Emissions of Gases and Volatile Organic Compounds from Residential Heating: A Comparison of Brown Coal Briquettes and Logwood Combustion

Abstract

Coal continues to be a major source of energy for residential heating in some parts of the world due to its low price and good availability. However, only little information on emissions for coal combustion in small-scale appliances, in particular manually-operated stoves, is available. This study investigates the emissions of gases and volatile organic compounds (VOCs) from brown coal briquettes (BCBs) burned in a typical Central European wood stove and compares them to emissions from spruce wood logs. Special emphasis was placed on the evolution of emissions over consecutive batches. In comparison to wood, BCBs made from Lusatian lignite showed higher emissions of compounds that were attributed to the decomposition of lignin, while emissions that were attributed to having originated from pyrosynthesis did not show significant differences between both fuels. Furthermore, a 20-fold higher emission factor for SO2 was obtained from BCB combustion, which is known for its deleterious effect. In addition to a reduction in the carbon footprint, replacing BCBs with logwood as a fuel for residential heating might be beneficial for human health due to vast differences in SO2 emissions, whereas a potential effect from the reduction of organic emissions is questionable due to the rather small differences in organic emissions.

Brown Coal and Logwood Combustion in a Modern Heating Appliance: The Impact of Combustion Quality and Fuel on Organic Aerosol Composition

“…CO emissions from BCB burning however showed much greater variability between individual experiments; 4 h averages of individual experiments can be as just as low as wood combustion with approximately 900 mg MJ –1 (Table S4, BCB2) but also approximately twice as high with 1900 mg MJ –1 (BCB3). Furthermore, CO emissions from BCB burning seemed low when compared to EFs from other combinations of solid fuels and manually fueled heating appliances . In SL experiments, a significant part of CO was emitted during the burn-off phase (secondary/tertiary air supplies closed and primary fully opened for shut-down of appliance) at the end of an experiment (Figure S2), whereas, in BCB experiments, this phase was not contributing largely to overall CO emissions.…”

“…The combustion procedure used in this study has already been described in a previous study. 19 Briefly, combustion experiments were designed to cover a period of 4 h. Due to inherent differences, the ease of ignition and combustion rate, the mass of fuel, and the number of batches that were burned varied between both fuels. For SL experiments, one experiment comprised five consecutive batches of fuel with a weight of ca.…”

“…In particular, coal combustion in residential, small-scale heating appliances has been shown to pose a major burden to human health, having accounted for 10% of ambient PM 2.5 pollution but for 32% of pollution-related premature deaths in China in 2014 . Generally, toxicological responses in in vitro and in vivo studies have been shown to vary among residential heating appliances and solid fuels, , and differences in responses are thought to be caused by varying physical properties and chemical compositions of PM, − depending on the type of fuel, − type of appliance, ,− and combustion conditions. ,− …”

Photochemical Aging Induces Changes in the Effective Densities, Morphologies, and Optical Properties of Combustion Aerosol Particles

“…The use of the stove and fuels in these experiments is explained in detail elsewhere. 45 CAST Burner. A combustion aerosol standard (CAST) burner (Cast Jing Ltd.) 43 was used for soot particle production 46,47 using propane gas as fuel.…”

“…The overall experimental conditions and gaseous emissions from the stove, including both FTIR and SPI-ToF-MS results as well as used solid fuels, are discussed in detail by Martens et al (2021). 45 Particle Optical Properties. Particle optical properties were directly measured by a seven-wavelength aethalometer (Aethalometer AE33, Magee Scientific 43 ).…”