DOI: 10.3303/CET25117040 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Paper Received: 16 December 2024; Revised: 20 March 2025; Accepted: 5 May 2025 
Please cite this article as: Im-Orb K., Arpornwichanop A., Detchusananard T., Wiranarongkorn K., 2025, Process Analysis of Biomass 
Gasification and Sorption-enhanced Water Gas Shift Coupled with CO2 Utilization via Reforming for Hydrogen Production, Chemical 
Engineering Transactions, 117, 235-240  DOI:10.3303/CET25117040 
  

 CHEMICAL ENGINEERING TRANSACTIONS  
 

VOL. 117, 2025 

A publication of 

 

The Italian Association 
of Chemical Engineering 
Online at www.cetjournal.it 

Guest Editors: Fabrizio Bezzo, Flavio Manenti, Gabriele Pannocchia, Almerinda di Benedetto 

Copyright © 2025, AIDIC Servizi S.r.l. 
ISBN 979-12-81206-17-5; ISSN 2283-9216 

Process Analysis of Biomass Gasification and Sorption-

Enhanced Water Gas Shift Coupled with CO2 Utilization Via 

Reforming for Hydrogen Production 

Karittha Im-orba, Amornchai Arpornwichanopb,c, Thanaphorn Detchusananardb, 

Kunlanan Wiranarongkornd,* 

a Program in Food Process Engineering, School of Food-Industry, King Mongkut’s Institute of Technology Ladkrabang, 

Bangkok, 10520, Thailand 
b Center of Excellence in Process and Energy Systems Engineering, Department of Chemical Engineering, Faculty of 

Engineering, Chulalongkorn University, Bangkok 10330, Thailand 
c Bio-Circular-Green-economy Technology & Engineering Center, Department of Chemical Engineering, Faculty of 

Engineering, Chulalongkorn University, Bangkok, 10330, Thailand 
dDepartment of Basic Science and Physical Education, Faculty of Science at Sriracha, Kasetsart University, Sriracha 

Campus, Chonburi, 20230, Thailand 

 kunlanan.w@ku.th  

 

The development of bio-based products for substituting petroleum-based products has received much attention 

due to environmental concerns. Hydrogen is an important chemical feedstock and energy carrier that can be 

derived from agricultural residue. Gasification is a thermochemical process that can convert biomass into syngas 

(H2+CO), while sorption-enhanced water gas shift (SEWGS) is a promising technology used to produce H2 and 

simultaneously separate CO2 in the same time. However, high energy is required for CO2 compression and 

storage. This study proposes the integration of biomass gasification and SEWGS coupled with CO2 utilization 

via reforming. The effect of key technical parameters, i.e., reforming reactors and percentage of recycled CO2, 

on H2 yield, system energy efficiency and H2/CO ratio of synthesis gas generated from reformers, are 

investigated. The correlation between key parameters and process performance is modeled through Aspen Plus 

process simulation program. Parametric analysis indicates key factors affecting syngas yield and overall energy 

efficiency with enhanced CO2 utilization. A performance comparison between gasification-SEWGS coupled with 

two different types of reforming (dry reforming and tri-reforming) using CO2 as a co-reactant is discussed, 

indicating the process with the highest H2 purity and overall energy efficiency. 

1. Introduction 

Due to the global warming issue, renewable resources, especially biomass, have become important raw material 

for generating clean chemicals and energy. Biomass gasification (BG) is a promising technology that converts 

biomass into synthesis gas (H2 and CO) with a higher heating value. This synthesis gas serves as an essential 

intermediate for chemical and fuel production. For hydrogen production applications, raw syngas from biomass 

gasification requires multiple separation steps for gas cleaning and conditioning to produce high-purity H2. Many 

researchers have proposed sorption enhanced water gas shift (SEWGS) technology to simultaneously increase 

H2 yield through the water-gas shift reaction and remove CO2 from the product, thereby overcoming the limitation 

of the water gas shift (WGS) reaction (Stevens Jr et al., 2010). In addition to producing high-purity H2, this 

technology generates CO2 as a byproduct. However, capturing CO2 requires significant energy for compression 

and storage. Consequently, converting CO2 into additional syngas is an efficient method to increase product 

yield and energy efficiency, while providing environmental benefits.  

