In situ composition measurements of Bunsen reaction solution by radiation probes

Kubo, Shinji  ; Nagaya, Yasunobu  

Measuring equipments are integral to chemical process controls. A stable hydrogen production by the Iodine-Sulfur thermochemical water-splitting process is relatively difficult because of lack of existing in situ composition measurement techniques for multiple components and corrosive solution. Composition regulations of Bunsen reaction solution is particularly important, since a closed cycle system provided with this process causes that the many streams with different composition return to this section. Accordingly Bunsen solution becomes changeable composition. Radiation probes have a potential for applications to determine this multiple component solution while the non-contact approach avoids the corrosive issues. Moreover the probes have features of the promptness, contact-less and sequential use. Laboratory scale experiments to evaluate these possibilities of the measurement were conducted with use of simulated Bunsen solution, HIx solution and HSO solution, containing HI, I, HSO and HO and sealed radiation sources. Radiations were counted, which were interacted with the solutions in various compositions around room temperature contained in vessels. For HIx solution, the obtained counting rates were correlated with hydrogen volume concentrations; moreover, the application of the Monte Carlo method suggests possibilities that the detector responses for HIx solution by the radiation probes are predictable. For HSO solution, iodine atoms had significant influences on the relationship between output values of two -ray density meters, cesium source as higher energy and barium source as lower energy. This results suggest that the neutron-ray probe, the -ray probes of both lower energy and higher energy have possibilities to determine the composition of Bunsen solution of HIx and HSO solutions.