Domestic lump coal combustion: Characterization of performance and emission from field obtained Braziers

Size: px

Start display at page:

Download "Domestic lump coal combustion: Characterization of performance and emission from field obtained Braziers"

Jasper Evelyn Leonard
5 years ago
Views:

SeTAR Centre, University of Johannesburg 2.

1 Domestic lump coal combustion: Characterization of performance and emission from field obtained Braziers Daniel Masekameni 1,2, Tafadzwa Makonese 1,2, Patricia Forbes 3, Harold Annegarn 1,2 1. SeTAR Centre, University of Johannesburg 2. Department of Geography, Environmental Management and Energy Studies, University of Johannesburg 3. Chemistry Department, University of Pretoria Conference 213 Cape Town, 3 September 213

2 Background Lump-coal combustion still remains the major source of poor indoor air quality in Townships Despite the mass electrification program coal still remains a primary commodity for poor households Lack of access to modern and clean energy in low socioeconomic settlement further increases exposures Projected rapid increases in price of electricity further delay the replacement of dirty energy sources Government embarked on Basa njengo Magogo as shortmedium term intervention to coal exposures Program proves less success due to stove/fuel factors never taken in to consideration. 213 Masekameni et al.

3 Background cont The field survey was conducted in Tembisa Township, Madela-kufa 1&2 informal settlement and Vusimuzi informal settlement This settlements are off-grid an relies on cheap fuels for cooking, heating and lighting Lack of income source also factor the ability to afford clean energy sources Tembisa is located in Gauteng Province and its under the admiration of Ekurhuleni metropolitan municipality This paper reports on quantitative findings on emissions from three field obtained coal combustion stoves. Masekameni et al.

4 Township Lighting Techniques Classical fire-lighting methodology Unburnt fuel = air pollution Cool zone SVOC condensation Hot zone VOC distillation Flame zone Flame zone VOCs and SVOCs combusted Hot zone VOC distillation Masekameni et al.

5 Observations Basa njenga magogo Classical fire lighting Masekameni et al.

6 Rationale of study Poverty and unemployment force people to rely on cheap energy fuel Over population burdens the provisions of basic services such as housing, sanitation and infrastructure Poor people congregate in informal settlement without basic services and dirty fuel dominate their energy market The exposures are further increased by the use of leaky and unvented Imbaulas Most houses in informal settlements are not well ventilated leading to high accumulation of gases and particles Masekameni et al.

7 Testing Protocol and Parameters SeTAR Heterogeneous testing protocol was employed Each test was done using 5L pot Emissions performance followed the hood method as suggested by Ahuja 1987 Testo flue gas analyser was used for the analysis of stack gases. Dust track was used to quantify the emissions of particles Thermocouples were used to measure temperature Dilution system was used to cool down particles temperature and regulate mass concentration Masekameni et al. 213

Stove characterization Maximum hole(a1) Medium case(a2)

standard in construction the devices Grouped according to

exceptional case obtained from field A1 and A2 with big

8 Stove characterization Maximum hole(a1) Medium case(a2) Low case(a3) Various imbaulas obtained from the field No standard in construction the devices Grouped according to number of holes ranging from high to low Imbaula A1 is an exceptional case obtained from field A1 and A2 with big primary air hole while A3 is without Masekameni et al, 213

9 Experimental Set-Up - hand made out of 2 litre metal paint drums - perforations of varying sizes around the sides - In this example, high number of holes Masekameni et al, 213

10 PM 2.5 (mg/m^3) PM2.5 Smoke vs Time (left) and Fire Power & Cumulative PM (Right) Combustion burning phases - High number of holes (Traditional and BnM) Cumulative Mass of Total PM (g) Fire-Power (KW) BnM Max holes Trad Max holes 6 TSP (BnM) TSP (Trad) 4 5 Fire-Power (Trad) Fire-Power (BnM) % Time (minutes) CO/CO2 BnM Max CO/CO2 Trad Max Time (minutes) BnM support the 8% reduction on particulates Fire power for both stoves is much similar BnM fire reported to be quicker to use The CO:CO2 ratio is quite high for both stoves After pyrolysis the CO:CO2 ratio for BnM steadily rises Masekameni et al, 213 Time(minutes)