Many studies investigated CO2 utilization captured from SEWGS. For example, Qian et al. (2015) evaluated 

technical and economic performance of coal gasification and SEWGS integrated with tri-reformer for H2 and 

methanol production. Yang et al. (2021) analyzed thermochemical and economic efficiency of gasification 

235



integrated with tri-refomer to convert CO2 into additional syngas, which was used as a reactant of ethylene glycol 

production. Al-Rowaili et al. (2024) studied the technical and economic performance of vacuum residue 

gasification and SEWGS coupled with CO2 utilization through dry reformer for methanol synthesis. Liu et al. 

(2025) compared the performance of two CO2 utilization methods—reverse Boudouard reaction, and dry 

reforming—using CO2 captured from BG integrated with SEWGS for CO2 utilization. Based on these studies, 

many researchers have focused on CO2 utilization technologies to convert CO2 into high-value chemicals. Dry 

reforming and tri-reforming are two potential technologies for converting CO2 to syngas, an important 

intermediate chemical. However, there is limited research comparing the technical performance of these two 

technologies when integrated with BG and SEWGS for CO2 utilization.  

Consequently, this study proposes a comparative analysis of BG and SEWGS integrated with two different 

reforming technologies: dry reforming and tri-reforming, through process simulation using the Aspen Plus 

program. The effects of reforming temperature and percentage of recycled CO2 on process performance 

including overall H2 yield, energy efficiency, and H2/CO ratio of syngas generated from the reformers, will be 

analyzed and discussed.  

2. Process description 

In this study, cassava rhizome was utilized as a biomass feedstock for gasification and SEWGS, coupled with 

two different types of reforming reactors: dry reformer and tri-reformer. The ultimate and proximate analyses of 

cassava rhizome are presented in Table 1. 

2.1 BG and SEWGS coupled with CO2 utilization process 

Figure 1 shows the schematic diagram of the BG and SEWGS process, coupled with a dry reformer (DR) (a) 

and a tri-reformer (TR) (b), as modeled in the in Aspen Plus program. The process consists of two sections: BG-

SEWGS, which produce high-purity H2 and CO2 utilization through dry or tri- reforming to generate additional 

synthesis gas. The Peng-Robinson equation of state was selected as the property method to calculate the 

physical properties of gas components.  

In the first section, dry biomass was fed into a gasifier to produce syngas, simulated by a fluidized-bed gasifier. 

The gasifier comprises three reaction zones; pyrolysis; combustion, and reduction zones. The pyrolysis zone 

was simulated using an RStoic reactor (PYRO), incorporating the yield of products reported in the literature, 

which biochar yield calculated based on mass balance. The outlet gas from the pyrolysis zone was then fed into 

the combustion zone, while biochar; considered a non-conventional component, was separated from the 

pyrolysis gas and decomposed to conventional components (N2, O2, H2, S, C, and ash) using RYield reactor 

(DECOMP). These components were subsequently introduced to combustion zone, simulated using an RPlug 

reactor (OXY). After combustion, the outlet gas was fed into the reduction section, modeled by RPlug reactor 

(RED). The reactions and kinetic rates occurring in the OXY and RED reactors are included in Table 2. The raw 

syngas from gasifier including H2, CO, CO2, CH4, and other impurity, was then fed into SEWGS system for gas 

cleaning and conditioning. The SEWGS technology shifts CO and H2O into H2 and CO2 as a byproduct, while 

simultaneously removing CO2, resulting in the production of high purity H2. The captured CO2 was released from 

the CaO adsorbent in a calciner, modeled by an RGibb reactor, and the CaO was subsequently recycled for 

reuse in the process (Detchusananard et al., 2024). 

