Effects of a sodium carbonate (Na2CO3) additive on the conversion of phenethyl phenyl ether (PPE) in high-temperature water

Bond cleavage of lignin model compounds into aromatic monomers using supported metal catalysts in supercritical water

“…One possibility is that hydrolysis of 2-phenethyl phenyl ether into phenol and 2-phenethyl alcohol might occur without catalysts3536. The other possibility is that homolytic cleavage of C–O occurred to form phenethyl and phenoxy radicals37, which produce styrene and phenol, respectively.…”

Roles of Na 2 CO 3 in lignite hydroliquefaction with Fe-based catalyst

“…4a shows, with the increasing addition of NC, the water yield monotonously diminishes from 8.61% to 2.29%, suggesting that the addition of NC results in an obviously reducing water production. One possible reason is the promotion of NC to the hydrolyzation reaction of abundant oxygen-containing moieties (such as carbonyl groups and ether bonds) in lignite [28]. Another possible reason is the promotion of NC to the water-gas shift reaction in the liquefaction system [37].…”

“…However, an additive amount of above 3% results obviously in an increasing PA yield, probably due to a relatively high ratio of NC (compared to FC) in the lignite hydroliquefaction. In summary, in the FC-catalyzed lignite hydroliquefaction, the NC can play an important role in promoting the lignite conversion into light products (especially oil), which is probably ascribed to the promotion of NC to the depolymerization of macromolecular structures in lignite [28,36].…”

“…Likewise, this paper focused on the investigation on lignite hydroliquefaction with Fe-based catalyst. It is well-known that the lignite contains abundant oxygen-containing moieties, which can be more easily hydrolyzed due to the promotion of alkali carbonates such as Na 2 CO 3 [26][27][28][29][30][31][32][33]. Thus, it is suggested that if alkali carbonate is added into the lignite hydroliquefaction system with Fe-based catalyst, it probably affects the lignite hydroliquefaction process.…”

“…Roberts et al [27] reported that the ether bond was strongly polarized by addition of alkali carbonate, subsequently resulting in strongly promoting the yields of toluene, 2 and 4-benzyl phenol in benzyl phenyl ether conversion with superheated water. Eom et al [28] reported that in the phenethyl phenyl ether (PPE) hydrolysis reaction with Na 2 CO 3 , the formed Na + -PPE adduct was a pivotal intermediate, which was dissociated to produce phenol, styrene and ethylbenzene through the parallel routes of heterolytic β-ether bond cleavage and α-hydrogen abstraction. Fu et al [29,30] found that under both synthesis gas-Co/Mo and hydrogen-Co/Mo systems with Na 2 CO 3 , the average oil yield increased and the oil product was quite fluid at room temperature (even after many recycles).…”