Abstract: In the thermochemical water splitting process by Cu-Cl cycle, oxygen gas is produced by an endothermic thermolysis process at a temperature of 530oC. Oxygen production reactor is a three-phase reactor involving cuprous chloride molten salt, copper oxychloride solid reactant and oxygen gas. To perform optimal performance, the oxygen reactor requires accurate control of heat transfer to the molten salt and decomposing solid particles within the thermolysis reactor. In this paper, the scale up analysis of the oxygen reactor that is heated by an internal helical tube is performed from the perspective of heat transfer. A heat balance of the oxygen reactor is investigated to analyze the size of the reactor that provides the required heat input for different rates of hydrogen production. It is found that the helical tube wall and the service side constitute the largest thermal resistances of the oxygen reactor system. In the analysis of this paper, the Cu-Cl cycle is assumed to be heated by two types of nuclear reactor, which are HTGR and CANDU SCWR. It is concluded that using CANDU SCWR requires more heat transfer rate by 3-4 times than that when using HTGR. The effect of the reactor aspect ratio is also studied and it is found that increasing the aspect ratio decreases the number of reactors and the rate of decrease in the number of reactors decreases by increasing the aspect ratio. Comparisons between the results of this study and pervious results of material balances in the oxygen reactor show that the size of the oxygen reactor is dominated by the heat balance rather than the material balance.
Abstract: Three sulphonic acid-doped polyanilines were
synthesized through chemical oxidation at low temperature (0-5 oC)
and potential of these polymers as sensing agent for O2 gas detection
in terms of fluorescence quenching was studied. Sulphuric acid,
dodecylbenzene sulphonic acid (DBSA) and camphor sulphonic acid
(CSA) were used as doping agents. All polymers obtained were dark
green powder. Polymers obtained were characterized by Fourier
transform infrared spectroscopy, ultraviolet-visible absorption
spectroscopy, thermogravimetry analysis, elemental analysis,
differential scanning calorimeter and gel permeation
chromatography. Characterizations carried out showed that polymers
were successfully synthesized with mass recovery for sulphuric aciddoped
polyaniline (SPAN), DBSA-doped polyaniline (DBSA-doped
PANI) and CSA-doped polyaniline (CSA-doped PANI) of 71.40%,
75.00% and 39.96%, respectively. Doping level of SPAN, DBSAdoped
PANI and CSA-doped PANI were 32.86%, 33.13% and
53.96%, respectively as determined based on elemental analysis.
Sensing test was carried out on polymer sample in the form of
solution and film by using fluorescence spectrophotometer. Samples
of polymer solution and polymer film showed positive response
towards O2 exposure. All polymer solutions and films were fully
regenerated by using N2 gas within 1 hour period. Photostability
study showed that all samples of polymer solutions and films were
stable towards light when continuously exposed to xenon lamp for 9
hours. The relative standard deviation (RSD) values for SPAN
solution, DBSA-doped PANI solution and CSA-doped PANI
solution for repeatability were 0.23%, 0.64% and 0.76%,
respectively. Meanwhile RSD values for reproducibility were 2.36%,
6.98% and 1.27%, respectively. Results for SPAN film, DBSAdoped
PANI film and CSA-doped PANI film showed the same
pattern with RSD values for repeatability of 0.52%, 4.05% and
0.90%, respectively. Meanwhile RSD values for reproducibility were
2.91%, 10.05% and 7.42%, respectively. The study on effect of the
flow rate on response time was carried out using 3 different rates
which were 0.25 mL/s, 1.00 mL/s and 2.00 mL/s. Results obtained
showed that the higher the flow rate, the shorter the response time.