High temperature and high pressure 1H n.m.r. and e.s.r. studies on coal liquefaction reactions

Changes in chemical reactions during coal liquefaction of Yallourn brown coal and Akabira bituminous coal were monitored by using high temperature and high pressure 1H n.m.r. A simple high temperature and high pressure e.s.r. cell was constructed and the variation in concentration of free radicals during coal liquefaction reactions was monitored under the same experimental conditions as for n.m.r. With the liquefaction and coking reaction, typical spectra of n.m.r. and e.s.r. were obtained and could distinguish the reaction steps: swelling; liquefaction; coking. The combination of high temperature and high pressure n.m.r. and e.s.r. is promising to the chemistry of coal liquefaction reactions.