Table 2. Changes of Light and Heavy Components after Tar Cracking.

	calcination time
	coal	PC	HPC	ZHPC-1min	ZHPC-3min	ZHPC-5min	ZHPC-8min
light component (g)	0.3551	0.4390	0.4537	0.3698	0.3728	0.3551	0.3618
heavy component (g)	0.9689	0.7620	0.5512	0.3279	0.3100	0.2813	0.3045
light component ratio (%)	26.8	36.55	45.15	53	54.60	55.80	54.30