Hydrogen Production via Oxidative Steam Reforming of Biodiesel
By-products over Ni/CeO
2
-ZrO
2
/Al
2
O
3
Catalyst
Krongthong Kamonsuangkasem
1
, Supaporn Therdthianwong
1 +
and Apichai Therdthianwong
2
1
Department of Chemical Engineering
King Mongkut’s University of Technology Thonburi, Bangkok, Thailand
2
Fuel Cell and Hydrogen Research and Engineering Center
King Mongkut’s University of Technology Thonburi, Bangkok, Thailand
Abstract. Yellow glycerol and crude glycerol, by-products of biodiesel, are renewable resource that can be
used for sustainable production of hydrogen. The oxidative steam reforming of biodiesel by-products over
Ni/CeO
2
-ZrO
2
/Al
2
O
3
catalyst were investigated and the effluents from reforming of both by-products were
compared with that of pure glycerol. Preliminary analysis of yellow glycerol showed that there were
methanol and fatty acid methyl esters in it whereas the presence of potassium (K) and sodium (Na) was
observed in crude glycerol. The catalytic activity of Ni/CeO
2
-ZrO
2
/Al
2
O
3
catalyst was studied isothermally
under atmospheric pressure at water-to-glycerol and oxygen-to-glycerol molar ratio of 9:1 and 0.5:1,
respectively. Under these conditions, the glycerol was reformed to H
2
, CO
2
, CO and CH
4
with small amount
of C
2
gas products that were measured by gas chromatograph. The results showed that the yellow glycerol
was completely converted in gas phase and provided hydrogen yield and selectivity at 71% and 72%,
respectively, whereas crude glycerol was nearly completed to convert in gas phase and gave the lowest
hydrogen yield and selectivity at 37% and 42%, respectively because of the presence of coke formation.
Therefore, the potential to produce hydrogen gas with low price feedstock like yellow glycerol was highly
recommended with respect to pure glycerol.
Keywords: hydrogen production, glycerol, oxidative steam reforming, Ni/CeO
2
-ZrO
2
/Al
2
O
3
1. Introduction
Biodiesel production has been rapidly increased with the increase of energy demand, and it is forecasted
that biodiesel could make up as much as 20% of all transportation fuels in 2020 [1]. It would lead to increase
of glycerol production in the amount excess the market demand lowering its price. This by-product glycerol
must be treated and purified before using it as an industrial feedstock for applications in food, cosmetics,
pharmaceutical and other industries. For the purification process, high cost was spent and energy was
consumed. Therefore finding alternative feasible use for by-product glycerol has become imperative. Among
possible use for glycerol, hydrogen production from glycerol has recently attracted much attention. The
hydrogen can be used to generate electricity directly in fuel cell. Conversion of glycerol to hydrogen has
been carried out by several techniques, such as aqueous-phase reforming [2], pyrolysis [3], supercritical
water reforming [4], steam reforming [5], partial oxidation reforming [6], and oxidative steam reforming [7].
Many researchers focused on steam reforming process of pure glycerol which were studied on operating
parameters [5,8] and performance of catalyst [9-14].
Thermodynamic analysis [7] presented that the most favorable conditions for hydrogen production via
autothermal reforming were at temperature, water-to-glycerol molar ratio and oxygen-to-glycerol molar ratio
of 900-1000 K, 9-12 and 0.0-0.4, respectively. Douette et al. [15] performed glycerol reforming at various
+
Corresponding author. Tel.: + 66 2 470 9222x403; fax: +66 2 470 9325.
E-mail address: supaporn.the@kmutt.ac.th (S. Therdthianwong).
107
2011 International Conference on Chemistry and Chemical Process
IPCBEE vol.10 (2011) © (2011) IACSIT Press, Singapore