Analysis of Pyrolysis Characteristics and Kinetics of Cigar Tobacco and Flue-Cured Tobacco by TG-FTIR

Figures & Tables

Sample	T_S (°C)	T_max (°C)	R_max (% min⁻¹)	R_mean (% min⁻¹)	ΔT_1/2 (°C)	D_i (10⁻⁷%² °C⁻³ min⁻²)	Residue (%)
CFT
5	130	313	−2.01	−0.43	105	2.02	24.46
10	134	323	−3.96	−0.86	112	6.99	24.73
15	142	330	−5.78	−1.27	121	12.91	25.71
20	146	335	−7.65	−1.68	122	21.61	26.11
CWT
5	131	297	−2.16	−0.43	72	3.30	24.75
10	140	307	−4.21	−0.83	76	10.62	27.56
15	144	310	−6.22	−1.23	79	21.61	28.25
20	151	315	−8.18	−1.62	82	33.94	28.97
FCT
5	101	188	−1.82	−0.47	60	7.51	18.75
10	103	197	−3.73	−0.92	62	27.30	20.06
15	108	201	−5.60	−1.36	64	54.80	21.38
20	115	206	−7.30	−1.80	65	85.30	21.82

Wavenumber (cm⁻¹)	Functional groups	Compounds	References
3500–4000 (selected:3566)	O-H Symmetrical and asymmetrical stretching	H₂O	(14, 42, 45)
2250–2500 (selected:2359)	Asymmetrical stretching in O=C=O	CO₂	(14, 45)
2850–3030 (selected:3016)	C-H Stretching	CH₄	(43)
2000–2250 (selected:2190)	Stretching vibration in CO	CO	(14, 45)
1710–1800 (selected:1749)	C=O Stretching	Carbonyl groups	(14, 45)
1050–1200 (selected:1180)	C-O Stretch	Hydroxyl groups	(14)
1450–1650	Aromatic C=C-C ring stretch	Aromatics	(42, 43)
3070–3130 (selected:3076)	Aromatic C-H in plane bend	Aromatics	(42, 43)
966		NH₃	(42)

Sample	Stage	Reaction	Fitted equation	A (min⁻¹)	E_a (kJ mol⁻¹)	Correlation coefficient R²
CFT	II	D1	Y = −10165.86x + 6.09	4.49 × 10⁴	84.5	0.995
	III	F3/2	Y = −23551.40x + 26.44	7.12 × 10¹³	195.8	0.990
	III	F2	Y = −28195.40x + 34.48	2.65 × 10¹⁷	234.4	0.997
CWT	II	D1	Y = −10305.79x + 5.30	7.74 × 10⁴	85.7	0.998
	III	F3/2	Y = −22403.96x + 25.26	4.17 × 10¹³	186.2	0.963
	III	F2	Y = −27020.35x + 33.40	1.73 × 10¹⁷	224.7	0.984

Sample	Stage I		Stage II		Stage III

	Temperature interval (°C)	Mass loss (%)	Temperature interval (°C)	Mass loss (%)	Temperature interval (°C)	Mass loss (%)
CFT
5	40–130	2.84	130–283	22.60	283–397	26.43
10	40–134	2.88	134–292	23.26	292–411	26.78
15	40–142	3.03	142–296	23.07	296–415	26.77
20	40–146	3.06	146–299	23.35	299–424	27.34
CWT
5	40–131	2.81	131–273	20.04	273–407	25.33
10	40–140	2.85	140–284	20.83	284–417	24.65
15	40–144	2.84	144–287	20.94	287–419	24.32
20	40–151	2.96	151–291	21.08	291–426	24.44
FCT
5	40–101	1.29	101–216	21.09	216–401	38.82
10	40–103	1.10	103–227	22.27	227–405	38.41
15	40–108	1.15	108–232	21.76	232–408	38.19
20	40–115	1.27	115–240	22.12	240–416	37.40

