Emission Factors for Biofuels and Coal Combustion in a Domestic Boiler of 18 kW

Marianna Czaplicka,Tomasz Rachwał,Bogusław Komosiński,Ewelina Cieślik

doi:10.3390/atmos10120771

Marianna Czaplicka, Tomasz Rachwał + Show 2 more

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https://doi.org/10.3390/atmos10120771

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Abstract

The differences in the pollutant emissions from the combustion of bituminous coal and biofuels (wood, straw, and miscanthus pellets) under real-world boiler operating conditions were investigated. The experiments were performed on an experimental installation that comprised an 18 kW boiler, used in domestic central heating systems, equipped with a retort furnace, an automatic fuel feeder, a combustion air fan, and a fuel storage bin. The emission factors of gaseous pollutants, particulate matter, organic carbon, elemental carbon, and polycyclic aromatic hydrocarbons (PAHs), as well as some PAH concentration ratios for coal and biofuel combustion, were determined. The obtained results indicate that fuel properties have a strong influence on the emission factors of gaseous and carbonaceous pollutants. The total particulate matter (PM) emissions from the biofuel combustion were about 5-fold lower than those from the coal burned in the same boiler. The emission factors of the total carbons from the biofuel combustion were between 10 and 20 times lower than those from the coal combustion. The mean organic carbon (OC) and elemental carbon (EC) emission factors, based on the burned fuel, were 161–232 and 42–221 mg/kg for the biofuels and 1264 and 3410 g/kg for the coal, respectively. The obtained results indicate that molecular diagnostic ratios, based on the concentration of PAHs, vary significantly, depending on the fuel type.

Highlights

Biofuel combustion emits a substantial amount of CO, which can contribute to the CO2 level through oxidation [1,2]
The determined molecular diagnostic ratios (MDRs) are similar to the results presented in other publications despite different combustion conditions and physicochemical properties of biofuels
- The emissions of particulate matter (PM) from the biofuel combustion were about 5-fold lower than those from the coal burned in the same boiler

Summary

Introduction

Biofuel combustion emits a substantial amount of CO, which can contribute to the CO2 level through oxidation [1,2]. Forest and agriculture solid biomass fuels are used as the main or additional fuel in power plants with boilers of various types and in households as a traditional bioenergy. Mainly wood and plant residues, are important sources of primary energy and account for about 13% of global fuel consumption [3]. It is well known that, during combustion, the structural organic compounds in biomass play a role similar to lithotypes in coal [5]. The emission factors (EF) for coal and biofuels under specific combustion conditions have been presented in numerous papers [6,7,8,9]. The emissions from the combustion and composition of the organic compounds released from biomass burning depend on, among other things, the fuel composition, combustion rate, and boiler type [10,11]. Reductions in the total CO, organic carbon (OC), elemental carbon (EC), particulate matter (PM), and polycyclic aromatic hydrocarbon (PAH)

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