Three-stone Fire Research Articles

Gasifier use for cooking and biochar production by smallholder farmers in Rwanda

Rwanda’s rural households primarily use biomass fuel, leading to fuel waste and air quality related issues. The study compared two-top-up lift draft (TLUD) gasifier types (Gastov and Karundura) with a three-stone fire (TSF) cookstove in Bugesera and Huye Districts, Rwanda, using standardized cooking tests (SCT) and a qualitative survey. Key indicators included cooking time, fuel usage and biochar yield while the survey collected information about fuel availability, frequency of use, gasifier design, benefits and challenges. The study utilised descriptive statistics and ANOVA for analysis. The study revealed that the TSF cooked a standardised meal faster than the gasifier did, but the gasifiers reduced fuelwood consumption by 25–50% and produced biochar. The survey responses revealed low fuelwood availability, with fuel savings, temperature control, reduced need for constant supervision, biochar production, and reduced time needed to gather fuelwood, more hygienic and attractive appearance cooking have been revealed. Most household cooks reported that the gasifier stoves produced less smoke and were safer for women and children’s health. The biochar produced by the TLUD gasifiers was perceived as positive as it combines biochar production and bioenergy, reduces off-farm biomass gathering, improves energy security and produces sufficient biochar to improve soil productivity.

Personal exposures to fine particulate matter and carbon monoxide in relation to cooking activities in rural Malawi.

Background: Air pollution is a major environmental risk factor for cardiorespiratory disease. Exposures to household air pollution from cooking and other activities, are particularly high in Southern Africa. Following an extended period of participant observation in a village in Malawi, we aimed to assess individuals' exposures to fine particulate matter (PM 2.5) and carbon monoxide (CO) and to investigate the different sources of exposure, including different cooking methods. Methods: Adult residents of a village in Malawi wore personal PM 2.5 and CO monitors for 24-48 hours, sampling every 1 (CO) or 2 minutes (PM 2.5). Subsequent in-person interviews recorded potential exposure details over the time periods. We present means and interquartile ranges for overall exposures and summaries stratified by time and activity (exposure). We employed multivariate regression to further explore these characteristics, and Spearman rank correlation to examine the relationship between paired PM 2.5 and CO exposures. Results : Twenty participants (17 female; median age 40 years, IQR: 37-56) provided 831 hours of paired PM 2.5 and CO data. Concentrations of PM 2.5 during combustion activity, usually cooking, far exceeded background levels (no combustion activity): 97.9μg/m 3 (IQR: 22.9-482.0), vs 7.6μg/m 3, IQR: 2.5-20.6 respectively. Background PM 2.5 concentrations were higher during daytime hours (11.7μg/m 3 [IQR: 5.2-30.0] vs 3.3μg/m 3 at night [IQR: 0.7-8.2]). Highest exposures were influenced by cooking location but associated with charcoal use (for CO) and firewood on a three-stone fire (for PM 2.5). Cooking-related exposures were higher in more ventilated places, such as outside the household or on a walled veranda, than during indoor cooking. Conclusions : The study demonstrates the value of combining personal PM 2.5 exposure data with detailed contextual information for providing deeper insights into pollution sources and influences. The finding of similar/lower exposures during cooking in seemingly less-ventilated places should prompt a re-evaluation of proposed clean air interventions in these settings.

Personal exposures to fine particulate matter and carbon monoxide in relation to cooking activities in rural Malawi.

Background: Air pollution is a major environmental risk factor for cardiorespiratory disease. Exposures to household air pollution from cooking and other activities, are particularly high in Southern Africa. Following an extended period of participant observation in a village in Malawi, we aimed to assess individuals' exposures to fine particulate matter (PM 2.5) and carbon monoxide (CO) and to investigate the different sources of exposure, including different cooking methods. Methods: Adult residents of a village in Malawi wore personal PM 2.5 and CO monitors for 24-48 hours, sampling every 1 (CO) or 2 minutes (PM 2.5). Subsequent in-person interviews recorded potential exposure details over the time periods. We present means and interquartile ranges for overall exposures and summaries stratified by time and activity (exposure). We employed multivariate regression to further explore these characteristics, and Spearman rank correlation to examine the relationship between paired PM 2.5 and CO exposures. Results : Twenty participants (17 female; median age 40 years, IQR: 37-56) provided 831 hours of paired PM 2.5 and CO data. Concentrations of PM 2.5 during combustion activity, usually cooking, far exceeded background levels (no combustion activity): 97.9μg/m 3 (IQR: 22.9-482.0), vs 7.6μg/m 3, IQR: 2.5-20.6 respectively. Background PM 2.5 concentrations were higher during daytime hours (11.7μg/m 3 [IQR: 5.2-30.0] vs 3.3μg/m 3 at night [IQR: 0.7-8.2]). Highest exposures were influenced by cooking location but associated with charcoal use (for CO) and firewood on a three-stone fire (for PM 2.5). Cooking-related exposures were higher in more ventilated places, such as outside the household or on a walled veranda, than during indoor cooking. Conclusions : The study demonstrates the value of combining personal PM 2.5 exposure data with detailed contextual information for providing deeper insights into pollution sources and influences. The finding of similar/lower exposures during cooking in seemingly less-ventilated places should prompt a re-evaluation of proposed clean air interventions in these settings.

