Demand for cooking fuels in a developing country: To what extent do taste and preferences matter?

Overreliance on biomass energy, such as firewood and charcoal, for cooking in developing countries has contributed to high rates of deforestation and resulted in substantial indoor pollution, which has negatively impacted the health of many individuals. However, the effectiveness of public policies aimed at encouraging households to switch to cleaner fuels, such as liquefied petroleum gas (LPG) and kerosene, hinges on the extent to which they are mentally committed to specific fuels. Using data on four cooking fuels (charcoal, firewood, LPG, and kerosene) from the Ghana living standards survey, we found strong evidence that the most preferred fuel is LPG, followed by charcoal, with kerosene the least preferred. In addition, with the exception of kerosene that has price-elastic demand, the price elasticities of demand for the fuel types examined are inelastic. This finding suggests the so-called fuel-ladder is not robust.     

Performance of a domestic cooking wick stove using fatty acid methyl esters (FAME) from oil plants in Kenya

With depletion of solid biomass fuels and their rising costs in recent years, there has been a shift towards using kerosene and liquefied petroleum gas (LPG) for domestic cooking in Kenya. However, the use of kerosene is associated with health and safety problems. Therefore, it is necessary to develop a clean, safe and sustainable liquid bio-fuel. Plant oil derivatives fatty acid methyl esters (FAME) present such a promising solution. This paper presents the performance of a wick stove using FAME fuels derived from oil plants: Jatropha curcus L. (Physic nut), Croton megalocarpus Hutch, Calodendrum capense (L.f.) Thunb., Cocos nucifera L. (coconut), soyabeans and sunflower. The FAME performance tests were based on the standard water-boiling tests (WBT) and compared with kerosene. Unlike kerosene all FAME fuels burned with odorless and non-pungent smell generating an average firepower of 1095 W with specific fuel consumption of 44.6 g L^?1 (55% higher than kerosene). The flash points of the FAME fuels obtained were typically much higher (2.3–3.3 times) than kerosene implying that they are much safer to use than kerosene. From the results obtained, it was concluded that the FAME fuels have potential to provide safe and sustainable cooking liquid fuel in developing countries.     

Evaluation of the performance of improved biomass cooking stoves with different solid biomass fuel types

We have studied the performance of different types of improved solid biomass cookstoves (Two natural draft and one forced draft) in comparison to the traditional cookstove (control) while preparing a particular meal with a variety of solid biomass fuels (e.g. fuel wood, dung cake and crop residue). Five replicates of each type of cookstove and fuel were maintained. The study was conducted in an Indian rural kitchen. There was no significant difference in the indoor concentrations of PM_2.5 and CO when natural draft and traditional cookstoves were used with any type of solid fuel. However, significantly lower concentrations of PM_2.5 and CO were recorded with forced draft stoves compared to others. While cooking with different types of solid biomass fuels, the concentrations of PM_2.5 and CO in the indoor environment were decreased by 21–57% and 30–74% respectively with the forced draft cookstove in comparison to the traditional cookstove. The fuel consumption, cooking duration and thermal efficiency of a particular stove to prepare a particular amount of food also differ depending on the type of the solid fuel used for the cooking purpose. The thermal efficiency of traditional, natural draft and FD cookstoves were in the range of 15–17%, 16–27% and 30–35% respectively for different types of solid biomass fuels. However, further studies on the performance of stoves are required based on the size and type of fuel wood or crop residues.     

The effect of coal size on PM2.5 and PM-bound polycyclic aromatic hydrocarbon (PAH) emissions from a domestic natural cross-draft stove

