Coal And Your Saturday Afternoon
Coal Bin by Harold Hough
It’s Saturday afternoon and you invited some friends over for a barbecue. And, although it’s the last thing on your mind, the success of your soirée will depend a great deal on coal.
First, let’s start with your backyard. There isn’t a weed in site and the grass is thick and luxurious, thanks to coal. Well, thanks to coal, Queen Victoria and Jack the Ripper.
Herbicides originally came from coal tar, but it took a series of murders to make coal tar cheap and readily available. In the 1880's, a series of brutal murders of women were committed by Jack the Ripper in a poor slum district on the east side of London known as White Chapel. These murders alarmed Queen Victoria, who was advised that they were impossible to prevent due to the very dark alleys and streets of that part of the city. But, she didn’t want excuses. She wanted well lit streets. And, if the ruler of a quarter of the world’s population wanted lit streets, she got it. As a result, a lighting system was constructed in the city of London utilizing coal gas, a by-product of soft coal (bituminous) gasification.
The gas was piped throughout the city for lighting, and the coal tar remained as a waste product of the process. Thanks to chemists they were able to turn a waste product into a wide spectrum of chemicals critical to modern life.
The chemical composition of coal tar is highly varied, but the major constituents are: phenol, toluene and pyridine. In the early years of the 20th Century the German company of I G Faben was a pioneer in development of herbicides using these chemical building blocks. The result was an agricultural revolution that dramatically increased crop yields.
But, coal’s contribution doesn’t stop there. That glass of wine you are sipping while grilling those hamburgers contains sulfur dioxide, which keeps the wine from oxidizing. And where does sulfur dioxide come from? It’s a coal byproduct.
Don’t forget the heart of any barbecue – the charcoal briquettes. You may think they are made of hickory or mesquite wood, but they contain more anthracite coal fines than wood. That makes them burn hotter and more evenly than sawdust. It also allows coal mines to get rid of what was once a bothersome byproduct and makes dust control a profitable process.
There are loads of coal byproducts on the picnic table too. Those potato chips, pepperoni slices, and other snack foods use BHA and BHT, preservatives that keep the fat in the food from going rancid.
There is a lot of coal involved if you are watching auto racing on TV while eating those hamburgers. Some racing formats like drag racing use methanol as a fuel. Although much of the methanol in the US is made from natural gas, internationally much of this fuel comes from coal.
No matter what they use in their fuel tanks, there is a lot of coal used in producing the durable, light weight materials for auto racing. But there’s more. Those high performance racing tires have more in common with a coal mine than a rubber tree.
Although there is some natural rubber in racing tires, most of it is synthetic rubber. Traditionally synthetic rubber comes from several coal tar compounds, benzene, toluene, ethylene, and calcium carbonate. Much of the progress in the development of synthetic rubber came during the World Wars as warring countries were cut off from natural rubber supplies. The most popular synthetic rubber is Buna CB, of which 70% is used in tire production.
Coal products are critical in racing tires because they offer differing characteristics that are critical for high performance tires. Carbon black, which is produced from coal tar is critical for determining how soft or hard the tire tread is. Soft tread is great for traction, but wears out quickly. Carbon black gives the tire more abrasion resistance. Meanwhile, polybutadiene, which can be produced from coal, is used in the sidewalls because it can withstand the heating caused by repeated flexing. It also transfers heat, which helps keep the tires cool. But, because it is poor for providing traction, tire manufacturers often add styrene, (which is also a coal based chemical) to the tread part of the tire.
So, sit back, relax and enjoy your Saturday afternoon. You may not see heaps of coal of coal on your pristine lawn, but it is doing its bit to make your afternoon memorable.