摘要
中药渣是中药材煎煮后的残余物，其热解气化是中药渣类生物质处理应用的重要选择方向。为此，采用带有二级返料装置的循环流化床，对杞菊地黄丸药渣进行了气化试验。以200 ℃热空气为气化剂，研究了二级返料装置开启前后空气当量比（ER）对气化特性的影响，结果表明：①随着（ER）的增大，气化炉内温度升高，燃气热值和燃气中焦油含量降低，气化效率先增大后减小；②二级返料装置闭合时，较好的ER取值范围为0.24-0.30、燃气热值为5 100-5 800 kJ/m3、气化效率为71%-74%；③二级返料装置开启时，理想的ER取值范围为0.26-0.30、燃气热值为5 400-5 900 kJ/m3、气化效率为76%-78%。在二级返料装置开启状态下研究了水蒸气配比S/B对气化过程的影响，结果表明：①空气当量比为0.28时，随着S/B的增大，气化炉内温度逐渐降低，燃气中焦油含量升高，燃气热值先增加后减小，当S/B为0.4时燃气热值取得最大值（6 200 kJ/m3）；②在相同ER条件下，二级返料装置开启状态下燃气热值及气化效率均高于闭合状态。该研究成果可以为中药渣废弃物的高效清洁利用提供参考。
The pyrolysis gasfication of Chinese herb residues after decoction should be the best way of processing and utilizing such type of biomass. In view of this, a circulating fluidized bed with a secondary back feeding device was employed in an experimental study to research the gasification characteristic of herb residues of Qiju Dihuang （Qi chrysanthermum flower） pills. The air at about 200℃ was taken as a gasifying agent. The effects of air equivalent ratio （ER） on gasification were examined before and after the secondary back feeding device was turned on. The following findings were concluded. a. The gasification temperature in the fluidized bed gradually increased with the increase of ER, the calorific value and tar content both decreased. However, the gasification efficiency increased first but then decreased. b. When the secondary back feeding device was turned off, the optimum range of ER was 0.24 - 0.30, and the calorific value and gasification efficiency could reach 5100 – 5800 kJ/m3 and 71 - 74% respectively. c. When the secondary back feeding device was turned on, the optimum range of ER was 0.26 - 0.30, the calorific value and gasification efficiency were 5400 – 5900 kJ/m3and 76 - 78% respectively. The effect of steam to biomass ratio （S/B） on gasification was also studied when the secondary back feeding device was turned on. The results showed that when the ER was 0.28, the gasification temperature gradually reduced with the increase of the S/B, which resulted in the increase of tar in gas, and the calorific value increased first and then decreased. The maximum gas calorific value reached 6200 kJ/m3 at the optimum S/B value of 0.4. It is also indicated that under the same ER, the calorific value and gasification efficiency were both higher when the secondary back feeding device was turned on. The research can provide a new method for harmless disposal and resource utilization of the Chinese herb residues.
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2013年第10期127-132,共6页
Natural Gas Industry
基金
'十一五'国家科技支撑计划子课题'低焦油气化中小规模生产生物质燃气设备研发与示范'(编号:2010BAC66B02)
'十二五'国家科技计划子课题'热解气化制取生物燃气新技术与示范'(编号:2011BAD15B05-05)
关键词
中药渣
热解气化
循环流化床
二级返料装置
水蒸气配比
空气当量比
焦油
herb residues, pyrolysis gasification, circulating fluidized bed, secondary back feeding device, air equivalence ratio,steam to biomass ratio, tar