Residential coal combustion has played an important role in the domestic energy supply of Northern China for many decades and will do so for the foreseeable future, although it is also an important contributor to severe air pollution. Meeting the daily cooking and spacing-heating demands of rural residents in an eco-friendly manner necessitates cleaner-burning technologies for residential coal combustion. Several reports have suggested that appropriately sized coal be beneficial for optimizing the performance of domestic coal-fired stoves. The effects of coal size (<1.6 cm, 1.6–2.0 cm, 2.0–2.5 cm and >2.5 cm) on fine particulate matter (PM_2.5) and sixteen U.S. Environmental Protection Agency (EPA) priority polycyclic aromatic hydrocarbons (16-PAHs) emissions from a natural cross-draft stove, operating in different phases (ignition, high power heating, low power heating, ramping up and high power cooking) were analyzed in this study. Results indicated that decreasing the coal size enhanced thermal efficiency and reduced pollutant emissions. When the coal size decreased from >2.5 cm to <1.6 cm, the average emission factor (EF) of PM_2.5 over a complete combustion sequence decreased from 3.12 to 1.42 mg/MJ_net, and the EF of PM-bound total PAHs decreased from 44.9 to 10.9 μg/MJ_net. The corresponding toxic equivalent quantity (TEQ) decreased from 1.25 to 0.38 μg/MJ_net. Emissions and energy efficiencies varied markedly between the various combustion phases, adequate air supply during the high power heating and cooking phases reduced the EFs of PM_2.5 and PAHs, while the low power heating phase produced relatively more pollutants due to a fuel-rich condition.     

Changes from traditional solid fuels to clean household energies – Opportunities in emission reduction of primary PM2.5 from residential cookstoves in China

Household biomass and coal use is an important source of PM_2.5 emission in China due to low efficient burnings and large consumptions. Primary PM_2.5 emissions for different fuels are compared based on a compilation of data from emission measurements of Chinese cookstoves in literature. The burning of pellets had low PM_2.5 emissions at 0.42 and 0.18 g MJ_d⁻¹ for straw and wood pellets, respectively. There would be an emission reduction of about 80% compared to ordinary raw biomass fuel burning for cooking. The average emissions of PM_2.5 per useful energy delivered were 0.10 and 0.28 g MJ_d⁻¹ for anthracite briquette and chunk, but as high as 1.2 and 3.2 g MJ_d⁻¹ for bituminous briquette and chunk, respectively. Coals burned in the form of briquette may lower PM_2.5 emission by 60% compared to the burning of raw chunk. The adoption of improved high efficiency cookstoves would have a comparable reduction in primary emissions compared to a fuel switch. Gas should be promoted for cooking as primary PM_2.5 emissions are 1,2 orders of magnitude lower compared to those for solid fuels. More emission measurements and fuel consumption survey are needed to fill data gap and to support interventions of advanced fuel–stove combinations.     

Studies on porous radiant burners for LPG (liquefied petroleum gas) cooking applications

This paper deals with the performance tests of a PRB (porous radiant burner) used for LPG (liquefied petroleum gas) domestic cooking stoves. The burner consists of a two-layer porous media. The combustion zone is made up of silicon carbide, and alumina balls forms the preheating zone. For a given burner diameter, the performances of the burner, in terms of thermal efficiency and emission characteristics, are analysed for different equivalence ratios and thermal loads (wattages). The water boiling test as prescribed in the BIS (Bureau of Indian Standard): 4246:2002 was used to calculate the thermal efficiency of both the conventional LPG cooking stoves and the PRB. The maximum thermal efficiency of the LPG cooking stoves with a PRB was found to be 68% which is 3% higher than that of the maximum thermal efficiency of the conventional domestic LPG cooking stoves. Unlike the conventional LPG stoves, for which the CO and NO_X emissions were found in the ranges 400–1050 mg/m³ and 162–216 mg/m³, respectively, for the one with PRB, the same were in the ranges of 25–350 mg/m³ and 12–25 mg/m³. The axial temperature distribution in the burner showed that the reaction zone was close to the interface of the two zones and at a higher thermal load, it shifted towards the downstream. The surface temperature of the PRB was found to be uniform.     

