Draft:Defossilization

Defossilization is a term that often comes up in connection with the development of sustainable chemistry of the future. Defossilization means the substituion of fossil carbon sources, such as crude oil, natural gas and coal, by stocks which are renewable, including biogenic raw materials, recyclates, and atmospheric carbon dioxide for the manufacturing of organic chemicals including plastics. They do not increase the net amount of CO2 in the atmosphere and therefore do not exacerbate the greenhouse effect or climate change.

Meaning
Defossilization refers to the transition from the use of fossil carbon-containing raw materials such as coal, oil and natural gas to the use of renewable and sustainable carbon compounds. Defossilization describes the process of reducing and ultimately eliminating dependence on fossil fuels as a feedstock for the production of organic substances and materials, especially plastics. This process is crucial to limiting global warming and mitigating the effects of climate change, as the CO2 in defossilized materials is in a cycle and the concentration in the atmosphere does not increase any further. A successful transition requires not only a reduction in the use of fossil raw materials, but also a fundamental transformation of economic and energy infrastructures. This is because the measures for defossilization are often more cost-intensive than the unsustainable solutions used to date and in some cases also involve a high energy input. For this reason, the three basic strategies of the green economy (efficiency, consistency, sufficiency) should nevertheless be observed and implemented.

For example, there are already signs of bottlenecks in the availability of hydrogen, which forms the basis for the starting materials (methane, methanol) of many defossilized products.

A basic distinction is made between three sources of defossilized materials :


 * Carbon dioxide capture and utilization, where carbon dioxide from the atmosphere as well as from waste gas streams can be considered;
 * Biogenic materials and
 * Recovery, such as solvent or plastic recycling.

Etymology
The term is modelled on decarbonization in order to delineate those industrial sectors that cannot be decarbonized because they are based on chemical compounds of carbon.

Examples
There are many technologies for defossilization. Carbon capture and utilization (CCU), which provides the required raw material CO2, serves as the basis in many processes. This CO2 can then be used, for example, in methanation or methanolization, which in turn can serve as starting materials for e-fuels, chemicals and active pharmaceutical ingredients. Many defossilized substances also consist of biobased materials, such as packaging materials made from fungi or algae, or they use biological raw materials as starting materials, for example for bio-based plastics.

In some cases, biological waste streams are used (so-called second generation feedstock), which turns this waste back into raw materials and thus assigns them a value, leading to a more complete circular economy.

Chemical recycling is also included in defossilization, as this measure can be used to substitute new fossil oil in the production of plastics.

Difference to decarbonization
Defossilization and decarbonization are important terms in the climate debate, but they are often mistakenly used interchangeably, even though they represent different concepts. However, they complement each other and are both crucial in the fight against climate change.

Defossilization: defossilization means that carbon-containing products are still used, but the carbon comes from sustainable and renewable sources and no longer from fossil sources. When this material is disposed of (e.g. by incineration), CO2 may still be produced, but no more than what was used in the production of the material. This results in a CO2 or carbon cycle, which ultimately keeps the CO2 concentration in the atmosphere the same.

Decarbonization: The aim of decarbonization is to replace previously carbon-based technologies with carbon-free technologies. For example, through the electrification of processes or the use of hydrogen. As carbon is no longer used in this case, there is no risk of climate-damaging CO2 being produced.

Defossilization should only be used if decarbonization is not possible, as decarbonization is usually more energy-efficient and therefore cheaper than defossilization. For example, if a car is powered by e-fuels (defossilization), which are produced from renewable electricity, 75% of the energy stored in the fuel is converted into heat during combustion in the engine. However, if the car is operated electrically (decarbonization) and refueled directly with renewable electricity, only 20% of the energy is converted into heat and 80% can be used for locomotion

Areas of application
Defossilization is used where carbon cannot be replaced in the product and therefore decarbonization cannot be used. For example, in the case of active pharmaceutical ingredients, which are made up of molecules, which in turn consist largely of carbon atoms. These carbon atoms cannot be replaced, as otherwise it would be a completely different substance with fundamentally different properties. Chemistry sets limits in this case.

The same applies to those plastics that must continue to be used due to their specific properties, for example in vehicle construction due to their lightness and yet high robustness. Plastics consist of chains of carbon atoms for which there are no chemical alternatives.

Context
The history of defossilization is closely linked to the development of the environmental movement and the growing awareness of the negative impact of fossil fuels on the climate. In recent decades, international agreements such as the Paris Climate Agreement have strengthened the political will to stop climate change and thus also to promote defossilization. In the meantime, organizations have also been founded with the specific aim of promoting defossilization, such as the ccloop association in Switzerland.

Defossilization sometimes requires the restructuring of entire value chains, which is why it is a complex process that entails technological, economic and social challenges. It requires the commitment of governments, companies and society to shape a sustainable and climate-friendly future.

Criticism
Biogenic raw materials are often used for defossilized materials, as they absorb CO2 from the atmosphere as they grow. However, the extraction of non-fossil raw materials from biomass should not lead to an expansion of intensively farmed land at the expense of natural habitats. This would further increase environmental pollution, apart from CO2 emissions.

In addition, care must be taken to ensure that if non-fossil raw materials are obtained from biomass, this does not lead to competition with the agricultural cultivation of food

One point of criticism is that defossilization requires large amounts of sustainably generated electricity, which is currently not yet available and which is increasingly needed for electromobility.

Further criticism concerns e-fuels, as they would hinder the transition to a climate-neutral world. This is because the possibility of using them in traditional engines and processes can be used as an argument for not switching to new, more sustainable technologies and defossilization. However, the widespread use of e-fuels depends largely on their price, and it is unclear whether e-fuels can even be produced at a competitive price in the future given the current state of technology. However, it should be noted that defossilization in the narrower sense includes the material use of organic materials, but not their energy use. However, it is obvious that material from the same material flow can be used for both material and energy purposes and that certain materials can also be used for energy purposes (incineration) at the end of their life cycle after initially being used for material purposes.