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6.5.4 eFFeCTS oF FeedSToCk
As shown in Table 6.1, while APR can be applied to both the primary and secondary feedstock, so far, most of the work has been focused on the primary feedstock such as sugar, glucose, sorbitol, alcohols, ethylene glycol, and glycerol.
As Virent’s BioForming process based on APR develops, it is intended to apply
to the secondary feedstock as well. This will require some acid and/or enzyme
hydrolysis pretreatments to the feedstock. Here we briefly review some of the
reported studies on APR for both the primary and secondary feedstock. For the
primary feedstock, the discussion is further broken into two parts: (1) individual compounds having high vapor pressure such that APR is carried out in both
gas and liquid phases, and (2) individual compounds having low vapor pressure
such that APR occurs largely in the aqueous environment. Since the literature
for APR of biomass-derived products is extensive [1–7,12,14,16,17,56,60–64],
here we focus only on few recent studies on individual compounds and materials
[1–7,12,14,16,17,56,60–64].
6.5.4.1 aPr of ethylene Glycol, alcohols, and Glycerol
(Primary Feedstock with high Vapor Pressure)
APR of these compounds can occur in both the liquid and gas phases due to their
high vapor pressure under the reaction conditions. Dumesic et al. [4,16,48,49] have
extensively studied APR of ethylene glycol, particularly for alumina-supported Pt
catalysts. Their results are well reviewed by Alonso et al. [4] and Davda et al. [16].
Two recent novel studies are by D’Angelo et al. [31] who examined APR of ethylene glycol in a novel microchannel reactor and Chu et al. [38] who examined APR
of ethylene glycol on Co/ZnO catalysts prepared by the coprecipitation method.
APRs of various alcohols (methanol, ethanol, and other polyols) are well examined by Dumesic et al. [1–6,16,48], Park et al. [29], Cruz et al. [50], and Zhang
et al. [54].
The Department of Energy has identified glycerol as one of the 12 important
platform chemicals from biomass (see Chapter 7). In Chapter 4, we examined a
significant work reported on the steam reforming of glycerol. The reforming reaction
with glycerol results in [1–7,16]
C H O
8 3 → 3CO + 4H
(6.7)
3
2
APR of glycerol has also been widely studied, as indicated by the large amount of
literature on the subject [34–36,44,47,51–57,65]. The subject is also extensively covered in a number of reviews by Dumesic et al. [1–6], Davda et al. [16], and Vaidya and
Rodrigues [47]. Here we examine only few recent studies on the subject in brief detail.
Tuza et al. [65] examined the production of renewable hydrogen by APR of glycerol over Ni–Cu catalysts derived from hydrotalcite precursors. The reforming was
carried out in a batch reactor at 250°C and 270°C. The catalyst with 5% of Cu showed
high H 2 selectivity at 250°C. At 270°C, there was consumption of H 2 with time due
to hydrogenolysis of glycerol. The study proposed the main reaction routes, which