Protocols for thermal and emissions performance testing of domestic fuels and stoves

M.Phil.The combustion of fuels in poorly designed cookstoves is a major anthropogenic source of atmospheric emissions with severe environmental and health implications. It is widely acknowledged that these challenges are best addressed with the development and dissemination of clean cookstoves. Widely used stove testing protocols (UCB Water Boiling Test and variants) are often single task-based and not representative of real-world uses or likely combinations of the manner in which fuels, stoves and pots may be used. The hypothesis of this study is that a stove testing procedure that provides for testing of stove/fuel/pot combinations, in a sequence of heterogeneous tests, provides a better representation of thermal performance and emissions than existing protocols based on prescribed fuels and fuel loads, and single tasks. The study aimed to develop and evaluate a set of testing protocols for determining thermal efficiency and emissions performance of domestic fuels and cooking devices to satisfy the rigorous performance specifications expected for claims under the Clean Development Mechanism (CDM) carbon trading market. The Heterogeneous stove Testing Protocol (HTP) was developed and documented as a complete set of standard operating procedures (SOPs), using a template derived from the Desert Research Institute (DRI), Reno, Nevada, and used for performance evaluation of fuel/stove combinations. The effect of pot size on the performance of two paraffin wick stoves and a pressurised paraffin stove was assessed and was found not to be a major factor, which affected thermal efficiency only at the high power setting. Power setting was found to influence the thermal efficiency and combustion performance of all stoves tested, indicating the need for assessment of the devices across the full range of power settings (where feasible). The HTP was also employed in characterising the combustion performance of coal stoves, using three different ignition methods, giving qualitative and quantitative results. Compared to the bottom-lit up-draft (BLUD) ignition method, the Basa njengo Magogo, also referred to as the top-lit up draft (TLUD) method, proved to be a better method of coal fires ignition, in terms of reduced CO:CO2 ratio and less smoke generation than in conventional braziers. The bottom-lit down-draft (BLDD) ignition method, incorporated in the SeTAR prototype coal stove, was found to be effective in fuel utilisation and improved combustion efficiency compared to the TLUD and BLUD methods, with CO:CO2 emission factors below 1% for 230 minutes. A number of parameters employed by the Water Boiling Test (WBT) were examined and compared with the HTP (e.g. turn-down ratio; simmer process; hot-start phase; use of standardised fuels and test pots). The HTP was found to provide more representative performance data over a wide range of use scenarios, the equivalent of providing performance curves rather than the minimum and maximum performance points provided by the WBT. The findings of this study have shown that the Heterogeneous stove Testing Protocol is consistent, robust, and transportable; making it a valuable tool for stove design improvements, and for the assessment of stoves under voluntary and compulsory carbon markets

Analysis of household energy uses in Mubuga informal settlement, Gitega, Burundi

Abstract: This paper presents an analysis of household energy uses in an informal settlement in Mubuga, Gitega, Burundi. At the time of the survey, the informal settlement was not connected to the main electricity grid. A survey of 100 households was conducted and data were collected through structured and open interviews. Of the interviewed households, 84 percent indicated that they used fuelwood as a primary energy source for cooking. About 94 percent used charcoal for commercial (barbecuing/grilling meat) purposes and 22 percent used it for domestic cooking. For lighting, kerosene accounted for 55 percent followed by candles (36%) and rechargeable lanterns (10%). Households in Mubuga used multiple fuels to meet their basic energy needs. It is therefore recommended that intervention models that advocate for the use of multiple fuels should be promoted in the area, as it allows households to choose freely energy sources from a suite of options

Towards Sustainable Urban Organic Agriculture and Food Security in Zimbabwe: a Comparative Study of Urban Low and High Density Suburbs of Mabelreign-Marlborough-Westgate and Mabvuku-Tafara, Harare 2005-2008

A ZJER article on sustainable urban organic agriculture in Zimbabwe.The global food crisis is a real observable fact the world over and it is likely to remain with us if unsustainable food production methods are not in place. The food crisis is regarded as a serious number one problem the world over hence the need for its sustainable production is found under Target 1 of the Millennium Development Goals (MDGs). Food shortage and extreme poverty have not spared Zimbabwe of late due to recurring droughts and very high inflation of 2006-2008. This study investigated how two different urban communities, the urban poor in high density suburbs of Mabvuku-Tafara and the urban rich in the low density suburbs of Mabelreign, Madborough and Westgate, attempted to solve the food crisis. The urban poor were found doing seasonal farming in the urban periphery (off yard plots) and their farming wa? often inorganic, less paying and often exposed to the vagaries of nature. Tr.e low density urban 'farmers’often practiced on-plots perennial farming with ‘green-houses’and these on-plots gardens were often organic, researched on (soil testing for pH value) and hence better paying than the off- plots farming done by the high density farmers. The study employed mainly qualitative methodology comparing urban agricultural activities between the low and high density suburban dwellers of Harare during the peak of high inflation and droughts. It can be recommended from this comparative study that urban farming with the capacity to meet urban food demands has to wholly go organic so as to minimise land and water pollution in Harare waters. It is also envisaged that once urban farming goes organic the city fathers would enjoy an added economic advantage by cutting on water purification costs as an environmentally friendly and less polluting type of farming would be in place. It is therefore envisaged that the adoption of sustainable organic urban farming, has the potential to alleviate the urban food crisis as well as fight the effects of global warming

