Page 172 - CW E-Magazine (26-12-2023)

Special Report

Phenol dehydration appears, 97% of energy is consumed com- Innovative amidoxime nanofi ber
pared to the conventional system. (Chem. membranes for highly effi cient
C. Zhang et al have referred to the con- Eng. Technol., 2023; DOI: 10.1002/
ventional process of straight distillation ceat.2022001.62). adsorption of Ga(III) from waste
where the wastewater contains 2-5 wt% Bayer solution
phenol, which has to be separately dealt. A scalable stable porous coordi- [Gallium is required for several industries
These authors have advocated hetero- nation polymer synthesised from and its availability is limited and hence
geneous batch distillation using ethyl- low-cost precursors for effi cient attempts are being made to recover Ga
benzene as an entrainer. This was also C H /C H Separation from different sources.]
simulated. Here the wastewater has very 2 2 2 4 Z. Qin et al have come out with a new
low conc. (even 5 g per m) of phenol. H. Huang et al have referred to the and highly effi cient amidoxime nano-
The product phenol has only 470 ppm challenging title separation [This col- fi ber membrane preparation method with
of water. The proposed method is eco- umn has covered this subject]. Porous electrostatic spinning technology. The
nomically feasible and environmentally coordination polymers (PCPs) have been maximum adsorption capacity of 39.80
friendly. Experiments were done in 600 advocated, but these should lend for good mg 1g of Ga(III) at 30°C and a Ga conc.
mm i.d. column packed with Sulzer BX separation and low regeneration energy, of 200 mg/l was realised. The adsorption
gauze packing with a height of 4 m (which apart from affordable cost. PCPTJE-1 process is controlled by a chemical reac-
gives about 15 theoretical stages). (Chem. has been suggested, which has a very tion. This opens up a new way to recover
Eng. Res. Des., 2023, 195, July, 682-690; high uptake of 5.27 mmol per gm and scarce Ga. (Ind. Eng. Chem. Res., 2023;
DOI:10.1016/j.cherd.05.062). selective adsorption over C H at 1 bar DOI: 10.1021/acs.iecr.3C01410).
2
4
and 25°C. Theoretical calculations have Tuning the nucleation rates for
Ultrasound (u/s)-assisted leach- done and the selectivity originates from high-efficiency hydrolysis of
ing of rare earth elements (REE) the difference in hydrogen bonding and Sodium Vanadate (SV) solution
from phosphogypsum (PG) π interaction. (Green. Chem., 2023; DOI:
[PG is produced in large quantities in 10.1039/D3GC01114C). Vanadium recovery is industrially impor-
the acidulation of phosphate rock with Carbon molecular sieve mem- tant. Z. Wang et al have worked on SV slag
sulphuric acid and its valorisation has branes (CMSMs) for selective leaching solution and its hydrolysis. They
been covered in this column.] CO /CH and CO /N separation have tamed the nucleation rates and have
2 4 2 2 reported rapid nucleation within 10 sec.
S F. Lutre et al have considered PG as A. Rahimali Mamaghani et al have car- complete hydrolysis in 30 min., at higher
an alternate source of REEs, which are ried out the title separation. Temperature pH value of 2.4 and a lower temp. of 80°C.
scarce and badly required for a number was varied from 20 to 350°C and pressure The effi ciency of precipitation was 99%.
of critical items. The leaching effi ciencies from 1 to 40 bar. Multi-stage membranes These authors studied the mechanism of
are relatively low and these have been process design has been suggested. CO hydrolysis by in situ focused-bean refl ec-
2
augmented using u/s and 0.6 M H SO . capture from coal-fi red fl ue gas, biogas tance measurement and particle video
2
4
The leaching effi ciency is higher as well microscopy. (Ind. Eng. Chem. Res., 2023;
the rate. (Chem. Eng. Process – Process DOI: 10.1021/acs.iecr.3C01120).
Intensifi cation, 2023.101, Sep.109458;
DOI:10.1016/j.cep.2023.109458). Salting out: A novel purifi cation
technique in biorefi nery
Controllability and energy-sav-
ing ability of the Dividing Wall J. Tan et al have worked with bio-alcohols
Column (DWC) for Batch Dis- (BG) upgrading and natural gas (NG) with respect to reducing energy consump-
tillation (BD) were studied. An economic assessment tion in their recovery (isobutanol and
was done and the capture cost of €41.8 ethanol). One-step salting-out process is
DWC, originally practiced at BASF, is per tonne of CO and energy consumption reported. In one-step isobutanol could be
2
now widely used and there is a perception of 1.9 GJ per tonne CO is reported. The fully recovered and purifi ed to more than
2
that it is for continuous operation. X. optimal two stages for CO /CH separa- 95 wt% under saturated solution of K PO .
4
4
3
2
Qian et al have reported that this strategy tion are reported. Cost of €4.2 per tonne At 40°C in two-step method isobutanol can
can be adopted for batch columns; and of sweet NG and €23 per tonne of BG are be purifi ed up to 98.62%. (Desalination;
it outperforms the conventional system. reported. (Ind. Eng. Chem. Res., 2023; DOI: 10.1016/j.desal.2023.116790; 2023,
With middle-vessel batch distillation, it DOI: 10.1021/acs.iecr.3C0079]. 564,15 Oct, 116790).
th
172 Chemical Weekly December 26, 2023

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