MULTI-LASER IN-SITU ANALYZER FOR REAL TIME CONTROL OF deSO_x AND deNO_x PROCESSES IN A WASTE INCINERATOR PLANT

摘要

In this paper we report, for the first time, application of a multi-laser in-situ cross duct type tunable laser analyzer for simultaneous control of both selective catalytic reduction and desulphurization processes in a waste incinerator plant. Incorporation of two interband cascade laser (ICL) sources in Mid-IR wavelength range in one device enabled simultaneous monitoring of NO, SO_2, HCl and H_2O in a gas stream with high dust loading conditions at 170°C. Real time control of injection of lime and urea for deSO_x and deNO_x processes respectively was possible thanks to in-situ capability and the analyzer's response time below 3 seconds. The measurements were compared also with FTIR and chemiluminescence analyzers on site. The analyzer can also be configured to measure, in addition, ammonia and carbon monoxide. The analyzer is compatible with the same process interface as single gas tunable devices and thus an existing infrastructure for single gas deNO_x laser analyzers can be utilized. The analyzer requires no calibration on-site thanks to built-in reference cell. The system was operational 24/7 in continuous mode with no single maintenance break throughout the entire measurement campaign of several months.