became stable at approximately 25 hours on stream. As shown in Figure 5 , selectivity to toluene remained consistently above 95% across all test conditions, indicating minimal formation of undesired byproducts, with a slight decline at higher temperatures. Benzene formation was below 0.5 mol%, and heavier aromatics were negligible, confirming the catalyst’s high specificity for the desired dehydrogenation pathway. Increasing the reaction temperature led to a higher conversion but lower selectivity towards toluene. For the reactors in the same block, almost identical results were obtained, demonstrating high reactor-to-reactor repeatability. Run-02 Based on the test results of Run-01, Run-02 was conducted with all the reactors filled with the same catalyst to check reactor-to-reactor variance (see Figure 6 ). The effect of reaction pressure and H 2 gas co-feeding was investigated. The testing results are shown in Figure 7 . The run consists of three parts: • Part-1 : Up to TOS of 23h: atmospheric pressure. • Part-2 : TOS 25 to 47h: 15 barg. • Part-3 : TOS 47 to 72h: hydrogen gas was introduced (H2/MCH 0.40/1 mol/mol, 0.80/1 w/w). Throughout the run, the mass balance remains Reactor
1 2 3 4 5 6 7 8 9 101112 13141516
Figure 6 Reactor loading scheme for Run-02
Figure 4 shows the testing results of Run-01. The run lasted 75 hours. Different reactor temperatures were applied to the different blocks to investigate the dependence of conversion on temperature. For each block, 2x temperatures were applied. No conversion was found for the reactors filled only with inert material (R4, R8, R12, and R16), while the other 3x reactors within the same block showed almost identical results, demonstrating strong system stability and data reliability. The conversion for the reactors with the catalyst became stable already after 10 hours on stream, and the selectivity to toluene (major product) and benzene (side product)
15 10 5 12 8 4 0
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within 100 +/-3%. For the first two parts, increasing the pressure from atmospheric pressure to 15 barg resulted in a low conversion and also slightly lower selectivity to toluene. The H 2 yield remained around 6.10 +/-0.10 wt% based on the liquid feed rate, which is close to the theoretical yield at full conversion (6.1 wt%). Upon introducing H 2 into the gas stream, the conversion dropped, but the selectivity to toluene remained stable. The increase in the observed H 2 yield (ca 0.75 +/-0.15
0
7.5
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101 92 100 99 96 100
97 98
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85
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60 65
70
Elapsed run time
Figure 7 Test results of Run-02
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