Biomass Cookstoves Research Articles

Design Improvement, Thermal Efficiency Optimization and Comparative Study of a Natural Draft Chulha

ABSTRACT This work inscribes the rural-based biomass cookstove (chulha) fabrication with the aim of modification and enhancement of the existing natural draft low smoke heat-efficient stoves and also comparing its thermal efficiency output. This study is important from the perspective of a rural society who cooks their daily meals on biomass-based cookstoves/chulhas. Enhancing its thermal efficiency and reducing smoke emissions from biomass combustion in the cookstove are the primary focuses of this work. Principle used to design the improved chulha is double co-axial cylinder secondary combustion. Mild steel is used for fabricating maximum parts of the stove including the outer cylinder surface, and the inner cylinder surface is made of galvanized steel, and the insulation between both the surfaces of the cylinders is made of fiber glass wool. Addition of a novel insulating material in the chulha for thermal insulation, resizable air inlet, design and incorporation of smoke rings and pot seat in such a way that no smoke passes through the cooking utensil assisted in achieving better thermal efficiency of the cookstove. Pine wood, bamboo, sagun wood, sal wood and neem wood have been selected as per local availability as biomass feedstock for combustion. To calculate the thermal efficiency, a water boiling test (WBT) has been performed. Best thermal efficiency of 47.08% has been achieved for pine wood biomass feedstock and due to proper placements of the grate and the air inlets in the improved chulha design. Also, a very negligible or no smoke has been observed due to the introduction of the advanced design of the smoke ring and pot seat and the chimney for the outlet making a green energy-efficient biomass cookstove.

Evaluating the barriers to adoption of improved biomass cookstoves in Benue state, Nigeria

The prevalent use of inefficient traditional stoves for biomass cooking energy in Nigeria contributes to high rates of biomass consumption, deforestation, and harmful pollutant emissions. This study aimed to assess the constraints hindering the adoption of improved biomass cookstoves (IBCS) in Benue State, Nigeria. Data were randomly collected from 135 households and analyzed using descriptive (frequency, mean and percentage) as well as inferential statistics (binary probit regression). Findings revealed that 88% of households rely on fuelwood for cooking, with approximately 35% still using traditional stoves. However, 46% of households have adopted IBCS and recognized its advantages, including improved cooking speed, fuel economy, time savings in fuelwood collection, cost savings, and reduced smoke emissions. Additionally, various factors such as age, household size, access to credit, location, distance to market, membership of women's associations, fuelwood collection distance, and fuelwood sources were identified as constraints to IBCS adoption. To promote IBCS adoption, we recommend that development planners and extension officers raise awareness among households and provide them credit incentives through government and NGO support. This research significantly contributes to pertinent knowledge by shedding light on the challenges and opportunities associated with IBCS adoption in Nigeria, thereby informing policy and development initiatives in the country.

A bridge to clean cooking? The cost-effectiveness of energy-efficient biomass stoves in rural Senegal

Rural areas of sub-Saharan Africa have experienced limited progress towards the sustainable development goal of universal access to clean cooking. Energy-efficient biomass cookstoves (EEBCs) are considered a potential bridge technology, but EEBC models vary widely, and there is a lack of understanding about their real-world use implications. We conduct a randomized controlled trial in rural Senegal to compare a low-cost, locally produced stove designed to achieve fuel savings and an expensive, imported stove shown to be more efficient and emissions-reducing in the laboratory. We find that the two EEBCs perform similarly: both reduce fuel consumption but have no significant impact on cooking time and fuel collection, emissions, or objective health measures. We conclude that the technically advanced option is not cost effective for most of our sample, while the low-cost EEBC can be seen as a stop-gap solution that primarily reduces fuel use. The findings underpin the importance of customizing EEBC dissemination to local context and baseline cooking patterns.

