NO Removal from Simulated Diesel Engine Exhaust Gas by Cyclic Scrubbing Using NaClO2 Solution in a Rotating Packed Bed Reactor

Han Zhitao,Lan Tian,Dong Jingming,Pan Xinxiang,Gao Yu,Song Liguo,Ning Kaixuan,Sun Deping,Yan Zhijun,Yang Shaolong

doi:10.1155/2019/3159524

Han Zhitao, Lan Tian + Show 8 more

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https://doi.org/10.1155/2019/3159524

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Abstract

Experiments were conducted to remove NO from simulated flue gas in a rotating packed bed (RPB) reactor with NaClO2 as wet scrubbing oxidant and diesel exhaust gas as carrier gas. The effects of various operating parameters (rotational speed, solution pH, NaClO2 concentration, liquid-gas ratio, and NO and SO2 concentrations) on NO removal performance were investigated preliminarily. The results showed that with the increase of rotational speed, oxidant concentration, and liquid-gas ratio, NO removal efficiency increased obviously. NO removal efficiency increased largely with the decrease of solution pH, and a complete removal of NO could be attained at pH 4. NO concentration imposed little effect on NO removal efficiency while coexisting SO2 in exhaust gas could enhance NOx removal greatly.

Highlights

Around the world, more than 80% of trade cargos are transported through shipping, and ocean-going ships have made great contributions to the development of world economy [1]
Experiments were conducted to investigate the effect of rotational speed of rotating packed bed (RPB) rotor on NOx removal performance, and the results are shown in Figure 2. e basic conditions are as follows: the flow rate of diesel exhaust gas was about 280 m3/h, the gas temperature at the inlet port of the RPB reactor was about 100°C, NaClO2 concentration in 30 L solution was 0.20 mol/L, the flow rate of absorbent solution was set at 1000 L/h, and the absorbent solution temperature was maintained at 35°C
A cyclic wet scrubbing process with NaClO2 as an oxidant and RPB as a reactor was proposed to remove NOx from marine diesel exhaust gas. e effects of some key operating parameters on NOx removal performance had been investigated preliminarily. e results showed that the increase of rotational speed of RPB rotor could enhance NOx removal performance obviously. e absorbent solution pH imposed a great effect on NO oxidation efficiency

Summary

Introduction

More than 80% of trade cargos are transported through shipping, and ocean-going ships have made great contributions to the development of world economy [1]. Ough selective catalytic reduction (SCR) and exhaust gas recirculation (EGR) are two relatively mature De-NOx methods for marine diesel engines [7] and their NOx challenges efficiencies are high enough, there are still some problems limiting their large-scale applications. When they combine with De-SOx techniques to simultaneously remove SOx and NOx from marine exhaust gas, such an integrated system is bound to have the disadvantage of large volume, high cost, and complex operation [8, 9]

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