In lab tests, a new composite pulled out corrosion-driving impurities from amine solution and slowed rusting of carbon steel.
Researchers developed a biodegradable composite made from functionalized zein nanoparticles and leonardite-derived humic substances. They tested it in methyldiethanolamine solutions loaded with H₂S and CO₂, where chloride and iron impurities are known to promote localized corrosion.
The material showed accessible adsorption sites and removed chloride and iron at the same time. Electrochemical tests and 45-day gravimetric measurements indicated measurable corrosion mitigation, alongside strong performance in short-term adsorption–regeneration cycles.
How the composite performed
The zein–humic composite was mostly amorphous, moderately mesoporous, and enriched with oxygen- and nitrogen-containing functional groups that provided adsorption sites. In the tested conditions, combined chloride–iron uptake was about 45–52 mg per gram, and the Freundlich adsorption model fit better than the Langmuir model. A multi-objective optimization reported near-complete chloride removal (98%) and high iron removal (91%), along with reduced corrosion rate. Electrochemical and 45-day weight-loss measurements showed measurable corrosion mitigation, including increased charge-transfer resistance, behavior consistent with mixed-type inhibition, and less localized attack. An exploratory Random Forest analysis highlighted adsorption capacity and residual chloride concentration as the variables most strongly associated with corrosion behavior. The composite retained about 85% of its working capacity over five adsorption–regeneration cycles. Screening-level life-cycle and techno-economic analyses suggested competitive environmental and operating performance relative to benchmark materials.
Lab evidence and caveats
The evidence comes from materials characterization, adsorption experiments in H₂S/CO₂-loaded methyldiethanolamine solutions, electrochemical testing, and 45-day gravimetric corrosion measurements, plus adsorption–regeneration cycling. Limitations include that the work describes performance under investigated lab conditions; the abstract does not specify real plant scale, long-term stability beyond the tested cycles, or how results translate to different operating chemistries. The life-cycle and techno-economic analyses are described only at a screening level.
// Source
Scientific Reports · 2026 · DOI: 10.1038/s41598-026-64192-6
Authors: Maysam Safe, Bizhan Honarvar, Nadia Esfandiari, Zahra Arab Aboosadi
Institutions: Islamic Azad University, Marvdasht