A Numerical and Experimental Performance Assessments of an Improved Natural Draft Biomass Cook Stove

ABSTRACT This article analyses the performance of an efficiently designed biomass cook stove using standard performance parameters. The investigation was first conducted using mathematical modeling developed in the ANSYS Fluent software. The results of primary air and the temperature profiles inside the combustion chamber were found through simulation. It revealed that the flue gas left the combustion chamber with an average velocity of 1.7 m/s. The average pot bottom and fuel bed temperatures were 650 K and 1100 K, respectively. A copper coil was wrapped around the combustion chamber wall to recover its waste heat. The recovered waste heat was utilized to warm the water flowing through the copper coil. The heated water could be used for other domestic applications. The fabricated design of the improved stove was experimented with water boiling test. The maximum thermal efficiency achieved was 42% with a firepower of 8.25 kW, after incorporating the waste heat recovery system, corresponding to 7.5 L test. The overall efficiency, which is the product of the modified combustion efficiency and the maximum thermal efficiency, was found to be 41.50%. The performance was found to be significantly better than that of a commercial biomass cook stove. The developed model was also evaluated for indoor CO, CO2 and PM emissions. The highest levels of CO2 and CO were 940 ppm and 23 ppm. The average amount of PM1, PM2.5 and PM10 found out to be 18 µg/m3, 20 µg/m3 and 35 µg/m3 respectively.

Effect of Thermal Mass on Fuel Consumption of Solid Biomass Cooking Stoves

The use of rudimentary cooking stoves has harmful consequences not only for the health of users but also for the environment. Faced with these problems, studies are being carried out to develop more efficient stoves. The materials used for the construction and/or design of cooker range from heavy materials to light materials. However, cookers built from heavy materials accumulate a portion of the heat produced in their walls. The objective of this study is to demonstrate the influence of thermal mass on the fuel consumption of cookers. The study concerns not only a set of stoves taken from the literature but also a set of stoves that we tested. The two sets of stoves differ in terms of their characteristics: Single-pot wood stove without chimney or skirt, Single-pot wood stove without chimney with skirt, Multi-pot wood stove with chimney, Single-pot charcoal stove without chimney or skirt, etc. The adapted approach consists of classifying all stoves by category. Then, for each category, the mass of the cookers as well as the quantity of fuel necessary for the same cooking task will be compared. It appears that for all the stoves taken from the literature and all the stoves submitted to the test, in each of the categories, the higher the mass of the stove, the more fuel it consumes for the same cooking task.

Influence of secondary air opening on the performance of gasifier-based improved biomass cookstove

Influence of secondary air opening on the performance of gasifier-based improved biomass cookstove

Initiatives and programs from Indian perspective for improved biomass cook stove (IBCS) technology: a way towards sustainability

Initiatives and programs from Indian perspective for improved biomass cook stove (IBCS) technology: a way towards sustainability

A combined combustion and conjugate heat transfer analysis of a hybrid draft biomass cookstove

A cookstove comprises both fluid and solid regions, with combustion gases representing the fluid domain and the combustion chamber wall and insulation forming the solid regions. These solid regions are made of different materials and make significant contributions to stove performance. So far, most studies conducted on biomass stoves have only analysed the fluid domain, neglecting solid regions. The current study integrates combustion and conjugate heat transfer analysis, encompassing both fluid and solid domains, to investigate the fluid flow and heat transfer behaviour of a hybrid draft biomass cookstove (HDBC) using CFD. This analysis aims to gain insights into the impact of stove materials on its performance. The study analysed six cases of HDBC, testing different combinations of materials: two for the combustion chamber (ceramic-cement and stainless-steel) and three for insulation (ceramic wool, perlite, and vermiculite). The combustion of biomass and the formation of soot are modelled using reaction kinetics and a one-step soot model, respectively. The CFD findings for thermal efficiency, CO, and PM2.5 emissions derived using combustion and soot model demonstrated closed alignment with the experimental result with variations of 3%, 19%, and 23%, respectively. It was observed that stoves with stainless-steel combustion chamber material exhibit better thermal and emission performance compared to ceramic-cement stoves, with perlite taking the edge over other insulation materials. The success of these materials is attributed to their superior thermophysical properties, which play a significant role in material selection.

