply chains. This limits dependence on imported materials and therefore contributes to a country's sovereignty.

Citizens can support the bioeconomy by choosing bio-based products, sorting organic waste and staying informed. Decision-makers can create favourable policies, fund research, encourage local industries and promote ambitious environmental standards.