响应面法优化竹材热裂解制备生物油的工艺研究

Optimization of Bamboo Pyrolysis Process to Prepare Bio-oil by Response Surface Methodology

为了提高竹材生物质流化床快速热裂解制备生物油产率,利用响应面法优化其最佳工艺条件。试验选择热裂解温度(450～550℃)、气相停留时间(1.5～2.5 s)和物料粒径(0.18～0.22 mm)三因素作为独立变量,采用中心组合设计建立模型和考察上述因素对生物油收率的影响。结果表明三因素对生物油收率具有显著影响而它们之间的交互作用均不显著。依据所得到的模型,在各因素设定范围内获得的最佳工艺条件为:热裂解温度519.0℃、气相停留时间2.1 s、物料粒径0.18 mm,生物油理论收率为58.17%。在该条件下进行的三次重复试验,竹材生物油的实际平均收率为57.85%,与模型预测值58.17%无显著差异。响应面法简便、高效,优化结果能给生物质流化床快速热裂解制备生物油制备工艺提供一定的参考。

In order to increase the yield of bio-oil from bamboo biomass by fast pyrolysis process in a fluidized bed, the response surface methodology （RSM） was applied to optimize the process conditions, and the pyrolysis temperatures （450-550℃）, vapor retention times （1.5-2.5 s）, and particle sizes of bamboo （0.18-0.22 mm） were selected as independent variables. The central composite design （CCD） was used to build the model and to analyze the effects of the above variables on the yield of the bio-oil, and the results show that the three variables have obvious effects on the bio-oil yield. However, the interactions between the three variables have no significant influence. According to the established model, the optimal conditions within the experimental ranges for bio-oil yield are： pyrolysis temperature is 519.0℃, vapor retention time is 2.1 s, and the particle size is 0.18 mm, and the theoretical yield is 58.17% at the above optimal conditions. With these optimal conditions, the average actual value of the bamboo bio-oil yield in three replicated experiments is 57.85%, which is not significantly different from the predicted value of 58.17% by the model. The RSM is simple and convenient, and the results would provide a scientific reference for the preparation of bio-oil from bamboo biomass by fast pyrolysis in fluidized beds.