Emission factors of domestic coal-burning braziers

Abstract

We present experimental results of emission factors from a suite of domestic coal-burning braziers (lab fabricated and field collected) that span the possible range of real-world uses in the Highveld region of South Africa. The conventional bottom-lit updraft (BLUD) method and the top-lit updraft (TLUD) method were evaluated using coal particle sizes between 20 mm and 40 mm. Emission factors of CO2, CO and NOx were in the range of 98–102 g/MJ, 4.1–6.4 g/MJ and 75–195 mg/MJ, respectively. Particulate matter (PM2.5 and PM10) emissions were in the range 1.3–3.3 g/MJ for the BLUD method and 0.2–0.7 g/MJ for the TLUD method, for both field and lab-designed stoves. When employing the TLUD method, emission factors of PM2.5/PM10 reduced by up to 80% compared with those when using the BLUD method. Results showed the influence of ventilation rates on emission factors, which reduced by ~50% from low to high ventilation rates. For energy-specific emission rates, the combined (3-h) PM10 emission rates were in the range of 0.0028–0.0120 g/s, while the combined average CO emission rates were in the range of 0.20– 0.26 g/s, with CO2 emission rates in the range of 0.54–0.64 g/s. The reported emission factors from coal braziers provide the first comprehensive, systematic set of emission factors for this source category, and fill a major gap in previous efforts to conduct dispersion modelling of South African Highveld air quality.

Design and performance evaluation of wood-burning cookstoves for low-income households in South Africa

“…Cooking pots and the use of pot lids Hart™ aluminium 6 L capacity pots, commercially available and widely used for cooking in South Africa and regionally, were used in the experiments. For the water-heating task, an amount of water (5 L for the large pots) was heated from ambient temperature to the target temperature (about 70 °C), not higher -to prevent losses through evaporation [6]. When the water temperature reached 70 °C the pot was swapped with a fresh 5 L pot of water.…”

“…The pot was used together with the lid to minimise evaporative losses, which would complicate the energetic calculations resulting in high fuel consumption rates and low efficiency numbers. It was imperative to minimise or divert the steam from the pot from the combustion flow to protect the experiment from extraneous factors [6].…”

“…The heterogeneous stove testing protocol A heterogeneous stove testing protocol (HTP) was employed; that is, a collection of tests and methods describing the procedures for thermal efficiency, particle and gaseous emissions performance, firepower, and fuel-burn rate. The SeTAR Centre, University of Johannesburg [6] provided the HTP facility.…”

“…Poor households in some SSA countries where electricity access is high, such as in South Africa, are likely to continue using solid fuels as they cannot afford electricity [6]. Electricity in these communities is used for lighting and entertainment, but not for cooking or space-heating [7].…”

Influence of coal properties on the performance of fixed-bed coal-burning braziers

“…Carbon monoxide (CO), carbon dioxide (CO 2 ), particulate matter (PM 2.5 and PM 10 ) were selected as indicator pollutants because of their prominence in health and environmental studies, as well as air quality dispersion modelling (Makonese et al, 2017;Shahraiyni & Sodoudi, 2016;Penney et al, 2010).…”