IEA low NO(sub x) combustion project Stage III. Low NO(sub x) combustion and sorbent injection demonstration projects. Final report, volume II. Technical summary

摘要

This report summarizes the main results from an IES project concerning the demonstration of low-NO(sub x) combustion and sorbent injection as techniques for the control of NO(sub x) and SO(sub x) emissions from pulverized coal fired utility boilers. The project has built upon information generated in two previous stages of activity, where NO(sub x) and SO(sub x) control processes were evaluated at both fundamental and pilot-scales. The concept for this stage of the project was for a unique collaboration, where the participating countries (Canada, Denmark and Sweden, together with the United States) have pooled information from full scale boiler demonstrations of low-NO(sub x) burner and sorbent injection technologies, and have jointly contributed to establishing a common basis for data evaluation. Demonstration testing was successfully carried out on five wall-fired commercial boiler systems which ranged in size from a 20 MW thermal input boiler used for district heating, up to a 300 MW electric utility boiler. All of these units were fired on high-volatile bituminous coals with sulfur contents ranging from 0.6-3.2 percent. At each site the existing burners were either modified or replaced to provide for low-NO(sub x) combustion, and provisions were made to inject calcium based sorbent materials into the furnace space for SO(sub 2) emission control. The results of sorbent injection testing showed moderate levels of SO(sub 2) removal which ranged from approximately 15 to 55 percent at an injected calcium to sulfur molar ratio to 2.0 and with boiler operation at nominal full load. Sulfur capture was found to depend upon the combined effects of parameters such as: sorbent type and reactivity; peak sorbent temperature; coal sulfur content; and the thermal characteristics of the boilers. (8 refs., 58 figs., 6 tabs.).