KOH对超临界水中褐煤连续制氢的影响

采用连续式超临界水反应装置,以20%的水煤浆为反应原料,考察了不同KOH/煤质量比、温度、压力对褐煤制氢过程的影响。实验结果表明,在水煤浆中添加KOH可以提高碳气化率及H2的体积分数和产率,在600℃、25 MPa、KOH/煤质量比为4.1%时,与未加KOH相比,气相产物收率由29.6%提高到49.5%,碳气化率由23.0%增大到31.5%;H2的产率由135.4 mL/(g daf coal)提高到239.1 mL/(g daf coal)。随着温度的升高,H2产率逐渐增大,650℃时达到287.8 mL/(g daf coal),是500℃时的5.4倍;高温、高压下,KOH对煤气化过程的催化作用更为明显。

Effect of KOH on hydrogen production from lignite in a continuous supercritical water reactor

Hydrogen-rich gas production from Chinese Xiaolongtan lignite was performed in a continuous supercritical water reactor with feeding of coal water slurry. The effects of KOH/coal weight ratio, temperature and pressure on carbon gasification efficiency, product distribution and yields of gas were investigated. At KOH/coal weight ratio of 4.1% (600℃, 25MPa), carbon gasification efficiency reaches to 31.5%. The content of hydrogen in gas is 38.5% and its yield reaches to 239.1mL/(g daf coal). There is a notable increase in the yield of hydrogen with the elevation of reaction temperature. The yield of hydrogen increases from 53.0mL/(g daf coal) to 287.8mL/(g daf coal) when temperature increases from 500℃ to 650℃. The catalytic performance of KOH is distinct at higher temperature. The increase of pressure also has positive impact on yield of hydrogen.