CFD simulation of a forced draft biomass cookstove for different airflow conditions

Households in developing countries rely on traditional cooking methods despite low-efficiency and high risks of air pollution and health. Various improved biomass cookstove technologies have been developed to address this issue, but there is still room for improvement in biomass cooking technology. This research aims to enhance the biomass cookstove by investigating its performance under different air inlet conditions using computational fluid dynamics analysis. The impact of air flow rate and the position of the secondary air inlet on the thermal efficiency of the biomass cookstove is examined. The eddy dissipation combustion model and k-epsilon turbulence model are utilized in ANSYS Fluent to simulate the combustion process. The cookstove's performance is assessed at three different air flow rates (0.01, 0.02, and 0.03 kg/s) and at two different secondary air inlet positions. The highest thermal efficiency is observed at secondary air inlet located 50 mm below the outlet at a flow rate of 0.03 kg/s. The computational findings from this investigation show a significant connection between the air inlet conditions and the thermal efficiency of the biomass cookstove. Repositioning the secondary air inlet to a location with more available space for complete combustion improves thermal efficiency compared to traditional designs.

Performance Analysis of Dhaba Size Improved Biomass Cook Stove for Commercial Application as Clean and Efficient Cooking Solutions

The current study evaluates the behaviour of the Dhaba-size cook stove for commercial applications in rural area. Further, the study focuses on its impact on the biomass saving and the surrounding environment. The Dhaba-sized cook stove system was installed for the experimental investigation in R.S.Gruh Udyog, Borsad, Anand, Gujarat. The results obtained based on pre-and post-installation of the system, the system was assessed the cooking pattern, biomass and time consumption, smoke emission, and socio- economic effect. During the experiment, 10 batches of Rice Papdi were cooked uniformly. The Dhaba-size Improved Biomass Cook Stove (IBCS) is used for only boiling water, and atta iscooked on Traditional type of Cook stove. Initially, the traditional type of cook stove was used for water boiling and the other for cooking of atta. Based on the results for pre-installation and post-installation conditions, it was found that wood consumption per day was reduced with the reduction in time. As per discussion with the beneficiary, he is happy with the design, efficiency, and performance of it.

Effects of Cooking with Liquefied Petroleum Gas or Biomass on Stunting in Infants

BackgroundHousehold air pollution is associated with stunted growth in infants. Whether the replacement of biomass fuel (e.g., wood, dung, or agricultural crop waste) with liquefied petroleum gas (LPG) for cooking can reduce the risk of stunting is unknown.MethodsWe conducted a randomized trial involving 3200 pregnant women 18 to 34 years of age in four low- and middle-income countries. Women at 9 to less than 20 weeks’ gestation were randomly assigned to use a free LPG cookstove with continuous free fuel delivery for 18 months (intervention group) or to continue using a biomass cookstove (control group). The length of each infant was measured at 12 months of age, and personal exposures to fine particulate matter (particles with an aerodynamic diameter of ≤2.5 μm) were monitored starting at pregnancy and continuing until the infants were 1 year of age. The primary outcome for which data are presented in the current report — stunting (defined as a length-for-age z score that was more than two standard deviations below the median of a growth standard) at 12 months of age — was one of four primary outcomes of the trial. Intention-to-treat analyses were performed to estimate the relative risk of stunting.ResultsAdherence to the intervention was high, and the intervention resulted in lower prenatal and postnatal 24-hour personal exposures to fine particulate matter than the control (mean prenatal exposure, 35.0 μg per cubic meter vs. 103.3 μg per cubic meter; mean postnatal exposure, 37.9 μg per cubic meter vs. 109.2 μg per cubic meter). Among 3061 live births, 1171 (76.2%) of the 1536 infants born to women in the intervention group and 1186 (77.8%) of the 1525 infants born to women in the control group had a valid length measurement at 12 months of age. Stunting occurred in 321 of the 1171 infants included in the analysis (27.4%) of the infants born to women in the intervention group and in 299 of the 1186 infants included in the analysis (25.2%) of those born to women in the control group (relative risk, 1.10; 98.75% confidence interval, 0.94 to 1.29; P=0.12).ConclusionsAn intervention strategy starting in pregnancy and aimed at mitigating household air pollution by replacing biomass fuel with LPG for cooking did not reduce the risk of stunting in infants. (Funded by the National Institutes of Health and the Bill and Melinda Gates Foundation; HAPIN ClinicalTrials.gov number, NCT02944682.)

