8 Innovations for the climate

They won’t, by themselves, solve the climate crisis… but they give hope!

THE FACTORY THAT PURIFIES THE AIR

How it works ?

The largest CO² capture plant (one of the main greenhouse gases) in the world was inaugurated in September 2021 in Iceland. Thanks to the fans, air is sucked into eight collectors. The CO² is filtered there with a special material and then collected. The air expelled from the other side of the fans is therefore almost pure! The captured CO² is mixed with water and injected through pipes more than 800 meters into the ground to be stored there, before being quickly transformed into stone. With this promising project, the Swiss start-up Climeworks and the Icelandic company Carbfix want to reduce the amount of CO² present in the air and thus partially limit global warming.

what can change

Every year, 4,000 tons of CO² can be eliminated thanks to this plant. This is small compared to the 34 billion tons emitted in the world in 2020, it is imperative at the same time to reduce our emissions (industry, transport, etc.) But it goes in the right direction, especially if this type of factory multiplies!

ALMOST GREEN STEEL

How it works ?

Steel is made from iron, obtained by smelting ore. To do this, you have to burn coal. But there are alternative methods. Hydrogen (a chemical element present in water, usable in the form of gas as an energy carrier) does not melt the ore, but allows it to be purified and obtain iron, which can be transformed into steel. Electrolysis (an electric current passes through materials to trigger a chemical reaction) could make it possible to transform iron ore into metal without releasing CO².

what can change

The steel industry was responsible for 7% to 9% of global CO² emissions in 2020 and this material is present everywhere. Hence the importance of manufacturing “greener” steel! But these innovations have to face two challenges: the hydrogen itself still comes mainly from fossil fuels (natural gas, oil, etc.) rejecting the CO². And the investments needed to transform such a huge industry (nearly 2 billion tons of steel produced each year!) are colossal. However, the Swedish Hybrit project based on “green” hydrogen will continue its tests until 2024, and American start-up Boston Metal is planning its foundry for 2024.

SOLAR PANEL WINDOWS

How it works ?

Solar panels convert the sun’s energy into electricity using special materials: semiconductors. By absorbing the sun’s rays, they release electrons that form an electric current. Silicon is the most used material to manufacture them. But there are others that are more innovative, such as perovskite panels.

what can change

Silicone solar panels, opaque and heavy, must be placed in places capable of supporting their weight and that do not require the passage of light, such as the roofs of buildings; or directly on the floor. Perovskite panels, which are lighter, potentially equally efficient and semi-transparent, can be used as glazing, then able to produce electricity! Its two main shortcomings are its short shelf life – a few months or years, while silicon lasts 25 years – and the toxicity of certain components, such as lead. Challenges that manufacturers are trying to face, which have already launched production plants, such as Saule Technologies in Poland.

HYDROGEN TRANSPORT

How it works ?

A hydrogen vehicle is electric, it feeds its battery with hydrogen and releases… water vapour! A technology allows this feat: the fuel cell. Inside this, the chemical reaction between the hydrogen in the tank and the oxygen in the air releases heat, water and electrons that form an electric current. The hydrogen tank guarantees fast recharging and better range than an “only” electric vehicle. Many cities (Auxerre, Pau, etc.) welcome hydrogen buses and, in 2020, the French State announced major investments in this sector.

What can change?

Vehicles that drive without emitting CO²: the dream! Hydrogen trains and even airplanes are being developed. However, in addition to ensuring the safety of the machines, it is necessary to implement all the infrastructure that accompanies it, such as fueling stations and a sector for the production of hydrogen from green energy sources – wind, solar, etc.

WOOD WITH SUPERPOWERS

How it works ?

What if it were possible to improve wood, make it stronger and limit its degradation? This is what laboratory projects (the University of Maryland, in the United States) and start-ups (the French company Woodoo) promise. The researchers treat the wood by heating it and compressing it, or removing its lignin (a kind of glue it contains) to replace it with a resin – a chemical compound, which may be of natural origin. In this way, they obtain a more solid material that does not rot.they may even have new properties: transparent, or sharp enough to be turned into knives!

what can change

Working with wood generally consumes less energy than other materials (concrete, metals, etc.) and generates less CO² emissions. These processes would also allow the use of certain woods not exploited by industrialists. It remains to be seen whether these “new woods” will be technically and financially competitive enough to compete with other materials.

PALM OIL WITHOUT PALM

How it works ?

What if we switched from the famous palm oil to a more sustainable alternative? Instead of extracting oil from plants, such as palm trees, laboratories and start-ups (the University of Bath, in England, the Americans from C16 Biosciences, etc.) made a somewhat crazy bet of producing it from yeast . These microorganisms are actually capable of producing oil -similar to palm oil- by consuming and transforming food and agricultural waste!

what can change

Palm oil is widely used today, from food to cosmetics and biofuels. But the palms needed to produce it are usually grown by destroying wild forests, especially in Southeast Asia. This massive deforestation, in addition to destroying ecosystems, is responsible for many CO² emissions due to the cutting of trees, the machinery used, the destruction of swamps, etc. However, replacing such gigantic production – tens of millions of tons of oil per year! If demand increased, plants would have to be grown to feed the yeast. And the problem would be transferred to other cultures!

METAL COLLECTION PLANTS

How it works ?

Metal growing in fields is not a science fiction scenario! This is possible thanks to plants called “hyperaccumulators”: plants that, when growing, absorb metals present in the soil and store them in their stems, leaves or sap. Phyllanthus rufuschaneyi for nickel, Brassica juncea for gold… Depending on the plant, it is possible to “harvest” different types of metals. They are recovered by burning the plants, or using them directly in the chemical, metallurgical, glass industry… Fields in Greece or Albania already collect 150 kilos of nickel per hectare!

what can change

Harvesting metals this way is less polluting than extracting them through mines, even if the amount of metal obtained is much smaller. This technology would also allow for effective cleaning of floors, and make available to other local crops that have become unfit for agriculture. This process takes -10 to 30 years- and still needs to be improved, but it is already raising high hopes, as there are undoubtedly many “metal capture” plants yet to be discovered!

ALGAE THAT CAPTURE CO²

How it works ?

When they are cultivated, these tiny algae are able to capture CO², present in the atmosphere through photosynthesis, and thus purify the air. Hence the idea of ​​installing microalgae “factories” next to industrial sites that reject CO². Once the latter has been captured by plants, it can be re-injected into crops to prevent it being released directly into the atmosphere. In Montalieu-Vercieu in Isère, industrialists and the University of Nantes have teamed up to harness CO² emissions and heat from cement manufacturing to grow microalgae. Another field of application: water treatment. Microalgae have the ability to “clean” wastewater by absorbing pollutants such as nitrates. A method already used in Australia and Spain.

what can change

Microalgae and their properties raise great hopes. In addition to being able to absorb CO², some of them are edible. and they can be sources of proteins and nutrients; or usable in cosmetics to impart color or texture to a product. But it is on the side of green chemistry that the applications are the most promising: biofuels, bioplastics… These algae can even replace petroleum in certain cases!

Texts: Corentin Paillassard and Laure Blancard – Illustrations: Kevin Deneufchâtel

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