Fig. 1. MPA conversion as a function of initial ethanol concentration at T = 473 °C, P = 246 bar, [MPA]₀ = 1 mM, Φ = 1, τ = 6 s.

Fig. 2. MPA conversion as a function of time for T = 473 °C, P = 246 bar, [MPA]₀ = 1 mM, Φ = 1. Squares indicate experimental data for [EtOH]₀ = 0 mM, dashed line indicates predicted profile for [EtOH]₀ = 0 mM, triangles indicate experimental data for [EtOH]₀ = 0.1 mM, and solid line indicates predicted profile for [EtOH]₀ = 0.1 mM.

Fig. 3. MPA conversion as a function of initial MPA concentration at T = 473 °C, P = 246 bar, [EtOH]₀ = 1 mM, Φ = 1, τ = 9 s.

Fig. 4. Predicted OH concentration profiles as a function of time for a varying initial ethanol concentration at T = 473 °C, P = 246 bar, [MPA]₀ = 1 mM, Φ = 1. Solid line corresponds to no ethanol in the organic stream, dotted line corresponds to [EtOH]₀ = 0.1 mM, dashed line to [EtOH]₀ = 1.0 mM, and dot–dash line to [EtOH]₀ = 2.4 mM.

Fig. 5. Predicted HO₂ concentration profiles as a function of time for a varying initial ethanol concentration at T = 473 °C, P = 246 bar, [MPA]₀ = 1 mM, Φ = 1. Solid line corresponds to no ethanol in the organic stream, dotted line corresponds to [EtOH]₀ = 0.1 mM, dashed line to [EtOH]₀ = 1.0 mM, and dot–dash line to [EtOH]₀ = 2.4 mM.

Fig. 6. Effect of uncertainty on the rate constant for the reaction H₂O₂ + OH → H₂O + HO₂. The center bold line represents the MPA conversion profile for the Baulch 1994 rate at T = 473 °C, P = 246 bar, [MPA]₀ = [EtOH]₀ = 1 mM, Φ = 1. The lower line corresponds to multiplying the prefactor by the uncertainty factor (UF = 3.1), and the upper line corresponds to dividing the prefactor by the uncertainty factor.

Fig. 7. Major reaction pathways for MPA in the co-oxidation model. Bold arrows indicate dominant pathways and boxes indicate stable products and intermediates CO, CO₂, CH₄, and H₃PO₄.

Fig. 8. Comparison of MPA conversion and CH₄ carbon fraction for two initial concentrations of formaldehyde to the MPA conversion and CH₄ carbon fraction for the oxidation of pure MPA. All experiments were run at T = 473 °C, P = 246 bar, [MPA]₀ = 1 mM, Φ = 1, τ = 6 s.

Rate parameter changes made to co-oxidation mechanism

Units are cm, mol, s, and cal.

Dominant reaction fluxes for co-oxidation of MPA and ethanol

Average predicted molar flux through major pathways from τ = 0–10 s (10⁻⁶ mol/L/s) for a set initial concentration of MPA mixed with four initial concentrations of ethanol. T = 473 °C, P = 246 bar, [MPA]₀ = 1 mM, Φ = 1.