OP-II-3

PP-III-52via impregnation method. The TGA/DTA results of the LiFePO 4 precursor performedunder flowing nitrogen was shown in Figure 1. While the broaden endothermic peaksattributed to water evaporation was found at temperatures between 60°C and 160°C,the small endothermic peaks at 250°C caused by organic compound decompositionwere also observed. The peak appeared at 500°C is due to the crystallization ofLiFePO 4 . This result corresponded well with the continuous weight loss from ambienttemperature to ~550°C. The observed initial weight loss before 160°C, the stepweight loss between 170°C and 270°C, and the final weight loss from 450-550°Ccorresponded to the elimination of absorbed water, decomposition of organiccompounds, and crystallization of phosphate, respectively. Therefore the precursorwas calcined above 550°C to obtained LiFePO 4 crystallized phase. This agreed wellwith the results from the XRD analysis.Mass loss (%)10095908580Mas s los sDelta T119753Delta T ( o Cx10 5 )Relative intensity: LiFePO 4: Ni: Ni(OH 3 ) 2 6H 2 O: Ni(OH)2: NiO: impurityNi/LiFePO4 calcined 800ºC, reduced at 700ºCNi/LiFePO 4 calcined 800ºCLiFePO 4 calcined 900ºCLiFePO 4 calcined 700 ºCLiFePO 4 calcined 500 º C750 200 400 600 800Temperature ( o C)110 20 30 40 50 60 702 theta (degrees)Fresh LiFePO 4Figure 1. The TGA/DTG curves for the LiFePO 4 olivine (left) and XRD patterns of olivine andNi/olivine prepared at stated conditions (right).XRD of the Ni/ LiFePO 4 catalyst calcined at 800°C, with a support calcined at700°C, shows that the olivine phase is maintained along with trace amount of phasesrelated to Ni (Ni, NiO, Ni(OH) 2 , Ni(NO 3 ) 2 6H 2 O). After reduction process at 700°C,signals of NiO and other intermediate phases related to Ni became less pronouncedwhile intensity lines of Ni phase were amplified. Prepared catalyst was tested byplacing in a secondary reactor receiving producer gas from a laboratory scaleprimary continuous fixed bed gasifier firing coffe bean waste at 1.5 g/min. Productgases were simultaneously measured using dedicated TCD-NDIR analyzer. Ingeneral, addition of olivine or Ni/olivine significantly improves both quality and qualityof product gases as noticed from superior gas yield, LHV, H 2 /CO ratio, as well ascold gas efficiency with highest enhancement attained with nickel catalyst. In realpractice, using only olivine may be sufficient due to high cost of nickel and itsvulnerability to various metal poisoning substances.536