On-line spectroscopic system for monitoring of sulfuric acid decomposition by near infrared and infrared spectroscopy

Abstract

Iodine sulfuric cycle is the most economical hydrogen production process for future energy generation and replacement of fossil fuel. In order to understand the kinetics of sulfuric acid decomposition as well as maximize the efficiency of the process, it would be necessary to monitor the concentrations of SO3, SO2, H2O and H2SO4 as a continuous on-line fashion. Currently, IR spectroscopy had been mainly investigated since selective features of each component can be observed in IR region; while, the resulting spectral features are greatly dominated by water rotational features. Alternatively NIR spectroscopy is also potential for the sample purpose, since water could be less overlapping with those of other analytes and the better linear relationship (concentration vs. absorbance) could be achieved. High temperature gas cell was build and NIR spectra of sulfuric acid in gas phase were collected. The sulfuric acid bands were clearly identified from 7500 to 5000cm-1, and these bands were decreased with time. Additionally, the results from the use of IR spectroscopy were also compared. Either NIR or IR spectroscopy, a spectroscopic method would be the only analytical solution that can monitor sulfuric acid decomposition as an on-line manner with high speed.