The document discusses thermodynamic analysis of biomass gasification. It analyzes the reaction thermoneutral points (R-TNPs) for gasifying rice husk with different gasifying agents and their ratios. Key findings include: - For CO2 alone, R-TNPs decreased with higher CO2:carbon ratios, with syngas output and CO2 conversion also decreasing. Heat requirements initially rose then fell with a heat exchanger. - R-TNPs were not found for H2O alone at any ratio. - With CO2+H2O, R-TNPs were only obtained at low total gasifier agent:carbon ratios. Higher ratios supported

1. Group Members:
Pritish Shardul
Mohit Meena
Guide: Mr. Ganesh Kale,
Senior Scientist,
NCL, Pune

2. Introduction
 Gasification is a process that converts organic or fossil based
carbonaceous materials mainly into carbon monoxide,
hydrogen and carbon dioxide
 Today there is a huge demand for fuel because of the
increasing population. Biomass is renewable resource and is
available very easily. It is the third among the primary energy
sources after coal and oil
 The gasification of biomass allows the production of a
synthesis gas or “syngas”, consisting primarily of H2, CO, CH4,
CO2 and N2, which further has a variety of uses

3. Introduction
 A thermodynamic analysis of the process of biomass
gasification was conducted to find the Thermoneutral Points
(TNP’s) for different gasifying agents for different compositions
of the input streams to the gasifier
 Reaction TNP’s (R-TNP’s), Process TNP’s (P-TNP’s) with and
without Heat Exchanger were calculated and product gas
compositions at TNP’s were analysed for syngas production,
syngas ratio, %CO2 conversion and heat utilities during the
course of this study

4. Introduction
 It is assumed that the exit products of the coal gasifier are in
thermodynamic equilibrium.
 HSC Chemistry software is well known software that uses
the Gibbs free energy minimization algorithm to find the
equilibrium product composition from a feed mixture and
has been used in gasification studies earlier
[Kumabe K, Hanaoka T, Fujimoto S, Minowa T, Sakanishi K.
Co-gasification of woody biomass and coal with air and
steam. Fuel 2007;86:684–9.]
 We have also used HSC Chemistry 5.11 for our calculations

5. Literature Survey
 We downloaded many abstracts and shortlisted around 80
relevant abstracts
 We sorted out the shortlisted abstracts in the following
divisions
- Thermodynamic Analysis
- Experimental
- Modelling
- Reviews
- Theoretical

6. Biomass Selection
 We chose Rice husk as the biomass to be gasified.
Composition by weight: 47.8% C, 5.1% H, 38.9% O, 0.1% N
(Ref : Jenkins, B.M. & Ebeling, J.M, Correlation of physical &
chemical properties of terrestrial biomass with conversion,
symposium, Energy from biomass & waste, Pg no-371)
 Weight for 1 mole of rice husk is calculated to be 25.105 grams
 We calculated the compositions in moles for one mole of
carbon in biomass as follows,
For 1 mole carbon, 0.6402 moles of H2, 0.3052 moles O2,
0.0008 moles N2
 Temperature range considered in this study is 500-1000 °C

7. Methodology
PART A : R-TNP Analysis
 For a particular feed condition, we calculated the output
composition of the reactor using 'Equilibrium Compositions'
module of HSC Chemistry 5.11 at temperatures ranging from
500 to 1000 °C, with intervals of 50 °C and constant pressure
of 1 bar
 Using those compositions and 'Reaction Equations' module of
HSC Chemistry 5.11, we calculated the reaction enthalpy at
respective temperatures

8. Methodology (cont.)
PART A : R-TNP Analysis
 By plotting the graph of Enthalpy vs. Temperature we
calculated the R-TNP's of the reaction
 We calculated the product gas compositions at the R-TNP's
and analysed the parameters: Syngas, Syngas Ratio, %CO2
Conversion, Heat utility (without HE), Reduced Heat Utility
(with HE)

9. 1. Gasifying Agent: CO2
 We defined the parameter CCBR (CO2 to Carbon in biomass
molar ratio)
 We varied CCBR in the input of the gasifier. Values of CCBR
are: 0, 0.5, 1, 1.5, 2, 2.5, 3, 4, 5
 From the graphs of enthalpy change vs. temperature for all
the CCBR, we found that thermoneutral points (TNP’s) can
be obtained for all the CCBR considered except 0 and 0.5
Thermoneutral temperature decreased with increase of
CCBR

10. Reaction TNP’s
-160
-140
-120
-100
-80
-60
-40
-20
0
20
40
500 550 600 650 700 750 800 850 900 950 1000
Enthalpy(KJ)
Temp (oC)
Reaction Enthalpy
CCBR 5
CCBR 4
CCBR 3
CCBR 2.5
CCBR 2
CCBR 1.5
CCBR 1
CCBR 0.5
CCBR 0

