油砂的热分析实验能指导油砂的干馏炼油。利用热分析仪在不同升温速率下将样品从室温加热到终温550℃,在热裂解阶段的350～520℃温区内,TG失重与铝甄实验所测含油率非常吻合,是沥青等重有机质裂解产油主要区间。应用DAEM模型、FWO模型以及C-R模型对产油区间计算活化能值并进行比较。结果表明,DAEM和FWO模型拟合度高,计算所得值基本一致,活化能在整个反应区间内不是定值,在150～320 kJ/mol范围内变化,当趋近220 kJ/mol左右时热裂解基本结束;被广泛应用的C-R模型拟合不理想,值明显偏低,由于所选机理函数是建立在单一基元反应假设上的,而实验表明印尼油砂热解是包含多个基元反应相互平行、连续、重叠或竞争过程的复杂的非均相反应,因此造成了C-R模型的局限性。%Study of oil sand pyrolysis by thermogravimetric analysis could guide the work of oil recovery by retorting.The pyrolysis experiments were carried out using thermogravimetric analyzer from room temperatwre to a final temperature of 550 ℃ under various heating rates.The results show that 350 ℃~ 520 ℃ in cracking stage is the main oil production region,where the TG weight loss data were in good agreement with the oil yields data by Fischer Assay.It＇s attributed to the cracking of heavy organic substances,especially bitumen.DAEM,FWO and C-R models were used to calculate the activation energy of oil production region respectively.The results implied that the pyrolysis of oil sand could be well described by DAEM and FWO models.The values of activation erengy approximately keep consistency with each other and are not constant throughout the chosen region within the range from 150 kJ/mol to 320 kJ/mol,then over the cracking process at about 220 kJ/mol.However,the C-R model which has been extensively applied in oil sand pyrolysis has unsatisfied with fitting results,the values of activation energy were significantly on the low side compared with DAEM results.The reason for the limitations of C-R model is that the chosen mechanism function is depended on a assumption of single elementary reaction,however,the process of pyrolysis in experiments is a complex heterogeneous reaction which is consisted of many elementary reactions paralleled,continued,overlapped or competed with each other.
展开▼
