Lv Tong, Fang Mengxiang, Li Huaixiang, Yan Jiqing, Cen Jianmeng, Xia Zhixiang, Tian Jianglei, Wang Qinhui
State Key Laboratory of Clean Energy Utilization, Zhejiang University Hangzhou 310027 P. R. China
Energy Research Base, Zhejiang University Qingshanhu, Lin'an Hangzhou 311300 P. R. China.
RSC Adv. 2021 May 18;11(29):17993-18002. doi: 10.1039/d1ra01981c. eCollection 2021 May 13.
The chemical percolation devolatilization (CPD) model can simulate the formation of various products during the coal pyrolysis process and predict the products composition relatively accurately. In this study, the pyrolysis products of a typical low-rank coal were calculated using the CPD model, and several model improvements were proposed by combining the experimental results in a lab-scale pyrolysis system. The chemical structural parameters calculated from the Genetti correlations were verified by adjusting the initial fraction of char bridges ( ) from 0.098 to 0.25. A yield difference (Δ ) was defined in this paper to analyze the consumption of tar fragments in the model, and it was found that the deviations between experiments and calculations resulted from the weak influence of crosslinking. A modification expression was adopted to amplify the tar consumption: , which improved the accuracy of the model on the tar yield with errors of less than ±0.5 wt%. Furthermore, this paper also developed a correlation in an exponential form about gas composition, which attempted to extend the application of the CPD coalification reference mesh for the coal away from interpolation triangles. The improved model by the correlation predicted CH, CO, and CO yields for this typical low-rank coal accurately in most cases. Compared with the original CPD model, the modified model showed better agreement with the experimental results and predicted 71.4% and 88.6% of the data points in this work within ±10% and ±20% errors, respectively.
化学渗滤脱挥发分（CPD）模型可以模拟煤热解过程中各种产物的形成，并相对准确地预测产物组成。在本研究中，使用CPD模型计算了典型低阶煤的热解产物，并结合实验室规模热解系统的实验结果提出了几种模型改进方法。通过将焦炭桥键的初始分数（）从0.098调整到0.25，验证了根据Genetti相关性计算得到的化学结构参数。本文定义了产率差（Δ）来分析模型中焦油片段的消耗情况，发现实验与计算结果之间的偏差是由交联作用的微弱影响所致。采用修正表达式来放大焦油消耗：，这提高了模型对焦油产率的预测精度，误差小于±0.5 wt%。此外，本文还建立了一个关于气体组成的指数形式的关联式，试图将CPD煤化参考网格在远离插值三角形区域的煤的应用范围进行扩展。通过该关联式改进后的模型在大多数情况下能够准确预测该典型低阶煤的CH、CO和CO产率。与原始CPD模型相比，改进后的模型与实验结果的吻合度更好，在本研究中分别有71.4%和88.6%的数据点预测误差在±10%和±20%以内。