11. Reaction TNP’s
550
570
590
610
630
650
670
690
710
730
750
1 1.5 2 2.5 3 3.5 4 4.5 5
TNP(oC)
CCBR
TNP’S

12. CCBR
R-TNP
oC
CO2(g)
moles
CO(g)
moles
H2O(g)
moles
H2(g)
moles
CH4(g)
moles
N2(g)
moles
C
moles
1 728.4831 0.4989 1.4924 0.1203 0.5024 0.0087 0.0008 0
1.5 688.1006 0.9606 1.518 0.1707 0.4495 0.0099 0.0008 0.0115
2 665.2904 1.4324 1.538 0.2076 0.4136 0.0095 0.0008 0.0202
2.5 648.5094 1.9114 1.5512 0.236 0.3861 0.0089 0.0008 0.0285
3 635.3741 2.3938 1.5636 0.2588 0.3645 0.0084 0.0008 0.0342
4 615.2267 3.3678 1.5809 0.2939 0.3315 0.0074 0.0008 0.0439
5 600 4.3489 1.5921 0.3202 0.3066 0.0066 0.0008 0.0524
Reaction TNP’s

13. CCBR
R-TNP
oC
Syngas
(moles)
Syngas
Ratio
% CO2
Conversion
1 728.4831 1.99482 0.336652 50.115
1.5 688.1006 1.96747 0.296094 35.9573
2 665.2904 1.95162 0.268934 28.38
2.5 648.5094 1.93733 0.248923 23.544
3 635.3741 1.92809 0.233109 20.2067
4 615.2267 1.91235 0.209659 15.805
5 600 1.8987 0.192576 13.022
Reaction TNP’s

14. Gasifying Agent: CO2 - Trends
 Syngas, Syngas Ratio and % CO2 conversion decreased with
increase in CCBR
 Heat utility (without HE) increased linearly with increase in
CCBR
 However, Heat utility (with HE) decreased then remained
constant with the increase of CCBR

15. Reaction TNP’s
1.88
1.9
1.92
1.94
1.96
1.98
2
1 1.5 2 2.5 3 3.5 4 4.5 5
Syngas(moles)
CCBR
Syngas

16. Reaction TNP’s
0.15
0.2
0.25
0.3
0.35
1 1.5 2 2.5 3 3.5 4 4.5 5
SyngasRatio
CCBR
Syngas Ratio

17. Reaction TNP’s
0
10
20
30
40
50
60
1 1.5 2 2.5 3 3.5 4 4.5 5
%CO2Conv.
CCBR
% CO2 Conversion

18. Configuration (Heat Utility) without Heat Exchanger

19. Heat Utility at Reaction TNP’s
60
80
100
120
140
160
180
1 1.5 2 2.5 3 3.5 4 4.5 5
Heatutility(KJ)
CCBR
Heat Utility (without HE)

20. Configuration (Reduced Heat Utility) with Heat Exchanger

21. Heat Utility at Reaction TNP’s
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
1 1.5 2 2.5 3 3.5 4 4.5 5
Heatutility(KJ)
CCBR
Reduced Heat utility (with HE)

22. 2. Gasifying Agent: H2O
 We defined the parameter HCBR (H2O to Carbon in biomass
molar ratio)
 We varied HCBR in the in the input of the gasifier. Values of
HCBR are: 0, 1, 2, 3, 4
 From the graphs of enthalpy change vs. temperature for all
the HCBR, we found that no thermoneutral points can be
obtained for any of the HCBR considered

23. Reaction TNP’s
-160
-140
-120
-100
-80
-60
-40
-20
0
500 550 600 650 700 750 800 850 900 950 1000
Enthalpy(KJ)
Temp (oC)
Reaction Enthalpy
HCBR 0
HCBR 1
HCBR 2
HCBR 3
HCBR 4

24. 3. Gasifying Agent: CO2 & H2O
 We defined the parameter GaCR (Gasifying Agents to
Carbon in Biomass molar ratio)
 We varied GaCR from 1 to 4 in the input of gasifier and
considered different combinations of CCBR and HCBR for
each GaCR
 For GaCR = 1, R-TNP’s were obtained only for 1/0
 For GaCR = 2, P-TNP’s were obtained only for 2/0
 For GaCR = 3, P-TNP’s were obtained for 3/0, 2.5/0.5
 For GaCR = 4, P-TNP’s were obtained for all combinations
which had CCBR greater than or equal to 3

25. Reaction TNP’s at GaCR = 1
-160
-140
-120
-100
-80
-60
-40
-20
0
20
500 550 600 650 700 750 800 850 900 950 1000
Enthalpy(KJ)
Temp (oC)
Reaction Enthalpy
1/0
0.5/0.5
0/1.0

26. Reaction TNP’s at GaCR = 2
-140
-120
-100
-80
-60
-40
-20
0
20
500 550 600 650 700 750 800 850 900 950 1000
Enthalpy(KJ)
Temp (oC)
Reaction Enthalpy
2/0
1.5/0.5
1.0/1.0
0.5/1.5
0.0/2.0

27. Reaction TNP’s at GaCR = 3
-140
-120
-100
-80
-60
-40
-20
0
20
500 550 600 650 700 750 800 850 900 950 1000
Enthalpy(KJ)
Temp (oC)
Reaction Enthalpy
3/0
2.5/0.5
2.0/1.0
1.5/1.5
1.0/2.0
0.5/2.5
0.0/3.0

28. Reaction TNP’s at GaCR = 4
-140
-120
-100
-80
-60
-40
-20
0
20
500 550 600 650 700 750 800 850 900 950 1000
Enthalpy(KJ)
Temp (oC)
Reaction Enthalpy
4/0
3.75/0.25
3.5/0.5
3.25/0.75
3.0/1.0
2.5/1.5
2.0/2.0
1.5/2.5
1.0/3.0
0.5/3.5
0.0/4.0