Assessment of Health Risks Associated with Particulate Matter and Carbon Monoxide Emissions from Biomass Fuels Utilization in Western Kenya

Purpose: The use of biomass fuels poses great threats to environmental degradation and public health risk accounting for 32% of the total attributable burden of diseases due to indoor air pollution (IAP) in especially Africa. Heavy reliance on biomass fuels for household energy in Kenya makes the country more vulnerable with 90% of the rural population relying on biomass fuels for domestic purposes. The objective of this study was to assess cooking fuel types and efficiency of improved biomass stoves in fuel consumption in Western, Kenya.
 Methodology: The data were collected through continuous real-time monitoring of kitchen Particulate Matter and Carbon II Oxide concentration for a period of 24 hours using UCB-PATS and CO monitors, questionnaires and time activity budgets. The total target population was 383 households and 204 households were selected as the sample size for HH survey. The sample size was determined using sample size algorithm by Boyd et al. (2014) where a sample size is determined by the sample population size. Selection of households for indoor air monitoring was done through quasi system where there was a predefined criterion from survey data. Tables and means were used to present results.
 Findings: The study found that Hazard quotients (HQ) for both long-term and short-term PM exposure using all stoves were all above 1 implying that health risk is real. During 24-hour cooking duration, three-stone stove using crop residues produced 145.8 times higher PM2.5 compared to RfD (Reference Dose) value while Cheprocket produced 26.4 times higher than PM2.5 RfD. People using solid biomass fuels are likely to experience headaches and running nose by the end of 24-hour period as a result of CO exposure when mud rocket stove, three stone stove and Cheprocket stoves were used. However cooks who use Chepkube stoves are not likely to experience any adverse health effects from CO exposures since the HQs were less than 1 using both wood and crop residues as fuel. The study concluded that, improved biomass stoves provided an overall reduction in pollutant concentration compared to three-stone fire but the local innovation Chepkube stove that has been classified as ungraded stove had the highest pollutant reduction. There is no health risk associated with exposure to peak CO within the 1-hour duration from all biomass stoves monitored in the study area.
 Recommendation: The study recommended that user education is necessary on kitchen practices to reduce overall exposure from improved stove utilization.

Briquettes from Pinus spp. Residues: Energy Savings and Emissions Mitigation in the Rural Sector

This study analyzes the household energy needs of the indigenous community of San Francisco Pichátaro, Michoacán, Mexico, and the use of Pinus spp. wood residues for the production of briquettes. The energy and emission performances of wood briquettes were evaluated on the field and in the laboratory. On-field surveys and measurements show that most users combine the use of fuelwood and LPG for cooking and heating water, and 65% of people use fuelwood daily (40% of houses consumed more than 39 kg per week). The use of biomass waste is an energy option in rural communities and contributes to reducing firewood consumption and mitigating GHGs. Briquettes gasification to heat water reduces 74% of GHG emissions, increases the thermal efficiency by 30%, and reduces pollutant emissions of CO, CH4, and PM2.5, NMHC, EC, and OC by 50% to 75% compared to a three-stone fire. The use of briquettes on the Patsari stove showed energy savings of 12% and a 36% reduction in CO2e compared to the “U” type open fire. The briquettes could reduce the fuelwood consumption by 318 t/year. It is possible to produce briquettes at a cost similar to or cheaper than fuelwood and generate a local market (circular economy) with local benefits.

