Evolution Mechanism of Macromolecular Structure in Coal during Heat Treatment: Based on FTIR and XRD In Situ Analysis Techniques

Table 2

Statistic results of the infrared spectral structural parameters of five coal samples before and after pyrolysis.

Sample number	Temperature (°C)	Structural parameters
		GZ	Raw coal	–	1.965	0.885	1.062	0.585
100°C	–		1.941	0.880	1.063	0.592
200°C	–		1.894	0.867	1.066	0.599
300°C	–		1.817	0.842	1.072	0.606
400°C	–		1.693	0.794	1.087	0.612
500°C	–		1.492	0.699	1.127	0.619
HB	Raw coal	–	1.843	0.830	0.997	0.546
	100°C	–	1.821	0.825	0.997	0.552
	200°C	–	1.777	0.813	1.000	0.559
	300°C	–	1.705	0.790	1.005	0.565
	400°C	–	1.588	0.745	1.020	0.572
	500°C	–	1.399	0.656	1.057	0.578
HN	Raw coal	–	1.766	0.812	0.954	0.541
	100°C	–	1.721	0.776	0.931	0.555
	200°C	–	1.701	0.771	0.932	0.562
	300°C	–	1.660	0.760	0.934	0.568
	400°C	–	1.592	0.738	0.939	0.575
	500°C	–	1.483	0.695	0.953	0.581
KL	Raw coal	2.947	1.687	0.760	0.912	0.502
	100°C	2.916	1.667	0.756	0.913	0.508
	200°C	2.852	1.626	0.745	0.915	0.514
	300°C	2.743	1.561	0.723	0.920	0.520
	400°C	2.559	1.454	0.682	0.934	0.526
	500°C	–	1.281	0.600	0.968	0.532
SX	Raw coal	2.668	1.528	0.688	0.826	0.455
	100°C	2.641	1.510	0.684	0.827	0.461
	200°C	2.583	1.473	0.674	0.829	0.466
	300°C	2.484	1.413	0.655	0.833	0.472
	400°C	2.317	1.316	0.617	0.845	0.477
	500°C	–	1.160	0.543	0.877	0.483

The parameter calculation method: .