29. GaCR
CCBR/
HCBR
TNP
oC
CO2(g)
moles
CO(g)
moles
H2O(g)
moles
H2(g)
moles
CH4(g)
moles
N2(g)
moles
C
moles
1 1/0 728.483 0.4989 1.4924 0.1203 0.5024 0.0087 0.001 0
2 2/0 665.290 1.4324 1.538 0.2076 0.4136 0.0095 0.001 0.0201
3 3/0 635.374 2.3938 1.5636 0.2588 0.3645 0.0084 0.001 0.0342
3 2.5/0.5 718.730 2.0504 1.4485 0.5612 0.5767 0.0011 0.001 0
4 4/0 615.227 3.3678 1.5809 0.2940 0.3315 0.0074 0.001 0.0439
4 3.75/0.25 612.965 3.2257 1.5054 0.4032 0.4577 0.0145 0.001 0.0044
4 3.5/0.5 647.993 3.0412 1.4533 0.5743 0.5547 0.0055 0.001 0
4 3.25/0.75 728.611 2.8031 1.4465 0.8077 0.5816 0.0004 0.001 0
4 3/1 858.285 2.5239 1.4761 1.0865 0.5537 0.00001 0.001 0
Reaction TNP’s

30. GaCR
CCBR/
HCBR
TNP
oC
Syngas
(moles)
Syngas
Ratio
% CO2
Conversion
1 1/0 728.483 1.99482 0.336652 50.115
2 2/0 665.290 1.95162 0.268934 28.38
3 3/0 635.374 1.92809 0.233109 20.20667
3 2.5/0.5 718.730 2.0252 0.398136 17.984
4 4/0 615.227 1.91235 0.209659 15.805
4 3.75/0.25 612.965 1.96314 0.304065 13.98133
4 3.5/0.5 647.993 2.00804 0.381711 13.10857
4 3.25/0.75 728.611 2.02811 0.402081 13.75077
4 3/1 858.285 2.0298 0.37511 15.87
Reaction TNP’s

31. GaCR = 4 - Trends
 R-TNP first slightly decreased with HCBR then increased
 Syngas increased (from 1.9124 to 2.0298 moles per moles of
Biomass) with increase in HCBR
 Syngas ratio showed a maxima (of 0.403) at HCBR = 0.714
 % CO2 conversion first decreased then increased with increase
in HCBR
 Heat utility (with HE) increased with increase in HCBR
 However, Heat utility (without HE) first decreased slightly and
the increased with increase in HCBR

32. Reaction TNP’s at GaCR = 4
600
650
700
750
800
850
900
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
TNP(oC)
HCBR
TNP

33. Reaction TNP’s at GaCR = 4
1.9
1.92
1.94
1.96
1.98
2
2.02
2.04
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Syngas(moles)
HCBR
Syngas

34. Reaction TNP’s at GaCR = 4
0
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
syngasRatio
HCBR
Syngas Ratio

35. Reaction TNP’s at GaCR = 4
10
11
12
13
14
15
16
17
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
%CO2Conversion
HCBR
% CO2 conversion

36. Reaction TNP’s at GaCR = 4
18
20
22
24
26
28
30
32
34
36
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
HeatUtility(KJ)
HCBR
Reduced Heat Utility (with HE)

37. Reaction TNP’s at GaCR = 4
250
270
290
310
330
350
370
390
410
430
450
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
HeatUtility
HCBR
Heat Utility (without HE)

38. Methodology
PART B: Process TNP Analysis (without HE)
 We calculated the Biomass preheating value for temperatures
between 500 to 1000 °C, with intervals of 50 °C.
Cp value of Rice husk was taken as 2.094 J/gK [Kaupp (1984)]
 We then calculated the preheating value of gasifying agents
(CO2 and H2O) for respective temperatures. Cp value of CO2
and H2O was taken from Perry's Chemical Engineers'
Handbook 7e
 We then calculated the Process enthalpy (without Heat
Exchanger) as the sum of Reaction enthalpy, Biomass
preheating and Gasifying Agents preheating
(Figure 1)

39. Configuration (Heat Utility) without Heat Exchanger

40. Methodology (cont.)
PART B: Process TNP Analysis (without HE)
 We plotted the graph of Process enthalpy without heat
exchanger vs. Temperature and calculated the P-TNP's without
HE
 We calculated the product gas compositions at the P-TNP's
and analysed the parameters: Syngas, Syngas Ratio, %CO2
Conversion, Reaction Enthalpy at P-TNP's

41. 1. Gasifying Agent: CO2
 We varied CCBR in the input of gasifier from 0 to 5
 From the graphs of enthalpy change vs. temperature for all
the CCBR, we found that TNP’s can be obtained for all the
CCBR except 0 and 5

42. Process TNP’s without Heat Exchanger
-150
-100
-50
0
50
100
150
200
250
300
350
500 550 600 650 700 750 800 850 900 950 1000
Enthalpy(KJ)
Temp oC
Process Enthalpy (without HE)
CCBR 0
CCBR 0.5
CCBR 1
CCBR 1.5
CCBR 2
CCBR 2.5
CCBR 3
CCBR 4
CCBR 5