Properties and emission factors of cloud condensation nuclei from biomass cookstoves – observations of a strong dependency on potassium content in the fuel

Abstract. Residential biomass combustion is a significant source of aerosol particles on regional and global scales influencing climate and human health. The main objective of the current study was to investigate the properties of cloud condensation nuclei (CCN) emitted from biomass burning of solid fuels in different cookstoves mostly of relevance to sub-Saharan east Africa. The traditional three-stone fire and a rocket stove were used for combustion of wood logs of Sesbania and Casuarina with birch used as a reference. A natural draft and a forced-draft pellet stove were used for combustion of pelletised Sesbania and pelletised Swedish softwood alone or in mixtures with pelletised coffee husk, rice husk or water hyacinth. The CCN activity and the effective density were measured for particles with mobility diameters of ∽65, ∽100 and ∽200 nm, respectively, and occasionally for 350 nm particles. Particle number size distributions were measured online with a fast particle analyser. The chemical composition of the fuel ash was measured by application of standard protocols. The average particle number size distributions were by number typically dominated by an ultrafine mode, and in most cases a soot mode was centred around a mobility diameter of ∽150 nm. The CCN activities decreased with increasing particle size for all experiments and ranged in terms of the hygroscopicity parameter, κ, from ∽0.1 to ∽0.8 for the ultrafine mode and from ∽0.001 to ∽0.15 for the soot mode. The CCN activity (κ) of the ultrafine mode increased (i) with increasing combustion temperature for a given fuel, and (ii) it typically increased with increasing potassium concentration in the investigated fuels. The primary CCN and the estimated particulate matter (PM) emission factors were typically found to increase significantly with increasing potassium concentration in the fuel for a given stove. In order to link CCN emission factors to PM emission factors, knowledge about stove technology, stove operation and the inorganic fuel ash composition is needed. This complicates the use of ambient PM levels alone for estimation of CCN concentrations in regions dominated by biomass combustion aerosol, with the relation turning even more complex when accounting for atmospheric ageing of the aerosol.

74 Epidemiology and Outcomes of Cooking and Cookstove-related Burn Injuries: A World Health Organization (WHO) Global Burn Registry (GBR) Report

Abstract Introduction Cooking- and cookstove-related burns (CSBs) comprise a large proportion of burn injuries globally. A cookstove is any apparatus that provides heat and is used for cooking (e.g., three-stone fire, traditional or improved cookstove). There are limited data on patterns of cooking behaviors and CSBs to inform prevention initiatives and advocacy. We aimed to describe the epidemiology, risk factors and outcomes of cooking-related burns and CSBs, specifically. Methods Patients with cooking and non-cooking related burns from 2018 to 2020 were identified in the World Health Organization (WHO) Global Burn Registry (GBR). Patient demographics, cooking arrangement, injury characteristics [mechanism, total body surface area (TBSA), revised Baux score] and outcomes were described. Differences in proportions and medians were compared. Bivariate regression was performed to identify risk factors associated with occurrence of CSB. Results GBR contained data of 6,965 burn-injured patients from 17 countries; 88% were from middle-income countries. One quarter of burn injuries (1,723 burns) were cooking-related. More than half of cooking-related burns (55%) occurred in females. Median age for cooking-related burns was 11 years (IQR 2–35). Of cooking-related burns, 22% were cookstove-related burns (CSBs; 311 burns). The most common mechanism in CSB was flame (87%), whereas the most common mechanism in other cooking burns was scald (62%). Patients with CSBs were more often female (65% vs 53%; p< 0.001) and much older than patients with other cooking burns (32 years, IQR 22–47 vs 5 years, IQR 2–30). CSBs were significantly larger in TBSA size (30%, IQR 15–45% vs 15%, IQR 10–25%; p< 0.001), had higher revised Baux scores (70, IQR 46–95 vs 28, IQR 10–25; p< 0.001) and more often resulted in death (41 vs 11%; p< 0.001) than other cooking burns (Table1). Patients with CSBs were more likely to be burned by fires (OR 4.74; 95% CI 2.99–7.54) and explosions (OR 2.91, 95% CI 2.03–4.18) than other cooking injuries. Kerosene had the highest odds of CSB than all other cooking fuels (OR 2.37, 95% CI 1.52–3.69). Conclusions Cooking-related burns are common and have different epidemiology than CSBs, specifically (e.g., more often female, older, larger burn size, higher mortality). CSBs were more likely caused by structural factors (e.g., explosion, fire) than behavioral factors (e.g., accidental movements) when compared to other cooking burns.

