Influences of the Introduced O-Containing Functional Groups on the Gaseous Pyrolysis Product of Superfine Pulverized Coal

An O-containing structure in coal can affect the pyrolysis process; however, the influence of the introduced O-containing functional groups has rarely been investigated. To study this issue, two kinds of representative coal were selected for superfine pulverization and chemical oxidation. The C-13-NMR and FTIR experiments demonstrated that O-containing functional groups, such as carboxyl, could be added into the carbon skeleton after 5 wt% peracetic acid modification. It was found that 1 wt% and 5 wt% hydrogen peroxide solutions had no such ability, but the 1 wt% solution could expand the pore structure and increase the specific surface area. Thermogravimetric experiments in the air showed that peracetic acid oxidation could increase the weight loss rate below 400 degrees C and reduce ignition temperatures. Pyrolysis experiments in the tube furnace proved that the amount of CO released increased and the commencing temperature decreased by 50 degrees C after the modification of peracetic acid. The generation paths of C2H4 and C6H6 changed; new generation peaks appeared near 200 degrees C. It has been strongly confirmed that superfine pulverization and chemical oxidation modification has obvious synergistic effects on the introduction of O-containing functional groups, especially for anthracite samples.