Oxidative potential of fine particulate matter emitted from traditional and improved biomass cookstoves

Reduced PM2.5 emissions from improved cookstoves do not necessarily equate to reduced exposure to toxic PM2.5, due to changes in PM2.5 chemical composition and toxic potency.

Waste heat regeneration from thermoelectric generator based improved biomass cookstove (TIBC): Modelling of TEG system utilizing DC-DC converter with fuzzy logic MPPT

Most of the people in the rural areas cook their food in traditional biomass cookstove which emits a lot of emission that leads to poor health of the women and children. This paper points out a technology that utilises a thermoelectric generator (TEG), which converts thermal energy into electrical energy directly. A TEG is a small plate made of semiconductor p-n junctions connected electrically in series and thermally in parallel. The difference in temperature produced on the hot side and cold side of the TEG is proportional to the voltage generated. The TEG is integrated into the wall of the inner combustion chamber of the biomass cookstove with the help of heat plate and the cold side of the TEG is connected to a flower-type heat sink to maintain the temperature difference. The power generated by the TEG is used to drive a 12 V DC fan which helps to keep the cold side of the TEG relatively cooler and direct the same air inside the inner combustion chamber of the cook stove through holes to increase the air-to-fuel ratio. As a result, it improves the cookstove's combustion, thereby reducing emissions and increasing thermal efficiency. For testing the efficiency of the TEGs available in the market, a hit and trial method is used by taking TEGs of different specifications and connecting them to a hot side and a cold side test bed and then finally the performance is realized. Therefore, for every different TEG, a hardware has to be made for final conclusion of the result. To eliminate the hit and trial method, the electrical characteristics of thermoelectric generator module has been analysed by modeling a TEG module in MATLAB/Simulink and implementing it with fuzzy logic control (FLC) based MPPT utilizing a DC-DC boost converter with a constant as well as variable load. This fuzzy logic-based scheme exhibits fast dynamic response and precisely tracks the maximum power point (MPP) from TEG under varying load conditions. Based on the robust performance of the obtained simulation results, the TEG module is integrated and tested in the laboratory using a thermoelectric generator based improved biomass cookstove (TIBC). The novelty lies on the concept of using MATLAB/Simulink platform by modeling the FLC based MPPT incorporating boost converter to test the performance of TEG module for its integration with TIBC and eliminating traditional hit and trial method. This TIBC is able to power the fan directly within just 2–3 min using the electricity generated by the TEG module. The maximum power generated from the TIBC is 6.25 W using a single TEG. The fan requires 1.4 W and rest of the power was used to charge auxiliary battery.

Numerical study for the combustion analysis of wood volatiles in porous radiant burner for the application of biomass cooking stove

This article presents a computational study of wood volatiles combustion in a two-layer porous radiant burner (PRB) at different power inputs (1–3 kW) and porosity ranges from 0.7 to 0.9 respectively. A 2-D computational model is designed to numerically solve the combustion of wood-volatiles and air. A finite volume technique is utilized to solve governing equations including; continuity equation, momentum equation, species transport equation, radiative transport equation, and gas and solid phases energy equations. The utilized model is validated with previous literature for a two-layer porous radiant burner and the deviation of comparison is found within the acceptable range. The results reveal that the higher temperature was found in the central part of the burner and the minimum at the circumference. The longitudinal temperature distribution along the central line ruled out the occurrence of flashbacks. Moreover, the transport species contours reveal that the maximum combustion reactions occur in the upper layer of the porous zone. Further, the radiation efficiency decreases with input power and increases with porosity. The maximum value of radiation efficiency is found 36% at 1 kW and porosity of 0.9. while the minimum is 26% found at 3 kW and porosity of 0.7. The overall assessment showed that the PRB-based cooking stove is capable for providing a desired temperature range and efficient radiation efficiency in the range of 1–3 kW of power input.

