CRY HAVOC AND LET LOSE THE COAL OF WAR
Coal has powered industry for centuries, so it’s no surprise that it has also powered war. Some of its uses are obvious like powering trains that move materials and fueling the forges that produce tanks and ships. However, that black lump of rock is found in some of the most surprising places.
Take thermal sensors that allow the US army to own the dark and give warheads the ability to sense and destroy tanks and other emitters of heat. The passive sensor includes three compounds; polyvinyl fluorides, derivatives of phenylpyrazine, and cobalt phthalocyanine. Polyvinyl floride is produced from the coal based chemical ethane while phenylpyrazine requires phenyls. cobalt phthalocyanine requires naphthalene, which is a primary component of moth balls and comes from coal tar.
Not all coal applications are so subtle. Coal also provides the “bang” to war with TNT. TNT, or more specifically, 2,4,6-trinitrotoluene, is a yellow-colored solid best known as an explosive that is insensitive to shock. The explosive yield of TNT is considered to be the standard measure of strength of bombs and other explosives. Therefore a 20 kiloton nuclear bomb has the equivalent strength of 20,000 tons of TNT.
Ironically, TNT was first prepared in 1863 by German chemist Julius Wilbrand and originally used as a yellow dye. They were unaware of its explosive nature because it was so hard to detonate. The base of TNT is toluene, which is a byproduct of making coke from coal. Although many other militaries use other explosives, the US military is still a major user of TNT. In addition, many other explosives like plastic explosive also use coal products like toluene and benzene.
Not all coal applications in war are deadly to humans. In WW 2, another coal based compound saved tens of thousands of lives by killing mosquitoes. The chemical was DDT. Dichlorodiphenyltrichloroethane (DDT) was first synthesized in 1874, but its insecticide properties weren’t discovered until 1939 – just in time for WW 2. DDT was used extensively during World War II by the Allies to control the insect carriers of typhus, which nearly eliminated the disease in many parts of Europe. In the South Pacific, it was used to control malaria and dengue fever. A precursor chemical of DDT is benzene, which comes from coal tar.
DDT wasn’t the only coal based product that improved the health of our troops. The loss of the natural quinine sources in the Dutch East Indies to the Japanese in the early stages of WW 2 were the catalyst that allowed chemist Robert Burns Woodward to discover a method for making synthetic quinine. Woodward was successful and the base chemical needed for synthetic quinine was found to be aniline - which is prepared commercially by the reduction of nitrobenzene, a product of coal tar.
Since modern war is mobile, rubber is critical. 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 also has a place in feeding our troops (and I don’t mean the food tastes like coal). America’s current field ration is the MRE (meals ready to eat). MRE pouches must be able to stand up to abuse tests such as obstacle course traversal in field clothing pockets, storage outdoors anywhere in the world, shipping under extremely rough circumstances (such as by truck over rocky terrain), 100% survival of parachute drops, 75% survival from free failure drops, and severe repetitive vibration. That requires a tough package of aluminum foil, polyethylene, nylon and polyester. Three of those layers (polyethylene, nylon and polyester) all require coal based precursor chemicals.