Figure 3
From: Catalytic depolymerization of a typical lignite for improving tar yield by Co and Zn catalyst
GC × GC-MS chromatogram of the different tar. 3D contour plot (left), and 2D contour plot (right): a, a1, tar from raw coal; b, b1, Co-2 tar; c, c1, Zn-1 tar. The marked zones on the 2D contour plot represented phenols, one-ring aromatics, two-ring aromatics and alkanes.
