Coal and fuel manufactured from coal, which can burn smokelessly, has made Britain's towns and cities cleaner and ended the smog's once caused by smoke.
Smokeless fuels can be divided into two main categories: Natural Smokeless Fuel and Manufactured Smokeless Fuel. As the names suggest one of these fuels is a product of Mother Nature, the other is made as a result of processing the coal.
Anthracite coal is a naturally smokeless fuel and is still mined in South Wales today, albeit in limited quantities.
Coalite or Supertherm are examples of manufactured smokeless fuels. Although different processes are used to produce a smokeless 'coal' the majority of these are based on reducing the volatile content (the gaseous component of the coal that creates the smoke), pulverising, curing and binding the coal/anthracite into a briquette.
The warm cosy glow normally associated with coal can be enjoyed via an open fire, a roomheater, a stove, or a cooker when using smokeless fuels.
Coke was the first man-made smokeless solid fuel gained from coal. It is produced by heating coal to a certain temperature in the absence of oxygen. This liberates by-products for use elsewhere and at the same time gives silvery-grey, clean and economical solid fuel for the home and many grades for industry use. Coke is sized by taking it over large screens to grade the product for industrial use.
Coal can be made to suit special varieties of coke for different uses in industry by blending various types of coal. One example is for sugar refining.
Coal's treasure trove
The wealth you can get from coal and just some of the many things that can be made from coal and its by-products.
Hold a small piece of coal over a Bunsen burner and you expect certain things to happen. One piece of the coal may catch alight in a tarry, smoky sort of way. Other pieces will change appearance as smoke is released. There will be a pleasant smell and an unpleasant mess of smuts and smoke.
This imperfect burning of coal opened the door to a treasure trove of by-products. The range of by-products that can be obtained from coal is generally divided into two families.
The coal itself releases some by-products - such as thick brown smoke containing gas, tar and ammonia liquor.
Example: - ordinary tar
The others result from further chemical and physical treatments of the by-products, producing explosives, cleaning agents, plastics and much more.
Example: - disinfectant fluid
Photograph of a modern open fire burning smokeless fuel
A Smokeless Living Fire
Smokeless fuels and modern coalburning appliances combine a cheerful living coal fire with an efficient, clean burn.
The beauty of the simple coal fire has been appreciated from the first but the old-fashioned open fire was wasteful. Probably 80 per cent of the heat went up the chimney. It demanded frequent attention and it made smoke which polluted the air.
Even in days when Britain had a much smaller population and coal and labour were cheap, it was realised that it was silly to burn coal in an open grate. The Victorians developed some excellent grates - including one with heat-radiating metal bars, a deep pit to hold several days' ash and a controlled convection and chimney-draught system. But coal was so cheap, this sort of grate remained just a good idea.
However, after the Second World War, coal was scarce and waste was intolerable. Fogs became smogs. Far fewer people had servants to service the fires. Something had to be done.
Householders began installing slowburning 'all night' fires. With the new grate they adjusted a lever to cut down the amount of air reaching the coal - and the fire kept alight all night and burned more efficiently all day. But these were not the complete answer. Although they burnt smokeless fuels remember the Clean Air Act - there was still too much heat going up the chimney. Two things were necessary: better fuels and better appliances to burn them. The fuels Homefire, Phurnacite and others, have already been described. All are smokeless and are manufactured coal products, as distinct from raw coal.
Many families have central heating and if they want economy and efficiency they may well have a coal-fired system. In a small house a roomheater with a back boiler may be enough to warm the room and several radiators. Some roomheaters and central heating boilers burn inexpensive ordinary coal smokelessly.
Warmth you can see
Modern open fires are labour-saving and burn smokeless fuels. Fitted with a back boiler, they can also heat all the hot water for a family as well as a few radiators. People who love a fire they can see and yet demand very high efficiency can have it, thanks to armoured glass. Heat-storage cooker/water heaters are cherished by good cooks - two hotplates, two ovens, very hot and simmering hot. They heat water and warm the kitchen too.