Reaction kinetics of sodium nitrite and ammonium chloride system considering conversion rate

Key words:  sodium nitrite and ammonium chloride system  hydrogen ion concentration range  conversion rate  reaction kinetic equation

Abstract:

It is difficult to predict the heat/nitrogen generation of NaNO₂/NH₄Cl system because the reactant conversion rate is not considered in traditional reaction kinetic equation. The H⁺ concentration range, reaction conversion rate and its changeable rule for nitrogen generation reaction were investigated by experimental analysis method. The influence degree of each factor was studied by grey correlation analysis. The parameters of reaction kinetic equation introduced by reactant conversion were calculated by the Newton-Raphson method, through which the prediction method of the heat/nitrogen generation reaction were discussed. It is found that the H⁺ concentration range for nitrogen production of NaNO₂/NH₄Cl system is cH⁺≤0.0225 mol/L(or pH≥1.65). And the reactant conversion rate increases with increasing of reactant, H⁺ concentration and temperature. The correlation between reactant conversion and reactant concentration is the strongest and reaches 0.8. The reaction kinetic equation with reactant conversion is dη=4.74×10^4e-3389/Tc1.545H⁺c1.346₀(1-η)2.346, or (1-η)-1.346-1=4.74×10^4e-3389/Tc1.545H⁺c1.346_0t, η<1, which is effective and convenient to predict the heat/gas generation reaction status.