Spontaneous heat generation evaluation

When coal is stored in piles or silos for a long period of time, a phenomenon occurs in which the oxygen in the air reacts with the carbon in the coal, generating heat. Sometimes. In particular, coal types with a low degree of coalification, such as sub-bituminous coal, contain many oxygen-containing functional groups such as -OH and -COOH, so there are many sites for oxygen adsorption, and they tend to generate heat. there is.

Spontaneous heat generation test device

Spontaneous heat generation test device

Spontaneous heat generation test device

Approximately 1g of the sample crushed to -0.25mm is collected, filled into a quartz sample cell, and set in a heat-insulated spontaneous heat generation test device. The sample is heated to 110℃ in a 100% nitrogen inert gas flow, and after the device and sample temperature have stabilized, the gas is switched from nitrogen to 100% oxygen. Then, measure the time it takes for the temperature to rise to 200℃ in an adiabatic state.

Temperature rise profile from spontaneous heating test

Temperature rise profile from spontaneous heating test