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In this study, strontium is used as an alloying element for improving the pitting resistance of Mg-5Al-4Sn based alloys in an alkaline solution. Potentiodynamic polarization measurements suggest that the addition of strontium increases the robustness of the pitting resistance as a result of the higher pitting potential and wider range of passive potential. Electrochemical impedance spectroscopy (EIS) confirms the formation of a solid passive film on the alloy surface due to a significant increase in the passive film and the charge transfer resistance, as well as lower film and double layer constant phase element magnitude values. Additionally, the potentiostatic polarisation results also show a lower passive current density and passive film stability, resulting in an increase in the breakdown time when the amount of strontium added to the alloy increases from 0.0 to 1.0 wt%. Furthermore, the scanning electron microscopy results indicate that insignificant corrosion is observed on alloy specimens containing strontium, whereas there is fierce corrosion on alloy based surfaces. This robust corrosion resistance could be attributed to the α-grain reduction and refined precipitates at the alloy grain boundaries, resulting in promoted formation of the passive film which is formed from a mixture of magnesium, aluminum and tin oxides/hydroxides, as confirmed by the X-ray photoelectron spectroscopy results.

Leaf extracts are widely used to mitigate the steel corrosion in an acidic environment. This work focuses on the effective acidic inhibition of a Piper Betle leaf extract (PBLE) that can be added to a green corrosion inhibitor system, giving a high corrosion inhibition performance of steel in a 0.1 M HCl solution. The relatively destructive potentiodynamic (PD) and potentiostatic (PS) polarizations combined with some non-destructive electrochemical techniques, including linear polarization resistance (LPR) and electrochemical impedance spectroscopy (EIS), perform the high corrosion inhibition likely a mixed behavior for steel in investigated solution. Surface analysis demonstrates that the nano porous film formation is PBLE concentration dependent. The results indicate that the inhibition efficiency is increased by the addition of PBLE at a concentration up to 2000 ppm due to a compact, robust, and uniform protective film formation. Moreover, an increase in PBLE concentration up to 2500 ppm decreased the inhibition efficiency due to a decrease of the PBLE species’ activity in the solution that significantly affects the nano porous film formation. This work suggests a new inhibitor that can be added to a green corrosion inhibitor system for delivering high corrosion resistance of steel through a controlled surface treatment.

Desulphurization by reactive adsorption was studied on sand abrasive blasting grit/ bentonite. The adsorbent was characterized by determining the composition, adsorption isotherms, specific surface area, pore volume and average pore diameter. Adsorption experiments were performed in continuous system at 260�300oC, 25 atm and volume hourly space velocities of 1-2 h-1. The efficiency of adsorption was evaluated at desulphurization of a synthetic reaction mixture and a catalytic cracking gas oil.

Hydrogenolysis of glycerol was conducted on catalyst of the type mixed oxide of Cu-Cr doped with NiO on g-Al2O3. The prepared catalyst was analyzed by XRD, IR and TPR. Catalytic tests were carried out on a laboratory plant in continuous flow system on a reactor equipped with heating mantle, at molar ratio of glycerol / hydrogen of 1/300, glycerol volume hourly space velocities 1000s-1, temperatures 200-220oC and pressures 3-5 bar. The main reaction products identified were propylene glycol and hydroxyacetone. Glycerol conversion increases with temperature and pressure on ranges of parameters studied. Selectivity to propylene glycol increases with increasing of temperature and pressure and the selectivity to hydroxyacetone decreases with increasing of temperature and pressure on the variation range of the parameters studied.