Synthesis of tungsten carbide from waste date palm tree carbon by mechanical alloying

Abstract

The abundance of date palm tree wastes consists of foliar (RDFo), frond (RDFr) and thorn (RDTh) has led to the environmental problem in Saudi Arabia. Thus, in this study, the wastes have been proposed to be used as the precursor for activated carbon (AC) production. TGA studies suggest the temperature of 400°C is suitable for the pyrolysis process of wastes to select the best raw material for the activated carbon production. Activated carbon from RDFr with a specific surface area of 21.5 m2g-1, after analyzed by Nitrogen adsorption analysis (NAA) was chosen and activated chemically using phosphoric acid (H3PO4) as dehydrating agent. The effect of different acid concentration ranging from 10 to 80% (v/v) was studied to produce high surface area of AC. The products were further characterized using proximate analysis, FTIR, NAA and FESEM. The results showed that the pore development of AC produced was influenced by acid concentrations. The highest BET specific surface area of AC, 1247 m2g-1 was achieved by using 60% (v/v) of H3PO4. The selected AC was used as catalyst support in tungsten carbide (WC) synthesis. In this process, WC was prepared from tungsten trioxide precursor and magnesium as reducing agent using mechanical alloying method before undergoing heat treatment at 850°C. The products were characterized using single point BET surface area, XRD and FESEM. XRD analysis showed that the WC hexagonal phase was produced in the presence of tungsten semicarbide hexagonal phase in the final products. This is due to the insufficient ratio of reducing agent and shorter time for alloying process.