For CO2 utilization, two process configurations of BG-SEWGS with different types of reforming reactors were 

compared to produce additional synthesis gas. In the dry reforming reactor, 50 % of the captured CO2 was used 

as feedstock for the dry reforming reaction, where it reacted with CH4 at an S/C ratio of 1 and a temperature of 

850 ºC. The tri-reformer (Figure 1b) operated at the same temperature as BG-SEWGS-DR with a 

CH4/CO2/H2O/O2 molar ratio of 1:1:1:1. The SEWGS, calciner and reformers (both dry and tri reformers) were 

simulated using RGibb reactor to calculate gas composition by minimizing Gibb Free energy. The operating 

conditions used in these processes, BG-SEWGS-DR and BG-SEWGS-TR, are shown in Table 3.  

2.2 Technical analysis 

In this study, the effect of temperature and the CO2/CH4 ratio (%CO2 recycle) on performance of different 

reforming reactors coupled with BG-SEWGS were compared using the following criteria: overall H2 production 

generated from BG-SEWGS and reformers, overall energy efficiency, and the H2/CO ratio of syngas produced 

through different reformers. The overall energy efficiency was calculated using Eq(1) 

4 4

100 = 
+ +

%
  

syngas syngas

sys

biomass biomasss CH CH

m LHV

m LHV m LHV overall energy input
 (1) 

236



Table 1: Ultimate and proximate analyses of cassava rhizome (Pattiya et al., 2007) 

Ultimate Analysis (%wt dry basis) Proximate analysis (%wt dry basis)  

LHV C H N O S Volatile matter Fixed carbon Ash Moisture 

51.59 6.69 1.27 40.45 <0.1 77.75 18.20 4.05 8.31 18.47 

 

 

Figure 1 The schematic diagram of biomass gasification (BG) and sorption enhanced water-gas shift (SEWGS) 

coupled with dry reformer (DR) (a) and tri-reformer (TR) (b) in Aspen Plus program 

3. Results and discussion  

3.1 Effect of reforming temperature on overall H2 yield, H2/CO ratio and energy efficiency  

This work proposed a comparison of the utilization of CO2 in two configurations: BG-SEWGS-DR and BG-

SEWGS-TR. Figure 2 shows the effect of reforming temperature on the overall H2 yield and H2/CO molar ratio 

of BG-SEWGS systems with different types of reformers; a dry reformer (Figure 1a) and a tri-reformer (Figure 

1b). As the temperature increases, both processes produce the same H2 yield from BG-SEWGS units. In CO2 

utilization section, additional syngas was produced through the dry reforming or tri-reforming unit, with 

production increasing as the temperature rises. This results in an overall increase in H2 yield, peaking at 800 ºC 

(65.91 kmol/h) for BG-SEWGS-DR and at 700 ºC (61.62 kmol/h) for BG-SEWGS-TR before gradually declining. 

The increase in yield is attributed to the favorability of the endothermic steam and dry reforming reactions at 

higher temperature in the tri-reformer. However, in BG-SEWGS-TR, this also limits the exothermic water-gas 

shift reaction. Additionally, some H2 is consumed through combustion with O2.  

When comparing the H2/CO molar ratio of syngas produced by the dry reformer and tri-reformer using internally 

captured CO2, the results indicated that the H2/CO in both cases decreased with increasing temperature due to 

the limitations rise in CO production at higher temperatures. However, the H2/CO ratio of BG-SEWGS-TR is 

lower than BG-SEWGS-DR at temperatures between 400-600 ºC, but becomes higher at temperatures above 

600 ºC. This is because the combustion reaction, which consumed H2 produced by the steam and dry reforming 

reaction, is more favorable at lower temperatures. Conversely, the steam reforming reaction in BG-SEWGS-TR 

is more favorable at high temperatures. 

Regarding the energy efficiency of the two configurations (Figure 3), the process with the dry reformer exhibits 

higher system energy efficiency at temperature above 600 ºC. This is because BG-SEWGS-TR produces less 

H2 yield and requires more energy for the steam and oxygen feed streams. Table 4 shows the energy 

consumption in each unit of two process configurations.   

(b) 

(a) 

237



Table 2: Reactions and kinetic rates used in gasifier model (Detchusananard et al.,2024; Eikeland et al.,2015). 

