Page 187 - CW E-Magazine (13-8-2024)

Special Report Special Report

state NMR. Selectivity was over 90%. the cost is an adverse factor. (ACS as catalysts. Work was also done for C-7 Galvanizing & passivation chemical treatments
(ChemSusChem, 2024: DOI: 10.1002/ Omega, 2024: DOI: 10.1021/acso- to C-12 primary alcohols. Hf(IV) and
cssc.202400647). mega.3C04651). Ti(IV) trifl ates gave highest conversion for corrosion prevention of metals
with alkene yields of more than 70%, at
Selective transformation of Modifying of magnetic uio- 140-180°C. (Green Chem., 2024: DOI:
5-hydroxymethylfurfural 66-nH as a new nanosorbent 10.1039/D4GC01038H). IntroductIon The biggest disadvantage of galva- Dr. S.K. ChaKravorty
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(HMF) to 3-hydroxymethyl- by thermo-alkaline-hydrolysis or centuries, metals have been nizing is its cost. While hot-dip galva- Consultant (Plant Engineering)
used extensively in our everyday nizing (HDG) may be cheaper for coat-
cyclopentanone (HMcP) over technology for highly effi cient 2,3-Pentanedione (Pd) from Flives. From aluminium and cop- Email: chakravorty4410@gmail.com
ing large steel structures, it can be less
ni catalysts enrichment of and determina- lactic acid (LA) per in electrical wiring to gold and silver cost-effective for smaller pieces such as the advantages of galvanizing
tion of quercetin in apple peel N. Dhiman et al have reported the title in jewellery, silverware and electronics, nuts and fasteners. Additionally, galva- Some of the notable advantages of
M.V. Morales et al have discussed the conversion using ZrO (Polymorphic) metals have been used for a variety of nized surfaces have a dullish grey ap- galvanization include(10, 11):
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critical factors which affect the title R. Chang et al have reported that mag- as the catalyst. This catalyst exhibits purposes. One of the most widely used pearance that may not be aesthetically It is one of the most effective tech-

transformation. Ni was supported on netic UIO-66-NH -MH 0.05 has higher high selectivity, activity and stability metals is iron, or more specifically, its pleasing for some applications. niques for protecting the surfaces of
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different carbon supports and metallic adsorption than the title adsorbent and for the title reaction. 95.5% selectivity more popular alloy form, steel. Steel iron and steel against corrosion. A
has also signifi cantly higher magnetic is reported at 325°C. (Green Chem.2024: IS used in appliances, automotive At first glance galvanizing appears tonne of coated zinc saves at least
properties. The maximum capacity was DOI: 10.1039/D4GC02097A). panels, signs, buildings and bridges. How- to be a simple procedure. But, in fact, around 20-30 tonnes of iron from
65.30 mg per gm. Even after 7 cycles ever, like other metals, steel is prone it includes five stages; each of which corrosive destruction.
96.3% adsorption capacity was realised. Selective hydrodeoxygenation to corrosion. This continuous process influences the final result(9): The galvanization process provides
(Sepn. Purfn. Technol., 2024: DOI: of furfural (F) to 2-methylfuran eventually leads to the loss of material 1. Degreasing: Metal constructions not only a low initial cost, but also
10.1016/j.seppur.2024.128054, 353, (MF) thickness, decreased material strength, should be thoroughly cleaned from one of the lowest lifecycle costs
partA, Jan.2025, 128054). perforation and reduced service life. greasy stains or oils. among all of the protective coating
Y. Yao et al have worked on the title There are numerous methods for coat- 2. Etching: At this stage the metal techniques. Other corrosion preven-
oxides with different structure and ac- Sustainable upgrading of glyce- process which involves a concerted ing metallic surfaces, each with its own is cleaned of the already accumu- tion systems, such as polymer pow-
id-base properties. Testing was done in rol (G) into glycidol (Gd) and combination of hydrogenation and set of limitations and benefits(1-6). lated corrosion. This is important ders and paints, have continuously
a batch stirred reactor and competing its derivatives under continu- hydrogenolysis. Highly dispersed MoP However, in this article only, galvani- for parts that have already been in seen cost increases of high magni-
reactions are discussed. It seems Ni/ ous-fl ow conditions catalysts, supported on SiO , was used zing, pickling and passivation process operation. tude. Moreover, they require fre-
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ZrO catalyst gives a selectivity of 73%; and at full conversion of F, 96.3% selec- will be discussed. 3. Washing: Removes various parti- quent inspection and maintenance,
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Ni/HSAG-ox gives 87% selectivity. A. Sivo et al have reported the title tivity to MF was realised at 120°C, 1.0 cles left after etching. which adds to lifecycle costs.
(ChemSusChem., 2024; DOI:10.1002/ process which can be easily integrated MPa (20% MoP/SiO ) in a continuous Galvanization 4. Drying: Specialists heat the pro- Because hot dip galvanized steel
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cssc.202400559). with downstream synthetic steps to fi xed bed reactor. (Ind. Eng. Chem. Res., Galvanizing involves immersing duct with special equipment up to requires very little maintenance for
2023: DOI: 10.1021/acs.iecr.3C02804). the metal (mostly steel or iron) in a 100°C. Due to the high tempera- its life span, which could be as high
orange mesocarp extract molten zinc bath. Once removed, the ture, the flux salts are dried. as 50-70 years, the initial cost alone
(oME) as a natural surfac- upgradation of AquaSolv omni coated metal reacts with oxygen and 5. And, finally, the process of galva- is the total lifecycle cost.
tant: Impact on fl uid-fl uid and (AqSO) biorefi nery: access to carbon dioxide in the atmosphere to nizing. The product is completely This technique has the longest his-

