Chapter energy and technology the enhancement of skin

6.5. Town gas, coal tar, illuminating oil and petroleum

Coal was the energy basis of the (first) industrial revolution, but it was (and still is) bulky, inconvenient and dirty. Yet it was the primary fuel for heating buildings and driving trains and ships for the over a century (in the case of trains and ships) and for two centuries in the case of buildings. The famous “pea soup” London fogs were a feature of very major European and American industrial city, not restricted to London. They were a fact of urban life as late as the last half of the twentieth century when natural gas finally replaced coal as a domestic fuel in Europe and America. They remain so in China and elsewhere in the developing world. Not only did the smoke leave its black imprint on every building and every gentleman’s collar and every lady’s handkerchief, it caused asthma, emphysema, lung cancer and heart disease. Life expectancy in northern Chinese cities lags behind industrial countries by several years.

Dirty coal has kept its choke-hold on the urban home-heating market so long, despite the availability of alternatives, for one reason only: it was “dirt cheap”. But while coal fires could heat a room, a coal-burning stove could cook food, and a coal-burning furnace could also heat water and provide central heating, there was one important domestic energy service that coal (or its predecessor, wood) could not provide, at least in raw form. That service gap was illumination. Lighting is so important to people, even the poorest, that in the 18^th century people in England spent as much as a quarter of their incomes on lighting, mostly by candles or whale-oil lamps. (Oil for lamps from the blubber of sperm whales, was the basis of New England’s prosperity in the late 18^th and early 19^th century. The species was nearly hunted to extinction for its oil, and is now protected). But candles and oil lamps were not suitable for street lighting, and the need for street lighting was growing even faster than the cities themselves.

The first street lighting solution came about as a result of the demand for coke by the iron industry. Coking produces a gaseous by-product, called coke-oven gas, which nobody wanted at the time because it was so smelly (due to the presence of sulfur dioxide and ammonia). Coke-oven gas, in those days, was generally flared. It was William Murdoch, one of the employees of the steam engine manufacturer Watt & Boulton, who first produced a cleaner gaseous fuel from the coke. He used a process now called “steam reforming”, in which red-hot coke reacts with steam to produce a mixture of hydrogen and carbon monoxide. This gas became known as “town gas” because it rapidly became the fuel for street lighting in London, Paris, New York, and other big cities. It also served for interior lighting (replacing candles) wherever the expanding network of gas pipes made it possible to deliver the fuel inside a house. Town gas was widely distributed in cities around the world by the end of the 19^th century, and continued to be used until after WW II. (Some of those old pipes now deliver natural gas).

Of course, the iron (and steel) industry required more and more coke, eventually resulting in a glut of the by-product coke-oven gas. Cleaning it for domestic use (in combination with town gas) was technically possible. The sulfur dioxide could be removed by passing it through a solution of quicklime, similar to what is done today in large coal-burning electric power plants. But getting the ammonia out of the coke-oven gas was too expensive until German chemists realized that it could be converted into ammonium sulfate, a valuable fertilizer. Nitrogenous fertilizers were increasingly necessary to increase the grain yield of European farmlands, as the population was growing fast. Coke oven gas became a primary source of nitrogen fertilizers for several decades in the late 19^th century. Of course, extracting the ammonia and the sulfur left the gas much cleaner, and less smelly. This improvement soon allowed other uses. One man who found such a use was Nikolaus Otto, of Cologne. But that begins another story, the development of the gas-burning stationary (and later, liquid burning mobile) internal combustion engine, discussed in Section 6.7).

The gas-light industry produced another nasty by-product: coal tar. In Britain this product was mostly used, at first, to caulk ships-bottoms and to seal leaky cellars and roofs. However, those German chemists recognized an opportunity for developing products of higher value and began to support fundamental research on coal-tar chemistry at several institutions. Nevertheless, the first important discovery occurred in England in 1858. A chemistry student, W.H. Perkin, accidentally synthesized a brilliant mauve color from aniline, a derivative of coal-tar, while he was searching for a way to synthesize quinine. Perkin saw the value of synthetic dye materials for the British cotton industry, and began to manufacture the mauve dye commercially. In the following year Perkin also succeeded in synthesizing another dye color, alizarin, the coloring agent in "rose madder."

However, Perkin’s early lead was trumped by German chemists, who also synthesized alizarin and began production. The firms Badische Anilin und Soda Fabrik (BASF), Bayer, and Hoechst were all in business by 1870. Thereafter the Germans gradually forged ahead, by investing heavily in research. More and more aniline-based dyes were introduced in the 1870's and ‘80's, culminating in 1897 with a major triumph: BASFs successful synthesis of indigo (which the British imported from India). This remarkable firm also developed the successful "contact" process for manufacturing sulfuric acid in the 1890's. The firm began work on the most important single industrial chemical process of all time: the synthesis of ammonia from atmospheric nitrogen. Synthetic ammonia was needed to manufacture nitrate fertilizers to replace the natural sodium nitrates that were then being imported from Chile. The basic research was done by a university chemist, by Fritz Haber, while the process design was accomplished by BASF chemist, Karl Bosch. The first laboratory-scale demonstration of the Haber-Bosch process took place in 1909. The process was shelved for a while due to the (temporarily) low price of a competing nitrogenous fertilizer, calcium cyanamid, made from calcium carbide. (Calcium carbide was being mass-produced by the Union Carbide Company at that time for acetylene lamps). Finally, under the pressure of war-time shortages, a full-sized ammonia plant did go into production in 1916 to supply nitrates for fertilizers and munitions in Germany.

Still, the German chemical industry was predominantly based on synthetic dye manufacturing through the 1920's.¹⁰ Indeed, it was experience with color chemistry that led to several major pharmaceutical breakthrough's (including the anti-syphilis drug "salvarsan"), and helped the Germans take a leading role in color photography.

The gas-light industry had been created primarily to serve a growing demand for illumination. It could only do this, however, in large cities where a central gas-distribution system could be economically justified. However in the 1850's most of the population of the world still lived in small towns or rural areas where gas light from coking coal was not an option. The alternative illuminants at that time were liquid fuels: whale oil and kerosene. (Acetylene came later). Whale oil was cleaner burning and generally preferable, but the supply of whales from the oceans of the world was being rapidly depleted. Animal fats were a possible substitute, but the oil had a bad smell. Kerosene could be produced in small quantities from coal, but not in useful amounts. Petroleum – known for centuries as “rock oil” – was the other alternative.