Effect of the air flows ratio on energy behavior and NOx emissions from a top-lit updraft biomass cookstove

Biomass as an energy source for three-stone cookfires is commonly used for cooking and heating rural and isolated households in developing countries; therefore, indoor air quality decreases. In this work, the effect of the air flows ratio (combustion air/gasification air, CA/GA: 2.8, 3.0, and 3.2), and the start type, cold (CS), and hot (HS), on the energy behavior and emissions from a forced-draft top-lit updraft (TLUD) cookstove, using wood pellets as fuel, is studied. Furthermore, the gasification process was thermodynamically characterized. The TLUD cookstove assessment was carried out following a modified water boiling test (WBT). The highest thermal efficiency of the cookstove was 26.74%. The lowest specific CO, NOx, and total suspended particle matter (TSPM) emissions were 1.8 g/MJd, 106 mg/MJd, and 78.32 mg/MJd, respectively; this was attributed to a proper mixture between the producer gas and the combustion air. The gasification process showed a better energy yield under the hot start due to the preheating induced in the cookstove reactor. The optimal values of the producer gas heating value (LHVpg), cold gas efficiency (CGE), and the biochar yield (Ychar) were 3.53 MJ/Nm3, 58.61%, and 12.49%, respectively. Here, an opposite effect was found for the air flows ratios assessed. The cookstove behavior improved as the mixture between CA and GA was suitable, achieving the maximum at CA/GA = 3.0. However, the NOx emissions increased with the increment of CA/GA ratios (from 2.8 to 3.2). Therefore, future works must address the NOx emission reduction without penalizing performance or permanent emissions from the TLUD cookstoves.

Wood cookstove use is associated with gastric cancer in Central America and mediated by host genetics

Biomass cookstove food preparation is linked to aero-digestive cancers, mediated by ingested and inhaled carcinogens (e.g., heterocyclic amines, and polycyclic aromatic hydrocarbons). We investigated the association between gastric adenocarcinoma, wood cookstove use, H. pylori CagA infection and risk modification by variants in genes that metabolize and affect the internal dose of carcinogens. We conducted a population-based, case–control study (814 incident cases, 1049 controls) in rural Honduras, a high-incidence region with a homogeneous diet and endemic H. pylori infection, primarily with the high-risk CagA genotype. We investigated factors including wood cookstove use, H. pylori CagA serostatus, and 15 variants from 7 metabolizing genes, and the interactions between wood stove use and the genetic variants. Male sex (OR 2.0, 1.6–2.6), age (OR 1.04, 1.03–1.05), wood cookstove use (OR 2.3, 1.6–3.3), and CagA serostatus (OR 3.5, 2.4–5.1) and two SNPs in CYP1B1 (rs1800440 and rs1056836) were independently associated with gastric cancer in multivariate analysis. In the final multivariate model, a highly significant interaction (OR 3.1, 1.2–7.8) was noted between wood cookstove use and the rs1800440 metabolizing genotype, highlighting an important gene-environment interaction. Lifetime wood cookstove use associates with gastric cancer risk in the high-incidence regions of Central America, and the association is dependent on the rs1800440 genotype in CYP1B1. H. pylori CagA infection, wood cookstove use and the rs1800440 genotype, all of which are highly prevalent, informs who is at greatest risk from biomass cookstove use.

Assessing household fine particulate matter (PM2.5) through measurement and modeling in the Bangladesh cook stove pregnancy cohort study (CSPCS)

Biomass fuel burning is a significant contributor of household fine particulate matter (PM2.5) in the low to middle income countries (LMIC) and assessing PM2.5 levels is essential to investigate exposure-related health effects such as pregnancy outcomes and acute lower respiratory infection in infants. However, measuring household PM2.5 requires significant investments of labor, resources, and time, which limits the ability to conduct health effects studies. It is therefore imperative to leverage lower-cost measurement techniques to develop exposure models coupled with survey information about housing characteristics. Between April 2017 and March 2018, we continuously sampled PM2.5 in three seasonal waves for approximately 48-h (range 46 to 52-h) in 74 rural and semi-urban households among the participants of the Bangladesh Cook Stove Pregnancy Cohort Study (CSPCS). Measurements were taken simultaneously in the kitchen, bedroom, and open space within the household. Structured questionnaires captured household-level information related to the sources of air pollution. With data from two waves, we fit multivariate mixed effect models to estimate 24-h average, cooking time average, daytime and nighttime average PM2.5 in each of the household locations. Households using biomass cookstoves had significantly higher PM2.5 concentrations than those using electricity/liquefied petroleum gas (626 μg/m3 vs. 213 μg/m3). Exposure model performances showed 10-fold cross validated R2 ranging from 0.52 to 0.76 with excellent agreement in independent tests against measured PM2.5 from the third wave of monitoring and ambient PM2.5 from a separate satellite-based model (correlation coefficient, r = 0.82). Significant predictors of household PM2.5 included ambient PM2.5, season, and types of fuel used for cooking. This study demonstrates that we can predict household PM2.5 with moderate to high confidence using ambient PM2.5 and household characteristics. Our results present a framework for estimating household PM2.5 exposures in LMICs, which are often understudied and underrepresented due to resource limitations.

