Page 171 - CW E-Magazine (25-3-2025)

Special Report Special Report

A novel non-aqueous Facile design of continuous series of hydroxylated compounds (e.g., from adsorptive separation. MX/PX, for required to solve this problem resulting the carrier for removing H-acid (1-amino-
absorbent of amino counter-current, dual fl ow, alcohol and phenolic compounds). The MX, was originally done via alkylation/ in economic benefits. Biology-based 8-naphthol-3,6-disulphonic acid)
functionalized ionic liquid and capture SMB adsorptive poly(METAC:1-butanol) polymer exhi- dealkylation with isobutylene but in the processes are under implementation, Compared to non-imprinted polymer
(AFIL) for effi cient CO processes bited the highest adsorption capacity of recent past adsorptive separation has e.g., in Sydney, Australia, 3000-tonnes (N/P), H-SIP exhibited superior salt
capture 2 46 ±5mg per gm and 46 ±4per gm Co and been commercialized for MX.] of waste could give 0.5-tonnes of gold resistance in the presence of Na SO , 20
4
2
[This column has covered many papers Protein-based therapeutics have gained a Ni, respectively, which compete with X. Cui et al have come out with an interes- and 800-tonnes of Cu. The start-up is to 80 mg/L. High selectivity of H-acid/
T-acid or H-acid/2-NSA is reported.
concentrating on printed circuit boards
on CO absorption/desorption includ- lot of importance, and their purifi cation conventional materials. Deionized water ting and potentially useful way of sepa- (PCBs). 1-tonne of PCBs contains at Elution was done with aq. NaOH. (Can.
allowed highest desorption effi ciency,
2
ing new amines, catalysing desorption, involves SMBC. which makes the process “greener” and rating MX, which exploits the differences least 200-kg Cu, 0.4-kg silver, and 0.09-kg J. Chem. Eng., 2024; DOI: 10.1002/
etc. and the subject continues to attract G. Carta, who have made many valuable highly cost effective. (New Jl. of Chemis- in molecular length and alkyl distribution gold. Biological processes are under cjce.25432).
attention.] contributions in this area, has opined that try, 2024; DOI: 10.1039/D4nJ02316A). among xylenes. These authors have pro- consideration even for Nd from magnets.
W. Zhao et al have reported the use of multi-column system as well as systems vided a length-matched MOF, formulated Leveraging liquid-liquid
[TETAH][3-Br-PhO]-PEG200 in dif- where the load fl ow rate varies over time, Liquid-Liquid Extraction as Al(OH)[O C-C H O-CO ], featuring an The Royal Mint in UK is using cut- extraction (LLE) for
2
2
2
4
ferent proportions for absorbing CO . can be employed to improve producti- (LLE) for in-situ carboxylic effective pore size corresponding to MX ting-edge chemistry to extract gold from contaminant removal
2
The absorption mechanism has been vity and reduce consumption of systems acid recovery via continuous molecular length combined with multiple PCBs in minutes. Metals make up close to
elucidated using C NMR and FTIR under mass transfer control condition membrane-based emulsion negative O hydrogen bond donors distri- half of an average smartphones weight D.J. Glatz and B. Cross have referred to
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spectroscopy. The results indicate that using a mechanistic mode. This work separation bution for preferential separation of the (minus the battery). Gold and Pd content the use of LLE for removing a variety
25°C and mass ratio of 3:7 leads to provides the means to rapidly design intermediate-size MX, from the tertiary are low, but it is still valuable. of contaminants in wastewater, some
absorption capacity to 2.37 mol per kg. periodic counter-current, dual flow Y. Chen et al have referred to some o-, m-, p- X mixture. MX uptake was re- of which are refractory/untreatable. In
Desorption was done at 120°C. (Chem. capture system. (J. Chem. Technol. Bio- in situ LLE of fermentation products cord high and selectivity for MX/PX was Flash joule heating involves applying recent years, the US EPA has identi-
