抄録
In this study, we have investigated the oxidation properties of a brown coal at low temperature under humid atmosphere. Dried brown coal samples of approximately 0.78 g were enclosed in IL of aluminum coated Tedlar bag with water of 0.22 g and pseudo-air consisting of 21 % O_2/He. Then it was heated in a drying oven between 60 and 90 ℃. Gas sampling and analysis by gas chromatography and mass spectroscopy were took place. We have found that the water vapor significantly promote the oxidation of brown coal. The mass spectroscopic investigation with stable isotopes including ^<18>O_2 and H_2^<18>O reveals that the water vapor reacts predominantly with brown coal surfaces. Then the removal of hydrogen (proton) from the complex by oxygen to form water vapor and the evolution of CO_2 from the coal surface occur simultaneously, resulting in promotion of low temperature oxidation. Those findings will help to understand the self-combustion phenomena of brown coal.