Time Use Implication of Clean Cookstoves in Rural Settings in Ghana: A Time Use Study.

Whilst the health benefit of using clean cookstoves and fuels is widely known, there is limited information on the non-health benefit of these stoves, especially in low-middle-income countries. This paper reports the time use implications of using clean cookstoves and fuels by comparing liquified petroleum gas (LPG), an improved biomass cookstove (BioLite), and traditional biomass cookstoves (three-stone fires) in Ghana. Using survey-based time diaries, information on all the activities undertaken by study participants during a 24-h was collected and analyzed. The findings of the study show that LPG users spent significantly less time gathering firewood compared to the users of improved cookstoves and three-stone fires. LPG users spent slightly less time per cooking episode, generally, and there was no significant difference in cooking time across the three cookstoves mostly due to stove stacking. Time spent engaging in economic activities was highest for LPG users and improved biomass cookstove users, at least when compared to three-stone fire users. In this study, we provide evidence on the time use implications of clean cookstoves, highlighting their non-health benefits and supporting efforts towards the adoption and sustained used of clean cookstoves

Efficiency of Three-Stone Fire and Improved Cooking Stoves using on-farm and off-farm fuels in semi-arid Tanzania

In Tanzania, fuelwood availability for cooking is an increasing challenge for rural households struggling to meet this need. Here, a possible pathway for smallholder farmers to reduce their dependency on off-farm fuelwood is evaluated. We compare the cooking performance of on-farm produced fuels, like wood from Gliricidia sepium (Jacq.) Kunth ex Walp. and Cajanus cajan (L.) Millsp. (pigeon pea stalks) with the off-farm fuelwood species Mimusops obtusifolia (Lam. Sapotaceae). Fuel performance was tested using Three-Stone Fire stoves and artisan-made Improved Cooking Stoves. We conducted 75 cooking tasks, cooking a standardized pre-defined meal with two pots in five villages in Chamwino and Kongwa districts, Dodoma region. The Controlled Cooking Test design assessed four key performance indicators: (1) time until water is boiling in pot A, (2) time until food item in pot A is ready to be consumed, (3) total cooking time per meal, including food items in pots A and B, (4) total fuel consumption per meal, including food items in pots A and B. Compared to the off-farm fuel, on-farm fuels perform better across the four key performance indicators. The results show that with regard to total cooking time per meal, including food items in pots A and B and total fuel consumption per meal, including food items in pots A and B, Improved Cooking Stoves used less time and fuel than Three-Stone Fire stoves. Regarding the key performance indicators time until water is boiling in pot A and time until food item in pot A is ready to be consumed, Three-Stone Fire stoves are faster than Improved Cooking Stoves, thus suggesting that Three-Stone Fire stoves are beneficial when cooking with only one pot. In order to reduce fuel and time consumption during cooking, the results suggest switching from off-farm to on-farm fuels; however, the choice of stove will depend on the cooking task performed.

Quality and Performance Evaluation of Jatropha Oil Blended with Kerosene for Cooking Stoves in Ethiopia

In Ethiopia, the majority of rural household uses firewood with three-stone fire for cooking. Due to poor performance of the stove, there are major health issues created by indoor air pollution. To alleviate this problem, various efforts are undergoing such as the use of plant oil as an alternative fuel for cooking. This plant’s oils are available in the rural areas with minimal effort and water. In this study, Jatropha oil was blended with kerosene to present it as an alternative fuel for the rural poor in Ethiopia. The blends of varying proportions of Jatropha oil and kerosene were prepared, analyzed, and compared with the fuel properties of kerosene. The viscosity of Jatropha oil was reduced in ranges 86.3% to 4.5% by heating the oil from 30°C to 100°C. In order to understand the value of the blended fuel, the blended fuel was used for the evaluation of the performance of a stove for its thermal efficiency and indoor air pollution. Thermal efficiency of the newly designed bio-oil stove (Jatrok stove) was 52–66% with its specific fuel consumption ranging from 30 to 37 g/L and the fire power of the stove ranging from 1398 to 1433 watt using 10% to 40% Jatropha oil in the blend. In the case of emission, the Jatrok stove showed 11.5 to 9.5 grams of carbon monoxide (CO) and 352 to 289 grams of carbon dioxide (CO2) to boil 2.5 liters of water.The performance of the Jatrok stove using blended fuels was evaluated and compared with other domestic cooking stoves available in Ethiopia, making the stove comparable. A wider dissemination of such kind of plant oil blended with a kerosene-operated stove could reduce the environmental load in addition to lessoning the indoor air pollution in the kitchen.

