高温高压下煤在溶剂中溶胀特性及动力学分析

Kinetic Analysis and Swelling Behavior of Coal in Solvent at Elevated Temperature and Pressure

根据溶胀测量原理,结合位移传感器,设计了一种可以在高温高压条件下测量煤样在溶剂中溶胀的装置.测量获得了不同颗粒粒度B3煤样在神华循环油中、N_2气氛下溶胀比随温度的变化曲线,同时考察了初始压力、气氛和煤阶对煤样高温溶胀特性的影响,并采用非等温溶胀动力学方程对溶胀数据进行拟合分析.结果表明,不同颗粒粒度B3煤样的溶胀比随温度的升高而增大,在300℃时达到最大溶胀比,随着温度的进一步升高,溶胀比减小,煤层高度开始降低.增大初始压力和H_2气氛下有利于煤样的溶胀.煤样在四氢萘中的溶胀比较在循环油中大.非等温溶胀动力学拟合分析表明,煤在溶剂中溶胀遵循简单级数反应机理函数,活化能在20kJ/mol^60kJ/mol之间.

According to the swelling measurement principle, combined with a linear variable differential transformer （LVDT） deformation transducer, an apparatus for measuring coal swelling in solvent at elevated temperature and pressure was made. Changes of swelling ratio of the different particle size B3 coal in N2 atmosphere in Shenhua recycle oil were measured. The effect of initial pressure, atmosphere, and coal rank was investigated, and non-isothermal swelling kinetic equation was used to fit the swelling data. The results show that the changes of swelling ratio of B3 increase with temperature increasing, achieve the maximum at 300 ℃ and decrease because of the coal cracking. The higher initial pressure and H2 atmosphere are helpful to coal swelling in solvent. The swelling ratios of the coals in tetralin are relatively higher than that in recycle oil. The non-isothermal swelling kinetics analysis show that the coal swelling in the solvent follows a simple series reaction mechanism and the activation energy is between 20 kJ/mol and 60 kJ/mol.