神华煤液化反应初期动力学研究

为研究神华煤反应初期动力学行为,在容积180 m L搅拌高压釜中,使用循环溶剂为供氢溶剂,利用"863"催化剂进行煤直接液化反应。采用传统的集总反应动力学模型,将原料煤分为快反应组分,慢反应组分和惰性组分3部分,并计算各级反应动力学活化能。结果表明:快反应煤向油、气和沥青烯组分(PAA)转化的总反应活化能为279.74 k J/mol,慢反应煤向PAA转化的活化能为57.80k J/mol。在开始的4 min内,煤的转化率及PAA的产率由于煤的热解而迅速增加;在后续4~15 min时,转化率增加缓慢,PAA产率基本稳定,并开始降低,表现出了典型的中间产物的特性。当煤的转化率超过55%时,在氢自由基的生成上,溶解氢将发挥重大作用。

Study on the liquefaction kinetics of Shenhua coal at initial stage

In order to research liquefaction kinetics of Shenhua coal at initial stage,the direct liquefaction of Shenhua coal was carried out in a 180 mL stirring autoclave using “863” catalyst and coal derived recycle solvent.A traditional lumped kinetic model was used in this study.Accordingly,the coal sample was classified into fast converting part,slow converting part and inert part.Activation energy (Ea) of each first order reaction was calculated.Results show that the total reaction Ea of fast converting part is 279.74 kJ/mol,that of slow converted part to pre-asphaltenes and asphaltenes is 57.80 kJ/mol.In the first 4 minutes of reaction,the conversion rate and yield of preasphaltenes increase sharply,and in the sequent 4-15 minutes,the yield of PAA is approximately constant or slightly declines,meanwhile the oil yield gradually increases in the whole reaction.In addition,the research also suggests that the dissolved hydrogen demonstrates more important on production of hydrogen free-radicals when the conversion is more than 55％.