VATIS UPDATE Article

Recently, three low-temperature DeNOx industrial units have been carried out in Jiangsu Yizhou Coking Co., Ltd., China, for removal of NOx from coke oven flue gas. These units were all loaded with high-efficiency low-temperature DeNOx catalysts developed by Prof. WANG Shudong’s Group from Dalian Institute of Chemical Physics (DICP). The commercialization promotion of the coke oven flue gas denitrification was launched last year. WANG’s group joined with Jiangsu WOTE Environmental Protection Equipment Engineering Co. Ltd and Jiangsu Yizhou Coking Co., Ltd to establish a low-temperature DeNOx industrial demonstration unit for reduction of NOx emissions from the 3# coke oven. This unit was put into operation las November.

According to the on-line Continuous Emission Monitoring System (CEMS) monitoring data, this efficient Selective Catalytic Reduction (SCR) catalyst showed a very high and stable NOx reduction efficiency with 90%~95%. The concentration of NOx in effluent maintained less than 70 mg/m3. So far, the unit has been running for more than seven months and the catalysts show good stability and sulfur-resistance. Based on the results of the industrial demonstration unit, WANG’s group optimized the proprietary catalyst and reactor design. The DeNOx efficiency is improved, while the pressure drop of the reactor is greatly reduced.

This year, Jiangsu Yizhou Coking Co., Ltd continued to collaborate with DICP to improve the technology for denitration construction of the remaining three coke ovens. From May to June, the three industrial units were debugged and run. Results showed that all technical indexes of the DeNOx system fulfilled its design demand. This efficient SCR catalyst showed a high and stable NOx reduction efficiency with 98%~99% during running. The concentration of NOx in effluent also reached less than 20 mg/m3, which is far below the emission standard of NOx for coking chemical industry.