The previous blogs reported results at one pressure, 20 barg. Thus, the hydrogen concentration in the liquid was constant for all experiments. In order to determine the power of the hydrogen concentration for the power law model, additional experiments were run at 10, 30 and 40 barg for the TMP2 reaction. The rate constants for each experiment were estimated. A plot of the ln(rate constant) vs. the ln(h2 concentration) is shown below.
The slope is the power of the hydrogen concentration term in the power law model. This result agrees with the Langmuir-Hinshelwood model used to generate the data. If a LH model were being fit, the additional pressure variation would be needed to confirm (or disprove) the assumed hydrogen effect.
In a similar fashion, experiments could be conducted at different temperatures and the slope of ln(k) vs. 1/T used to determine the activation energy of a reaction.