Reactor temperature profiles of non-thermal plasma reactor using fiber Bragg grating sensor

•To demonstrate for the first time the reactor temperature real-time monitoring of the atmospheric pressure packed-bed non-thermal plasma reactor using FBG sensor embedded inside the plasma reactor stream.•FBG sensor embedded in the plasma reactor can provide accurate plasma temperature because the temperature measurement is performed within plasma stream. It is important to directly measure temperature within the plasma stream because of non-thermal plasma has shown a very localized thermodynamic equilibrium in nature.•From the reactor temperature profiles, we were able to examine the appropriate carrier gases and optimum applied voltage in order to optimize plasma process. Plasma operation at higher temperature can enhance the efficiency of pollutants decomposition but too high temperature can cause damage to the plasma reactor. The temperature profile of atmospheric pressure non-thermal plasma packed-bed reactor was monitored using a single 1550nm fiber Bragg Grating (FBG) sensor with sensitivity of 10.8pm/°C. The FBG was embedded at the midpoint of the reactor which was packed with barium titanate (BaTiO3) pellets. Four types of carrier gas for plasma generation were manipulated with different applied voltages for each gas in order to investigate the behaviour of the temperature profiles of non-thermal plasma (NTP). Results showed that using air and nitrogen, plasma produced higher average reactor temperature, which is approximately 207°C and 202°C respectively, in a 30-min interval with the maximum applied voltage of 16kV. The reactor temperature for helium carrier gas revealed the lowest, approximately 77°C. Reactor temperature profiles for each type of gas is different due to the gas composition and breakdown voltage behaviour. From the reactor temperature profiles, we were able to examine the appropriate carrier gases and optimum applied voltage operating range in order to enhance plasma process for treating pollutants in future work since higher temperature affect the rate of chemical reaction.