Characterization And Analysis Of Activated Carbons Prepared From Biomass In A Microwave Tube Reactor

This work establishes the technical feasibility of producing a value added product,activated carbon(AC),from a henna leaves powder(HLP)and walnut shell(WNS),using K2CO3 as the activating agent and microwave heating tube pyrolysis as the energy source.There are different rates of impregnation ratios(IRs)(e.g.K2CO3:HLP and K2CO3:WNS of 0.5,1.0,1.5),different activation temperatures(e.g.450,500,550 and 600?)and activation times(e.g.20,40,60 and 80 min),respectively.Activation processes were obtained using CO2 as oxidizing gas.The effect of various process parameters such as impregnation ratio,activation temperature,activation time on percentage yield and adsorption capacity of iodine(I2)and methylene blue(MB)of the ACs were investigated.In this study the AC prepared from HLP has maximum percentage yield,iodine adsorption and MB values are 83.71%(450 0C,20 min,IR=0.5),586.915 mg/g(500?,20 min,IR=1)and 427.75 mg/g(600?,80 min,IR=0.5)respectively.While the maximum percentages yield,I2 and the MB adsorption values are 62.75%(450 0C,20 min,IR=1),1545.06 mg/g(600?,60 min,IR=1),and 470.95 mg/g(600?.60 min,IR=1)for ACs obtained from WNS.The optimum operation conditions were introduced for the preparation of AC is HLPAC under(500?,20 min,1)and WNSAC(600?,60 min,1).The Scanning Electron Microscope(SEM)analysis revealed the heterogeneous surface structure of the HLPAC at(IR=1,500? and 20 min)and WNSAC at(IR=1,600?,60 min)clearly depicted the presence of macropores which acted as channels to the microporous network.However,the surface groups at(3417.74 cm-1)were due to the presence of hydroxyl groups(O-H stretch)on the surface of HPLAC(IR=1,500?,20 min)and WNSAC(600 ?,60 min,1).Peaks at 1000 cm-1 and 794.67 cm-1 were found,which corresponded to benzyl hydroxyl C-surface,as determined by the Fourier Transform Infrared Spectroscopy(FTIR)analysis.The proximate and ultimate analyses of HLPAC(IR=1,500?,20 min)and WNSAC(IR=1,600?,60 min)were carried out by standard methods.The X-ray diffraction(XRD)peaks of the different ratios of HLPAC were observed under 20.94°,28.34°and 40.56°,while for the WNSAC,two peaks were shown under 21.48°and 40.36°respectively.