Preface. Plastics are just one of 500,000 products made out of oil and gas, but very important to just about every aspect of society, from making vehicles lighter so go further using less energy, to clothes, food storage, bags, toothbrushes, buckets, garbage bins, toys, carpets, fleece, plastic lumber, chairs, bottles and more.
The reason fossil fuels are used to make half a million products is that they are mostly just carbon and hydrogen: Natural gas 20% C 80% H, petroleum 84% C 12% H, and coal 84% C 5% H.
If you wanted to make plastics from something “greener” and more sustainable, what on earth is both abundant and chock-a-block with carbon and hydrogen that can replace fossil fuels? Let us start with abundant. The world is mostly made of soil, air, water, and plants. Dirt will not work, it’s 47% oxygen, 28% silicon, 8% aluminum, 5% iron, 3.6% calcium, 3% sodium, 3% potassium, and 2% magnesium. Air is nitrogen and oxygen. Water is hydrogen and oxygen, but no carbon.
That leaves biomass — plants such as trees, crops, and grasses, which has both carbon and hydrogen. But there’s a whole lot of other crap that would have to be removed at great energy and monetary expense since there’s also O, N, Ca, K, Si, Mg, Al, S, Fe, P, Cl, Na, Mn, Ti. Biomass carbon varies quite a bit, from 35–65% of the dry weight, and hydrogen roughly 6%.
But it also takes a lot of energy to use biomass instead of oil and gas, which flows through pipelines cheaply. Biomass has to be cut, transported, cut or mashed into tiny pieces, and conveyed to a plastics factory before it composts or spontaneously combusts. And it’s expensive to remove some or all of the non carbon and hydrogen elements out.
…click on the above link to read the rest…