Mutagenicity- and pollutant-emission factors of pellet-fueled gasifier cookstoves: Comparison with other combustion sources

Emissions from solid-fuel burning cookstoves are associated with 3 to 4 million premature deaths annually and contribute significantly to impacts on climate. Pellet-fueled gasifier stoves have some emission factors (EFs) approaching those of gas-fuel (liquid petroleum gas) stoves; however, their emissions have not been evaluated for biological effects. Here we used a new International Organization for Standardization (ISO) testing protocol to determine pollutant- and mutagenicity-EFs for a stove designed for pellet fuel, the Mimi Moto, and for two other forced-draft stoves, Xunda and Philips HD4012, burning pellets of hardwood or peanut hulls. The Salmonella assay-based mutagenicity-EFs (revertants/megajouledelivered) spanned three orders of magnitude and correlated highly (r = 0.99; n = 5) with EFs of the sum of 32 particle-phase polycyclic aromatic hydrocarbons (PAHs). The Mimi Moto/hardwood pellet combination had total-PAH- and mutagenicity-EFs 99.2 and 96.6% lower, respectively, compared to data published previously for the Philips stove burning non-pelletized hardwood, and 100 and 99.8% lower, respectively, compared to those of a wood-fueled three-stone fire. The Xunda burning peanut hull pellets had the highest fuel energy-based mutagenicity-EF (revertants/megajoulethermal) of the pellet stove/fuel combinations tested, which was between that of diesel exhaust, a known human carcinogen, and a natural-draft wood stove. Although the Mimi Moto burning hardwood pellets had the lowest fuel energy-based mutagenicity-EF, this value was between that of utility coal and utility wood boilers. This advanced stove/fuel combination has the potential to greatly reduce emissions in contrast to a traditional stove, but adequate ventilation is required to approach acceptable levels of indoor air quality.

A Laboratory Assessment of 120 Air Pollutant Emissions from Biomass and Fossil Fuel Cookstoves.

Cookstoves emit many pollutants that are harmful to human health and the environment. However, most of the existing scientific literature focuses on fine particulate matter (PM2.5) and carbon monoxide (CO). We present an extensive data set of speciated air pollution emissions from wood, charcoal, kerosene, and liquefied petroleum gas (LPG) cookstoves. One-hundred and twenty gas- and particle-phase constituents-including organic carbon, elemental carbon (EC), ultrafine particles (10-100 nm), inorganic ions, carbohydrates, and volatile/semivolatile organic compounds (e.g., alkanes, alkenes, alkynes, aromatics, carbonyls, and polycyclic aromatic hydrocarbons (PAHs))-were measured in the exhaust from 26 stove/fuel combinations. We find that improved biomass stoves tend to reduce PM2.5 emissions; however, certain design features (e.g., insulation or a fan) tend to increase relative levels of other coemitted pollutants (e.g., EC ultrafine particles, carbonyls, or PAHs, depending on stove type). In contrast, the pressurized kerosene and LPG stoves reduced all pollutants relative to a traditional three-stone fire (≥93% and ≥79%, respectively). Finally, we find that PM2.5 and CO are not strong predictors of coemitted pollutants, which is problematic because these pollutants may not be indicators of other cookstove smoke constituents (such as formaldehyde and acetaldehyde) that may be emitted at concentrations that are harmful to human health.

Energy and exergy efficiencies of four biomass cookstoves using wood chips

With the growing need for comprehensive analysis of energy conversion systems for performance evaluation and improvement, this study investigates the energy and exergy performance of four biomass cookstoves using wood chips as fuel source. The cookstoves evaluated include the three-stone fire, charcoal stove, modified charcoal stove, and top-lit updraft (TLUD) cookstove. The performance of the cookstoves was carried out following the standard cookstove testing protocol of water boiling test in cold and hot start conditions. Relevant parameters were measured at five-minute interval until the water reached the boiling temperature of 100 °C; the test was replicated four times for each stove and the mean value reported. The result of the study revealed that energy efficiency of the cookstoves was higher than the exergy efficiency both in the cold and hot start. The efficiencies increased steadily with time until the water reached 100 °C boiling temperature. The energy, and exergy efficiency in the cold and hot start condition of the cookstoves appear similar with no obvious difference; that is, the performance of the cookstoves appear the same irrespective of whether the stove is used in the cold or hot start condition. The TLUD cookstove offered better energy and exergy efficiencies compared to other cookstoves investigated.

