189
CO H
CH H O
+
↔
+
3 2
4
2
(7.6)
Deposition and gasification of carbon
CH
H C
4
2
2
↔
+
(7.7)
2
2
CO
CO C
↔
+
(7.8)
C H O
H CO
+
↔
+
2
2
2
2
2
(7.9)
C H O
H CO
+
↔
+
2
2
(7.10)
The nature and properties of the catalyst significantly influence the catalytic conversion of GDR. Various types of catalysts, namely, the nickel-based, cobalt-based, and
noble metal-based catalysts, have been widely used in reforming studies.
Nevertheless, catalysts containing Ni have always been chosen due to their excellent activity and stability, easily available, and cheapness in cost compared to noble
metals such as Rh, Pt, and Pd (Thyssen et al. 2013). However, Ni-based catalysts are
prone to be easily deactivated through the carbon deposition. Thus, the aim of this
paper is to review the potential of various types of catalysts in GDR. Apart from
that, the effect of reaction parameters, i.e., reaction temperature, gas hourly space
velocity, and reactants partial pressure, and thermodynamics analysis will be elaborated in detail.
7.2 Catalysts for Glycerol Dry Reforming
One of the obstacles in the application of GDR is the rapid degradation of catalyst
due to carbon formation. From thermodynamic analysis based on total Gibbs energy
minimization method, Friestas and Guirardello (2014) proposed that dry reforming
shows the highest susceptibility towards carbon formation among other reforming
technologies for glycerol. Low temperatures below 600 °C and high pressures at
above 3 bar will favor the formations of ethylene (C 2 H 4 ) and ethane (C 2 H 6 ), thus
contributing to the significant amount of carbon during glycerol dry reforming. In
another earlier work, Wang et al. (2009) evaluated glycerol dry reforming using
thermodynamic analysis and suggested that Boudouard reaction is the dominant
carbon formation reaction during glycerol dry reforming. The amount of carbon
increases with the increase of CO 2 -to-glycerol ratio which leads to the increase of
CO in the system. Nevertheless, Wang et al. (2009) suggested that carbon formation
could be controlled by using suitable catalysts during glycerol dry reforming.
Compared to steam reforming which has been widely explored for glycerol, it is
only recent that the catalytic studies on glycerol dry reforming are available in the
open literature. Among the earliest group that has worked on the glycerol dry
reforming, Lee et al. (2014b) have performed the process using Ni catalyst sup7 A Short Review on Production of Syngas via Glycerol Dry Reforming
CO H
CH H O
+
↔
+
3 2
4
2
(7.6)
Deposition and gasification of carbon
CH
H C
4
2
2
↔
+
(7.7)
2
2
CO
CO C
↔
+
(7.8)
C H O
H CO
+
↔
+
2
2
2
2
2
(7.9)
C H O
H CO
+
↔
+
2
2
(7.10)
The nature and properties of the catalyst significantly influence the catalytic conversion of GDR. Various types of catalysts, namely, the nickel-based, cobalt-based, and
noble metal-based catalysts, have been widely used in reforming studies.
Nevertheless, catalysts containing Ni have always been chosen due to their excellent activity and stability, easily available, and cheapness in cost compared to noble
metals such as Rh, Pt, and Pd (Thyssen et al. 2013). However, Ni-based catalysts are
prone to be easily deactivated through the carbon deposition. Thus, the aim of this
paper is to review the potential of various types of catalysts in GDR. Apart from
that, the effect of reaction parameters, i.e., reaction temperature, gas hourly space
velocity, and reactants partial pressure, and thermodynamics analysis will be elaborated in detail.
7.2 Catalysts for Glycerol Dry Reforming
One of the obstacles in the application of GDR is the rapid degradation of catalyst
due to carbon formation. From thermodynamic analysis based on total Gibbs energy
minimization method, Friestas and Guirardello (2014) proposed that dry reforming
shows the highest susceptibility towards carbon formation among other reforming
technologies for glycerol. Low temperatures below 600 °C and high pressures at
above 3 bar will favor the formations of ethylene (C 2 H 4 ) and ethane (C 2 H 6 ), thus
contributing to the significant amount of carbon during glycerol dry reforming. In
another earlier work, Wang et al. (2009) evaluated glycerol dry reforming using
thermodynamic analysis and suggested that Boudouard reaction is the dominant
carbon formation reaction during glycerol dry reforming. The amount of carbon
increases with the increase of CO 2 -to-glycerol ratio which leads to the increase of
CO in the system. Nevertheless, Wang et al. (2009) suggested that carbon formation
could be controlled by using suitable catalysts during glycerol dry reforming.
Compared to steam reforming which has been widely explored for glycerol, it is
only recent that the catalytic studies on glycerol dry reforming are available in the
open literature. Among the earliest group that has worked on the glycerol dry
reforming, Lee et al. (2014b) have performed the process using Ni catalyst sup7 A Short Review on Production of Syngas via Glycerol Dry Reforming