热解焦化过程烟气末端净化关键技术与应用进展

热解焦化行业烟气温度低、水汽含量高、且夹带焦油和炭黑等复杂物质,导致电力行业传统烟气净化技术难以适用于该领域。为了给热解焦化过程末端烟气治理升级改造提供思路与参考依据,笔者总结了该领域具有前景的末端烟气净化技术应用进展,指出干法脱硫-布袋除尘-低温脱硝技术和活性焦脱硫脱硝一体化技术是目前比较成熟的焦化烟气净化技术;催化陶瓷纤维滤管一体化技术虽然在国外玻璃等行业应用比较成功,但在国内焦化烟气领域应用时间不长,应注意潜在的技术风险;氧化-湿法吸收技术由于产生二次污染等问题制约了规模化推广。通过剖析应用过程存在的问题,提出相应的解决方案,明确各工艺未来的研究方向及升级路线,指出干法脱硫-布袋除尘-低温脱硝技术研究应集中于脱硫灰的处理、失效催化剂的回收再利用和工艺深度优化;活性焦脱硫脱硝一体化技术研究应关注多循环周期中活性焦的特性演变、再生过程碳损耗控制及废焦粉的回收利用;催化陶瓷纤维滤管技术研究应解决潜在的氨逃逸、催化剂失活、焦油糊管等问题。最后,结合热解焦化烟气特征,指出热解焦化末端烟气净化的关键在于低温脱硝技术与其他污染物控制技术的匹配与整合,同时明确了未来热解焦化烟气净化技术将向设备一体化、维护简单化与运行低成本化的方向发展。 The flue gas from pyrolysis and coking industry is always in low temperature range and contains high content of water vapor as well as other other pollutants such as tar and carbon black,making the traditional flue gas purification technology for power plant unsuitable for the pyrolysis and coking fields. In order to provide new ideas and references for the technology upgrade of end-stage flue gas treatment in pyrolysis and coking processes,the latest application progress of the promising end-stage flue gas purification technology was summarized. Accordingly,the two relatively mature coking flue gas purification technical routes were dry desulfurization/bag filter dedusting/low temperature denitrification and integrated desulfurization and denitrification of activated coke. Although the integrated technology of catalytic ceramic fiber filter has been successfully applied in glass industry abroad,it was still not long for its application in the field of coking flue,deserving more attention for potential risks. In addition,oxidation coupling wet absorption technology was not widely used in industry due to its serious secondary pollution. After analyzing the existing problems of the current technologies,solutions were proposed with clear research directions and upgrading routes for the further development of these technologies. To improve the process of dry desulfurization/bag filter dedusting/low temperature denitrification,the further research will mainly focus on treatment of desulfurization ash,recovery of spent catalysts and in-depth process optimization. Researches on integrated desulfurization and denitrification of activated coke should focus on the evolution of activated coke characteristics in multiple cycles,control of carbon loss during regeneration and recovery of waste coke powder. Potential issues of integrated technology of catalytic ceramic fiber filter need be further examined,such as ammonia escape,catalyst deactivation and blocking tube by tar. Finally,combining the characteristics of pyrolysis coking flue gas,it was