A recent article on io9 featured the infamous “killer fog” episode in 1950s London. The “fog” (actually smog) dates back to the Regency period when coal became the usual fuel for domestic and commercial use in London. Was this raw coal or was it oven coke? My understanding is that coal to be used for smelting iron is baked into coke- a product with most of the volatiles boiled out and consisting mostly of carbon and ash. If the noxiousness of London smog was due to volatiles like sulfur, ammonia, creosote, etc., then why wasn’t coke used instead of raw coal?
Coke is more expensive than coal because it requires energy to produce it. In addition it’s difficult to use for domestic applications because it’s difficult to ignite and keep burning. Even anthracite coal is difficult to use in that regard, and like coke, it would have been reserved for industrial application.
Here are some articles about this:
Back when I lived in England about 60 years ago we used to burn coal, and not coke, to heat our house in winter.
I had an open coal fire in England in the 1980s. That was probably unusual by then though. I think switching people from coal to coke, especially for boilers, was one of the ways the smogs were eventually eliminated, after their peak in the early 1950s. IIRC there used to be “Smokeless Zones” where only “smokeless fuel” (which in practice usually meant coke, I think) could be burned.
Coke was commonly for sale for domestic use throughout the 20th century, and used in the 19th century as well, but for stoves or kitchen ranges ( cast iron or steel ovens, of types from that invented by Alexis Soyer to the modern AGA [ very expensive and middle-class ] which ran on coal, coke, wood or any fuel available ) before gas cooking from the 1850s and electric cooking from 1900 or thereabout took over for poorer people.
Coke proposals were made as early as 1809 in London; and from the National Archives:
The Chartered Gas Light and Coke Company was the first gas undertaking in the world, concerned chiefly, until the 1880s, with the production of gas for lighting purposes. It was incorporated by Act of Parliament in 1810 and the charter was granted by the Prince Regent in 1812.
Rootschat refers to a Hawker of Coke born in 1901: He sold coal, probably on a horse drawn cart, I can remember them (just) on the streets of London. Coke is converted coal. ‘solid substance left when volatile parts have been distilled from coal’ ( Oxford dictionary)
Outside the City of London, I really sincerely doubt there are any Hawkers of Coke left in Britain.
Although it burns intensely, coke is a bugger to get going, and most people probably preferred the brighter dancing flames of coal. But obviously a large proportion of kitchens used it in London or the rest.
Coal merchants through the 20th century would deliver sacks of coal, coke, or and of the other products of coal to any household, either from a horse-drawn cart in the earlier years or a lorry. Right through the 19th century to about WWII coal men seemed to often wear heavy sou’wester type headgear. Obviously they were biggish men. They usually emptied the sacks down a coal-hole in the pavement or left the sacks where the householder chose.
QFT. I spent my summer weekends in the 1990s working at a blacksmith shop at a Renaissance Faire; we primarily used coke for the working forge we had in the shop. Compared to coal, coke is really reluctant to catch on fire. 
Getting the forge (with coke as fuel) lit in the morning, especially on a humid summer morning, was a compete PITA. I needed to carefully build an initial fire with wood or paper (usually impregnated with a bit of lamp oil), then slowly put some coke on top of that fire. Then, I’d have to feed the fire a ton of air (through both bellows and a hidden electric blower) for 10-15 minutes before it’d really catch…and, even then, it only caught on the first time about 75% of the time.
St. Louis had a similar problem in 1939. Coke was considered as an alternative, but ruled out because of cost. The short-term solution was to wash soft coal until supplies of cleaner burning anthracite could be built up.
you ask hard questions Lumpy, but very good ones.
Coke was not used too much in ordinary domestic hearths, but was perfectly ok in central heating systems, I know, as a kid it was my job to get up every morning 6.30 am to clean out and feed our central heating boiler, took a good 30 mins every morning. I can’t remember how much we used a month, 5 to 10 tons I guess.
Coke was cheaper than coal, not more expensive, it was also a by-product of the coal gas industry which is why it was cheaper, since effectively it was being used twice.
IIRC it tended to have plenty of sulphur in it, at least ours did. Never got to taste breakfast properly for years until I left home.
You do have to remember the sheer concentration of population density in most cities at that time during the 1950’s.Most cities had not yet really begun their urban spread, industry and housing were absolutely crowded together - all burned coal and coke. Many workplaces were still powered by steam engines, this might come as a surprise to folk but it meant that there was more of the stuff being used.
There is quite a history here, many houses did not have inside toilets, they often had only one hearth, the electrical supply was up to 13 amps, but was often less than that - I even remember stripping out wiring in some houses that were bare conductors in wood trunking. The electrical supply was not reliable, but gas was, so lots of people used gas - which was produced in the town gasworks using coal. Many of those gasworks were right in the middle of town.
This is just after the war, we had some really vicious winters around then which also increased coal use. Britain still had a substantial steel industry, and all the related forging, casting and metal bashing engineering industries, trains were all steam driven.
The electrical supply was not yet in a nationally connected grid, each town or city had its own power generation belonging to the town council - all these tended to be right in the centre of town, they all burned coal although some could dual fuel with oil. I remember that if you went from one city to another, you had to change all your plugs because there was no national standard.
You know, when I read this post, I start to feel real old
5 to 10 tons a month?!?
Late '60s, early '70s, we had a solid-fuel boiler (Crane 20A) for our hot water and a Parkray glass-fronted stove for the living room. We mostly used Gloco nuts which I think from the appearance were reformed coke - sometimes I think we just had lump coke delivered, and sometimes anthracite beans. As already stated, none of these was a treat to get started but once they were up and running they burned OK in a closed stove with a forced draught.
Since our house was too new to have a coal-hole, we kept it in a 10cwt concrete bunker which after a while my Dad adapted into a 1 ton bunker. Shovelling the last hundredweight out of it was a pain, though. 
I remember that in the 60s, large parts of Sheffield were on direct current, not AC. This was because it was generated by the steelworks and sold to the surrounding houses. I worked at the time for a company that made catering equipment, and there was sufficient demand for them to produce a DC version of some products.
5 to 10 tons a month?!?
Yes, it was a children’s care home, so it was somewhat larger than the average two or three bedroom semi
As I recall, parts of the North-East were on a different voltage too at one time.
Coal, coke and fuel generally were scarce after the war when the mines were worn out by years of war and Depression, and what coal there was was often ‘nutty slack’ which had a poor calorific content. Ration levels, already low, sank still further and bread was rationed for the first time.
We used coke in the fire (never coal) though Grandma still used coal.