Wood ash dilemma-reduced quality due to poor combustion performance

Recycling of wood ash is based on the presumption that moderate concentrations of environmentally harmful elements are a part of the nutrient cycle and do not increase in net concentrations in the forest soil. It is assumed that the same quantities of harmful elements are harvested from the forest and recycled back. This principle does not apply to polycyclic aromatic hydrocarbons (PAHs) since these pollutants are formed during the combustion process, especially when the combustion performance is poor. Additionally, industrial combustors are adjusted in order to reduce NO_x-emissions, indirectly causing formation of PAHs. This study examined fly ash from combustion of pulverized wood for its elemental and PAH concentrations during a period of 9 weeks. The 16 EPA-PAH concentrations range between 40 and 300 mg kg⁻¹. Re-burning of the ash reduces the PAH concentrations to 0.24 mg kg⁻¹ and organic carbon concentration from 40% to 5%, enhancing its composition significantly. It is important to determine the amount and fate of PAHs spread on forest soils with wood ash to ensure the improvement of the health of the forest ecosystem. Maximized energy efficiency of industrial boilers is the key to reducing anthropogenic emissions of greenhouse gases and enabling a sustainable nutrient recycling system.     

Environmental and economic assessment of producing hydroprocessed jet and diesel fuel from waste oils and tallow

Animal fats and waste oils are potential feedstocks for producing hydroprocessed esters and fatty acids (HEFA) jet and diesel fuels. This paper calculates the lifecycle greenhouse gas (GHG) emissions and production costs associated with HEFA jet and diesel fuels from tallow, and from yellow grease (YG) derived from used cooking oil. For YG, total CO₂ equivalent (CO₂ eq.) GHG emissions of jet and diesel were found to range between 16.8–21.4 g MJ⁻¹ and 12.2–16.9 g MJ⁻¹ respectively. This corresponds to lifecycle GHG emission reductions of 76–81% and 81–86% respectively, compared to their conventional counterparts. Two different system boundaries were considered for tallow-derived HEFA fuels. In System 1 (S1), tallow was treated as a by-product of the rendering industry, and emissions from rendering and fuel production were included. In System 2 (S2), tallow was considered as a by-product of the meat production industry, and in addition to the S1 emissions, cattle husbandry and slaughtering were also included. The lifecycle emissions (CO₂ eq.) from HEFA jet fuel for S1 and S2 were estimated to be 25.7–37.5 g MJ⁻¹ and 67.1–83.9 g MJ⁻¹ respectively. HEFA diesel lifecycle emissions were found to be 21.3–33.3 g MJ⁻¹ for S1 and 63.4–80.5 g MJ⁻¹ for S2. Production costs for these fuels were calculated using a discounted cash flow rate of return model. The minimum selling price was estimated to be 880 $ m⁻³–1060 $ m⁻³ for YG-derived HEFA, and 1050–1250 $ m⁻³ for tallow-derived HEFA fuels.     

Identification and characterization of trace metals in black solid materials deposited from biomass burning at the cooking stoves in Bangladesh

In this study we have reported the emissions of trace metals from biomass burning at the cooking stoves. Black solid materials deposited from two different types of biomass (rice husk coils – type 1; mixed (straw, bamboo, cow dung, leaves and plants) biomasses - type 2) burning at the cooking stoves were collected from the top of the stoves (but inside the roof of the kitchen) in Narsingdi, Dhaka, Bangladesh. Systematic chemical analysis was done for both samples. Lead, mercury, iron and calcium were identified in sample type-1, and lead, iron and magnesium were identified in sample type-2. The concentration of the trace element was determined with an atomic absorption spectrophotometer. The average concentrations of lead, iron, cadmium calcium, potassium and magnesium were 95.6, 11520, 8.33, 1635, 17.1 and 443.1 mg kg⁻¹, respectively in sample type-1. The average concentration of lead, iron, cadmium calcium, potassium and magnesium were 125.2, 12360, 12.0, 1648, 21.5 and 534.2 mg kg⁻¹, respectively in sample type-2. However, the average concentrations of the determined trace elements followed the sequences, Fe > Ca > Mg > Pb > K > Cd. The emission of lead, iron, cadmium, calcium, potassium and magnesium were much higher from mixed biomass (type-2) compared than the rich husk coils (type-1). The mixed biomass produced about 31% higher lead, 44% higher cadmium, 26% higher potassium, and 21% higher magnesium compared than the rice husk coils. This is the first systematic analysis for the trace metal emissions from different types of biomass burning at the cooking stoves in Bangladesh.     

