With the world looking at lightweight materials to improve the efficiency of cars and other vehicles to curb greenhouse gas emissions, is it possible to make cars out of petroleum waste?
Research is going on the world over for ever-lighter materials that are strong enough to be used in the bodies of cars. At present, lightweight materials made from carbon fibre, same as the material used for tennis rackets and bicycles, comes in exceptional strength with low weight. However, these materials are expensive.
Well, researchers at Massachusetts Institute of Technology (MIT) and elsewhere have come up with a way of making these lightweight fibres out of an ultra cheap feedstock — the heavy, gloppy waste material left over from the refining of petroleum material.
WHY PETRO WASTE IS ADVANTAGEOUS?
The first thing is that the new carbon fibre made from petro waste comes cheap. The next thing is that it can have compressional strength, meaning it could be used for load-bearing applications. The new process is described in the journal Science Advances, in a paper by graduate student Asmita Jana, research scientist Nicola Ferralis, professor Jeffrey Grossman, and five others at MIT, Western Research Institute in Wyoming, and Oak Ridge National Laboratory in Tennessee.
THE STUDY
The researchers began the study about four years ago in response to a request from the Department of Energy. The Department had sought ways to make cars more efficient and reduce fuel consumption by lowering their overall weight.
It is a known fact that heavier cars require bigger engine, stronger brakes, and so on. If the weight of the car body is reduced, then additional weight could be saved.
CARBON FIBRE
Composites from carbon fibres are not a new idea. In automobile industry, it has been used in a few very expensive models. The new research aims to turn that around by providing a low-cost starting material and relatively simple processing methods, the researchers said.
The cost of quality Carbon fibres needed for automotive use now come to 10 dollars to 12 dollars per pound. It can go to hundreds of dollars a pound for specialized application like spacecraft components.
PETROLEUM PITCH
Instead of using a refined and processed petroleum product, the researchers experimented with the dregs left after the refining process, a material known as petroleum pitch.
Pitch is messy, which is a mixture of heavy hydrocarbons. It is useless for combustion although it can burn. It is too dirty a fuel this is especially true with tightening environmental regulations. As the “inherent value of these products is very low, they are often land filled.
The researchers are also looking at alternative source of pitch such as coal pitch, a similar material that is a byproduct of coking cool, used for example for steel production
On the research, Jana said that pitch was made of these heterogeneous set of molecules where you would expect that if you change the shape or se you would expect the properties to change dramatically. “We were able to reproduce the results with such startling accuracy.” she says, “to the point where companies could take those graphs and be able to predict” characteristics such as density and elastic modulus of the fibres.
The work produced results showing by adjusting the starting conditions, carbon fibres could be made that were not only strong in tension, as most such fibres are, but also strong in compression, meaning they could potentially be used in load-bearing applications. This opens up entirely new possibilities for the usefulness of these materials, they say.
