Test and study on spontaneous ignition temperature of a Philippine coal

Abstract

Temperature programmed method is adopted to study spontaneous combustion of a Philippine coal. A tested sample exposed to the air and a reference sample isolated from the air are placed and heated in an oven. When the tested sample temperature reaches a certain value, spontaneous combustion occurs, causing the temperature increase curves of the two samples separating. Two different holders, isothermal copper tube and stainless steel basket, are used respectively to simulate two different temperature and oxygen concentration boundary conditions. The results show that spontaneous ignition temperature of the coal in the isothermal tube only with top cover ventilation is about 120°C, while that of the sample in the basket with six-surface ventilation is about 100°C. Additionally, as the temperature of the sample in the basket is higher than 40°C, the temperature increase curve deviates from the original trend due to heat release from oxygen adsorption.

Keywords:

• Philippine coal
• Spontaneous combustion
• Ignition temperature
• Temperature Programmed method
• Testing