Financial analysis of cooking energy options for India

A financial analysis of cooking energy options is attempted for India using data from a field study and real costs and prices. The fuels considered are; fuelwood, kerosene, biogas, liquid petroleum gas (LPG) and electricity. Traditional and efficient devices and different discount rates are used in the analysis. Financial analysis for rural areas shows that the efficient Astra-stove using wood is the least cost option and biogas, which is the only quality fuel option for rural areas, is the most expensive option. The subsidised kerosene option is cheaper than wood in the traditional stove. The ranking of options from low to high costs is from fuelwood to kerosene to LPG to biogas. In the urban situation, the subsidy on kerosene distorts the energy ladder. Kerosene is the low cost fuel option, and fuelwood in the traditional stove is among the most expensive options. The existing subsidies on kerosene, LPG and electricity seem to benefit middle and high income groups, particularly in urban areas. Low income households in urban and rural areas are forced to use fuelwood in traditional stoves, which is not only a low quality fuel but is also a high cost cooking energy option. The efficiency of the device is shown to be a crucial factor in determining the cost of using a fuel. Low income households are disadvantaged, as they use traditional low efficiency wood stoves. A need to alter energy policies to promote quality fuels and efficient devices in an accessible way to low income households is highlighted.     

Wood fuel use in the traditional cooking stoves in the rural floodplain areas of Bangladesh: A socio-environmental perspective

A study was conducted, using a multistage simple random sampling design, to determine the structural characteristics of the traditional cooking stoves, amount of wood fuel consumed in the rural floodplain areas in Bangladesh, and also to figure out the socio-economic and environmental consequences of wood fuel usage in the traditional cooking stove. The study showed that family size, income, amount cooked and burning hours significantly affected the amount of wood fuel used per family per year. Taking into account different family sizes, the study observed that 4.24 tonne fuelwood were consumed per family per year. The study showed that 42% of families used only biomass fuel, 5% used liquefied petroleum gas (LPG) and 53% used kerosene along with biomass fuels. The main source of biomass fuel was homestead forests (40%). It has been figured out that the incomplete combustion of biomass in the traditional cooking stove poses severe epidemiological consequences to human health and contributes to global warming. The study also showed that 83% of the respondents would prefer improved cooking stoves over traditional cooking stoves.     

Popularizing household-scale biogas digesters for rural sustainable energy development and greenhouse gas mitigation

Biogas utilization has undergone great development in rural China since the government systematically popularized household-scale biogas digesters for meeting the rural energy needs in the 1970s. In order to comprehensively estimate the significance of biogas utilization on rural energy development and greenhouse gas emission reduction, all types of energy sources, including straw, fuelwood, coal, refined oil, electricity, LPG, natural gas, and coal gas, which were substituted by biogas, were analyzed based on the amount of consumption for the years from 1991 to 2005. It was found that biogas provided 832749.13 TJ of energy for millions of households. By the employment of biogas digesters, reduction of greenhouse gases (GHG) was estimated to be 73157.59 Gg CO₂ equivalents (CO₂-eq), and the emission by the biogas combustion was only 36372.75 Gg CO₂-eq of GHG. Energy substitution and manure management, working in combination, had reduced the GHG emission efficiently. The majority of the emission reduction was achieved by energy substitution that reduced 84243.94 Gg CO₂, 3560.01 Gg CO₂-eq of CH₄ and 260.08 Gg CO₂-eq of N₂O emission. It was also predicted that the total production of biogas would reach to 15.6 billion m³ in the year 2010 and 38.5 billion m³ in the year 2020, respectively. As a result, the GHG emission reductions are expected to reach 28991.04 and 46794.90 Gg CO₂-eq, respectively.     

