生物质焦炭颗粒气化过程模拟与分析  

Simulation and analysis of gasification process of biomass coke particles

作　　者：杨建蒙[1] 鲁许鳌[1] 徐刚 王洪远 郭志城 YANG Jianmeng;LU Xuao;XU Gang;WANG Hongyuan;GUO Zhicheng(School of Energy,Power and Mechanical Engineering,North China Electric Power University,Baoding 071003,China)

机构地区：[1]华北电力大学能源动力与机械工程学院,河北保定071003

出　　处：《热力发电》2020年第7期41-47,共7页Thermal Power Generation

摘　　要：生物质能源的合理利用对减少环境污染和碳减排具有重要意义。本文利用气化过程的随机孔模型为工具,进行了半焦颗粒气化过程的数值计算,并对半焦气化的相关准则数进行了分析。结果表明:在1123 K气化温度下,颗粒半径小于0.26 mm时气化过程由化学反应过程控制,颗粒半径在0.26~1.45 mm范围时由化学反应过程和CO2扩散过程共同控制,当颗粒半径大于1.45 mm时,由CO2扩散过程控制;气化温度在973~1223 K时,随温度升高,CO2的扩散过程对反应速率的影响逐渐增大,温度超过1223 K时,CO2扩散过程成为影响气化反应速率的主要因素。在实际气化中,可以采取减少焦炭粒径的方法加速气化过程,粒径应当控制在1.45 mm以下;如果颗粒粒径小于0.26 mm时可采取升高气化温度的方法加速气化,防止气化速率完全由CO2扩散过程控制;对于1 mm焦炭颗粒,应当保持气化温度低于1223 K。Rational utilization of biomass energy is of great significance to reducing environmental pollution and carbon emission reduction.Using the stochastic pore model of gasification process as a tool,numerical calculation of semi-coke particles gasification process was carried out,and the relevant criteria of semi-coke gasification were analyzed.The main conclusions are as follows.At gasification temperature of 1123 K,the gasification process is controlled by chemical reaction process when the particle radius is less than 0.26 mm,by both chemical reaction process and CO2 diffusion process when the particle radius is 0.26~1.45 mm,and by CO2 diffusion process when the particle radius is greater than 1.45 mm.When the gasification temperature is 973~1223 K,the higher the temperature,the greater the influence of CO2 diffusion on the reaction rate.When the temperature exceeds 1223 K,the CO2 diffusion becomes the main factor affecting the gasification reaction rate.In actual gasification,the method of reducing coke particle size can be adopted to accelerate the gasification process,and the particle size should be controlled below 1.45 mm.If the particle size is less than 0.26 mm,the gasification can be accelerated by increasing the gasification temperature to prevent the gasification rate from being completely controlled by the CO2 diffusion process.For 1 mm coke particles,the gasification temperature should be kept below 1223 K.

关 键 词：生物质 半焦气化 准则数 数值模拟 化学反应动力学 CO2扩散过程 

分 类 号：TK62[动力工程及工程热物理—生物能]