43. CCBR
TNP
oC
CO2(g)
moles
CO(g)
moles
H2O(g)
moles
H2(g)
moles
CH4(g)
moles
N2(g)
moles
C
moles
0.5 714.931 0.3081 0.8768 0.1171 0.4927 0.0151 0.001 0.3
1 655.605 0.7993 0.8063 0.205 0.4024 0.0163 0.001 0.3781
1.5 619.546 1.3119 0.7202 0.266 0.3426 0.0157 0.001 0.4522
2 591.731 1.832 0.6327 0.3134 0.297 0.0148 0.001 0.5205
2.5 568.257 2.3542 0.5492 0.3524 0.2597 0.0139 0.001 0.5827
3 547.193 2.8771 0.4697 0.386 0.2278 0.0131 0.001 0.64
4 509.452 3.9189 0.3303 0.442 0.1748 0.0116 0.001 0.7393
Process TNP’s without Heat Exchanger

44. CCBR
TNP
oC
Syngas
(moles)
Syngas
Ratio
% CO2
Conversion
0.5 714.931 1.3695 0.56193 38.38
1 655.605 1.2087 0.49907 20.07
1.5 619.546 1.0628 0.475701 12.54
2 591.731 0.9297 0.469417 8.4
2.5 568.257 0.8089 0.47287 5.832
3 547.193 0.6975 0.48499 4.0966
4 509.452 0.5051 0.529216 2.0275
Process TNP’s without Heat Exchanger

45. Gasifying Agent: CO2 - Trends
 P-TNP’s, Syngas and %CO2 conversion decreased with
increase in CCBR
 Syngas Ratio showed a minima (of 0.469) at CCBR =2.056
 Reaction Enthalpy at P-TNP’s was calculated and it showed a
decrease with increase in CCBR

46. Process TNP’s without Heat Exchanger
500
550
600
650
700
750
0.5 1 1.5 2 2.5 3 3.5 4
TNP(oC)
CCBR
P- TNP

47. Process TNP’s without Heat Exchanger
0.4
0.6
0.8
1
1.2
1.4
0.5 1 1.5 2 2.5 3 3.5 4
Syngas(moles)
CCBR
Syngas

48. Process TNP’s without Heat Exchanger
0.4
0.45
0.5
0.55
0.6
0.5 1 1.5 2 2.5 3 3.5 4
SyngasRatio
CCBR
Syngas Ratio

49. Process TNP’s without Heat Exchanger
0
5
10
15
20
25
30
35
40
45
0.5 1 1.5 2 2.5 3 3.5 4
%CO2conversion
CCBR
%CO2 conversion

50. Process TNP’s without Heat Exchanger
-120
-110
-100
-90
-80
-70
-60
-50
0.5 1 1.5 2 2.5 3 3.5 4
Enthalpy(KJ)
CCBR
Reaction Enthalpy at P-TNP's

51. 2. Gasifying Agent: H2O
 We varied HCBR from 0 to 4 in the input of gasifier
 From the graphs of enthalpy change vs. temperature for all
the HCBR, we found that TNP can be obtained only for HCBR
= 1, in the range of 500-1000 °C
HCBR
TNP
oC
CO2(g)
moles
CO(g)
moles
H2O(g)
moles
H2(g)
moles
CH4(g)
moles
N2(g)
moles
C
moles
Syngas
moles
Syngas
Ratio
% CO2
Conv.
1 580.012 0.4341 0.2164 0.5254 0.7704 0.1721 0.001 0.1775 0.9868 3.56 47.46

52. Process TNP’s without Heat Exchanger
-200
-100
0
100
200
300
400
500 550 600 650 700 750 800 850 900 950 1000
Enthalpy(KJ)
Temp C
Process Enthalpy (without HE)
HCBR 0
HCBR 1
HCBR 2
HCBR 3
HCBR 4

53. 3. Gasifying Agent: CO2 & H2O
 We varied GaCR from 1 to 4 in the input of gasifier
 For GaCR = 1, P-TNP’s were obtained for all the
combinations of CCBR and HCBR considered
 For GaCR = 2, P-TNP’s were obtained for three combinations
2/0, 1.5/0.5, 1/1
 For GaCR = 3, P-TNP’s were obtained for two combinations
3/0, 2.5/0.5
 For GaCR =4, only 1 P-TNP was obtained for 4/0

54. Process TNP’s at GaCR = 1
-100
-50
0
50
100
150
500 550 600 650 700 750 800 850 900 950 1000
Enthalpy(KJ)
Temp oC
Process Enthalpy (without HE)
1/0
0.5/0.5
0/1

55. Process TNP’s at GaCR = 2
-100
-50
0
50
100
150
200
500 550 600 650 700 750 800 850 900 950 1000
Enthalpy(KJ)
Temp oC
Process Enthalpy (without HE)
2/0
1.5/0.5
1.0/1.0
0.5/1.5
0.0/2.0

56. Process TNP’s at GaCR = 3
-50
0
50
100
150
200
250
300
500 550 600 650 700 750 800 850 900 950 1000
Enthalpy(KJ)
Temp oC
Process Enthalpy (without HE)
3/0
2.5/0.5
2.0/1.0
1.5/1.5
1.0/2.0
0.5/2.5
0.0/3.0

57. Process TNP’s at GaCR = 4
-50
0
50
100
150
200
250
300
350
400
500 550 600 650 700 750 800 850 900 950 1000
Enthalpy(KJ)
Temp oC
Process Enthalpy (without HE)
4/0
3.75/0.25
3.5/0.5
3.25/0.75
3.0/1.0
2.5/1.5
2.0/2.0
1.5/2.5
1.0/3.0
0.0/4.0

