船舶尾气臭氧氧化-海水吸收的脱硫脱硝新工艺研究

Simultaneous Removal of SO_2 and NO_x from Ship Exhaust Through a Combination of Ozone Oxidation and Sea Water Scrubbing

通过模拟试验研究了臭氧氧化结合海水吸收同时脱除船用发动机排气中SO2和NOx的新工艺。在管式反应器内研究了反应温度、n(O3)/n(NO)(物质的量之比)、碳氢、SO2等对臭氧氧化NO的影响,并对模拟尾气进行了臭氧氧化结合海水吸收的脱硫脱硝试验。结果表明,n(O3)/n(NO)对臭氧氧化NO影响很大,NO氧化率随n(O3)/n(NO)呈线性增长,n(O3)/n(NO)为1,反应温度分别为常温、150℃和200℃时,NO氧化率分别达到99.0%、98.3%和98.1%;反应温度低于200℃时,温度对臭氧氧化NO影响很小,而当反应温度升至275℃时,NO氧化率明显下降,这与臭氧在较高温度下分解有关;SO2在O3/NO/SO2/N2/O2体系和O3/NO/C2H4/SO2/N2/O2体系中对臭氧氧化NO都没有影响;200℃以下,C2H4对臭氧氧化NO影响很小,而在275℃时,C2H4对臭氧氧化NO有一定促进作用;模拟尾气经臭氧氧化-海水吸收后,脱硫率为98.5%,n(O3)/n(NO)为1时的脱硝率为91.0%,NO能耗为56.4 g/(kW.h)。

A new process, which is capable of removing SO2 and NOx simuhaneously from ship exhaust through combination of ozone oxidation and sea water scrubbing, was experimentally studied. The experiments were carried out in a tube reactor located in a tube furnace, and the influences of reaction temperature, n （ 03 ）/n （NO） molar ratio and the presence of hydrocarbon and SO2 on the oxidation of NO by O3 were made. Simultaneous removal of SO2 and NOx from a simulated flue gas by the new process was investigated. The test results show that the influence of n （ O3 ）/n （NO） ratio on NO oxidation was significant. NO oxidization rate increased linearly with the increase of n（ O3 ）/n（NO） ratio. When n（ O3 ）/n（NO） ratio became 1, the NO oxidization rate reached 99.0% , 98.3% and 98.1% respectively at room temperature, temperature of 150 ℃ and 200 ℃. The influence of reaction temperature on NO oxidation was small at the temperature below 200 ℃. When the reaction temperature rose up to 275 ℃, the NO oxidation rate decreased remarkably. This suggests that the reaction temperature has a strong influence on NO oxidation because of fast 03 decomposition at high temperature. No reaction was detected for SO2 in both O3/NO/ SO2/N2/O2 system and O3/NO/C2H4/SO2/N2/O2 system. The influence of hydrocarbon on NO oxidation was negligible at the temperatures below 200 ℃, but the hydrocarbon （ C2 H4 ） had a little effect on the NO oxidation at the temperature of 275 ℃. Using a simulated flue gas containing 400 × 10 ^-6 SO2 and 400 × 10 ^-6 NO by 03 oxidation at n（ 03 ）/n（NO） = 1.0 and subsequent sea water scrubbing, the removal efficiency of NOx and SO2 reached 91.0% and 98.5% respectively, and NO the energy consumption was 56.4 g/（kW · h）.