燃煤电厂活性焦脱硫过程模型及实验

Experimental study on mathematical model of activated coke desulfurization in coal-fired power plants

为促进活性焦脱硫技术在燃煤电厂中的应用,基于物料守恒方程、线性推动力传质速率方程和Langmuir吸附等温线方程建立了活性焦固定床动态吸附过程的数学模型,并在实验室搭建的活性焦固定床试验台测试吸附穿透曲线。发现轴向返混模型更加精确。在活性焦质量一定时,利用所得模型研究了床层空隙率、最大吸附量、SO2入口质量浓度、空塔线速度对穿透特性的影响,结果表明:改变床层空隙率对穿透曲线无明显影响;活性焦最大吸附量增大会增加穿透时间;空塔线速度和SO2入口质量浓度的增大会缩短穿透时间。这为燃煤电厂活性焦脱硫的工程设计提供理论指导。

In order to promote the application of activated coke desulfurization technology in coal-fired power plants,a test bench of activated coke in fixed bed was built in the laboratory.Small scale boilers and gas distribution device were used to simulate the flue gas in power plants.The adsorption isotherms and dynamic adsorption breakthrough curves were measured.According to the material balance equation,the LDF mass transfer rate equation and the Langmuir adsorption isotherm equation,the mathematical model was established to describe the dynamic adsorption process.It was found that when the axial back mixing model was considered,the result is more accurate.In constant active coke mass,the adsorption model was used to analyze the effects of the voidage,the maximum adsorption capacity,SO2 mass concentration of entrance,and superficial velocities on the penetration curve.The results show that there is no significant effect on the breakthrough curves for various voidages.With the increase of the maximum adsorption capacity,the breakthrough time will increase.The increase in superficial velocities and SO2 mass concentration of entrance will shorten the breakthrough time.These results provide a reference for activated coke desulfurization in engineering design of power plants.