58. GaCR
CCBR/
HCBR
TNP
oC
CO2(g)
moles
CO(g)
moles
H2O(g)
moles
H2(g)
moles
CH4(g)
moles
N2(g)
moles
C
moles
1 1/0 655.605 0.7993 0.8063 0.205 0.4024 0.0163 0.001 0.3781
1 0.5/0.5 623.6980 0.6311 0.4779 0.3699 0.6428 0.0636 0.0010 0.3274
1 0/1 580.012 0.4341 0.2164 0.5254 0.7704 0.1721 0.001 0.1775
2 2/0 591.731 1.832 0.6327 0.3134 0.297 0.0148 0.001 0.5205
2 1.5/0.5 560.256 1.5802 0.3708 0.5787 0.4512 0.0551 0.001 0.4938
2 1/1 518.773 1.2883 0.1726 0.8608 0.5059 0.1366 0.001 0.4025
3 3/0 547.193 2.8771 0.4697 0.386 0.2278 0.0131 0.001 0.64
3 2.5/0.5 514.018 2.5669 0.2587 0.7174 0.3283 0.0471 0.001 0.6272
4 4/0 509.452 3.9189 0.3303 0.442 0.1748 0.0116 0.001 0.7393
Process TNP’s without Heat Exchanger

59. GaCR
CCBR/
HCBR
TNP
oC
Syngas
(moles)
Syngas
Ratio
% CO2
Conversion
1 1/0 655.605 1.2087 0.49907 20.07
1 0.5/0.5 623.6980 1.1207 1.345051 -26.22
1 0/1 580.012 0.9868 3.560074 -
2 2/0 591.731 0.9297 0.469417 8.4
2 1.5/0.5 560.256 0.822 1.216828 -5.34667
2 1/1 518.773 0.6785 2.931054 -28.83
3 3/0 547.193 0.6975 0.48499 4.096667
3 2.5/0.5 514.018 0.587 1.269037 -2.676
4 4/0 509.452 0.5051 0.529216 2.0275
Process TNP’s without Heat Exchanger

60. Gasifying Agent: Both -Trends
 P-TNP’s and Syngas production decreased with increase in
HCBR for both GaCR 1 and 2
 Syngas ratio showed an increase with increase in HCBR for
both the GaCR
 Reaction enthalpy at P-TNP’s decreased with increase in
HCBR

61. Process TNP’s without HE at GaCR = 1 & 2
500
520
540
560
580
600
620
640
660
680
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
TNP(oC)
HCBR
P- TNP's
GaCR 1
GaCR 2

62. Process TNP’s without HE at GaCR = 1 & 2
0.6
0.7
0.8
0.9
1
1.1
1.2
1.3
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
syngas(moles)
HCBR
Syngas
GaCR 1
GaCR 2

63. Process TNP’s without HE at GaCR = 1 & 2
0
0.5
1
1.5
2
2.5
3
3.5
4
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
SyngasRatio
HCBR
Syngas ratio
GaCR 1
GaCR 2

64. Process TNP’s without HE at GaCR = 1 & 2
-120
-100
-80
-60
-40
-20
0
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1
Enthalpy(KJ)
HCBR
Reaction Enthalpy at P-TNP's
GaCR 1
GaCR 2

65. Methodology
PART C: Process TNP Analysis (with HE)
 We calculated the Product Gas Cooling Energy released at
respective temperature. Product gas consisted of CO2(g),
CO(g), C, H2O(g), H2(g), CH4(g) and N2(g). Cp values of all the
components were taken from Perry's Chemical Engineers'
Handbook 7e
 We then calculated the Process enthalpy (with Heat
Exchanger) as the sum of Reaction enthalpy, Biomass
preheating, Gasifying Agents preheating + Product Gas
Cooling (Figure 2)

66. Configuration (Reduced Heat Utility) with Heat Exchanger

67. Methodology (cont.)
PART C: Process TNP Analysis (with HE)
 We plotted the graph of Process enthalpy with heat
exchanger vs. Temperature and calculated the P-TNP's with
HE
 We calculated the product gas compositions at the P-TNP's
and analysed the parameters: Syngas, Syngas Ratio, %CO2
Conversion, Reaction Enthalpy at P-TNP's

68. 1. Gasifying Agent: CO2
 We varied CCBR in the input of gasifier from 0 to 5
 From the graphs of enthalpy change vs. temperature for all
the CCBR, we found that TNP’s can be obtained for all the
CCBR except 0

69. Process TNP’s with Heat Exchanger
-150
-130
-110
-90
-70
-50
-30
-10
10
30
50
500 550 600 650 700 750 800 850 900 950 1000
Enthalpy(KJ)
Temp oC
Process Enthalpy (with HE)
CCBR 0
CCBR 0.5
CCBR 1
CCBR 1.5
CCBR 2
CCBR 2.5
CCBR 3
CCBR 4
CCBR 5

