Detection of carbon content in a high-temperature and high-pressure environment using laser-induced breakdown spectroscopy

A laser-induced breakdown spectroscopy (LIBS) technique has been applied to detect the carbon content in fly ash, char and pulverized coal under high-pressure and high-temperature conditions. An automated LIBS unit has been developed and applied in this experiment to demonstrate its capability in actual power plant monitoring. Gas composition effects were examined to obtain the best operating parameters under actual plant conditions. The results were compared to those obtained using the conventional method, showing satisfactory agreement. LIBS can detect carbon content even under the high-pressure conditions typical of gasification thermal power plants. LIBS is capable of a detection time of 1 min, as compared to over 30 min of sampling and analysis time required by the conventional methods (JIS-M8814 and JIS-M8815), and offers various merits as a tool for actual power-plant monitoring.