Experimental Study and Model Analysis of Sodium Desulfurization in Marine Application

Abstract

A flue gas desulfurization test bed was built to mainly carry out the desulfurization experiment of marine diesel engine exhaust gas. According to the typical exhaust conditions of marine diesel engines, the experiment was conducted by using washing water. Different Na⁺ concentrations, absorbent pH values, proportions x of SO₄²⁻ and inlet SO₂ concentrations were tested. The gas liquid ratio were in the range 1.5–2.5 L/m³. The desulfurization efficiency model of sodium method washing was also built, making the gas liquid ratio, Na⁺ concentration, and absorbent pH value, the proportion of SO₄²⁻ and inlet SO₂ concentration merge into a dimensionless comprehensive influencing factor ε. Finally, based on fitting the experimental results, it obtained a semi-empirical expression of desulfurization efficiency η and ε was η=f(ε, θ, Φ), of which θ and Φ were empirical parameters related to mass transfer and temperature respectively. Experimental results indicated that desulfurization performance increased with an increase in Na⁺ concentration and absorbent pH value, and it increased with a decrease in the proportion of SO₄²⁻ and inlet SO₂ concentration. At the current operating conditions, the highest SO₂ removal efficiency can be up to 98.7%. A desulfurization efficiency model obtained by further analysis and comparison of experimental data made up for deficiency of engineering design based on experience, providing the basis and reference for independent development of the sodium method ship desulfurization system design software.