Chitosan coagulation–membrane filtration of Chlorella vulgaris

Filtration separation of Chlorella vulgaris, a species with excellent potential for CO₂ capture and lipid production, was studied using a surface-modified hydrophilic polytetrafluoroethylene (PTFE) membrane. Coagulation using chitosan effectively removed turbidity at >100 mg l⁻¹ chitosan. The membrane filtration flux at 1 bar was increased with chitosan dose. The filtered cake at the end of filtration tests peaked in solid content at 100 mg l⁻¹ chitosan, reaching 30.5% w/w, about 50% higher than that of the original suspension. Coagulation using 100 mg l⁻¹ chitosan followed by PTFE membrane filtration at 1 bar is a feasible process to harvest C. vulgaris from the algal froth.     

Reduction of tars by dolomite cracking during two-stage gasification of olive cake

The effective implementation of biomass gasification has to overcome some difficulties such as the minimization of tars. On the other hand, with a proper design of experimental conditions, biomass gasification can be directed towards the production of hydrogen. The aim of the present study was to investigate the use of dolomite as catalyst to improve tar removal and hydrogen production by a two-stage steam gasification process, using olive cake as raw material. Fixing the olive cake gasification conditions on the first reactor (900 °C, steam flow rate of 190 mg min⁻¹, O₂ flow rate of 7.5 cm³ min⁻¹), the cracking of tars was prompted by: a) steam gasification (steam flow rate in the range 40-190 mg min⁻¹) at 1000 °C, b) catalytic gasification, using dolomite (5% wt.). It was found that increasing steam flow rate up to 110 mg min⁻¹ involves an increase in hydrogen fraction due to the enhancement of water gas and water gas shift reactions. Also, the influence of dolomite was studied at 800 and 900 °C in a second reactor, finding better results at 800 °C, which gave an hydrogen fraction of 0.51.     

A comparative analysis of woody biomass and coal for electricity generation under various CO2 emission reductions and taxes

Mitigating global climate change via CO₂ emission control and taxation is likely to enhance the economic potential of bioenergy production and utilization. This study investigated the cost competitiveness of woody biomass for electricity production in the US under alternative CO₂ emission reductions and taxes. We first simulated changes in the price of coal for electricity production due to CO₂ emission reductions and taxation using a computable general equilibrium model. Then, the costs of electricity generation fueled by energy crops (hybrid poplar), logging residues, and coal were estimated using the capital budgeting method. Our results indicate that logging residues would be competitive with coal if emissions were taxed at about US$25 Mg⁻¹ CO₂, while an emission tax US$100 Mg⁻¹ CO₂ or higher would be needed for hybrid poplar plantations at a yield of 11.21 dry Mg ha⁻¹ yr⁻¹ (5 dry tons ac⁻¹ yr⁻¹) to compete with coal in electricity production. Reaching the CO₂ emission targets committed under the Kyoto Protocol would only slightly increase the price of fossil fuels, generating little impact on the competitiveness of woody biomass. However, the price of coal used for electricity production would significantly increase if global CO₂ emissions were curtailed by 20% or more. Logging residues would become a competitive fuel source for electricity production if current global CO₂ emissions were cut by 20–30%. Hybrid poplar plantations would not be able to compete with coal until emissions were reduced by 40% or more.     

Modeling and prediction of NOx emission in an LPG–diesel dual-fuel CI engine

Different alternative fuels have been proposed by various researchers in diesel engines in view of increased NO_x and particulate emissions. Out of the various methods proposed, dual fueling is one of the most important techniques that helps solve the different operational problems related to diesel engine combustion and emission. In the current study, modeling and predicting the formation of NO_x emission in a duel fuel liquefied petroleum gas (LPG)–diesel engine has been undertaken. Simulations have been conducted for various LPG flow rates at different engine loads and the predicted NO_x values are compared with the experimental values. The results found that there is a decent agreement between the forecasted and the investigational results, where the average difference is within 13.7%. Furthermore, it is found that minimum NO_x emission was observed for an LPG flow rate in the range of 0.4–0.6 kg/h and when the engine is running with 75% loading.     

