Chin.J.Chem.Eng. ›› 2018, Vol. 26 ›› Issue (10): 2153-2161.doi: 10.1016/j.cjche.2018.03.003

• Energy, Resources and Environmental Technology • Previous Articles     Next Articles

Characteristics of reactivity and structures of palm kernel shell (PKS) biochar during CO2/H2O mixture gasification

Guozhang Chang1,2, Ximin Yan2, Pengyu Qi2, Mei An1, Xiude Hu1, Qingjie Guo1,2   

  1. 1 State Key Laboratory of High-efficiency Coal Utilization and Green Chemical Engineering, College of Chemistry and Chemical Engineering, Ningxia University, Yinchuan 750021, China;
    2 Key Laboratory of Clean Chemical Processing of Shandong Province, College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, China
  • Received:2017-11-30 Revised:2018-02-22 Online:2018-10-28 Published:2018-11-14
  • Contact: Qingjie Guo,E-mail
  • Supported by:

    Supported by the Key Project of the Natural Science Foundation of Shandong Province (ZR2015QZ02), the Key Research & Development Program of Shandong Province (2016GSF117005), the introduction of scientific and technological innovation team of Ningxia Hui Autonomous Region (2016), and Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering (2017-K22).

Abstract: Palm kernel shell (PKS) biochars with different levels of carbon conversion were initially prepared using a tube furnace, after which the reactivity of each sample was assessed with a thermogravimetric analyzer under a CO2 atmosphere. The pore structure and carbon ordering of each biochar also examined, employing a surface area analyzer and a Raman spectroscopy. Thermogravimetric results showed that the gasification index Rs of the PKS biochar decreased from 0.0305 min-1 at carbon conversion (x)=20% to 0.0278 min-1 at x=40%. The expansion of micropores was the dominant process during the pore structure evolution, ad mesopores with sizes ranging from 6 to 20, 48 to 50 nm were primarily generated during gasification under a CO2/H2O mixture. The proportion of amorphous carbon in the PKS biochar decreased significantly as x increased, suggesting that the proportion of ordered carbon was increased during the CO2/H2O mixed gasification. A significantly reduced total reaction time was observed when employing a CO2/intermittent H2O process along with an 83.46% reduction in the steam feed, compared with the amount required using a CO2/H2O atmosphere.

Key words: Palm kernel shell, Reactivity, Pore structure, Carbon ordering degree, CO2/intermittent H2O gasification