Town gas

Town gas or coal gas refers to a fuel gas that was widely used from the middle of the 19th century and was mostly produced by the city by means of coal gasification . It was used to illuminate streets and apartments and there also to operate gas stoves and gas water heaters . Town gas in the public gas networks in Europe was replaced by natural gas in the second half of the 20th century - in 2009 there were still isolated gas networks in China that ran on town gas.

composition

Town gas is a gas mixture of different gases. The exact composition varies depending on the gasworks and production process, the type of gas scrubbing and the coal used. The composition of town gas for the former Vienna gasworks Simmering is given as follows:

• Hydrogen H ₂ (51%)
• Methane CH ₄ (21%)
• Nitrogen N ₂ (15%)
• Carbon monoxide CO (9%)

In addition, various other gases occur in traces, including small amounts of water vapor and traces of carbon dioxide CO ₂ , oxygen O ₂ and other volatile hydrocarbons C _m H _n .

In order to increase the calorific value of the pure coal gas , water gas , consisting primarily of carbon monoxide and hydrogen, was added to town gas at the beginning of the 20th century . After the Second World War , a start was made to reduce the toxic carbon monoxide content and to add more natural gas (methane) to town gas. These additional admixtures also changed the percentage of the individual gases depending on the gasworks and epoch.

Toxicity

The inhalation of city gas leads to carbon monoxide poisoning and therefore many deaths, including through suicidal abuse ( " turning up the gas tap "). Because of the “gentle” toxicity of carbon monoxide, the method was used in around 20% of suicides.

Charles Norris , from 1918 to 1935 the chief medical examiner of New York City , counted alone in 1925, 618 fatal accidents due to unintentional carbon monoxide poisoning, to 388 suicides and three murders.

Today, natural gas is technically relatively uncomplicated as a combustible gas, which makes coal gasification for town gas production superfluous. Town gas is no longer produced in Germany today. In countries with large coal reserves and no major natural gas reserves (e.g. China), however, it is still used in households. With natural gas, suicides in the form of inhalation poisoning are almost impossible.

production

Town gas is produced by degassing hard coal in the absence of air in retorts or chamber furnaces. The processes for producing water gas and generator gas in coking plants are similar . Coke oven gas consists mainly of hydrogen, methane and carbon monoxide .

history

Production of hard coal gas

The prehistory begins with the discovery of coal gases in the early days of modern chemistry. The Flemish scientist Johan Baptista van Helmont (1577–1644) discovered a “wild spirit” emanating from heated wood and charcoal and called it “gas” (derived from chaos) in his book “Origins of Medicine” (1609) . Similar experiments were carried out independently in other regions, such as Johann Becker in Munich (1681) and John Clayton in Wigan, England (1684). The latter used the "coal spirit" for salon entertainment. The first functional gas lighting was invented by William Murdoch (later Murdock) (1754–1839), who is said to have first heated coal in his mother's tea kettle to produce lighting gas . He further explored the processes of manufacture, cleaning and storage - first he lit his house in Redruth (1792), then the entrance to the police headquarters in Manchester (1797), later the Boulton and Watt factory premises in Birmingham and finally the large spinning mill in Salford in Lancashire in 1805.

Professor Johannes Petrus Minckeleers lit his lecture room at Leuven University from 1783, and Lord Dundonald lit his house in Culross, Scotland, from 1787, with the gas being transported in locked tank wagons from the local coking plant. In France, Philippe Lebon patented gas firing in 1799 and demonstrated its use for street lighting in 1801. Other examples are numerous in France and the United States.

Gasworks

→ Main article : Gasworks

The first commercial gas works, however, were not built in Great Peter Street until 1812 by the London and Westminster Gas Light and Coke Company , whose coal gases were conducted through wooden pipes to Westminster Bridge and supplied gas lamps since New Year's Day 1813. In the USA, Rembrandt Peale and four partners set up the Gas Light Company of Baltimore (Leuchtgaswerke Baltimore) based on town gas, while Fredonia, New York State, has been using natural gas since 1821. The first gas works on the European continent was built in Hanover in 1825 by the Imperial Continental Gas Association (ICGA) - by 1870 there were already more than 340 gas works in Germany that produced town gas from coal, wood, peat, resin or rosin (see resin gas ) and other fabrics.

The first supply of pressurized gas lines took place in London in 1807, with which thirteen gas lamps, each with three gas nozzles, were fired in glass lamps that illuminated the length of Pall Mall . This goes back to the inventor and entrepreneur Fredrick Winsor and the master locksmith Thomas Sugg, who manufactured and laid the pipes. Further laying in private households was hindered primarily by rights of way , which had to be laboriously obtained for laying pipes under the street. Without these obstacles, William Murdock and his student Samual Clegg could supply large areas with coal gas.

