František Hopan

Effect of fuels and domestic heating appliance types on emission factors of selected organic pollutants

This study reports on the first complex data set of emission factors (EFs) of selected pollutants from combustion of five fuel types (lignite, bituminous coal, spruce, beech, and maize) in six different domestic heating appliances of various combustion designs. The effect of fuel as well as the effect of boiler type was studied. In total, 46 combustion runs were performed, during which numerous EFs were measured, including the EFs of particulate matter (PM), carbon monoxide, polyaromatic hydrocarbons (PAH), hexachlorobenzene (HxCBz), polychlorinated dibenzo-p-dioxins and furans (PCDD/F), etc. The highest EFs of nonchlorinated pollutants were measured for old-type boilers with over-fire and under-fire designs and with manual stoking and natural draft. Emissions of the above-mentioned pollutants from modern-type boilers (automatic, downdraft) were 10 times lower or more. The decisive factor for emission rate of nonchlorinated pollutants was the type of appliance; the type of fuel plays only a minor role. Emissions of chlorinated pollutants were proportional mainly to the chlorine content in fuel, but the type of appliance also influenced the rate of emissions significantly. Surprisingly, higher EFs of PCDD/F from combustion of chlorinated bituminous coal were observed for modern-type boilers (downdraft, automatic) than for old-type ones. On the other hand, when bituminous coal was burned, higher emissions of HxCBz were found for old-type boilers than for modern-type ones.

The impact of co-combustion of polyethylene plastics and wood in a small residential boiler on emissions of gaseous pollutants, particulate matter, PAHs and 1,3,5-triphenylbenzene

The aim of this study was to simulate a banned but widely spread practice of co-combustion of plastic with wood in a small residential boiler and to quantify its impact on emissions of gaseous pollutants, particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs), and 1,3,5-triphenylbenzene (135TPB), a new tracer of polyethylene plastic combustion. Supermarket polyethylene shopping bags (PE) and polyethylene terephthalate bottles (PET) were burnt as supplementary fuels with beech logs (BL) in an old-type 20 kW over-fire boiler both at a nominal and reduced heat output. An impact of co-combustion was more pronounced at the nominal heat output: an increase in emissions of PM, total organic carbon (TOC), toxic equivalent (TEQ) of 7 carcinogenic PAHs (c-PAHs) and a higher ratio of c-PAHs TEQ in particulate phase was observed during co-combustion of both plastics. 135TPB was found in emissions from both plastics both at a nominal and reduced output. In contrast to findings reported in the literature, 135TPB was a dominant compound detected by mass spectrometry on m/z 306 exclusively in emissions from co-combustion of PE. Surprisingly, six other even more abundant compounds of unknown identity were found on this m/z in emissions from co-combustion of PET. One of these unknown compounds was identified as p-quaterphenyl (pQ). Principal component analysis revealed strong correlation among 135TPB, pQ and five unknown compounds. pQ seems to be suitable tracers of polyethylene terephthalate plastic co-combustion, while 135TPB proved its suitability to be an all-purpose tracer of polyethylene plastics combustion.

Aerosols and the methods of determining the characteristics of nanoparticles

The purpose of this paper is to address the issue of aerosols by defining and dividing them in terms of their size, spatial localization and composition. The paper briefly deals with the issue of the origins and formation of aerosols. Further, it describes the trends in measuring nanoparticles based on their electric field mobility behavior, condensation, optical properties and aerosol particle acceleration in an air-stream.

Production of dioxins and furans for various solid fuels burnt in 25 kW automatic boiler

There has been brown coal, black coal and maize straw in a pellet form burnt in an automatic boiler. Production of dibenzodioxins and dibenzofuranes, recomputated through toxicity equivalents, expressed as the emission factor relative to the fuel unit, has differentiated in a range of ca. three orders (0.05 up to 78.9 ng/kg) in dependence on a sort of the used fuel. The measured values have been compared with emission factors used for the emission inventory in the Czech Republic and Poland and with the emission limit applicable for waste incineration plants. The study has proven the influence of chlorine content in fuel on production of dioxins and furanes.

Lump wood combustion process

The article deals with the combustion process for lump wood in low-power fireplaces (units to dozens of kW). Such a combustion process is cyclical in its nature, and what combustion facility users are most interested in is the frequency, at which fuel needs to be stoked to the fireplace. The paper defines the basic terms such as burnout curve and burning rate curve, which are closely related to the stocking frequency. The fuel burning rate is directly dependent on the immediate thermal power of the fireplace. This is also related to the temperature achieved in the fireplace, magnitude of flue gas losses and the ability to generate conditions favouring the full burnout of the fuel’s combustible component, which, at once ensures the minimum production of combustible pollutants. Another part of the paper describes experiments conducted in traditional fireplaces with a grate, at which well-dried lump wood was combusted.

Emission of nanoparticles during combustion of waste biomass in fireplace

Contamination of air by solid particles is serious problem for human health and also environment. Small particles in nano-sizes are more dangerous than same weight of larger size. Negative effect namely of the solid particles depends on (i) number, (ii) specific surface area (iii) respirability and (iv) bonding of others substances (e.g. PAHs, As, Cd, Zn, Cu etc.) which are higher for smaller (nano-sizes) particles compared to larger one. For this reason mentioned above this contribution deals with measuring of amount, and distribution of nanoparticles produced form combustion of waste city biomass in small combustion unit with impactor DLPI.

Potential Utilization of Catalyst for the Combustion of Wood in Households

The application of stricter requirements on combustion devices is placing more pressure especially on the manufacturers of such devices. They can improve the emission parameters of their products e.g. by primary technical measures (modification of combustion air supply, modification of combustion chamber, introduction of a final combustion chamber, etc.) or by secondary technical measures, e.g. introduction of a catalyst into the exhaust route.

Is One Village able to Produce as Many Dioxins as a Big Waste Incineration Plant

Three large waste incineration plants incinerated c. 360 thousand tons of waste in 2009, during which time they emitted c. 40 mg of PCDD/F expressed as TEQ in flue gasses into the air. If heated by solid fuels only (c. 4 thousand tons of fuel), one average (hypothetical) village with two thousand inhabitants would emit c. 2 to 60 mg of PCDD/F expressed as TEQ in flue gasses into the air during the heating season. We can state that in term of PCDD/F emissions into the air, one village being heated with solid fuels has a potential to produce similar (in some cases even higher) amount of dioxins as a large waste incineration plant. Abstrakt Tři velké spalovny odpadů spálily v roce 2009 cca 360 tis. tun odpadů. Při tom vyprodukovaly cca 40 mg PCDD/F (vyjádřeno jako TEQ) ve spalinách. Jedna průměrná (hypotetická) vesnice s 2 tis. obyvatel by vyprodukovala během topné sezóny (v případě, ţe by byla vytápěna jen tuhými palivy – cca 4 tis. tun paliva) cca 2 – 60 mg PCDD/F (vyjádřeno jako TEQ). Lze konstatovat, ţe jedna vesnice vytápěná tuhými palivy vyprodukuje podobné mnoţství PCDD/F (někdy dokonce i více) do ovzduší jako jedna velká spalovna odpadů.