70. CCBR
TNP
oC
CO2(g)
moles
CO(g)
moles
H2O(g)
moles
H2(g)
moles
CH4(g)
moles
N2(g)
moles
C
moles
0.5 812.239 0.1006 1.3665 0.0423 0.5838 0.0069 0.001 0.026
1 720.674 0.5193 1.4481 0.1234 0.4965 0.0101 0.001 0.0226
1.5 686.357 0.9715 1.494 0.173 0.4469 0.01 0.001 0.0245
2 664.59 1.4374 1.5267 0.2086 0.4124 0.0095 0.001 0.0264
2.5 648.385 1.9124 1.549 0.2362 0.3859 0.0089 0.001 0.0297
3 635.522 2.3926 1.5663 0.2585 0.3647 0.0084 0.001 0.0327
4 615.714 3.3631 1.5907 0.2931 0.3321 0.0074 0.001 0.0388
5 600.67 4.3423 1.6063 0.3191 0.3077 0.0066 0.001 0.0448
Process TNP’s with Heat Exchanger

71. CCBR
TNP
oC
Syngas
(moles)
Syngas
Ratio
% CO2
Conversion
0.5 812.239 1.9503 0.427223 79.88
1 720.674 1.9446 0.342863 48.07
1.5 686.357 1.9409 0.29913 35.2333
2 664.59 1.9391 0.270125 28.13
2.5 648.385 1.9349 0.249128 23.504
3 635.522 1.931 0.232842 20.2466
4 615.714 1.9228 0.208776 15.9225
5 600.67 1.914 0.191558 13.154
Process TNP’s with Heat Exchanger

72. Gasifying Agent: CO2 - Trends
 P-TNP’s, Syngas production, Syngas ratio and % CO2
conversion decreased with increase in HCBR
 Reaction enthalpy at R-TNP’s increased and went from
exothermic region to endothermic region
 Reaction enthalpy for CCBR = 2.68 was zero. Thus, R-TNP
and P-TNP is same for CCBR 2.68

73. Process TNP’s with Heat Exchanger
550
600
650
700
750
800
850
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
TNP(oC)
CCBR
TNP

74. Process TNP’s with Heat Exchanger
1.91
1.915
1.92
1.925
1.93
1.935
1.94
1.945
1.95
1.955
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
Syngas(moles)
CCBR
Syngas

75. Process TNP’s with Heat Exchanger
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
SyngasRatio
CCBR
Syngas Ratio

76. Process TNP’s with Heat Exchanger
0
10
20
30
40
50
60
70
80
90
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
%CO2conversion
CCBR
%CO2 conversion

77. Process TNP’s with Heat Exchanger
-8
-7
-6
-5
-4
-3
-2
-1
0
1
2
0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
Enthalpy(KJ)
CCBR
Reaction Enthalpy at P-TNP's

78. 2. Gasifying Agent: H2O
 We varied HCBR in the input of gasifier from 0 to 4
 From the graphs of enthalpy change vs. temperature for all
the HCBR, we found that TNP’s can be obtained for all the
HCBR except 0

79. Process TNP’s with Heat Exchanger
-150
-100
-50
0
50
100
500 550 600 650 700 750 800 850 900 950 1000
Enthalpy(KJ)
Temp oC
Process Enthalpy (with HE)
HCBR 0
HCBR 1
HCBR 2
HCBR 3
HCBR 4

80. HCBR
TNP
oC
CO2(g)
moles
CO(g)
moles
H2O(g)
moles
H2(g)
moles
CH4(g)
moles
N2(g)
moles
C
moles
1 713.0330 0.2900 0.6788 0.3513 1.2262 0.0313 0.0010 0.0000
2 651.626 0.5681 0.3973 1.0765 1.4943 0.0346 0.001 0
3 611.497 0.7161 0.2478 1.9301 1.6375 0.0362 0.001 0
4 581.206 0.7982 0.1647 2.8489 1.7169 0.0371 0.001 0
Process TNP’s with Heat Exchanger
HCBR
TNP
oC
Syngas
(moles)
Syngas
Ratio
% CO2
Conversion
1 713.0330 1.905 1.806423 71
2 651.626 1.8916 3.761138 71.595
3 611.497 1.8853 6.608152 76.13
4 581.206 1.8816 10.42441 80.045

81. Gasifying Agent: H2O - Trends
 P-TNP’s and Syngas Production decreased with increase in
HCBR
 Syngas ratio and % CO2 Conversion increased with increase
in HCBR
 Reaction enthalpy at P-TNP’s decreased with increase in
HCBR

82. Process TNP’s with Heat Exchanger
550.000
570.000
590.000
610.000
630.000
650.000
670.000
690.000
710.000
730.000
1 1.5 2 2.5 3 3.5 4
P-TNP(C)
CCBR
P-TNP’s

83. Process TNP’s with Heat Exchanger
1.88
1.885
1.89
1.895
1.9
1.905
1.91
1 1.5 2 2.5 3 3.5 4
Syngas(moles)
CCBR
Syngas

84. Process TNP’s with Heat Exchanger
0
2
4
6
8
10
12
1 1.5 2 2.5 3 3.5 4
SyngasRatio
CCBR
Syngas Ratio

85. Process TNP’s with Heat Exchanger
70
71
72
73
74
75
76
77
78
79
80
81
1 1.5 2 2.5 3 3.5 4
%CO2conversion
CCBR
%CO2 conversion

86. Process TNP’s with Heat Exchanger
-60
-55
-50
-45
-40
-35
-30
1 1.5 2 2.5 3 3.5 4
Enthalpy(KJ)
CCBR
Reaction Enthalpy at P-TNP's

87. 3. Gasifying Agent: CO2 & H2O
 We varied GaCR from 1 to 4 in the input of gasifier
 For all the GaCR, P-TNP’s were obtained for all the
combinations of CCBR and HCBR considered

