Residential wood combustion (RWC) is a significant source of gaseous and particulate emissions causing adverse health and environmental effects. Several factors affect emissions, but the effects of ...the fuel wood species on emissions are currently not well understood. In this study, the Nordic wood species (named BirchA, BirchB, Spruce, SpruceDry, Pine and Alder) were combusted in a modern stove, and the emissions were studied. The lowest emissions were obtained from the combustion of BirchA and the highest from Spruce and Alder. The fine particle mass (PM2.5) was mainly composed of elemental carbon (50–70% of PM2.5), which is typical in modern appliances. The lowest PAH concentrations were measured from BirchA (total PAH 107 µg/m3) and Pine (250 µg/m3). In the ignition batch, the PAH concentration was about 4-fold (416 µg/m3). The PAHs did not correlate with other organic compounds, and thus, volatile organic compounds (VOCs) or organic carbon (OC) concentrations cannot be used as an indicator of PAH emissions. Two birch species from different origins with a similar chemical composition but different density produced partially different emission profiles. This study indicates that emission differences may be due more to the physical properties of the wood and the combustion conditions than to the wood species themselves.
The awareness of environmental pollution has been continuously growing in recent decades and is currently reaching its maximum. Europe and most developed countries are determined to ensure safe ...breathing air for their citizens, and the measures to do so are stricter than ever before. Combustion procedures remain the primary means of producing energy and warmth in Poland. Among the notable constituents of flue gases produced as a result of fuel combustion, solid particles (or particulate matter) hold significant prominence. The paper presents the chemical characterisation of particulate matter emitted from stationary and automotive emission sources. Stationary emission sources included the combustion process of fossil fuels (soft wood, bituminous coal, ecopea coal, culm) in domestic heating units and the process of combustion of bituminous coal in a power plant. Automotive emission sources included light duty and medium duty vehicles fuelled by diesel. Exhaust toxicity tests were carried out maintaining the real conditions of PM emission. In all field measurements particulate matter was gravimetrically measured and collected on quartz or glass fibre filters. Subsequently, the content of carbonaceous fraction, inorganic ions, and metals and metalloids was analyzed using different analytical techniques. The chemical composition of the particulate matter differed depending on the emission source. With respect to stationary combustion sources, the main factors determining solid particle emission are related primarily to the fuel quality. The duty of vehicles was also a factor that influenced the chemical characterisation of the particulate matter emitted from the engines.
The active substance used in oxidation honeycomb catalysts determined for real flue gas purification usually consists of precious metals such as platinum or palladium, while the most common is the ...mixture of the two mentioned elements, however high prices and limited availability of these elements encourages producers for the search for new, equally or better effective alternatives. In this study V2O5-WO3/TiO2 honeycomb catalyst was tested during the combustion test with commonly sold manually loaded stove. The catalyst was installed in the flue gas duct at the stove outlet. The experimental comparison of the flue gas composition at the catalyst inlet and at the catalyst outlet was performed. Flue gas sampling took place for whole combustion periods. Relatively high conversion rates by catalyst of CO (up to 87.1%), C3H8 (up to 61.3%) and TSP (up to 17.7%) were reached, which meant that the limit values of Commission regulation for mentioned kind of equipment were met during four, not only one period (in case of non-use of the catalyst). The V2O5-WO3/TiO2 catalyst has a great potential as the secondary emission control device for achieving low mass concentration of the certain pollutants in the flue gas.
•The heat energy output can be reduced to 35 – 40 % by the regulation ring usage.•Regulation rings decreased CO, and increased NOx concentrations.•NOx emission factors vary with fuel type, exceeding ...previous studies.•Vortex-fire bioethanol burner outperforms standard burners in heat output.
Bioethanol burners are significantly expanding devices in Europe, still considered preferably as the design element while its possible importance in the energy system of the household used to be neglected. The aim of this study was to determine the operating techno-environmental parameters as the heat output and the flue gas composition of the bioethanol fireplace with vortex flame. The measurement methodology was based on actual valid standard EN 16647 Fireplaces for Liquid Fuel. In general, three ethanol-based fuels were tested in combination with one bioethanol burner equipped with different regulation rings changing burner opening area. The average reached heat energy output ranged between 3.97 and 2.22 kW with maximal burner opening area (without the usage of regulation rings) for different fuels. By usage of the regulation rings, the heat energy output was reduced to 35 – 40 % of the nominal average heat output. Simultaneously the time of the burning of one fuel dose can be increased by regulation ring usage up to 195 % of the combustion time without the regulation ring. By placing the regulation rings on the burner bowl opening area, the flue gas composition was affected positively in terms of CO and negatively in terms of NOx.
The aim of this study is to determine the influences of chosen primary (mixing of standard recommended fuel with additives) and secondary (oxidation catalyst) measures on the composition of flue gas, ...produced by combustion of liquid fuels in a standard ethanol burner. The total amount of emitted NOx was decreased by 63%, after replacing the fuel by pure methanol, while the total amount of emitted CO was the lowest during pure ethanol usage. The implementation of chosen catalyst significantly affected the total amount of emitted CO with high conversion rates (82%–90%). The amount of emitted water vapour was increased by 0%–25% (per 1 kWh of released energy) when additives were used. Overall, applying the mentioned measures together proved to be very beneficial from the total amount of emitted CO and NOx point of view.
