金属元素对生物质一体化制氢的影响

摘要

The effects of different metals( K,Ca,Mg,Fe,Zn) on hydrogen yield,gas composition and carbon conversion were studied based on the integrated hydrogen production process from corn cob. The catalytic activities of different metal elements were found as the following sequence: K>Fe>Mg>Ca>Zn. Particularly, K showed the best catalytic effect with the carbon conversion of 85.65% and then, the effects of K on pyrolysis and gasification processes were discussed in detail. The results showed that the addition of K could promote the conversion of biomass during pyrolysis and gas-solid simultaneous gasification process. The carbon conversion were improved by 5.31 and 10.30 percent points in each step, respectively. Potential hydrogen yield of 86.97 g/kg and carbon conversion of 90.11% were achieved under the pyrolysis temperature of 600℃ and gas-solid simultaneous gasification temperature of 850℃. With the increase of temperature,the yield of biomass carbon decreased and the loss of K increased,which reached 13.56 % and 74.44 %,respectively at 850 ℃.%基于生物质一体化制氢工艺,考察了不同金属元素(K、Ca、Mg、Fe、Zn)对玉米芯制氢过程中产氢率、产品气体组成以及碳转化率的影响.结果表明:不同金属元素催化效果依次为K>Fe>Mg>Ca>Zn,其中K元素的催化效果最为明显,碳转化率达到85.65%,添加K能够促进生物质在热解段和气化段的热化学转化,分别使碳转化率最大提高了5.31和10.30个百分点.当热解温度600℃及气固同步转化温度850℃时,产氢率、潜在产氢率和碳转化率分别为70.02 g/kg、86.97 g/kg和90.11%.同时,随着温度升高,生物质炭产率降低,K元素损失变大,在850 ℃时,生物质炭产率和K元素损失分别为13.56 %和74.11 %