88. Process TNP’s GaCR = 1
-160
-140
-120
-100
-80
-60
-40
-20
0
20
500 550 600 650 700 750 800 850 900 950 1000
Enthalpy(KJ)
Temp oC
Process Enthalpy (with HE)
2/0
1.5/0.5
0.0/1.0

89. GaCR
CCBR/
HCBR
TNP
oC
CO2(g)
moles
CO(g)
moles
H2O(g)
moles
H2(g)
moles
CH4(g)
moles
N2(g)
moles
C
moles
1 1/0 720.674 0.5193 1.4481 0.1234 0.4965 0.0101 0.001 0.0226
1 0.5/0.5 709.568 0.4155 1.0557 0.2234 0.8589 0.0288 0.001 0
1 0/1 713.0330 0.2900 0.6788 0.3513 1.2262 0.0313 0.0010 0.0000
Process TNP’s with Heat Exchanger at GaCR = 1
GaCR
CCBR/
HCBR
TNP
oC
Syngas
(moles)
Syngas
Ratio
% CO2
Conversion
1 1/0 720.674 1.9446 0.342863 48.07
1 0.5/0.5 709.568 1.9146 0.813583 16.9
1 0/1 713.0330 1.905 1.806423 -

90. Process TNP’s at GaCR = 2
-160
-140
-120
-100
-80
-60
-40
-20
0
20
500 550 600 650 700 750 800 850 900 950 1000
Enthalpy(KJ)
Temp oC
Process Enthalpy (with HE)
2/0
1.5/0.5
1.0/1.0
0.5/1.5
0.0/2.0

91. GaCR
CCBR/
HCBR
TNP
oC
CO2(g)
moles
CO(g)
moles
H2O(g)
moles
H2(g)
moles
CH4(g)
moles
N2(g)
moles
C
moles
2 2/0 664.59 1.4374 1.5267 0.2086 0.4124 0.0095 0.001 0.0264
2 1.5/0.5 652.73 1.2654 1.2043 0.375 0.7044 0.0303 0.001 0
2 1/1 659.959 1.0503 0.9177 0.5917 0.9844 0.032 0.001 0
2 0.5/1.5 659.844 0.8178 0.649 0.8254 1.2482 0.0332 0.001 0
2 0/2 651.626 0.5681 0.3973 1.0765 1.4943 0.0346 0.001 0
Process TNP’s with Heat Exchanger at GaCR = 2
GaCR
CCBR/
HCBR
TNP
oC
Syngas
(moles)
Syngas
Ratio
% CO2
Conversion
2 2/0 664.59 1.9391 0.270125 28.13
2 1.5/0.5 652.73 1.9087 0.584904 15.64
2 1/1 659.959 1.9021 1.072682 -5.03
2 0.5/1.5 659.844 1.8972 1.923267 -63.56
2 0/2 651.626 1.8916 3.761138 -

92. Process TNP’s at GaCR = 3
-160
-140
-120
-100
-80
-60
-40
-20
0
20
500 550 600 650 700 750 800 850 900 950 1000
Enthalpy(KJ)
Temp oC
Process Enthalpy (with HE)
3/0
2.5/0.5
2.0/1.0
1.5/1.5
1.0/2.0
0.5/2.5
0.0/3.0

93. GaCR
CCBR/
HCBR
TNP
oC
CO2(g)
moles
CO(g)
moles
H2O(g)
moles
H2(g)
moles
CH4(g)
moles
N2(g)
moles
C
moles
3 3/0 635.522 2.3926 1.5663 0.2585 0.3647 0.0084 0.001 0.0327
3 2.5/0.5 623.346 2.184 1.2807 0.4612 0.6217 0.0286 0.001 0.0067
3 2/1 627.597 1.9311 1.0347 0.7131 0.8585 0.0342 0.001 0
3 1.5/1.5 630.18 1.6536 0.8113 0.9915 1.0782 0.0351 0.001 0
3 1/2 628.676 1.3587 0.6057 1.287 1.2817 0.0357 0.001 0
3 0.5/2.5 622.846 1.0468 0.4171 1.5993 1.4685 0.0361 0.001 0
3 0/3 611.497 0.7161 0.2478 1.9301 1.6375 0.0362 0.001 0
Process TNP’s with Heat Exchanger at GaCR = 3

94. GaCR
CCBR/
HCBR
TNP
oC
Syngas
(moles)
Syngas
Ratio
% CO2
Conversion
3 3/0 635.522 1.931 0.232842 20.24667
3 2.5/0.5 623.346 1.9024 0.485438 12.64
3 2/1 627.597 1.8932 0.829709 3.445
3 1.5/1.5 630.18 1.8895 1.328978 -10.24
3 1/2 628.676 1.8874 2.116064 -35.87
3 0.5/2.5 622.846 1.8856 3.520738 -109.36
3 0/3 611.497 1.8853 6.608152 -
Process TNP’s with Heat Exchanger at GaCR = 3

95. Process TNP’s at GaCR = 4
-140
-120
-100
-80
-60
-40
-20
0
20
500 550 600 650 700 750 800 850 900 950 1000
Enthalpy(KJ)
Temp oC
Process Enthalpy (with HE)
4/0
3.75/0.25
3.5/0.5
3.25/0.75
3.0/1.0
2.5/1.5
2.0/2.0
1.5/2.5
1.0/3.0
0.5/3.5
0.0/4.0

