"[L]arge particles may not be heated uniformly... consequently pyrolysis yields are less. Heating rate is also important. During slow heat-up as... in simple... s most coals begin to decompose [≈]350-400°C. ...[L]iquid and gaseous products ...peak ...[≈]425-475°C. This phase of pyrolysis ends ...[≈]500-550°C. ...[V]ery rapid heating [e.g.] in entrained flow gasifiers ...quickly by-passes this stage, so... evolution of liquids is nil."