Performance of catechin as a sustainable-green inhibitor to inhibit the hydrogen production of Al alloy waste dust

Abstract

Al alloy products produce hazardous waste dust during machining and surface treatment. Although the risk of dust explosion can be avoided by using the wet dust collector system, potential hydrogen explosion arises when Al alloy waste dust reacts with water. In this paper, catechin (CA) was selected to inhibit the hydrogen production of Al alloy waste dust and the hydrogen production curves of 6 different concentrations of CA were obtained. Characterization experiments were conducted on Al alloy waste dust before and after hydrolysis reaction through scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The inhibition mechanism of CA on hydrogen production was discussed by in the light of hydrolysis kinetics and adsorption models. The results show that the hydrolysis process of Al alloy waste dust is in line with the nucleation-growth model. When the CA concentration is 0.35 wt%, almost no hydrogen is produced. SEM-EDS shows that the surface of the hydrogen-inhibition product is smooth and dense. Given the reduction in metal hydroxide content, as indicated by XRD results, this confirms that CA is effective in inhibiting the hydrogen production of Al alloy waste dust. FTIR results show that the adsorption mechanism of CA includes chelation and electrostatic adsorption, and the formation of a passivation film on the surface of Al alloy waste dust to prevent the metal particles from contacting water, thereby inhibiting hydrogen production. This study offers a more sustainable solution for inhibiting hydrogen production of Al alloy dust in the wet dust collector system to ensure both production safety and environmental protection.