Hydrogen generation performance of waste aluminum alloy chips and powders

WOS: 000570291400001The objective of this work is to compare and evaluate hydrogen generation performance of 1050, 6013, and 7075 series commercial aluminum machining chips and powders obtained from mechanical milling of the chips. Prior to mechanical milling 20 wt.% NaCl was added to aluminum chips to activate aluminum. NaCl salt also functioned as a process control agent and prevented excessive cold welding of aluminum particles during intense plastic deformation applied by ball milling. Morphology of chips and powders was analyzed by scanning electron microscopy. Hydrogen generation experiments were performed by using distilled water and 1 M NaOH solution at 70 degrees C. the effect of temperature on the hydrogen production performance of aluminum alloys was also investigated in the range of 30-70 degrees C. Mechanically milled powders gave higher hydrogen generation yield compared to the chips. Severe cold working by mechanical milling accelerated the corrosion and increased the hydrogen production performance of the powders. Hydrogen production efficiency of milled powders in NaOH solution was approximately 3.5-7 times higher than milled powders in distilled water. Hydrogen yield of aluminum alloys increased with increasing alloy content and the highest values were obtained from Al 7075 powders in NaOH solution. It was also verified that the hydrogen yield increases with increasing reaction temperature