炭黑微料的平均粒径约在200-500纳米之间，但仍然在空气清洗技术可捕捉的范围之内。1公升柴油的热值相当于1立方天然气，但密度大多了。燃油锅炉受黑烟排放所困，如果燃油锅炉能解决黑烟与气味问题，意义重大。
       2020年1月1日，东莞市某燃油锅炉采用空气清洗技术，黑烟变白烟，而且没有气味（如下图）。
       Carbon particles are mostly in diameter from 200 nm to 500 nm, which is still under the range being caught by air cleaning technology. The following picture shows the smoke of a oil-fired boiler in Dongguang city being cleaning, the black smoke being changed into white.