- It is not constituent of coal but consists of a complex mixture of gaseous and liquid products due to thermal decomposition of coal substance.
- High volatile matter containing coal burns with a long flame, high smoke (pollutes air) and has low heating / colourific value. So lesser the percentage of the volatile matter better is the quality of the coal.
- Low volatile matter containing coal has good caking property.
- It forms hard and strong coke on carbonization. It also yields coke oven gas which is a source of many chemicals.
- Medium volatile matter containing coal has good caking property. It forms hard and strong coke on carbonization, it also yields coke oven gas which is a source of many chemicals.
- High volatile matter containing coal is used for coal gas production as the volatile matter is converted to gas and tar products by heat.
- High volatile matter burns with long and smoky flame but those having low volatile matter burns with shorter and clean flame.
- So, higher the volatile matter content the larger is the combustion space required in the furnace.
Hence, the volatile matter content of coal influences the furnace design.