Hybrid biomass from agricultural wastes via microwave irradiation system for sulphur dioxide gas adsorbent / Siti Anis Mohd Amran

Research on the SO2 adsorption on single and mixed activated carbon (AC) adsorbents from waste biomass has gained significant interest due to their availability, cheap, and high carbon content. This thesis estimate effectiveness of mixed biomass adsorbent with and without fly ash as natural catalyst for SO2 gas adsorption. Activated carbon was produced from single and mixed two types of carbon rich agricultural waste materials which were coconut shell (CS) and palm kernel shell (PKS) using microwave heating method by KOH chemical activation. Activation process was performed in a conventional microwave oven at fixed power and time of 600 W and 20 minutes respectively. The effects of various parameters such as mixed ratio of coconut shell:palm kernel shell (g/g) (0:100, 20:80, 50:50, 80:20, 100:0), impregnation ratio of KOH:mixed precursor (g/g) (0.5, 1.0, 1.5) and percentage of KOH as activating agent (30%, 40%, 50%) on the adsorption efficiency of the activated carbons were investigated. It was then characterized by proximate and ultimate analysis, iodine analysis, methylene blue analysis, scanning electron microscope (SEM), pore structure characterization, x-ray fluorescene (XRF) and fourier transform infrared spectroscopy (FTIR). The activated carbons were characterized and used as adsorbent for SO2 gas adsorption based on effect of mixed ratio, effect of mass sample, effect of temperature and effect of fly ash as catalyst. The results showed that microwave heating is an effective heating method of activated carbon production. The mixed CSPKSAc-40 (20:80) at 1.5 impregnation ratio for 40% KOH concentration produced high surface area and pore sizes in range of micropores at 200.62 m2g-1 and 1.9 nm. The iodine number and methylene blue removal increases from 30% to 40% concentration of KOH and decrease at 50% KOH. These findings were consistent with the surface morphology of samples from SEM image. The major chemical composition found in fly ash is SiO2 followed by AI2O3 >Fe2O3 >TiO2 >CaO >K2O.Adsorption of common gaseous pollutants of sulphur dioxide (SO2) on single (CS and PKS), mixed (CSPKSAc) and the aid of fly ash as catalyst on AC in a fixed bed reactor were studied in this thesis. The amount of SO2 gas adsorbed by single and mixed adsorbent of CSPKSAc was expressed as adsorption breakthrough time of SO2 from flue gas. Single PKSAc-40 and mixed CSPKSAc-40 (20:80) showed the longer breakthrough time of 17 minutes and 10 minutes, respectively. The obtained results showed that SO2 gas adsorption increased using catalyst of fly ash in comparison to AC alone. The FTIR observation shows that the mixed CSPKSAc is good adsorbent in SO2 gas adsorption due to the new band appeared at 1107.57 cm-1, 984.10 cm-1 and 602.58 cm-1 which is indicating of an –O-SO3- group,–SO2- group and S-O stretching, respectively. This study showed the mixed CSPKSAc-40 (20:80) for SO2 adsorption can be used as a good adsorbent.