Dissertation Les Caractères, La Bruyère

BaptizetLeïla                                                                                                                                                       1G6

Marian-Gheorghita Carla

Eco-friendly speed machine

Nowadays, 24% of the world’s carbon dioxide emissions are caused by transports, which equals to 43% of France’s carbon dioxide emissions. The mundane means of transport work with fossil fuels, as 91% of them use gasoline, against 7% for biofuels and 2% for electricity. As a result, scientists and engineers work on ways to make our conveyance more eco-friendly, considering that we will run out of fuel in the future. Still, there is one major problem: these biofuels still require large amounts of land to grow the feedstock from which they are derived, which may limit their deployment capacity.

As a new mean of transport, our company designed a completely new train which operates with an unprecedented type of bio-fuel: seaweeds biofuel. Indeed, this concept has never been commercialized as it is still a prototype as it is a new technology and could revolutionize the transport industry.

Our train is the most aerodynamically shaped in order to avoid as much air friction as possible, as its front is shaped as a triangle.

The harvested seaweeds are turned into oil (for 100kgs of them we can make 21 L of oil that is used as fuel for the train).

Seaweeds can be transformed into clean biofuels since they absorb more carbon dioxide during their cultivation than what their combustion in the engine emits. Furthermore, seaweeds consume more carbon dioxide (during the photosynthesis) than the plants’ average absorption, in fact seaweeds use 5 time more CO2 than a forest, and 100kg of them can absorb until 184 liters of CO2.

The first biofuel generationwhich usesbeetroot, wheat or rapeseed compete with nutritional supplies and entail soil degradations as well as significant deforestations, resulting in a surplus of greenhouse gases emissions. However, seaweeds’ culture requires as much cultivable surfaces as the last generation, therefore the use of microalgae is more profitable given that they are microorganisms that don’t need as much space (ahectare provides us with 14000 liters of fuel made from microalgae whereas ahectare provides us with only 470 liters of sojabean oil). Still, we are working on elaborating seaweed biofuel from invasive seaweed species which endanger the biodiversity of some ecosystems, like in the Mediterranean Sea or in Marseilles. It is an effective alternative to protect the environment.

What’s more, our ship will be able to cruise at 400km/h, which enables us to use Newton’s First law stating that and object can’t move unless it undergoes a force, which is the principle of inertia. Indeed, during the trip, the engine will enable our vehicle to be propelled at 400km/h, but half way during it the engine will stop providing the trains wheels with energy. As a result, the train will still go fast as it is propelled, but without using any energy, reducing its consumption.

To put the train is motion, the locomotive must overcome two opposing forces: Friction, which is the force that comes from the surface contact between train wheels and the rail. Air drag, which is the force that comes from the resistance of the air to the train movement.

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