## 4 Results and Discussion  
When preparing the dehydrogenation experiment, each loop was purged with 3 bar of N\({}_{2}\) at least five times, and the LOHC+ supply tank (Part F in Figure 9) was slightly pressurized to slowly fill the system with H18-DBT having a DoH \(>\) 99%. The heating loop was then started to increase the H18-DBT temperature to 300 \({}^{\circ}\)C. The reactor was also preheated with 30 cartridge heaters installed along the top and bottom walls. The reactor reached its target temperature in 200 min. The total heating capacities of the reactor and reservoir were 3 and 2 kW, respectively. It took approximately 270 min for the H18-DBT temperature in the heating loop to reach the pre-specified value. The heating loop was then shut off, and the dehydrogenation reaction was initiated by opening the reaction loop. For the test run discussed in the present report, hydrogen production was made from 26.3 L of H18-DBT by using the reaction loop and the chilling loop only. Heaters installed at reservoir and reactor continuously supplied the heat needed for the dehydrogenation reaction. Some minor degradation of DBT was unavoidable. The amount of H18-DBT initially introduced was 50 L, which was too large to satisfy the goal set for the funded research project: achieve 50% dehydrogenation within 500 min with a LOHC volume larger than 5 L. The liquid volume within the condenser was approximately 5 L, and the liquid volume within the heating loop (except the reservoir) was approximately 18.7 L. A controlled supply of reaction heat was made available to maintain the temperature of the medium leaving the reservoir at the specified value. Intermittent samplings of DBT from the reaction loop were conducted to estimate the transient change in the degree of dehydrogenation (DoD) from the measured refractive indices [26]. The achieved amount of dehydrogenation was 54.2% in 295 min (Figure 12). The accumulated volume of produced hydrogen (V\({}_{\rm H2}\)) was then calculated by multiplying the initial mole number of the DBT. The average hydrogen production rate during the first hour was 52.6 LPM with 1.5 kg of 0.5 wt% Pt/Al\({}_{2}\)O\({}_{3}\) catalyst. Also experimental results with ideal mixed batch reactor are shown in Figure 12 and Table 2[11; 27]. As shown in Figure 12, the experimental results of the present study with bench-scale process show almost similar reaction rate to ideal mixed batch reactor cases. Figure 11: (**a**) The schematic of reaction loop; (**b**) actual shape of the constructed reservoir with a flush chimney, Part “G”, and a weir. Unfortunately, the reaction kinetics of the catalyst pellet employed in the present study were not available. However, a screening test of commercial catalysts for the dehydrogenation of H18-DBT has been conducted [11]. The performance of the 0.5 wt% Pt/Al\({}_{2}\)O\({}_{3}\) catalyst supplied by Hydrogenious Technologies was approximately 25% faster compared to that of the 5.0 wt% Pt/Al\({}_{2}\)O\({}_{3}\) catalyst supplied by Sigma-Aldrich. A comparison with the predictions made with the empirical reaction kinetics in Equation (1) is provided in Figure 12. The reaction rates in Equation (1) were measured with a small-scale plug flow dehydrogenation reactor with 0.1-1.0 g of 5.0 wt% Pt/Al\({}_{2}\)O\({}_{3}\) catalyst [17]. V\({}_{\rm H2}\) was calculated using Equation (2), which is also borrowed from the same report. \[\rm r=5.4\times 10^{11}e^{(-17.27)}C_{H18-DBT}^{2.395\pm 0.045} \tag{1}\]  
\[\rm\frac{W_{cataly}}{F_{H18-DBT}}=\int_{1}^{X_{out}}\frac{dX_{H18-DBT}}{r} \tag{2}\]  
In the above equations,  
\( \begin{array}{ll}C_{H18-DBT}&\rm mol/L&\rm{Molar\ concentration\ of\ H18-DBT}\\ F_{H18-DBT}&\rm mol/s&\rm{Inlet\ molar\ flow\ of\ H18-DBT}\\ r&\rm mol/kg\,s&\rm{Reaction\ rate}\\ W_{cataly}&\rm kg&\rm{Weight\ of\ catalyst}\\ X_{H18-DBT}&\rm{Fractional\ conversion\ of\ H18-DBT}.\end{array} \)