96. GaCR
CCBR/
HCBR
TNP
oC
CO2(g)
moles
CO(g)
moles
H2O(g)
moles
H2(g)
moles
CH4(g)
moles
N2(g)
moles
C
moles
4 4/0 615.714 3.3631 1.5907 0.2931 0.3321 0.0074 0.001 0.0388
4 3.5/0.5 605.141 3.1271 1.3323 0.5235 0.5667 0.0249 0.001 0.0158
4 3/1 603.992 2.859 1.104 0.788 0.7781 0.037 0.001 0
4 2.5/1.5 607.881 2.5544 0.9082 1.093 0.9722 0.0374 0.001 0
4 2/2 608.611 2.2333 0.7292 1.4143 1.1507 0.0375 0.001 0
4 1.5/2.5 606.334 1.8976 0.5645 1.7502 1.3141 0.0378 0.001 0
4 1/3 601.561 1.5467 0.4154 2.1011 1.4632 0.0378 0.001 0
4 0.5/3.5 593.788 1.1805 0.282 2.467 1.598 0.0375 0.001 0
4 0/4 581.206 0.7982 0.1647 2.8489 1.7169 0.0371 0.001 0
Process TNP’s with Heat Exchanger at GaCR = 4

97. GaCR
CCBR/
HCBR
TNP
oC
Syngas
(moles)
Syngas
Ratio
% CO2
Conversion
4 4/0 615.714 1.9228 0.208776 15.9225
4 3.5/0.5 605.141 1.899 0.425355 10.65429
4 3/1 603.992 1.8821 0.704801 4.7
4 2.5/1.5 607.881 1.8804 1.070469 -2.176
4 2/2 608.611 1.8799 1.578031 -11.665
4 1.5/2.5 606.334 1.8786 2.327901 -26.5067
4 1/3 601.561 1.8786 3.522388 -54.67
4 0.5/3.5 593.788 1.88 5.666667 -136.1
4 0/4 581.206 1.8816 10.42441 -
Process TNP’s with Heat Exchanger at GaCR = 4

98. Process TNP’s with Heat Exchanger
550
570
590
610
630
650
670
690
710
730
750
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5
TNP(oC)
HCBR
TNP's
GaCR 1
GaCR 2
GaCR 3
GaCR 4

99. 3. Gasifying Agent: Both - Trends
 Syngas decreased with increase in HCBR
 Syngas ratio increased with increase in HCBR
 % CO2 conversion and Reaction enthalpy at P-TNP’s
decreased with increase in HCBR

100. Process TNP’s with Heat Exchanger
1.8
1.82
1.84
1.86
1.88
1.9
1.92
1.94
1.96
1.98
2
0 0.5 1 1.5 2 2.5 3 3.5 4
syngas(moles)
HCBR
Syngas
GaCR 1
GaCR 2
GaCR 3
GaCR 4

101. Process TNP’s with Heat Exchanger
0
2
4
6
8
10
12
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5
syngasratio
HCBR
Syngas ratio
GaCR 1
GaCR 2
GaCR 3
GaCR 4

102. Process TNP’s with Heat Exchanger
-160
-140
-120
-100
-80
-60
-40
-20
0
20
40
0 0.5 1 1.5 2 2.5 3 3.5 4
%CO2Conversion
HCBR
% CO2
GaCR 2
GaCR 3
GaCR 4

103. Process TNP’s with Heat Exchanger
-60
-50
-40
-30
-20
-10
0
10
0.5 1 1.5 2 2.5 3 3.5 4
Enthalpy(KJ)
HCBR
Reaction Enthalpy at P-TNP
GaCR 1
GaCR 2
GaCR 3
GaCR 4

104. Conclusions
 Sandeep et. al. varied SBR (Steam to Biomass Ratio) from
0.75 to 2.7. The hydrogen yield is found to be 104 g/kg of
biomass at SBR of 2.7. Significant enhancement in H2 yield
is observed at higher SBR compared with lower range SBR
REF: Sandeep, K., Dasappa, S., Oxy–steam gasification of
biomass for hydrogen rich syngas production using
downdraft reactor configuration
International Journal of Energy Research – 2013
 In our study, for SBR = 3, hydrogen yield is found to be
130.45g/kg of biomass

105. Conclusions
 Exothermal regions were obtained in the biomass
gasification with no oxygen in the input stream
 Biomass Gasification can be done auto thermally even
without any input of external oxygen or air
 Inbuilt oxygen content in biomass is large enough to carry
out the gasification process
 The product gas for some of the feed conditions can be
used for Fischer Tropsch process in petroleum industries

106. GaCR
CCBR/
HCBR
Syngas
(moles)
without HE
Syngas
Ratio
without HE
Syngas
(moles)
with HE
Syngas
Ratio
with HE
1 0/1 - - 1.905 1.806423
2 1.5/0.5 0.822 1.216828 - -
2 1/1 0.6785 2.931054 1.9021 1.072682
2 0.5/1.5 - - 1.8972 1.923267
3 2.5/0.5 0.587 1.269037 - -
3 1.5/1.5 - - 1.8895 1.328978
3 1/2 - - 1.8874 2.116064
4 2.5/1.5 - - 1.8804 1.070469
4 2/2 - - 1.8799 1.578031
4 1.5/2.5 - - 1.8786 2.327901
Syngas Ratio between 1 to 3
For Fischer Tropsch

107. THANK YOU