炭活化一体工艺可以缩短制备活性炭的工艺流程、节约投资且降低消耗,用于生产烟气净化活性炭具有较明显优势。在确定的生产工艺条件下,原煤很大程度上决定了活性炭的强度、孔结构和表面化学等,目前通过配煤利用原料煤自身特性调节活性炭产品各项性能的影响研究较少。选用国内不同变质程度的典型煤种为原料,以单种煤分别采用炭活化一体工艺和炭化-活化分段工艺制备活性炭,并且利用炭活化一体工艺配煤制备活性炭产品。对比得率及活性炭样品主要指标,将活性炭的孔结构及表面化学特性与其脱硝率关联,结果表明:炭活化一体工艺制备活性炭得率显著高于炭化-活化分段工艺的综合得率;炭活化一体工艺制备活性炭的耐磨强度、耐压强度均较分段工艺有所提升。利用褐煤、长焰煤单种煤为原料所制得的活性炭,其堆积密度、耐磨强度和耐压强度指标无法达到合格品要求。单种煤为原料制备的活性炭SCR脱硝率高低排序为:弱黏煤>无烟煤>长焰煤>褐煤。低变质程度的褐煤及长焰煤制备活性炭的中孔比例较高,但炭活化得率低,表面官能团不发达,尤其表面酸性含氧官能团含量少,导致其SCR脱硝率明显较低。无烟煤和弱黏煤配煤制备活性炭,孔隙发育兼具了2种煤的特点,比表面积和孔结构介于利用单种煤制备活性炭相关参数之间;配煤制备活性炭表面官能团丰富,尤其是酸性含氧官能团含量显著增加,促进了其SCR脱硝性能的提升。

Carbonization and activation integration process can shorten the process of activated carbon preparation, save investment and re⁃duce consumption, for the production of flue gas purification of activated carbon has more obvious advantages. Under the established pro⁃duction process conditions, raw coal determines the strength, pore structure and surface chemistry of activated carbon to a large extent. Atpresent, the influence of using the characteristics of raw material coal to adjust the performance of activated coal products is rarely studied.Typical coal of different rank is selected as raw materials, and the activated carbon is prepared by carbonization and activation integrated(CAI) and carbonization and activation segmentation (CAS) process respectively. And the use of CAI process with single coal to prepareactivated carbon products. Compared with the yield rate and the main indexes of activated carbon samples, the pore structure and sur⁃face chemical characteristics of activated carbon are correlated with the denitrification, and the results show that: the yield rate of activa⁃ted carbon prepared by CAI process is significantly higher than that of the comprehensive rate of CAS, and the abrasive resistanceand compression strength of activated carbon samples are improved compared with the segmented process. The bulk density, abrasive re⁃sistance and compression strength of the activated carbon prepared from lignite and long-flame coal cannot meet the requirements of na⁃tional standards. The SCR denitrification activity of activated carbon prepared from single coal is sorted as: weakly caking coal > anthracite> long flame coal > lignite. Activated carbon prepared from lignite and long flame coal has a high mesopore ratio, but the carbonizationand activation yield are considerable low, and the surface functional groups are not developed, especially the low content of acidoxygen-containing functional groups on the surface which leads to the poor denitrification performance of SCR. The specific surface areaand pore structure of activated carbon prepared by blending anthracite and weak coking coal are in between the parameters of the activa⁃ted carbon preparation from single coal. The activated carbon prepared from coal blending has abundant surface functional groups, and thetotal concentration of acidic/ basic sites is higher than that prepared from single coals. In particular, the concentration of acidicoxygen-containing functional groups is increased to promote the SCR denitrification performance of activated coke.

0 引言

1 原料煤

2 试验

   2.1 活性炭制备试验

   2.2 活性炭基本指标测定

   2.3 活性炭孔结构及表面化学测定

   2.4 活性炭脱硝率测定

3 结果与讨论

   3.1 炭活化一体化工艺与分段工艺对制备活性炭的影响

   3.2 炭活化一体制备活性炭及脱硝性能

   3.3 配煤对活性炭孔结构及脱硝性能的影响

4 结论