Performance and testing of large-size solar water heater cum solar cooker

The performance of a novel device has been tested. The device can be used as a collector cum storage type solar water heater during the winter, and, with minor adjustments, it can be used as a hot-box solar cooker. The device can provide hot water at 50–60°C in the evening, which can be maintained at 40–45°C until the following morning. It can also be used for cooking food for about 40 people. The efficiencies of the device as a solar water heater and as a solar cooker have been found to be 67.7% and 29.8%, respectively. The payback period varies between 1.64 to 5.90 years depending on the fuel it replaces. The payback periods are of increasing length with respect to the fuels firewood, coal, electricity, LPG and kerosene.     

Saving energy and reducing pollution by use of emulsified palm-biodiesel blends with bio-solution additive

Advances in biodiesel, emulsified diesel and artificial chemical additives are driven by consumer demand to save energy and reduce emissions from diesel engines. However, the effect of emulsified bio-solution/palm-biodiesel/diesel blends in diesel engines has not been assessed. Experimental results in this work demonstrate that the emulsified bio-solution/palm-biodiesel/diesel blends have the advantage in saving energy and reducing emissions of both polycyclic aromatic hydrocarbons (PAHs) and particulate matter (PM) from diesel engines. When comparing with P0 (premium diesel fuel as base fuel), E16P20 fuel (16 vol% bio-solution + 20 vol% palm-biodiesel + 64 vol% P0, an additional 1 vol% surfactant) saved 12.4% fuel consumption and reduced emissions of PM by 90.1%, total PAHs by 69.3%, and total BaP_eq (benzo[a]pyrene equivalent concentration) by 69.6%. Emulsified palm-biodiesel with bio-solution can be considered as a clean and alternative fuel.     

Cylinder pressure, performance parameters, heat release, specific heats ratio and duration of combustion for spark ignition engine

An experimental work were conducted for investigating cylinder pressure, performance parameters, heat release, specific heat ratio and duration of combustion for multi cylinder spark ignition engine (SIE). Ccylinder pressure was measured for gasoline, kerosene and Liquefied Petroleum Gases (LPG) separately as a fuel for SIE. Fast Fourier Transformations (FFT) was used to cylinder pressure data transform from time domain into frequency domain to develop empirical correlation for calculating cylinder pressures at different engine speeds and different fuels. In addition, Inverse Fast Fourier Transformations (IFFT) was used to cylinder pressure reconstruct into time domain. The results gave good agreement between the measured cylinder pressure and the reconstructed cylinder pressure in time domain with different engine speeds and different fuels. The measured cylinder pressure and hydraulic dynamotor were the sours of data for calculating engine performance parameters. First law of thermodynamics and single zone heat release model with temperature dependant specific heat ratio γ(T) were the main tools for calculating heat release and heat transfer to cylinder walls. Third order empirical correlation for calculating γ(T) was one of the main gains of the present study. The correlation gave good agreement with other researchers with wide temperatures range. For kerosene, cylinder pressure is higher than for gasoline and LPG due to high volumetric efficiency where kerosene density (mass/volume ratio) is higher than gasoline and LPG. In addition, kerosene heating value is higher than gasoline that contributes in heat release rate and pressure increases. Duration of combustion for different engine speeds was determined using four different methods: (I) Mass fuel burnt, (II) Entropy change, (III) Temperature dependant specific heat ratio γ(T), and (IV) Logarithmic scale of (P&;V). The duration of combustion for kerosene is smaller than for gasoline and LPG due to high heat release rate. Cylinder pressure measuring technique is a useful tool for understanding and analyzing the combustion characteristics and determining reliable statistical data that cannot measure directly. The present work contributes in determining combustion characteristics, development and optimal operating conditions of SIE for different fuels.     

Reducing subsidies on household fuels in India: how will it affect the poor?

Kerosene and LPG are widely used in households in India for lighting and cooking. These fuels have historically been subsidized. As part of the restructuring of the energy sector, the government is committed to limiting these subsidies. This paper examines the impact of reducing energy subsidies on the welfare of the poor. The paper uses data from nationally representative surveys of over 100,000 households. The paper concludes that the case for reducing LPG subsidies is strong. Although the kerosene subsidy is an inefficient means of subsidizing fuel use by the poor, reduction in it will need to be supported by other policies that would limit the adverse impacts.