11 PM 2.5 (mg/m^3) Cumulative Mass of Total PM (g) Fire-Power (KW) PM2.5 Smoke vs Time (left) and Fire Power & Cumulative PM (Right) Combustion burning phases Medium number of holes (Traditional and BnM) % BnM Medium holes Trad medium holes Time (minutes) CO/CO2 BnM Med CO/CO2 Trad Med TSP (BnM) Fire-Power (Trad) Time (minutes) TSP (Trad) Fire-Power (BnM) BnM support the 8% reduction in Particles emissions BnM maintains the fire power at kw while Traditional the fire power drops below 3kw after pyrolisis Traditional method CO:CO2 ratio drops below 2% for short time while CO:CO2 ratio for BnM remains higher than 2% through-out the test Masekameni et al, 213 Time(minutes)

12 PM 2.5 (mg/m^3) Cumulative Mass of Total PM (g) Fire-Power (KW) PM2.5 Smoke vs Time (left) and Fire Power & Cumulative PM (Right) Combustion burning phases Low number of holes (Traditional and BnM) BnM low holes Trad Low holes 12 TSP (BnM) Fire-Power (Trad) TSP (Trad) Fire-Power (BnM) % Masekameni et al, 213 Time (minutes) CO/CO2 BnM Min CO/CO2 Trad Min Time(minutes) Time (minutes) High emissions of particles for traditional lighting method The stove starve for primary air CO:CO2 ratio for BnM is quite low compared to traditional The fire power for BnM was maintained at 3kw while for traditional drops below 3kw

13 Cumulative Mass of Total PM (g) Overall Results 14 TSP BnM Max TSP BnM Med TSP BnM Min TSP Trad Max TSP Trad Med TSP Trad Min Masekameni et al, Time (minutes)

14 Fuel burn rate Test Case PM 2.5 Emissions per MJ (Fuel) [mg/mj] Fuel Burn Rate [kg/hr] CO Emissions per MJ (Fuel) [mg/mj] Combustion efficiency( CO/CO2) % Average time to boil BnM Low minutes BnM Medium minutes BnM High minutes Traditional Low minutes Traditional Medium minutes Traditional High minutes Masekameni et al, 213

15 Results and Discussion Imbaula with high holes had low emissions compared to the other two The particles emissions are very high on high holes Imbaula on traditional lighting methods High holes imbaula consumes more coal much quicker than the Medium and minimum holes one on BnM The traditional lighting method consumes more fuel than BnM as shown at the previous slide There is little variation between minimum and minimum holes imbaula on particle emissions Masekameni et al, 213

16 Conclusion It can be concluded based on the findings of this tests results that: Air holes for both primary and secondary air is a determinant factor in optimizing an Imbaula. Properly balanced air holes in a stove can positively lead to stove performing better in terms of reduced particles emissions, time reduction and fuel saving Having an Imbaula with maximum holes can bring improvements on combustion using either of the lighting method CO:CO2 ratio still high failing to drop below 2% in all stoves Masekameni et al, 213

17 Recommendation for further study A further detailed study on the exact number of holes, sizes, fuel support grate position and holes distribution patterns must be conducted to detects any improvements. Investigation of parameters in stove which will bring positive reduction on the CO:CO2 ratio A further study on the effect of fuel quality on emissions of particles and gases Masekameni et al, 213

18 Acknowledgements Thokozile Sithole for her assistance with the lab-work. Acknowledgments to GTZ, GIZ and CIM for establishing the SeTAR Stove Testing Laboratory and salary support Acknowledgment to SANEDI for a financial grant towards the establishment of the SeTAR Laboratory Acknowledgement to the University of Johannesburg for financial support for the SeTAR Centre. This work was supported in part through a grant from the Global Alliance for Clean Cookstoves (GACC) towards the establishment of the SeTAR Centre as a regional Stove testing centre. DM thanks City of Johannesburg, Environmental Health Department, for study support towards an MSc qualification. Acknowledgement to NACA for financial assistance in conferences Masekameni et al, 213

Emissions reductions from domestic coal burning: demonstration of an innovative bottom lit down draft stove

Emissions reductions from domestic coal burning: demonstration of an innovative bottom lit down draft stove Crispin Pemberton-Pigott 1, James Robinson 2, Cecil Cook 1, Vincent Molapo 1, and Harold Annegarn