All types of coal also contain sulfur, which, when burned, releases toxic air pollution. Sulfur content is determined by the conditions under which the coal is formed. Low-sulfur coal deposits develop in freshwater environments; high-sulfur deposits come from brackish swamps or marine-influenced environments .
Does coal contain Sulphur?
Sulfur is one of the hazardous elements in coal. The concentrations of sulfur are relatively high in coal. The major forms of sulfur in coal are pyritic, organic and sulfate. … Elemental sulfur also occurs in coal, but only in trace to minor amounts.
Why Sulphur content is not desirable in coal?
(ii) Nitrogen: – It has no calorific value and hence its presence is not desirable. (iii) Sulphur: – Sulphur adds to the calorific value of coal since the oxidation of sulphur is an exothermic process. … Hence a good quality coal should have low percentage of oxygen.
Which type of coal has the highest sulfur content?
How do you reduce Sulphur in coal?
Inorganic sulphur, in the form of pyrite (FeS2), can be removed from coal relatively easily simply by washing the coal. This method can result in a reduction of 10 – 50% of total sulphur content. However, again as with fuel switching the reduction is limited, plus large quantities of waste water are produced.
What are 4 types of coal?
Coal is classified into four main types, or ranks: anthracite, bituminous, subbituminous, and lignite. The ranking depends on the types and amounts of carbon the coal contains and on the amount of heat energy the coal can produce.
How do you test Sulphur in coal?
The sulphate sulphur is determined by extraction of coal with dilute hydrochloric acid. 5 gm. of coal (100 mesh) is digested with 300 c.c. of 3% hydrochloric acid for 40 hours at about 60°C. A higher temperature would cause the sulphur to escape as sulphuretted hydrogen gas.
Why should sulfur be removed from coal?
When coal is burned to produce energy, its chemical makeup is changed and sulfur is released. To avoid environmental problems with the sulfur, coal companies and power plants take measures to remove it before, during and after burning.
Is thermal coal black coal?
There are two kinds of black coal: thermal coal, and metallurgical or coking coal. Thermal coal, also called steaming coal, has a lower energy content and higher moisture and is used to generate electricity.
Which fuel has highest calorific value?
What is the cleanest form of coal?
Which is the highest quality of coal?
Anthracite: The highest rank of coal. It is a hard, brittle, and black lustrous coal, often referred to as hard coal, containing a high percentage of fixed carbon and a low percentage of volatile matter.
Which is the softest form of coal?
How do you reduce Sulphur?
Scientists have found different ways to reduce the amount of sulfur dioxide released from coal-burning power plants. One option is to use coal that contains less sulfur. Another option is to “wash” the coal to remove some of the sulfur.
How do you neutralize sulfur dioxide?
The scrubbing liquor can be bubbled through a slurry or either lime, Ca(OH)2, or limestone, CaCO3 and water. Either lime or limestone will combine with the sulfite ions from the flue gas to form gypsum, CaSO3. The SO2 that is captured in a scrubber combines with the lime or limestone to form a number of byproducts.
How can we reduce coal pollution?
One method is carbon capture, which separates CO2 from emissions sources and recovers it in a concentrated stream. The CO2 can then be injected underground for permanent storage, or sequestration. Reuse and recycling can also reduce the environmental effects of coal production and use.