Emissions of Nanoparticles from Small Combustion Equipment with Regard to the Combustion Mode and Wood Humidity

Abstract

Contamination of air by solid particles is serious problem for human health and also environment, especially in certain regions of the Czech Republic and Poland. Small particles in nano-sizes are more dangerous than same weight of larger size. Negative effect namely of the solid particles depends on number, specific surface area, respirability and bonding of others substances (e.g. PAH, As, Cd, Zn, Cu etc.) which are higher for smaller (nano-sizes) particles compared to larger one. With the approaching winter, yearly problems with distribution of particles from small combustion equipments arise. The annual emission balance indicate that the proportion of small sources to total air pollution (PAH, dust) is surprisingly expressive [1]. For this reason mentioned above this contribution deals with measuring of amount, and distribution of nanoparticles produced form combustion of wood in small combustion unit. <br />For combustion test in grave-free stoves were used three samples of wood (wet spruce, dry spruce and raw spruce) and two combustion modes. Nanoparticles from flue gas were characterized by the aperture low-pressure cascade impactor DLPI (separation and weighing of particles in sizes 30 ηm ÷ 10 µm). Wood were combusted in the form of ¼ logs.

Impact of Boiler Type, Heat Output, and Combusted Fuel on Emission Factors for Gaseous and Particulate Pollutants

“…Similar results have also been reported in previously conducted studies. − With boilers and tests that showed low values of CO and OGC and thus good combustion conditions, a relatively high content of PM0.1 was detected, i.e., approximately 15–30% (tests 1–4 and 21–23). In boilers with a worse combustion process, the PM0.1 share that was detected is only 5–10%, which is in accordance with previous studies. , …”

“…In boilers with a worse combustion process, the PM0.1 share that was detected is only 5−10%, which is in accordance with previous studies. 18,19 ■ CONCLUSION In total, six different solid fuels were combusted in five types of boilers at nominal and reduced heat output. The gaseous and particulate emissions were analyzed extensively.…”

“…A previous study showed that PM emissions from small-scale (household heating appliances) wood-fueled boilers are usually 33–320 mg/MJ, while those from coal-fired boilers are approximately 15–400 mg/MJ. In addition to the mass of particulate emissions, it is known , that the particle size in efficient combustion is smaller compared to some cases of inefficient combustion. Furthermore, it has been shown , that boilers work less efficiently when operating on reduced output and emit more particles and harmful gaseous compounds, originating from incomplete combustion.…”