Effect of producer gas addition on spectral characteristics of the natural gas flame

Abstract

The aim of this article is to show the results of investigation how mixing producer gas (PG) (a product of a biomass gasification process) into the natural gas (NG) flow affects spectral characteristics of flame at specific wavelengths, representing formation reactions of OH*, CO* and C₂* radical species, when the air equivalence ratio (ER) ranges from 1.0 to 1.3. In the current research, experiments were carried out for natural gas and mixtures of natural gas and producer gas. The producer gas was generated from wood pellets in a lab scale gasification reactor. Conventional flame emission spectroscopy methods were used for combustion process monitoring and control. This article presents the results of flame analysis by the emission spectroscopy method for registering chemiluminescent radical species OH*, CH* and C₂*. After analysing the profile shape of chemiluminescent species intensity distribution along the burner vertical axis, it was determined that the quenching effect takes part in the combustion zone at some specific conditions. Additionally, the shift of chemiluminescense intensity towards the burner nozzle was registered when natural gas was mixed with producer gas. This effect was due to the presence of hydrogen in the producer gas.