Size distribution of nano particles from residential fixed-bed coal combustion

Abstract: Particle size distribution (PSD) from domestic coal combustion is an important parameter as it affects air quality, climate modelling, and health. There is limited information in the literature on particle size distribution from residential fixed-bed coal combustion processes. This study aimed to investigate the influence of coal combustion phases (ignition, flaming, and coking) on PSD of fine and ultrafine particles. Fine particle emissions from combustion of D-grade type coal (Ø 40 – 60 mm), in a lab-fabricated coal brazier (imbaula), were monitored using a NanoScan Scanning Mobility Particle Sizer (SMPS). Experiments were carried out using the reduced smoke top-lit updraft method, colloquially known as the Basa njengo Magogo (BnM) method. Particles from the top-lit updraft (TLUD) showed an ultrafine geometric mean diameter centred at approximately 110 nm for the ignition phase, 55 nm for the pyrolysis/ flaming phase, and 33 nm for the transition phase. The particle mode diameter rapidly increased during the ignition phase (145 nm) and gradually decreased during the flaming phase (35 nm) and the transition phase (31 nm)

Public participation in technological innovation : the case of the Tshulu stove development programme

Abstract: The design of products for developing communities often excludes the end-users in the decision making process. The study aims to investigate public participation and engagement in the design and development of the Tshulu woodstove. Results of this research point to the need for improved communication between citizens and technical experts, as well as for narrowing the gap between the designer and the user by encouraging meaningful engagement and inclusion. Bottom-up approaches ensure sustained participation of the public, in turn increasing a sense of ownership in the product. These results have implications for energy policy and improved cookstove programmes for developing communities

Livelihoods and HIV /AIDS: a case study of Nhamoinesu Village, Zaka District, Zimbabwe

Magister Philosophiae (Land and Agrarian Studies) - MPhil(LAS)The Human Immune Virus (HIV) and Acquired Immuno Deficiency Syndrome (AIDS) isa pandemic that has worsened the plight of vulnerable communities and environments in Africa. It is estimated that 40,3 million adults and children are living with HIV and AIDS and 3.1 million adults and children died in 2004 in the world. Southern Africa is the most affected region with a very high HIV/AIDS prevalence rate. The primary objective of the proposed study was to examine livelihoods and coping strategies of HIV/AIDS-affected households of Zaka District in Zimbabwe. Attention was given to institutional frameworks for HIV/AIDS interventions as district and village level. A second objective of the study is whether interventions are appropriately aligned and responsive to household livelihoods and copingSouth Afric

Heterogeneous stove testing methods for the evaluation of domestic solid-fuel cookstoves

Abstract: More rigorous and detailed test procedures are desirable to determine the effect of various design modifications on the performance of fuel/cookstove combinations, and to optimize their performance. This research paper investigated the effect of a novel heterogeneous testing method to evaluate the performance of domestic solid fuel/cookstove combinations. The water-heating test (WHT) and the ‘hood’ method were used as the basis of the tests with additional variants of fuel load, power setting and method of ignition. The experimental cookstoves included a typical brazier (Imbaula), a new type Mozambique ceramic cookstove, the baseline Mozambique metal cookstove, and the bottom-lit down-drafting (BLDD) coal cookstove. Results showed that a heterogeneous testing method provides more representative performance data over a wide range of usage scenarios, the equivalent of providing performance curves rather than the minimum and maximum performance points provided by single tasked based methods. This novel heterogeneous testing method generates robust and diagnostic results with which to compare fuel/cookstove technologies. Cookstove designers and programme managers who wish to improve the design of existing and new cookstoves, and to promote efficient fuel/cookstove technologies based on sound laboratory tests can use the principles explored in this study

A comprehensive review on small-scale combustion technologies in Southern Africa, what is known, done and emergent knowledge gaps?

Abstract: This is a review paper written with the intention to shed light on continued reliance on high polluting energy sources in the Southern Africa. Tn developing countries the use oflow cost fuels including coal, wood, pellets, charcoal and cow dung remains an obstacle in ensuring the right to clean air. Tn this study, several stove to fuel combustion technologies researches, were reviewed for similarities/ commonalities and differences. The review highlights on critical health and environmental effects associated with burning of solid fuels using inefficient cookstoves. The review deepens the understanding on various clean energy interventions and policy formulation in several countries within the Southern Africa Development Communities (SADC) region. Studies indicated the development of stove alone will not be enough in enhancing or reducing air pollution, but emphasis shall be put on stove to fuel combination. Findings also suggest a lack of clear or practical policy intervention to restore household indoor air quality, while single policy intervention proven inadequate in many studies. In sub-Saharan region, policy intervention focuses on energy switch thus from traditional solid fuels to modern energy resources namely electricity and liquid petroleum gas (LPG). This approach is not feasible given the difficulties in electricity generation and supply system, housing infrastructure and cost implication. Tn conclusion, policies which support energy stacking present a viable solution to improved indoor air quality

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

Abstract: Many cookstove programmes implemented around the world aimed to reduce fuel consumption and pollutant emissions through the dissemination and adoption of improved cookstoves. A study was carried out for the design of wood-burning cookstoves for low-income households in South Africa by employing user-centred design and co-design/cocreation approaches. Six designed variants of the biomass stove were constructed. Water-heating and emissions tests, using black wattle wood, were conducted to evaluate them for thermal and emissions performance. The large hopper stove with two secondary air inlets ranked highest, with best performance regarding thermal and emissions parameters. It outperformed the small hopper stove in time to boil, heat flux and firepower, although the latter had higher thermal efficiency values..