In the 1850s, the gasworks switched production to water gas, which enabled coal to be used directly as a raw material instead of coke. In 1860, the BWG process ( blue water gas , invented by Carl Wilhelm Siemens in 1850 ) showed the use of kerosene gases, which are produced when refining gasoline materials, for use as illuminating gas. Instead of the production processes that were common up until then, which resembled those of a coking plant, Prof. Thaddeus SC Lowe showed the production of water gas in the absence of air in 1875. The CWG process was then the usual method of city gas generation from the 1880s to around the 1950s - the resulting city gas has a calorific value of around 20 MJ / m³, which is roughly half that of natural gas (37 MJ / m³). With the development of the incandescent mantle by Carl Auer von Welsbach in 1885, the light from gas lamps, now with a much higher luminosity, also became competitive with electrical lighting.

The use of coal gas had far-reaching social effects. First of all, it concerned the industry, the factories of which were first illuminated in the middle of the 19th century, and which enabled working hours there to be significantly extended, up to continuous night shifts (especially in the spinning mills in England). In addition, street lighting enabled increased urban traffic, but reading books also became a popular evening activity. Gasworks sprang up in almost every city in Great Britain that illuminated the cities via pressurized gas lines - with the invention of the gas meter in the late 1880s, city gas became common in private households and was increasingly used other than as illuminating gas.

The use of town gas for heating is a result of the use of heating oil to fire water boilers, which then supply the residential buildings as central heating. Their flames could also be replaced by gas flames.

In the time of commercial use of town gas, however, it was also in constant competition with electricity , which was perceived as cleaner, less dangerous, easier to use and without odor nuisance. The use of town gas as a light source was pushed back more and more and was mainly used for cooking and heating.

Replacement by natural gas

The decline in urban gas production is a result of the discovery of natural gas deposits in Europe, especially in the North Sea , and for Central Europe also the construction of gas pipelines from distant deposits, for example from Russia. In Great Britain, the switch to natural gas was decided in 1967 and completed with government funding by 1977 - 13 million households, 400,000 businesses and 60,000 industries were converted (with some dangerous structures discovered and taken out of service), and finally ended on September 1 1977 when converting a gas firing system in Edinburgh .

In Vienna and Augsburg (see in particular the Augsburg gas works ), for example, the changeover took place in a long-lasting process from 1969 to 1978. When retrofitting, the nozzles and seals on the respective combustion technology had to be replaced due to the different calorific value and the different operating pressure , or the devices were replaced by new ones designed for natural gas. There was also the problem that natural gas, which was rather dry compared to town gas, dried out classic hemp seals and thus became leaky.

In West Berlin , for reasons of independence, town gas was used until reunification , which was increasingly produced from light petrol and heavy oil from the 1950s and from Soviet natural gas from 1985. From 1991 to 1996 the appliances were gradually converted to natural gas.

literature

• Hanno Trurnit: History (s) behind the meter - The relationships between energy providers and their customers , Trurnit & Partner, Ottobrunn 2004, ISBN 3-00-000957-4 .
• Hanno Trurnit: And you can only see them in light: the history of gas and electricity, heat and water in Frankfurt and the region , / ed. On the occasion of the 175th anniversary of the Frankfurt gas and water supply from Mainova AG, Frankfurt am Main. Trurnit, Frankfurt am Main 2004, ISBN 3-9806986-3-7 .

Web links

• City gas production technology
• A few words to prevent accidents with coal gas. In:  Innsbrucker Nachrichten , March 18, 1875, p. 5 (online at ANNO ).

Individual evidence

1. ↑ Siqi Zheng, Rui Wang, Edward L. Glaeser, Mathew E. Kahn: The Greenness of China: Household Carbon Dioxide Emissions and Urban Development. (PDF) In: hks.harvard.edu. December 2009, accessed January 12, 2015 . 
2. ↑ ^{a b} Wiener Gasometer: Stadtgas, Leuchtgas und Erdgas im Gaswerk ( Memento of the original from March 4, 2016 in the Internet Archive ) Info: The archive link has been inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. 
3. ↑ Doctors newspaper: The number of suicides was a political issue
4. ↑ ^{a b} Advice for suicides
5. ↑ Deborah Blum: The Poisoner's Handbook: Murder and the Birth of Forensic Medicine in Jazz Age New York , Penguin Press, 2010.
6. ↑ After 170 years there is no more city gas in Berlin , Archiv Berliner Zeitung, accessed on August 14, 2008.
7. ↑ Gasag company portrait : The history of GASAG ( Memento of the original from December 24, 2012 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. .