在概述最新研发的微型流化床反应分析(micro-fluidized bed reaction analysis,MFBRA)方法与应用的基础上,应用该方法进一步研究了半焦-CO2、半焦-水蒸气等温气化反应动力学,并与热重分析(thermogravimet-ric analyzer,TGA)求取的气化反应动力学数据比较。在最小化气体扩散的实验条件下,利用MFBRA和TGA测定求算的半焦-CO2、半焦-水蒸气气化反应在受反应动力学控制的低温段的活化能非常接近,说明了MFBRA对等温气化反应分析的适用性和可靠性。实验研究还发现:半焦-CO2、半焦-水蒸气气化反应在MFBRA中受反应动力学控制的温度范围较在TGA中明显宽,且在具有明显扩散影响的高温段通过MFBRA测定的半焦-CO2气化反应表观活化能明显大于利用TGA测定的值,表明在MFBRA中受到的气体扩散抑制效应较小。
An effective technology for utilizing vinegar lees (VL), a biomass waste generated during its production, is much needed in China due to the huge consumption of vinegar. This study investigates the preparation of porous carbon (PC) from VL, now reporting on the adsorption capability of PC in removing phenol from its aqueous solution. The preparation of PC consists of carbonization of VL in N2 and activation in CO2. The results show that the optimal activation temperature and time in CO2 for VL char carbonized at 800 ℃ were 875 ℃ and 1 h, respectively. The PC prepared was found to have large specific surface area and micropore volume, with an adsorptive capacity for phenol from its aqueous solution much higher than that of commercial coconut shell activated carbon (CSAC). Adsorption of phenol from its aqueous solution by the VL-based PC was found to follow the isothermal Langmuir equation.