生物质混流式固定床气化炉运行特性分析

Gasification Performance of Biomass in a Coupled Drafting Fixed Bed Gasifier

以桉木为原料，对1.5 t/h 生物质混流式固定床气化炉运行特性进行了测试分析与评价，与文献报道的相关炉型包括上吸式、下吸式、两段式等炉型运行结果进行了比较。实验以气化炉空气通入量作为主要控制变量，对有或无水蒸气条件下的气化炉温度及压力分布、燃气组成、焦油与飞灰含量、气体产率等参数进行了较长周期的测试，结果表明：气化炉运行效果符合设计要求，各项指标相当于或优于传统的下吸式气化炉；气化炉运行温度与压力比较稳定；以冷燃气计算的燃气热值约为4900～5500 kJ/Nm＾3；气化效率约为70%～78%；燃气焦油含量约600～3500 mg/Nm3，运行负荷在50%以上时，焦油含量一般低于1500 mg/Nm3。研究结果有望为混流式气化炉的改进和操作提供优化建议，同时可为其他气化工艺设计提供参考依据。

This paper evaluated the gasification performance of a 1.5 t/h coupled drafting fixed bed gasifier using eucalypt, and compared the operating parameters to other fixed bed gasifiers from literatures including updraft, downdraft and two-stage. The air with or without steam input amount was selected as a major controlling variable, temperature and pressure distribution, syngas composition, tar and fly ash content, gas yield were tested in a long period. The results show that the operating performance of the coupled drafting gasifier meets the design requirements. The operating temperature and pressure are relatively stable. The syngas calorific value is approximately 4 900-5 500 kJ/Nm3. In most of running conditions, the cold gas efficiency of about 70%-78%could be obtained. The syngas tar content is mainly in the range of 600 - 3 500 mg/Nm3 and generally lower than 1 500 mg/Nm3 when running at capacities of higher than 50%. The parameters considered are all equal to or better than conventional downdraft fixed bed gasifier. The results are expected to improve the design and operation of the coupled drafting gasifier, and also to provide a reference for other gasification process.