Commonly sold bioethanol fireplaces can represent significant heat source, however due to their intermittent operation the heat energy output is strongly uneven. The aim of this study was to ...determine the possibilities of heat energy accumulation by individually built ethanol fireplace intended for commonly sold ethanol burner installation. For the measurements of heat energy output, long term tests of the individually built ethanol fireplace with 1, 2 and 3 consecutive combustion periods in a unique calorific room were performed. Accumulation ethanol fireplace has proven high ratio between accumulated heat energy after the ethanol burner last burn-out reaching from 21.4 to 48.4% according to the number of consecutive fuel doses. By usage of the described ethanol fireplace the time of heat energy releasing was increased from approximately 1.15, 2.35 and 3.55 h in case of ethanol burner usage in a non-accumulation fireplace for 1, 2 and 3 fuel doses to 6.5, 11 and 15 h in case of accumulation ethanol fireplace usage. This was also strongly connected with average heat output ranging between 2.54 to 2.47 kW in the case of ethanol burner usage in a non-accumulation ethanol fireplace and 0.38 to 0.59 kW in the case of accumulation ethanol fireplace usage.
An electrostatic precipitator (ESP) is an efficient device for removing fly ash from small-scale solid-fuel combustion. Under corona discharge, a gaseous medium becomes ionised, and particles become ...charged by colliding with ions. An electric field forces the movement of charged particles to remove gases and induces the movement of generated ions, causing secondary electrohydrodynamic flow. Thus, particle charge, the presence of neighbouring particles, an ESP electric field, and gas flow turbulence can enhance particle coagulation. Therefore, the ultrafine particle concentration in an ESP is expected to evolve under electrostatic removal and enhanced coagulation. In the present study, the contribution of coagulation is explored and confirmed using experimental measurements performed on an ESP used to control emissions from a 160-kW boiler with biomass combustion. The ESP was operated under several modes to obtain different coagulation conditions. Changes in particle concentrations were measured simultaneously using two techniques. It was found that coagulation could be responsible for up to 5% of the total removal efficiency, depending on the ESP operation parameters. The present study can promote a deeper understanding of the processes involved in electrostatic precipitation, and the obtained results can be useful for practical ESP engineering.
•Coagulation contributes to particle removal in an electrostatic precipitator.•Coagulation mechanisms are discussed, contribution of coagulation is predicted.•Two-type simultaneous measurements confirmed the prediction.
One of the most significant anthropogenic sources of atmospheric pollution is a home heating with solid fuels. Therefore, governments often financially support modernization of home heat sources. ...Modernization can result in new technology installation (heat pumps or gas condensing boilers etc.) or in upgrade of current technology by installation of a boiler with higher emission and efficiency standards. In the Czech Republic when a new boiler is installed, there are currently no legal requirements for a final inspection before use. This article presents the results of field measurements of five boilers with heat output 20–30 kW (three wood gasification and two wood pellets automatic boilers). The measurements (CO, TSP, thermal efficiency) were conducted during routine daily use. The goal of conducted investigation was to evaluate performance of currently subsidized wood gasification and automatic pellet boilers. Obtained results were compared to declared emission classification (according to EN 303–5:2012). All boilers failed to meet legal limits in one or more certification categories. Results lead to conclusion that there are four factors impacting generated pollution (boiler construction, operator awareness, quality of fuel, boiler maintenance). In order to decrease pollution from residential heating, all four factors shall be taken into consideration. If one factor is omitted, generated pollution immediately or progressively increases.
•DC corona discharge in ESP achieved 78% NOx removal from biomass boiler emissions.•Positive corona was more energy efficient than negative for NOx removal.•OH and O(3P) dominated NOx removal in ...positive corona, ozone in negative corona.
Direct current corona discharge was investigated to reduce nitrogen oxide (NOx) emissions from a 15-kW small-scale biomass boiler. The electrostatic precipitator was designed and operated under different regimes with both positive and negative polarities. A reduction in NOx concentration from 200 mg/m3 to 44/46 mg/m3 for positive/negative polarities was achieved, corresponding to a NOx removal efficiency of approximately 78 %. However, the specific input energy required for a positive corona (35.7 J/L) was lower than that for a negative corona (48.4 J/L), indicating an energy efficiency advantage for positive polarity. The results were analysed for NO decontamination involving reactions with OH radicals, ground-state oxygen atoms, and ozone. Positive corona favoured NOx removal via reactions with OH (21 % efficiency) and oxidation by oxygen (12 % efficiency), whereas negative corona promoted NO oxidation by ozone (75 % efficiency). The distinct distribution of electrons and active species, influenced by the non-uniform electric field and polarity, governs plasma chemical kinetics.
Ashes were prepared by annealing selected types of solid fuels (biomass: corn cobs, sunflower husks, olive pomace, hay pellets and rice husks; coal: lignite and bituminous; and alternative fuel: ...paper sludge) at different temperatures (550°C, 815°C and 975°C). Based on X-ray fluorescence spectra, the slagging/fouling indexes were used to study the effects of the type of ash and the ashing temperature on the ash fouling and slagging properties. Slagging indexes were compared with the ash fusion temperatures. Ash fusion temperatures were measured by a LECO AF-700. The lowest deformation temperature (below 1000°C) was seen for the ashes prepared from hay pellets and corn cobs. On the other hand, the deformation temperature exceeded 1500°C for ashes prepared from paper sludge, sunflower husks and rice husks. By calculating the different slagging/fouling indexes, all the ashes exhibited slagging/fouling problems of varying degrees.
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