Quantification of Carbonaceous Aerosol Emissions from Cookstoves in Senegal

ABSTRACT In some regions of the world, cooking with solid biomass fuels in open fires constitutes the largest source of elemental and organic carbon emissions. However, cooking-related carbonaceous aerosols are still poorly characterized. This paper presents an innovative characterization of elemental and organic carbon (EC and OC) emissions from cookstoves in West Africa. Four stove types (three-stone fire, rocket stove, basic ceramic stove, and gasifier) using two wood species (dimb and filao) were analyzed on a laboratory scale. The EC and OC emission factors based on fuel energy (EFs) when burning dimb were higher for all stoves, highlighting the need to account for the fuel type when reporting cookstove EFs. The highest EC EF was found for the rocket stove (0.18 ± 0.06 g MJ–1 and 0.06 ± 0.01 g MJ–1 for dimb and filao, respectively). The other tested stoves exhibited the same EC EF when burning dimb (0.09 ± 0.02 g MJ–1) and EC EFs ranging between 0.04 ± 0.01 and 0.05 ± 0.01 g MJ–1 when burning filao. The OC EF was highest, on average, for the gasifier (0.08 ± 0.01 g MJ–1), followed by those for the three-stone fire (0.18 ± 0.03 g MJ–1) and the basic ceramic stove (0.21 ± 0.08 g MJ–1). However, the results from testing the rocket stove and the three-stone fire under real cooking conditions using dimb wood indicate that the laboratory-scale tests overestimate the actual EC EFs. Also, the rocket stove did not show a reduction in wood use compared to the three-stone fire, suggesting that the carbonaceous aerosol emissions from the former produce more warming than those from the latter. Therefore, the total EC and OC stove emissions, in addition to the EFs, must be reported. As the impacts of carbonaceous aerosol highly depend on the location of emission, this study contributes valuable data to emission inventories and climate prediction models at national and regional levels.

First <em>injera</em> baking biomass gasifier stove to reduce indoor air pollution, and fuel use

Nearly 40% of the world population use biomass as their primary energy source, especially for cooking; but traditional and inefficient three-stone fires cause serious health issues and their high fuel consumption leads to deforestation problems. Ethiopian cuisine is mainly based on vegetable and meat dishes in the form of a thick stew, served on top of injera, a large sourdough flatbread made out of fermented teff flour. Injera is known for its energy intensive and time consuming baking. It has remained rarely researched for alternative energy sources, although some improved biomass firing stoves have been introduced in the Ethiopian market. Thus, there is a need for a new efficient and clean stove that can drastically reduce the fuel consumption, emissions and indoor air pollution. In the present manuscript, the first injera biomass gasification baking stove is presented and its performance reported. A thermal efficiency of 16% is achieved, the specific fuel consumption is reduced by 12.8% , and baking time reduced by 19% compared with the three-stone fire. CO (Carbon Monoxide) and PM (Particulate matter) emissions are reduced, compared to the three-stone fire, by 99% and 87%, respectively. Heat losses and stored heat in the system are also calculated. Results show that it is possible to increase the efficiency and reduce the fuel consumption if the insulation is improved, the heating up time between consecutive baked injeras reduced and longer injera baking sessions, like in community kitchens, promoted. This first successful attempt to bake injera using a biomass gasifier stove in the eastern part of Africa shows promising result and can lead to an efficient and clean biomass gasifier stove that could be widely disseminated for injera baking.

Fish Processing and Its Energy Dynamics in Zambia

This study presents field data and results on local fish processing, its energy supply, and consumption in the Northern Province of Zambia. The study also evaluates the impact of processing conditions on fish quality and cost for the different processing systems available in the selected communities. The result shows that fuelwood is the primary source of energy for fish processing used either in a modified three-stone fire (MTSF) system or a recently developed kiln. The charcoal smoking alternative had the least fuel consumption, yet was not considered as the preferred option due to the high cost of the fuel, a smaller quantity of fish processed per batch and longer processing time. The result also revealed that irrespective of the system used, the type of fish being processed and the pre-smoking drying time had a significant impact on the total energy consumption. Overall, the smoking kiln was found to increase the quantity of fish processed by five folds, reduce fuel use by 48% and reduce the overall smoking time per kilogram fish processed by 39%. A relatively higher fish quality was obtained with the use of the smoking kiln in comparison with the MTSF and the charcoal smoking system. The use of the smoking kiln as a fish processing system is recommended because it improves the quality of the fish, can scale up fish processing due to its capacity and reduces energy use with its associated costs.