Eng. Res. Des., 2024, 209, Sep.,102-110; technol., 2024; DOI: 10.1002/jctb.7716). posing emulsion formation problems. 5.3. Both vapour- and liquid phase fi xed an intense sub-second pulse of electric fi ed compounds that are classifi ed as
DOI: 10.1016/j.cherd.2024.07.057). Ionic polymer absorbents Membrane contactors are useful but bed tests confi rmed the above separation. current to chopped-up waste, resulting in
Effi cient purifi cation of inspired by deep eutectic require a large membrane area. These (Angew. Chem. Intl. Ed., 2024; DOI: heating up to more than 2700°C, which
authors have reported that a hydrophobic
butanone and ethyl acetate solvents to recover Co and Ni polytetrafl uoroethylene (PTFE) mem- 10.1002/anie.204008817). vaporises metals which are condensed
or dissolved into low-concentration HCl
from wastewater by extractive [This column has covered some papers brane-based emulsion separator (MBES) Recovery of valuable for separation. (Chem. Eng. News, 2024,
distillation on the recovery of Co, Ni, etc. from used enables continuous LLE for the recovery materials from electronic 29 July, 26-31).
th
batteries to fi ll the gap in the availability of an exemplary fermentation product,
Z. Ma et al have reported optimisation of the critical Co.] butyric acid, with improved throughput. waste
of the title separation-based on cost, The permeate fl ux of 290 litre per sq. m Selective adsorption of
thermodynamic and environmental H. Bastos et al have come out with a per hr with single-stage MBES system P. Patel has covered this subject as the aromatic sulfonic acid
analysis. The wastewater containing new strategy of using ionic polymers was calculated to be 1450 gm per sq. world is drowning in electronic waste (ASA) from wastewater emerging contaminants, which include
both butanone and ethyl acetate form a for the recovery of Co and Ni from m. per hr, which is much higher than and it seems that the fl ood of e-waste using a surface imprinted steroids, hormones, endocrine-disrupt-
ternary azeotrope and extractive distil- recovery solutions. Such ionic polymers the 9 gm per sq. m. per hr realised in a generated in 2022 contained $91-bn ing compounds, pharma and personal
lation was adopted. Four solvents were were made, e.g., by simple and fast membrane contactor, resulting in very worth of valuable metals and 40% of polymer (SIP); H-acid as a care products. Two types of LLE are
analysed. (Chem. Eng. Res. Des., 2024, photopolymerisation process combin- good economics. (Green Chem., 2024; those metals end up in a land fi ll or were representative contaminant considered: Solvation extraction (SE)
208, August, 782-794; DOI: 10.1016/j. ing [2-(methacryloxy)ethyl][trimethyl DOI: 10.1039/D4GC02772H). burned in incinerators or disposed of in and solvation with reaction extraction.
cherd.2024.07.048). ammonium chloride] (METAC) with a uncontrolled ways. Only 4% of some The separation of ASAs from waste- Here SE uses a solvent with a lower
Highly effi cient separation of metals were recovered. [The average water is problematic and more so as it is boiling point than water. The raffi nate
intermediate-size m-xylene person in the US threw away 21-kg of refractory and not biodegradable. J. Yao phase leaving the extraction column
(MX) from xylenes via electronics in 2022.] Innovative ways are et al have reported PEI/Cl-PS-DVB as will contain the amount of solvent that is
a length-matched Metal soluble in water and a stripping column
recovers this solvent. (Chem. Eng. Prog.
Organic Framework (MOF) (of AIChE), June 2024).
with optional oxygen sites
distribution Advances in crystallisation
[Separation of xylene isomers – o-, m-, and precipitation technologies
p- – is of great industrial importance as for biotherapeutics
pure OX can be separated by distillation
but MX and PX separation poses prob- M.D.C.P. Royo et al have discussed the
lem. Initially, and lately again, crystal- title subject and have referred to the
lization was used to get pure PX, apart characteristics of biotherapeutics which

170 Chemical Weekly March 25, 2025 Chemical Weekly March 25, 2025 171

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