Fate of sulphur during simultaneous gasification of lignin-slurry and
removal of hydrogen sulphide over calcium aluminate supported
nickel oxide catalyst
Kenji Koido
a, *
, Yutaro Watanabe
b
, Tomoyuki Ishiyama
b
, Teppei Nunoura
c
,
Kiyoshi Dowaki
b
a
Faculty of Symbiotic Systems Science, Fukushima University, 1 Kanayagawa, Fukushima, Fukushima, 960-1296, Japan
b
Department of Industrial Administration, Graduate School of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba, 278-8510,
Japan
c
Environmental Science Center, The University of Tokyo, Kashiwanoha 5-1-5, Kashiwa, Chiba, 277-8581, Japan
article info
Article history:
Received 28 September 2015
Received in revised form
28 August 2016
Accepted 1 September 2016
Available online 8 September 2016
Keywords:
High-temperature desulphurisation
Hot gas cleanup
Wet-biomass gasification
Sulphur balance
Nickel oxide catalyst
Lignin
abstract
The simultaneous process of synthesis gas production via lignin slurry gasification and high-temperature
removal of hydrogen sulphide from the synthesis gas over calcium aluminate supported nickel oxide
catalyst (NiO/CaAl
2
O
4
) was investigated. The goal of this study was to clarify the effects of the operating
temperature (750e950
C), moisture content of the lignin slurry (73e90 wt%), and catalyst loading (0.00
e0.61 g-catalyst/g-feedstock) on the sulphur balance of the process and to determine the appropriate
catalyst loading with cleaner biosyngas via utilisation of the sensible heat for smaller additional heat,
which is maintained at the temperature of the gasifier. The biosyngas generated from gasification of
lignin slurry, which contained hydrogen sulphide (H
2
S) and carbonyl sulphide (COS), was subjected to
sulphur removal catalysed by NiO/CaAl
2
O
4
; a sulphur yield on NiO/CaAl
2
O
4
of 0.14 mmol/g-lignin was
achieved at the moisture content of 80.0 wt%, the reaction temperature of 900
C, and the catalyst
loading of 0.16 g-catalyst/g-feedstock. For the catalytic H
2
S removal system applicable to solid oxide fuel
cells, the performance efficiency was introduced to discuss the optimal catalyst loading amount; the
performance efficiency was 0.63e0.72 S-mol%$g-lignin/kJ for the catalytic operations while 0.33 S-mol%$
g-lignin/kJ for non-catalytic operation.
© 2016 Elsevier Ltd. All rights reserved.
1. Introduction
Biogenous synthesis gas (biosyngas) is attractive because of the
growing need for reduction of fossil diesel fuel use, as a sustainable
hydrogen (H
2
) resource for fuel cells, and for mitigation of carbon
dioxide emission. There are two routes for biomass conversion into
hydrogen-rich gas, namely (i) Thermo-chemical conversion and (ii)
Bio-chemical/biological conversion. In the several kinds of
biomass-based H
2
production methods as presented in Table 1, the
biomass gasification methods are anticipated to become a domi-
nant technology for H
2
production based on the B1-H
2
scenario
developed as the Environmentally Compatible Energy Strategies
(ECS) project at International Institute for Applied Systems Analysis
(IIASA) (Barreto et al., 2003). Hydrogen is consumed in fuel cells,
such as polymer electrolyte fuel cells (PEFC) and solid oxide fuel
cells (SOFC); thus, the demand for H
2
should increase with pro-
gressive development of this technology (Balat and Kırtay, 2010).
At the same time, sulphur compounds such as hydrogen sul-
phide (H
2
S) and carbonyl sulphide (COS) are formed during bio-
hydrogen production processes. The reactions of biomass
gasification can be divided into gas formation and gas equilibrium
stages. Following reaction pathways are possible (Moon et al.,
2013):
(Pyrolysis)
C
x
H
y
O
z
/ aCO
2
þ bH
2
O þ cCH
4
þ dCO þ eH
2
þ fC
2þ
þ tar (1)
(Steam-tar reforming)
C
n
H
m
þ 2nH
2
O / (2n þ m/2)H
2
þ nCO
2
(2)
* Corresponding author.
E-mail address: koido@sss.fukushima-u.ac.jp (K. Koido).
Contents lists available at ScienceDirect
Journal of Cleaner Production
journal homepage: www.elsevier.com/locate/jclepro
http://dx.doi.org/10.1016/j.jclepro.2016.09.010
0959-6526/© 2016 Elsevier Ltd. All rights reserved.
Journal of Cleaner Production 141 (2017) 568e579