Equilibrium Studies on the System Water + Hydrogen Peroxide + Urea + Carbon Dioxide

To develop a new method for separating the residual liquid of peroxide urea production by the formation of gas hydrate, the equilibrium of the system water + hydrogen peroxide + urea + carbon dioxide was studied under the conditions of P ) (1.2 to 1.9) MPa and T ) (272.15 to 275.15) K. The equilibrium pressure and temperature of gas hydrate formation were investigated at the different concentrations of hydrogen peroxide and urea with the anionic surfactant sodium dodecyl sulfate (SDS) and the sodium dodecyl benzene sulfonate (SDBS) in the system and without either. It was found that the equilibrium pressure of gas hydrate formation increased with the increase of temperature and the mass fraction of hydrogen peroxide and urea. The addition of anionic surfactant SDBS and SDS lowered the equilibrium pressure of the gas hydrate formed. The equilibrium pressure of the gas hydrate formed was calculated by Chen-Guo thermodynamic model, and the calculated values were in accord with the experimental results.