Page 171 - CW E-Magazine (9-1-2024)

Special Report

Aerobic oxidation of alcohols
using a slurry loop membrane
reactor (SLMR)

B. Venezia and A. Gavriilidis have re-
ferred to the safety problems associated
with mixing O with organic substrates
2
and here continuous membrane reac-
tors offer an attractive solution. These
authors have reported oxidation as well
as hydrogenation reactions. The catalyst

is also effective for enantioselective Continuous synthesis of epoxi-
hydroxylation of benzylic C-H bonds des from alkenes by H O with
2
2
with H O . The example of 1-decene Titanium Silicalite (TS)-1 cata-
2
2
to epoxide is also reported. (Angew. lyst using flow reactors
Chem. Intl. Ed.; DOI: 10.1002/anie.
202306584). Y. Kon et al have reported the continuous
slurry was circulated around a loop; flat synthesis of 4-phenyl-1,2-epoxybutane
Teflon AF-2400 membrane was connec- Hydrogenation of CaCO for from 4-phenyl-1-butene in 90-98%
3
ted. The recycle flowrate was 100 times methane by a liquid organic H yields. Mixed solution of CH CN and
3
2
higher than the inlet. It is remarkable carrier in the presence of the CH OH preserves the Ti active site in
3
that k a of 1.2 s was realised and thus catalyst precursor, NiCO 3 TS-1 crystal structure. (Adv. Syn. Cata-
-1
L
for mass transfer controlled reactions lysis; DOI: 10.1002/adsc.202300181).
very high rates can be achieved. Both T. Shen et al have reported an uncom- Chemical recycling of polyole-
primary and secondary alcohols were mon process of converting CaCO finic waste to light olefins by
3
oxidised at 90-120 C and 2-6 bar using to CaO-CH by renewable H , which catalytic pyrolysis
o
4
2
a 1 wt% Au-Pd/TiO powder catalyst. avoids generation of unwanted CO . [Circular economy concept is now at
2
2
This design allows batch mode as well. centrestage.]
(Green Chem., 2023; DOI: 10.1039/
D3GC01242E). N. Netsch et al have studied catalytic
pyrolysis in an auger-type reactor at
Titanium salalen catalysed pilot scale by applying two different zeo-
enantioselective benzylic hy- lites and an amorphous silica-alumina
droxylation catalyst in situ at 400-500 C. In contrast
o
The H carrier was 9,10-dihydrophenan- to thermal pyrolysis of polyolefin-rich
2
C. Wartmann et al have used the Ti threne (DHP) and the catalytic effect of waste, high gaseous pyrolysis product
complex of the cis-1,2-diaminocyclo- NiCO at 400 C. It seems NiCO in situ yields of about 85 wt% are realised with
o
3
3
hexane (cis-DACH) derived Berkes- forms Ni particles of 200-900 nm size C -C olefin content of up to 67 wt%.
2
4
sel-Salalen ligand, which is a highly that promote CH formation. This is Catalyst can be regenerated. (Chem. Ing.
4
efficient and enantioselective catalyst an interesting study. (Ind. Eng. Chem. Tech.; DOI: 10.1002/cite.202300078).
for the asymmetric epoxidation of ter- Res., 2023; DOI: 10.1021/ac.iecr.
minal olefins with H O This catalyst 3c01314). Oxidation of benzylic primary
2
alcohol: use of aerobic oxidation
2.
with Cu/TEMPO in a batch
reactor
S. Lemaitre et al have reported the title
cost effective, productive and sustainable
method. This is reported for a phase 2
Chemical Weekly January 9, 2024 171
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