Studies On Synthesis And Performance Of Fish Scale Catalyst For Biodiesel

As a new biomass fuel, biodiesel has been a kind of substitute of traditional fuel because of its easily obtainment, the raw material’s renewbility, low emission of pollutants and the security of using. The performance of biodiesel catalyst has great impact on the quality, cost and enviroment benefit of biodiesel. In view of biodiesel catalyst development’s direction and bottleneck question, the work used an extremely common natural product---fish scale as raw material and prepared a new kind of solid base catalyst for biodiesel production. Fish scales have the characteristics of easy acquiring, inexpensive and environment-friendly, Therenfore this study has important economic value and theoretical significance.In this paper, the fish scales were carbonized uncompletely, impregnated KF, and then activated under certain temperature to be prepared as a new solid base catalyst. Through the transesterification of rapeseed oil and methanol, the activity of the catalyst was evaluated by conversion of rapeseed oil. Focusing on the optimization of the catalyst preparation conditions, we discussed the effects of carbonization temperature, loading amount, activation temperature on the catalyst performance. The results showed that: under the condition of 523K carbonization temperature,35.0 wt% loading amount (relative to the quality of fish scale),723K activation temperature, the fish scale catalyst had the best catalytic performance. We applied the optimized catalyst to the transesterification and studied the factors of methanol-oil molar ratio, catalyst amount and reaction time for the transesterification reaction. The results showed that:under the condition of 12:1 methanol-oil molar ratio,5.0 wt% catalyst amount(relative to the quality of rapeseed oil), the catalyst made the conversion reach 81.7% after an hour, and 95.0% after three hours.The raw fish scale, the fish scale catalyst and hydroxyapatite were scanned electron microscopy and infrared analysis, then the catalysts made at the different activation temperature were tested by XRD and BET. It is found that:fish scale is a kind of porous framework. And from this result we can infer that the fish scale carbonizated uncompletely reacted with KF, and the catalytic activity sites were generated. The deactivation of fish scale catalyst is mainly due to the loss of catalytic activity sites. Another reason is that the catalytic activity sites is covered by reactants and products.As a solid base catalyst for biodiesel, fish scale catalyst has an advantage of simple preparation and catalytic activity. In the process of catalyst preparation, usage and post-processing, it will have no bad affect on the environment with the significant features of the green catalyst. This recovery of the fish scale not only improves the utilization of waste, but also reduces environmental pollution.