Abstract:

Novel double loop circulating type of semi-dry flue gas treating technology for FCCU was developed in order to improve the stability and reliability of the conventional semi-dry process. Based on the fluidization research of desulfurization powder, an optimized gas velocity of desulfurization reactor was determined. The circulation intensity and utilization ratio of desulfurization agent was improved as a result of the double loop circulating method and reacting system, and thus the content of Ca(OH)₂ in desulfurization powder was cut from 6.00% to 2.74%, while Ca/S consumption ratio was also reduced by 15%. According to qualified analysis identification, the desulfurization powder was confirmed as general solid waste with a harmless recycling value. The successful application of this novel technology in Qingjiang Company has proved its numerous advantages: smooth and steady operation, high removal efficiency of pollutant, zero emission of waste water as well as the low cost of investment and operation.

Key words: semi-dry method, double loop circulating, FCC, flue gas purification, desulfurization powder

摘要：

为了提高常规半干法工艺的稳定性和可靠性，创新开发了半干法双循环催化裂化烟气净化技术。通过研究脱硫灰颗粒的流动特性，确定了半干法脱硫反应器的气速范围；创新开发的半干法双循环烟气净化工艺和反应系统技术，提高了脱硫剂的循环强度及利用率，外排脱硫灰颗粒中Ca(OH)₂质量分数由6.00%降低至2.74%,钙硫比降低了15%。经专业鉴定外排脱硫灰颗粒为一般固体废物，具有无害化利用价值。该技术已在清江石化成功应用，装置操作平稳、运行可靠、脱硫除尘效率高、无废水排放，满足GB 31570—2015《石油炼制工业污染物排放标准》及超低排放指标对SO₂和颗粒物的要求，投资和操作费用低。

关键词: 半干法, 双循环, 催化裂化, 烟气净化, 脱硫灰