A comparison of PAH emission sampling methods (cyclone, impactor) in particulate and gaseous phase

Four different domestic heating boilers and four types of fuel (lignite, wet wood, wood pellets and mixed fuel) were tested, and the emissions of the particulate matter (PM) and polycyclic aromatic hydrocarbons (PAHs) were correlated. Dekati low-pressure impactor (DLPI, Dekati) sorting of the PM fractions into PM0.1, PM1, PM2.5 and PM10 was used to determine the emission factors of the PAHs in a dilution tunnel via isokinetic sampling and was compared with a cyclone (Tecora). The 4 PAHs were mostly detected on the fine particles of PM1 in the DLPI and on the fine particles of PM2.5 in the cyclone, and in some cases, they were mainly detected in polyurethane foam (PUF) used for the collection of the gas phase placed behind the DLPI and cyclone. The effectiveness of DLPI sampling was generally comparable or lower than the cyclone sampling of the range 0.01-1.33 mg kg(-1).Web of Science18485584

Effects of the type of biomass and ashing temperature on the properties of solid fuel ashes

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 degrees C, 815 degrees C and 975 degrees 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 degrees C) was seen for the ashes prepared from hay pellets and corn cobs. On the other hand, the deformation temperature exceeded 1500 degrees 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.Web of Science212514

Coagulation contributing to electrostatic precipitation of ultrafine fly ash from small-scale biomass combustions

An electrostatic precipitator (ESP) is an efficient device for removing fly ash from small-scale solid-fuel com-bustion. 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 neigh-bouring 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 ob-tained results can be useful for practical ESP engineering.Web of Science16art. no. 10066

Heat energy accumulation construction for bioethanol burner

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.Web of Science911410

Influence of fuel mixture and catalyst on the ethanol burner flue gas composition

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 NO x 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.Web of Science887987

Specifics of electrostatic precipitation of fly ash from small-scale fossil fuel combustion

This paper investigates the removal efficiency of a honeycomb electrostatic precipitator (ESP) applied to control particulate matter (PM) emissions from a small-scale boiler with combustion lignite and hard coal. The specifics of the precipitation of emissions from small-scale boilers are discussed, and the design principles for relevant ESPs are presented and used. The ion-induced nucleation of sulfuric acid occurred, causing the drastic penetration of 19 nm particles through the ESP. Despite this, the overall collection efficiency was sufficient to meet the EU’s Ecodesign Directive requirements. Back corona was not detected. The optimal ESP performance is defined with further parameters: a current density of 0.5 mA/m2 at an electric field strength of about 2.7 × 105 V/m; a minimal specific collecting area of ESP (SCA) of 60 m2/(m3/s); and Nt-product of 4.5 × 1014 s/m3 . Such parameters of ESPs should ensure adequate PM emissions control for any type of boiler with similar emissions characteristics. The composition of collected fly ash particles was analysed, and a method for fly ash utilisation was proposed. This research may be helpful for designing ESPs to control PM emissions for small-scale units with fossil fuel combustion.Web of Science113art. no. 80

Biomass heating of small buildings

Import 18/11/2009Disertační práce se zabývá problematikou využití biomasy při vytápění malých objektů, typicky rodinných domů, se zaměřením na technické, ekonomické a enviromentální hodnocení takovéhoto řešení. V práci jsou popsány základní využívané formy paliv a jejich fyzikální a chemické vlastnosti a základní typy spalovacích zařízení. Na 5 nejběžnějších spalovacích zařízení byly provedeny spalovací zkoušky a bylo provedeno srovnání emisních faktorů znečišťujících látek při spalování biomasy a hnědého uhlí.This thesis is focused on points at issue of biomass heating of small buildings, typically detached houses. There is described technical, economical and environmental appraisal of this solution. There are described basic forms of fuels from biomass, theirs physical and chemical characteristics and basic types of combustion appliances. There were made combustion tests with 5 boilers and compared obtained emission factors from biomass and brown coal.Prezenční361 - Katedra energetikyvýborn

Světelné zdroje s elektronickými předřadníky a jejich vzájemné vlivy na elektrizační soustavu

Import 20/04/2006Prezenční výpůjčkaVŠB - Technická univerzita Ostrava. Fakulta elektrotechniky a informatiky. Katedra (451) elektroenergetik

Electrostatic precipitation as a method to control the emissions of particulate matter from small-scale combustion units

The aim of this study was to investigate the use of an electrostatic precipitator (ESP) for controlling the emissions of particulate matter (PM) from small-scale heating units, specifically boilers that combust solid fuel with a heating power output of <300 kW. The equilibrium between the required precipitation efficiency and the structural parameters of the ESP in combination with the applied voltage were determined. This study presents a method of optimising the applied voltage alongside the specific ESP structural parameters while retaining the required precipitation efficiency. The ESP was designed, optimised, and integrated into a 15-kW boiler without expanding its volume. The theoretically predicted voltages and resulting ESP efficiency (20 kV and 85% respectively) were verified by measuring the reduction in the particle number concentration. The measurements were based on different principles and simultaneously sampled. The PM concentrations were reduced below 40 mg/m(3) (0 degrees C, 101.3 kPa; at reference O-2 =10 %(vol)(.)) by nominal and reducing the heat power, which allowed the boiler to meet the requirements of the EU's Ecodesign Directive. The presented optimisation method can be used in the practical engineering of any type of ESP.Web of Science246art. no. 11902