煤的热解动力学研究

STUDY ON THE PYROLYTIC KINETICS OF COALS

热解是煤燃烧、气化和液化等热加工工艺中的基本过程之一,也是成煤过程中的基本环节。因此,研究煤的热解不仅为煤的热加工过程提供科学依据,也能为加深煤化学研究提供重要信息。溶剂抽提既是研究煤化学的重要方法,也是提取某些重要化工原料和燃料油的的重要加工过程,同时还可为抽余煤的合理利用提供必要的基础数据。

non-isothermal thermogravimatry was used to research the pyroly(?)c kinetic feature of deminerized coals, Soxhlet extraction residues and supercritical gas extraction residues of coals for elucidation the characterization of the thermal processing and utilization of coal residues.The experiments were carried out at heating rate of 10℃/min under nitrogen flow in a thermal balance. The peak on the differential thermogravimetry curve corresponds to the volatile gas evolution during the pyrolytic of coals. The curve with single peak was obtained for high rank coals while dual peak curve was for low rank coals. The peak temperature, at which the maximum pyrolytic reaction rate occurs, increases with increasing carbon content of coal. The maximum reaction rate has a linear relationship with H/C atomic ratio. There is a compensation effect between activation energy E and pre-exponential factor A in coal pyrolysis.E=20.00 log A+32.74 (C%>80%)E=14.22 logA+20.90(C%<80%)The kinetic compensation effect may be atributed to. mineral matter in coal and its porosity etc. We suggest a new expression, E/(100 F log A), as a parameter to characterize the pyrolytic reactivity of coals by which a linear relation was found, where F is coal conversion.