Reaction   Reaction rates (mol m-3s-1)  

Pyrolysis zone   

4 2 2 4 2 6 7 8

6 6 6 10 8 2

Biomass CH H CO C H C H C H

C H O C H H O biochar

→ + + + + + +

+ + +
 

  

Combustion zone   

2 2
1 25 0 5 0 75. ( ) . .C s O CO CO+ → +   

6

2

5
10 10 11 5 10

3 7 10
.

. exp C Or C C
RT

− − 
=   

 
 

2 2
0 5.CO O CO+ →   

2 2

5
5 0 25 0 51 8 10

1 78 10 . ..
. exp CO O COr C C C

RT

 − 
=   

 
 

4 2 2
0 5 2.CH O CO H+ → +   

4 2

5
15 0 7 0 82 02 10

3 58 10 . ..
. exp CH Or C C

RT

 − 
=   

 
 

2 2 2
0 5.H O H O+ →   

2 2

5
7 1 25 10

1 08 10
.

. exp H Or C C
RT

 − 
=   

 
 

6 6 2 2
4 6 3C H O O CO H O+ → +   

6 6 2

4
2 0 58 02 10

6 55 10 ..
. exp C H O Or C C

RT

 − 
=   

 
 

6 6 2 2
4 5 6 3.C H O CO H O+ → +   

6 6 2

5
11 0 51 26 10

2 4 10 ..
. exp C H Or C C

RT

 − 
=   

 
 

Reduction zone   

( ) 2 2
C s H O CO H O+ → +   

2

4
3 4 99 10

8 0 10
.

. exp C H Or C C
RT

−  − 
=   

 
 

2 2 2
CO H O CO H+  +    

2

2 2

4
2

4
2

1 26 10
2 78 10

1 26 10
2 58 10

.
. exp

.
. exp

CO H O

CO H

r C C
RT

C C
RT

−

−

 − 
=  − 

 

 − 
  

 

 

4 2 2
3CH H O CO H+ → +   

4 2

5
11 3 66 10

4 92 10
.

. exp CH H Or C C
RT

−  − 
=   

 
 

2
2( )C s CO CO+ →   5

14 3 68 10
3 18 10

.
. exp Cr C

RT

 − 
=   

 
 

6 6 10 8

6 6 4 2

0 4

0 15 0 1 0 75

.

. . .

C H O CO C H

C H CH H

→ + +

+ +
 

 

6 6

5
7 1 00 10

1 0 10
.

. exp C H Or C
RT

 − 
=   

 
 

10 8 6 6 4 2
2 0 5 0 5 1 5. . .C H CO C H CH H→ + + +   

1 6

10 8 2

5
14 0 53 50 10

1 0 10
. ..

. exp C H Hr C C
RT

− − 
=   

 
 

Table 3: Base case operating conditions in the process simulations  

Parameter  Value 

Gasifier temperature (ºC) 700 

S/C molar ratio in gasifier  3 

SEWGS temperature (ºC) 650 

S/C molar ratio in SEWGS 1.5 

CaO/C molar ratio 0.7 

Calciner (ºC) 850 

CO2 recycle (%) 50 

BG-SEWGS-DR Value BG-SEWGS-TR Value 

Dry reforming temperature (ºC) 850 Tri-reforming temperature (ºC) 850 

S/C molar ratio  1 CH4/CO2/H2O/O2 ratio 1:1:1:1 

238



3.2 Effect of percentage of recycled CO2 on overall H2 yield, H2/CO ratio, and energy efficiency  

The effect of the percentage of recycled CO2 (CO2/CH4 ratio) on overall H2 yield, the H2/CO molar ratio, and 

energy efficiency is shown in Figures 4 and 5. As illustrated in Figure 4, an increase in CO2 recycling raises the 

CO2/CH4 ratio, which is not beneficial for H2 production in either process. This is because higher CO2 levels 

favor the reverse side reaction in BG-SEWGS-DR and reverse WGS reaction in BG-SEWGS-TR, slightly 

reducing the amount of H2 produced.  

