Page 336 - Refining Biomass Residues for Sustainable Energy and Bioproducts

306 Refining Biomass Residues for Sustainable Energy and Bioproducts

combination of reaction kinetics and process conditions. In order to promote the
oxidation process the reactor should provide the maximum contact of the ozone gas
with the substrate. The key of a successful ozonolysis is to provide the highest oxi-
dation efficiency with minimal residual and ozone consumption, thus decreasing
the operation cost.
Many types of reactors have been tested for ozonolysis such as semibatch reactor
(Wan Omar and Amin, 2016; Peretz et al., 2017), fixed-bed-batch reactor
(Panneerselvam et al., 2013; Travaini et al., 2013), Drechsel trap reactor (Cesaro
and Belgiorno, 2013), rotatory reactor (Miura et al., 2012), bubble column reactor
(Cesaro and Belgiorno, 2013), and multilayer fixed-bed reactor (Heiske et al.,
20132013). The configuration of these reactors is shown schematically in Fig. 14.2,
and their optimum conditions are shown in Table 14.2.
Peretz et al. (2017) have investigated the production of bioethanol via ozonolysis
using a semicontinuous batch reactor using highly concentrated tannic acid (TA)
solution as a lignin model compound. Most of the TA disappeared within 3.5 h, and
maximum enzymatic activity was found at the first transition point, suggesting that
a very short ozonation results in the partial decomposition of TA (Peretz et al.,
2017). Thus the short ozonation could make the ethanol production more economi-
cal since it reduces energy input by up to 97%. Wan Omar and Amin (2016) have
studied the response surface methodology (RSM) optimization of oil palm frond
(OPF) via ozonolysis using semibatch reactor under the influence of OPF particle
size, OPF moisture content, reaction time, and ozone flow rate (Wan Omar and
Amin, 2016). The study showed that the particle size has a significant impact on
the lignin degradation whereas the total reducing sugar (TRS) content was affected

Figure 14.2 Types of reactors used in ozonolysis experiments: (A) batch reactor, (B)
rotatory reactor, (C) Drechsel trap reactor, (D) cylindrical reactor, (E) bubble column reactor,
(F) multilayer fixed-bed reactor, and (G) fixed-bed reactor (Travaini et al., 2016c).