Smokeless fuel

Smokeless fuel is a type of solid fuel which either does not emit visible smoke or emits minimal amounts during combustion. These types of fuel find use where the use of fuels which produce smoke, such as coal and unseasoned or wet wood, is prohibited.

As a result of many places banning smoke and pollution, studies have shown that overall air quality improved, and there were fewer annual deaths related to smoke.

briquettes

.

History

Smoke rising in Lochcarron, Scotland, is stopped by an overlying layer of warmer air (2006).

Coal was widely used for domestic cooking and heating during the Victorian period and up to the early 1950s in most urban areas in Britain. However, low-quality

sulphuric acid

.

London

In 1952, the

sulphur in the coal. Such manufactured fuels also burnt at a higher temperature, being a better and more efficient fuel for open fires as well as stoves

.

Benefits

Smokeless coal is more efficient than a conventional open coal fire indoors because the high working temperature is released into the room as infrared radiation, as can be judged by the bright red color of a mature fire. The hot gases produced are lost up the chimney, thereby reducing efficiency just as in an open coal fire. The gases mainly consist of carbon dioxide, carbon monoxide, and some water vapor. With little or no smoke or similar volatile compounds, chimneys remain cleaner longer and require cleaning less frequently. The main combustion reaction is:

C (s) + O₂ (g) → CO₂ (g)

In a restricted supply of air or oxygen toxic carbon monoxide can be formed:

2 C (s) + O₂ (g) → 2 CO (g)

Charcoal, either unprocessed or as shaped

example needed

] for domestic cooking.

Calorific value

Smokeless fuels generally have a high

calorific value, with that of anthracite being greater than dry wood for example, and many smokeless briquettes are made from this type of coal. Thus anthracite has a calorific value of 32.5 MJ/kg compared with that of dry wood of about 21 MJ/kg. Lignite or brown coal is even worse with a heat of combustion of only 15 MJ/kg, owing to the presence of non-combustible impurities. Bituminous coal

has a value lower than anthracite, but neither lignite nor bituminous coal are smokeless owing to their volatiles content.

Downsides

Smokeless fuels also have some disadvantages. Typically they can be harder to

flames due to reduced volatiles, but a generally higher ash content. Fines and dust can be produced by abrasion from mechanical movement, but the amount is minimal compared with that produced by bituminous coal. It is sometimes supplied wet, even in sealed plastic bags, but is easily dried since the moisture is superficial. There is an increased cost to the user or consumer owing to the costs of mass manufacture, although the loss of volatile chemicals such as coal tar

can offset those costs to the manufacturer. Those extra costs make the fuel more expensive than coal, but the effect is small at about a 30% premium over coal at 2020 prices.

Since all

coal bunker

.