Performance Improvement of Biomass Cookstove: Insights from Computational Fluid Dynamics and Prototype Testing

Performance Improvement of Biomass Cookstove: Insights from Computational Fluid Dynamics and Prototype Testing

Improvement of Ceramic Insulation of Cook Stoves Using Carbonized Organic Waste

Many households and small hotels in Kenya source their energy from biomass; mainly wood and charcoal. For the urban poor, their energy source is basically charcoal. With increasing population, rural urban migration, tough economic times, the use of charcoal must be as efficient as possible. In cognizance of this need, development of energy efficient biomass (charcoal) cook stoves is paramount.
 The main objective of the project was to optimize the insulating properties of ceramic insulation used in ceramic cook stoves using carbonized organic waste as the burnout additive. Carbonized organic waste herein referred to as char was collected and ground to fine dust. The char was used as a burnout medium in the clay to create pores, reduce density and increase porosity thereby improving insulation properties of the fired clay. Optimization was achieved by using different ratios of clay to char. Testing of biomass cook stove is provided for in ISO- 19867-0; the harmonized laboratory test protocol.
 The results showed that the apparent porosity of the sample increased from 34% with no char to 87% when the sample had 50% char. On the other hand, the bulk density reduced from 2.8 g/cm3 with no char to 1.2 g/m3 with 50% char. The prototype thermal efficiency was 33% and 25.8% for the control cook stove. The prototype and control cook stove cooking power were 0.97kW and 0.71kW respectively. The prototype PM2.5 emissions estimated to be 76 mg/MJd and CO emissions at 21 g/MJd which were lower than the Kenya standard KS 1814:2019 maximum emission of 137 mg/MJd and 25 g/MJd respectively
 This study has shown that when clay was mixed with char, there was a significant increase in desirable characteristics, which results in increased efficiency of biomass (charcoal) cook stoves and lower emissions.

Performance Optimization of Hybrid Draft Biomass Cookstove Using CFD

ABSTRACT The term “hybrid draft biomass cookstove” (HDBC) refers to a stove that employs both natural and forced drafts for its primary and secondary air supply. The HDBC optimization analysis is carried out in this work using computational fluid dynamics (CFD), considering the effect of forced draft secondary air mass flow rates to achieve the optimum (lower emissions and higher efficiency) HDBC performance. The analysis includes combustion and soot modeling to evaluate the thermal and emission performance of the stove. The CFD results are validated against the experimental data obtained from the water boiling test (WBT 4.2.3). The extremely low or high secondary air mass flow rate degrades the stove’s performance; hence, its optimization is essential. The optimal mass flow rate identified in this investigation was 0.017 kg/s, at which the thermal and emission performances of HDBC were evaluated. An eddy dissipation model is employed to simulate biomass combustion, considering the reaction kinetics of wood volatiles reacting with oxygen, and a one-step soot model is used to predict soot formation. The combustion model agreed well with the experimental data for efficiency and temperature, with an average deviance of 10% and 20%, respectively. However, it significantly overestimated CO emissions by 81% and achieved Tier 4 performance in simulation as opposed to Tier 0 in the experiment. The PM2.5 emissions were under predicted by the soot model, but both the CFD and the experiment results achieved Tier 4 performance as per the World Health Organization (WHO) standards. Hence, a one-step soot model was found to be effective in predicting soot formation.