Abstract:
To convert empty fruit bunch (EFB) into synthetic gas in steam gasification using NiO/Al[subscript2]O[subscript3] catalyst for tar cracking. The catalysts were modified with MgO and CeO[subscript]2 in order to improve catalytic activity. The modified catalysts were examined activity on tar cracking with steam in a small fixed-bed reactor and characterized by BET XRD and TPR techniques. Results showed that the presence of MgO and CeO[subscript]2 contributed to improvement in performance of Ni catalyst in terms of tar reduction and stability. This was attributable to better dispersion of Ni and lower sintering of active metal on support modified by either MgO and CeO[subscript]2. Effects of calcination temperature and catalyst preparation method on catalytic activity were investigated. It was found that the CeO[subscript]2-loaded catalyst prepared by co-impregnation and calcined at 500℃ appeared to be the best effective catalyst in terms of reduction tar. Moreover, the MgO-loaded catalyst calcined at 950℃ and prepared by sequential impregnation was found to be the most stable catalyst, especially at relatively high temperature. This might be due to forming of MgAl[subscript]2O[subscript]4, which is more thermally stable. Finally, the influence of reaction temperature and residence time on the catalytic activity also was studied. The results indicated that increasing of reaction temperature from 600℃ to 800℃ and residence time from 0.45 to 0.67 second can reduce the tar yield approximately 40% and 10% respectively.