When comparing the overall H2 yield between the BG-SEWGS-DR and BG-SEWGS-TR processes at the same 

CO2 recycling percentage, the BG-SEWGS-TR process results in a lower H2 yield because methane is partly 

consumed in the oxidation reaction. However, both processes exhibit the same decreasing trend in H2 yield with 

increasing CO2 recycling. Consequently, the H2/CO ratio in both processes decreases with increasing CO2 

recycling due to increased CO generation. Nevertheless, the H2/CO ratio of the BG-SEWGS-TR remains higher 

than that in the BG-SEWGS-DR process, as the presence of steam promotes the forward WGS reaction. 

Additionally, the system energy efficiency of BG-SEWGS DR process increases, reaching a maximum of 66.42 

% at 60 % CO2 recycling (Figure 5). This improvement may be attributed to the higher heating value of syngas, 

which contains more CO from the reverse side reaction. In contrast, the energy efficiency of the BG-SEWGS-

TR process shows only a slight increase with CO2 recycling, reaching at 34.41 % at 60 % CO2 recycling, due to 

the higher CO content from the reverse WGS reaction. 

  

Figure 2 Effect of temperature on overall H2 yield and 

H2/CO molar ratio of BG-SEWGS-DR and BG-SEWGS-

TR 

Figure 3 Effect of temperature on energy efficiency 

of BG-SEWGS-DR and BG-SEWGS-TR 

  

Figure 4 Effect of percentage of recycled CO2 on overall 

H2 yield and H2/CO molar ratio of BG-SEWGS-DR and 

BG-SEWGS-TR  

Figure 5 Effect of percentage of recycled CO2 on 

energy efficiency of BG-SEWGS-DR and BG-

SEWGS-TR 

0

5

10

15

20

25

0

20

40

60

80

400 500 600 700 800 900 1000 H
2/

C
O

 ra
tio

 o
f s

yn
ga

s 
fro

m
 

re
fo

rm
er

O
ve

ra
ll 

H
2

yi
el

d 
(k

m
ol

/h
)

Temperature (◦C)

BG-SEWGS-DR_H2 yield BG-SEWGS-TR_H2 yield

BG-SEWGS-DR_H2/CO BG-SEWGS-TR_H2/CO

0

20

40

60

80

400 500 600 700 800 900 1000O
ve

ra
ll 

en
er

gy
 e

ffi
ci

en
cy

 (%
)

Temperature (◦C)

BG-SEWGS-DR BG-SEWGS-TR

0

1

2

3

50

55

60

65

70

20 30 40 50 60 70 80 90 100 H
2/

C
O

 ra
tio

 o
f s

yn
ga

s 
fro

m
 

re
fo

rm
er

 

O
ve

ra
ll 

H
2

yi
el

d 
(k

m
ol

/h
)

CO2 recycle (%)
BG-SEWGS-DR_H2 yield BG-SEWGS-TR_H2 yield

BG-SEWGS-DR_H2/CO BG-SEWGS-TR_H2/CO

0

20

40

60

80

20 30 40 50 60 70 80 90 100O
ve

ra
ll 

en
er

gy
 e

ffi
ci

en
cy

 (%
)

CO2 recycle (%)

BG-SEWGS-DR BG-SEWGS-TR

239



Table 4: Energy consumption in each unit of BG-SEWGS-DR and BG-SEWGS-TR under the base case 

 BG-SEWGS-DR (kW) BG-SEWGS-TR (kW) 

Gasifier 1065.51 1199.6 

Heater 1 1199.60 1199.60 

Heater 2 617.75 617.75 

Cooler 1 -60.55 -60.55 

SEWGS -385.27 -385.27 

Calciner 4284.34 4284.34 

Cooler 2 -61.00 -534.67 

Cooler 3 -385.30 -385.30 

Dry/Tri-

reformer 

658.73 -582.426 

Heater 3 - 248.26 

Cooler 4 53.11 -53.11 

Cooler 5 -229.60 -1844.66 

Cooler 6 -6.86 -6.86 

4. Conclusions 

This study proposed a comparative analysis of the BG-SEWGS process integrated with two different types of 

reformers: a dry reformer and a tri reformer, for CO2 utilization. The effects of key parameters; reforming 

temperature and percentage of recycled CO2, on process performance (i.e., H2 yield, H2/CO molar ratio, and 

energy efficiency) were investigated. The results showed that increasing the reforming temperature enhanced 