fl uid-rock interactions during highly ethoxylated lignins (ELs) form a protective zinc carbonate layer. immersed in molten zinc, due to tory (around 140 years) of corrosion
chemical fl ooding in high yields through reactive The galvanizing process has multiple which it acquires a zinc sheath. protection to iron and steel.
produce value-added derivatives. Sus- extraction advantages that make it a popular A galvanized coating is easy to
A.A. Obuebite et al have referred to the tainability of this process is discussed. choice. For example, the zinc oxide History of galvanization apply and maintain.
use of surfactant fl ooding for secondary/ (Green Chem., 2024: DOI: 10.1039/ D. Rigo et al have worked on the title coating is highly stable, adheres tightly The term galvanization, as it applies By-products of the process can be

tertiary recovery of oil from depleted D4GC01565G). method for valorising lignins (from to the metal substrate and does not flake to corrosion, was simultaneously deve- recycled.
fi elds. These authors have used OME as biomass) which involves simultaneous off easily(7, 8). loped in France as well as in England in A galvanized surface can withstand

a potential green surface-active agent. catalyst screening for dehydra- functionalisation and extraction. Hydro- 1837. The method employed then was UV radiation without suffering any
The extract is obtained from the orange tion of primary alcohols from thermally treated wood solids were Galvanizing also affords galvanic to manually dip iron sheets into a hot damage.
mesocarp using alkaline water as solvent renewable feedstocks under refl uxed with EtOH : H O mixtures (70- protection. In other words, if the metal’s bath of molten zinc. The first patents A hot dip coated surface will not be

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and was characterised through FTIR. formation of alkenes at energy- 99 v/v %) in the presence of catalytic surface becomes exposed due to for galvanized metals were obtained damaged by transport and handling.
Stability at 100°C and compatibility saving mild reactions amounts of H SO (c=0.15 to 1.2 M). scratches, cuts or dents, the zinc coat- by M. Sorel of France and H.W. Craw-
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with divalent ions was checked. Micro- Ethoxylated Ls were obtained in 27-52 % ing will sacrifice itself by corroding ford from England. Within two years, Galvanization processes
emulsion system was characterised. An A. Allahveroiyev et al have reported yields; degree of substitution was up to preferentially. This helps protect the galvanized iron sheets became popular
additional oil is reported which shows the conversion of 1-hexanol to 1-hexene, 40.8 ETO groups/100 Ar. (Green Chem., steel substrate between maintenance for roofing applications in Europe and Hot dip (immersion) galvanization
its utility. Field testing was done, but using Lewis acids such as metal trifl ates 2024: DOI: 10.1039/D3GC03776B). operations. the US. Hot dip galvanization involves the

186 Chemical Weekly August 13, 2024 Chemical Weekly August 13, 2024 187

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