Conversion	CFT					CWT					FCT

	FWO		KAS		Difference	FWO		KAS		Difference	FWO		KAS		Difference

	E_a (kJ mol⁻¹)	Correlation coefficient R²	E_a (kJ mol⁻¹)	Correlation coefficient R²	(%)	E_a (kJ mol⁻¹)	Correlation coefficient R²	E_a (kJ mol⁻¹)	Correlation coefficient R²	(%)	E_a (kJ mol⁻¹)	Correlation coefficient R²	E_a (kJ mol⁻¹)	Correlation coefficient R²	(%)
0.1	207.4	0.984	210.3	0.982	1.40	160.4	0.993	161.0	0.993	0.35	102.2	0.999	100.1	0.999	1.02
0.2	249.9	0.995	254.2	0.994	1.72	206.9	0.987	209.1	0.986	1.05	120.4	0.999	118.9	0.999	0.76
0.3	253.5	0.994	257.6	0.994	1.59	229.3	0.990	232.2	0.989	1.26	121.4	0.996	119.6	0.996	0.92
0.4	252.2	0.995	255.9	0.994	1.42	228.8	0.992	231.4	0.991	1.12	155.4	0.994	154.7	0.994	0.35
0.5	222.2	0.995	224.0	0.994	0.77	215.6	0.993	217.2	0.993	0.74	172.3	0.996	172.0	0.996	0.15
0.6	219.3	0.994	220.6	0.993	0.58	221.9	0.994	223.5	0.994	0.74	171.9	0.996	171.2	0.996	0.38
0.7	266.4	0.999	269.7	0.988	1.21	238.0	0.989	240.0	0.988	0.82	173.5	0.998	172.5	0.998	0.52
0.8	301.3	0.992	305.7	0.991	1.43	234.3	0.994	235.2	0.994	0.38	162.6	0.984	160.5	0.982	1.06
0.9	315.2	0.993	319.3	0.993	1.28	259.3	0.994	260.5	0.994	0.45	192.1	0.983	190.4	0.980	0.84
Average	254.2		257.5			221.6		223.3			155.4		151.1

Mechanisms	Symbol	G(α)	f(α)
One-dimensional diffusion	D1	α²	12α−1 {1 \over 2}{\alpha ^{ - 1}}
Two-dimensional diffusion	D2	α + (1 − α)ln(1 − α)	[−ln(1 − α)]⁻¹
Three-dimensional diffusion	D3	[1−(1−α)13]2 {\left[ {1 - {{\left( {1 - \alpha } \right)}^{{1 \over 3}}}} \right]^2}	32(1−α)23[1−(1−α)13]−1 {3 \over 2}{\left( {1 - \alpha } \right)^{{2 \over 3}}}{\left[ {1 - {{\left( {1 - \alpha } \right)}^{{1 \over 3}}}} \right]^{ - 1}}
Avrami-Erofeev	A2	[−ln(1−α)]12 {\left[ { - \ln \left( {1 - \alpha } \right)} \right]^{{1 \over 2}}}	2(1−α)[−ln(1−α)]12 2\left( {1 - \alpha } \right){\left[ { - \ln \left( {1 - \alpha } \right)} \right]^{{1 \over 2}}}
Avrami-Erofeev	A3	[−ln(1−α)]13 {\left[ { - \ln \left( {1 - \alpha } \right)} \right]^{{1 \over 3}}}	3(1−α)[−ln(1−α)]23 3\left( {1 - \alpha } \right){\left[ { - \ln \left( {1 - \alpha } \right)} \right]^{{2 \over 3}}}
First-order reaction	F1	−ln(1 − α)	1 − α
1.5-order reaction	F3/2	2[(1−α)−12]−2 2\left[ {{{\left( {1 - \alpha } \right)}^{-{1 \over 2}}}} \right] - 2	(1−α)32 {\left( {1 - \alpha } \right)^{{3 \over 2}}}
Second-order reaction	F2	(1 − α)⁻¹ − 1	(1 − α)²
Contracting area	R2	1−(1−α)12 1 - {\left( {1 - \alpha } \right)^{{1 \over 2}}}	2(1−α)12 2{\left( {1 - \alpha } \right)^{{1 \over 2}}}
3D contracting volume	R3	1−(1−α)13 1 - {\left( {1 - \alpha } \right)^{{1 \over 3}}}	3(1−α)23 3{\left( {1 - \alpha } \right)^{{2 \over 3}}}