H2 yield in both technologies. However, BG-SEWGS-DR demonstrated superior performance, achieving a 

maximum H2 yield of 65.91 kmol/h and a system energy efficiency of 61.46 % at reforming temperature of 800 

ºC. This represented increases of 8.61 % and 82.97 %, respectively, compared to the BG-SEWGS-TR. 

Regarding the effect of CO2 recycling, it was found that increasing CO2 recycling elevated the CO2/CH4 ratio in 

dry and tri reformers. This favoured the inverse WGS reaction, which increased CO generation in the tri-reformer 

and reduced the total H2 yield. However, the presence of steam in the tri-reformer promoted the WGS reaction 

in the BG-SEWGS-TR, resulting in higher H2/CO ratio comparing to the BG-SEWGS-DR. In terms of system 

energy efficiency, the BG-SEWGS-TR required additional energy for preheating steam and O2, which lowered 

its efficiency relative to the BG-SEWGS-DR.  

Acknowledgments 

This work is supported by Kasetsart University Research and Development Institute, KURDI (YF(KU)45.67) and 

Faculty of Science at Sriracha, Kasetsart University, Sriracha Campus. 

References 

Al-Rowaili F.N., Zahid U., Khalafalla S.S., Jamal A., Al-Mutairi E.M., 2024, A New Approach for Producing 

Methanol via Process Integration of Vacuum Residue Gasification and NG Reforming aiming at Low CO2 

Emissions, an Extensive Techno-Economic Study, Chemical Engineering Science, 284, 119458. 

Detchusananard T., Wiranarongkorn K., Im-orb K., 2024, Techno-Economic Performance Analysis of Biomass-

to-Methanol with Solid Oxide Electrolyzer for Sustainable Bio-Methanol Production, Energy, 313, 133764. 

Eikeland M.S., Thapa R.K., Halvorsen B.M., 2015, Aspen Plus simulation of biomass gasification with known 

reaction kinetic, Proceedings of the 56th SIMS October 07-09, 2015, Linköping, Sweden.  

Liu H., Tang Y., Ma X., Tang J., Deng J., Yue W., 2025, Calcium Looping-Enhanced Biomass Gasification for 

Methanol Production: Integrating Methane Dry Reforming and Carbon Utilization, Separation and Purification 

Technology, 354, 129377. 

Pattiya A., Titiloye J.O., Bridgwater A.V., 2007, Fast Pyrolysis of Agricultural Residues from Cassava Plantation 

for Bio-oil Production. Asian Journal on Energy and Environment, 08(02), 496-502. 

Qian Y., Man Y., Peng L., Zhou H., 2015, Integrated Process of Coke-Oven Gas Tri-Reforming and Coal 

Gasification to Methanol with High Carbon Utilization and Energy Efficiency. Industrial and Engineering 

Chemistry Research, 54, 2519-2525.  

Stevens Jr R.W., Shamsi A., Carpenter S., Siriwardane R., 2010, Sorption-Enhanced Water Gas Shift Reaction 

by Sodium-Promoted Calcium Oxides, Fuel, 89, 1280-1286. 

Yang Q., Xu S., Zhang J., Liu C., Zhang D., Zhou H., Mei S., Gao M., Liu H., 2021, Thermodynamic and Techno-

Economic Analyses of a Novel Integrated Process of Coal Gasification and Methane Tri-Reforming to 

Ethylene Glycol with Low Carbon Emission and High Efficiency, Energy, 229, 120713. 

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	Process Analysis of Biomass Gasification and Sorption-Enhanced Water Gas Shift Coupled with CO2 Utilization Via Reforming for Hydrogen Production