基于热力学的生物油重整制氢低CO工艺优化

Process Optimization of Bio-oil Reforming for Hydrogen Production with Low CO Based on Thermodynamics

针对燃料电池氢源低CO含量的应用需求,对生物油水蒸气重整制氢工艺进行了热力学分析,并利用响应面法优化得到了高氢低CO工艺条件。在温度300~1500 K、压力0.1~0.7 MPa和水碳比1.0~7.0条件下,对生物油水蒸气重整制氢进行了热力学分析,发现高温、低压、高水碳比有利于产氢,低温、较高压力和高水碳比会抑制CO生成;确定反应温度、压力和水碳比为分析变量,以高氢产率和低CO干基摩尔浓度为优化目标,利用响应面法进行预测分析,得到了适合燃料电池应用的生物油水蒸气重整制氢低CO工艺条件。结果表明,预测的优化结果与相近反应条件下的实验对比结果接近;比较响应面预测优化结果的氢产率和CO干基摩尔浓度与Aspen Plus热力学模拟结果的相应值,参数误差均小于5%。生物油水蒸气重整制氢具有高氢低CO效果的热力学最优条件:温度为814.98 K,压力为0.10 MPa,水碳比为6.00,在此条件下,氢产率为88.74%,CO干基摩尔浓度为3.07%。

According to the application demand of low CO content in fuel cell hydrogen source,the thermodynamic analysis of bio-oil steam reforming process for hydrogen production was carried out,and the process conditions of high hydrogen and low CO were optimized and obtained by response surface method.Firstly,the thermodynamic analysis of hydrogen production by bio-oil steam reforming was carried out in the range of temperature 300-1500 K,pressure 0.1-0.7 MPa and water to carbon ratio 1.0-7.0.The results showed that high temperature,low pressure and high water to carbon ratio were favorable for hydrogen production,while low temperature,higher pressure and high water to carbon ratio could inhibit the formation of CO.Then,reaction temperature,pressure and water to carbon ratio were determined as the analysis variables,and the high hydrogen yield and low CO dry basis molar concentration were taken as the optimization objectives.The response surface method was used for prediction and analysis,and the low CO process conditions of hydrogen production by bio-oil steam reforming suitable for fuel cell application were obtained.The optimized results were compared with the experimental results under similar reaction conditions,and the values were close.Comparing the hydrogen yield and CO dry basis molar concentration of response surface prediction optimization results with those of Aspen Plus thermodynamic simulation results,the parameter error was less than 5%.The thermodynamic optimal conditions for hydrogen production by bio-oil steam reforming with the effect of high hydrogen and low CO were obtained as follows:temperature 814.98 K,pressure 0.10 MPa and water carbon ratio 6.00.In these conditions,the yield of hydrogen was 88.74%and the dry basis molar concentration of CO was 3.07%.