摘要
在550℃~650℃,24 MPa^30 MPa,反应停留16 s^46 s的条件下,对初始浓度0.05 mol/L^0.70 mol/L的甲酸溶液在超临界水中的降解过程进行实验研究。结果表明,甲酸降解的气体产物为H2、CO2和CO,其中H2、CO2为主要产物。高温有利于甲酸降解和H2生成。温度较高(>600℃)时,压力变化对甲酸降解无明显影响。在一定范围内延长反应时间可提高气体产物中H2的体积分数和碳气化率。甲酸初始浓度对甲酸降解机理有重要影响,浓度较低(<0.1 mol/L)时,甲酸降解主要包含脱羧反应和脱羰反应两条反应路径,其中脱羧反应为主反应路径;浓度较高时则有许多副反应发生。碱性添加剂不利于甲酸降解生成H2。
The decomposition of formic acid（0.05 mol/L^0.70 mol/L） in supercritical water was investigated under 550 ℃~650 ℃,24 MPa^30 MPa,and a residence time of 16 s^46 s.The results showed that the gaseous products from the decomposition are mainly H2,CO2 and CO;the yields of H2 and CO2 are much higher than that of other products.High temperature is in favor of H2 production,while the pressure exhibits less effect on formic acid decomposition at high temperature（ 600 ℃）.With the increase of the residence time from 16 s to 20 s,the molar fraction H2 in the gaseous products is increased steadily,along with the rapid increase of carbon gasification efficiency.The reaction routes are dependent largely upon the feedstock concentration.With a low concentration of formic acid in the feed（ 0.1 mol/L）,the decomposition includes decarboxylation and dehydration routes;the former is the dominant pathway.Higher formic acid concentration may bring on many side-reactions.Alkaline additives are harmful for the hydrogen production from formic acid decomposition.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2010年第4期403-408,共6页
Journal of Fuel Chemistry and Technology
基金
国家重点基础研究发展规划(973计划
2009CB220007)
关键词
甲酸
超临界水
反应机理
碱性添加剂
formic acid
supercritical water
reaction mechanism
alkaline additives
