摘要
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 CO_2 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 R_sof 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 CO_2/H_2O 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 CO_2/H_2O mixed gasification.A significantly reduced total reaction time was observed when employing a CO_2/intermittent H_2O process along with an 83.46% reduction in the steam feed,compared with the amount required using a CO_2/H_2O atmosphere.
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 Rsof the PKS biochar decreased from 0.0305 min-1 at carbon conversion（x）=20% to 0.0278 min-1at 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.
基金
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)
Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering(2017-K22)