Laboratory Testing of the Innovative Low-Cost Mewar Angithi Insert for Improving Energy Efficiency of Cooking Tasks on Three-Stone Fires in Critical Contexts

Currently, about 2.7 billion people across the world still lack access to clean cooking means. Humanitarian emergencies and post-emergencies are among the most critical situations: the utilization of traditional devices such as three-stone fires have a huge negative impact not only on food security but also on the socio-economic status of people, their health and the surrounding environment. Advanced Cooking Stoves may constitute better systems compared to actual ones, however, financial, logistic and time constraints have strongly limited the interventions in critical contexts until now. The innovative, low-cost Mewar Angithi insert for improving energy efficiency of three-stone fires may play a role in the transition to better cooking systems in such contexts. In this paper, we rely on the Water Boiling Test 4.2.3 to assess the performances of the Mewar Angithi insert respect to a traditional three-stone fire and we analyse the results through a robust statistical procedure. The potentiality and suitability of this novel solution is discussed for its use in critical contexts.

Gaseous and particulate emissions from a chimneyless biomass cookstove equipped with a potassium catalyst

Approximately three billion people cook with solid fuels, mostly wood, on open fires or rudimentary stoves. These traditional cooking methods produce particulate matter and carbon monoxide known to cause significant respiratory health problems, especially among women and children, who often have the highest exposure. In this work, an inexpensive potassium-based catalyst was incorporated in a chimneyless biomass cookstove to reduce harmful emissions through catalytic oxidation. Potassium titanate was identified as an effective and stable oxidation catalyst capable of oxidizing particulate matter and carbon monoxide. Using a cordierite monolith to incorporate potassium titanate within a bespoke, rocket-style, improved cookstove led to a 36% reduction in particulate matter emissions relative to a baseline stove with a blank monolith and a 26% reduction relative to a stove with no monolith. Additionally, the catalytic stove reduced particulate matter emissions by 82%, reduced carbon monoxide emissions by 70%, and improved efficiency by 100% compared to a carefully tended, three-stone fire. Potassium titanate was also shown to oxidize carbon monoxide at temperatures as low as 500 °C, or as low as 300 °C when doped with copper or cobalt.

Dealing with small sets of laboratory test replicates for Improved Cooking Stoves (ICSs): Insights for a robust statistical analysis of results

Improved Cooking Stoves (ICSs) represent the most commonly promoted solution to alleviate the burden associated with the use of traditional biomass in a short-term perspective. However, criticism is raising about the methodologies used for assessing their performance, with a particular focus on laboratory-based testing protocols. One of the key weaknesses of current protocols consists in the inaccurate and biased approach adopted for reporting and statistically analysing test results, which can lead to misleading conclusions about the actual improvements ensured by ICSs. This study proposes a robust procedure to deal with the statistical analysis of small sample sizes, and subsequently verify it through its application to an experimental comparison – based on the Water Boiling Test – between three models of stove. The results show that the current practice based on 3 or 5 replicates often produces biases in the analyses, as at least 13 replicates might be needed to achieve reliable results. Moreover, the study shows how the t-test is in most cases improperly applied, while the proposed procedure allows to deal both with normally and of non-normally distributed data sets in a robust way. In one case, the apparent improvement of an ICS model as compared to the three-stone fire, is refuted by the application of our procedure.

Simulation of Rocket Cook-Stove Geometrical Aspect for its Performance Improvement

The inefficient traditional three-stone fire cook stoves are used as benchmark for performance comparison in many of developing countries for every improved cook stove. In order to improve energy security in developing countries many modern cooking fuels and technologies are introduced. Even though there are geometrical parameters that can be considered to improve the efficiency of these cook stoves, this paper focus its study based on the comparison of simulation results for its height to predict its performance in terms of desired flow and heat distribution. This study will be useful for the manufacturing of stove with modified height to get desired performance.