Search Results (76)

A firewood stove’s combustion chamber can withstand temperatures of 1500 °C. To prevent the deterioration of a firewood stove due to excessive heat, it is necessary to use thermal insulation materials that stop heat transfer to the walls. These materials must be economical and durable. This work examines the materials used in the construction of combustion chambers of firewood stoves in southern Mexico and Central America. This field study collects information and samples of materials used in the manufacture of firewood stoves. Heat transfer experiments are conducted, and the thermal properties of each material are analyzed. As a result, methodology and information is provided for the manufacture of future plancha-type firewood stoves used in the study area, such as pine wood (pinus chiapensis) which is mainly used as casing for firewood stoves in coniferous forest areas; in addition, the use of wood ash as thermal insulation material is proposed since it does not present direct costs and has a thermal conductivity between 0.10 and 0.20 W/m°C and a melting point greater than 1500 °C. The next layer proposed is hollow brick, a high-temperature-resistant material that can be used as support due to its mechanical strength and low thermal conductivity of 0.6 W/m°C. Finally, the use of calcium hydroxide as a coating material is proposed, applied in the form of a paste or paint to detail the imperfections of the combustion chamber construction as it resists temperatures above 1000 °C. Full article

Particulate matter (PM) pollution is high in most Bulgarian regions, especially large urban areas. In a previous study covering one year of data collection and analysis by source apportionment techniques such as positive matrix factorization we show that the main source of high PM₁₀ (PM with a diameter of 10 μm or less) concentration in the city of Sofia is soil and road dust resuspension into the surface layer of the air. Resuspension has seasonal variations, with a relatively large impact (25%) associated with drying periods. In the present paper we combine classical indices (NDVI, BSI, NDMI) derived from Sentinel-2 imagery with meteorological and air quality data, as well as other related variables regarding yearly average traffic and inventory estimates, transportation infrastructure and demographic data, including motorized inhabitants and wood/coal stoves in use, by area. We apply statistical and machine learning methods to analyze the contribution of bare soil surfaces to the overall PM resuspension. Based on a series of stack ensemble meta-models with coefficient of determination $R^2\approx 0.9$ we conclude that the contribution of bare soil surfaces to the overall PM₁₀ resuspension is around $10\%$ (between $5\%$ and $15\%$), by our preliminary rough estimates. Full article

The emissions from biomass combustion systems have recently been the subject of increased attention. In addition to elevated concentrations of particulate matter and hydrocarbons (HCs) in the flue gas, significant levels of NO_x emissions occur depending on the used fuel, such as biogenic residues. In response to legal requirements, owners of medium-sized plants (≈100 kW) are now also forced to minimize these emissions by means of selective catalytic reduction systems (SCR). The implementation of a selective sensor is essential for the efficient dosing of the reducing agent, which is converted to ammonia (NH₃) in the flue gas. Preliminary laboratory investigations on a capacitive NH₃ sensor based on a zeolite functional film have demonstrated a high sensitivity to ammonia with minimal cross-influences from H₂O and NO_x. Further investigations concern the application of this sensor in the real flue gas of an ordinary wood-burning stove and of combustion plants for biogenic residues with an ammonia dosage. The findings demonstrate a high degree of agreement between the NH₃ concentration measured by the sensor and an FTIR spectrometer. Furthermore, the investigation of the long-term stability of the sensor and the poisoning effects of SO₂ and HCl are of particular relevance to the laboratory measurements in this study, which show promising results. Full article

This paper examines how best to use forest wood for energy application, considering that it is a limited natural resource. Eight systems are considered, including wood stoves, steam systems (boiler, power plant, and combined heat and power (CHP)), and gasification combined systems (gas turbine and combined cycle power plant, CHP, and Fischer–Tropsch). The methodology uses energy analysis and modelling and environmental/sustainability considerations to compare the energy systems. In terms of energy conversion efficiency, steam boilers and high-efficiency wood stoves for heating applications provide the highest efficiencies (~80 to 90%) and should be considered. Steam CHP systems provide lower overall energy conversion efficiencies (~75 to 80%) but do provide some electrical energy, and thus should be considered. The use of wood for the production of electricity on its own should not be considered due to low efficiencies (~20 to 30%). Particulate emissions hinder the application of high-efficiency stoves, especially in urban areas, whereas for industrial-scale steam boilers and CHP systems, particle separators can negate this problem. Gasification/Fischer–Tropsch systems have a lower energy efficiency (~30 to 50%); however, a sustainability argument could be made for liquid fuels that have few sustainable alternatives. Full article

Particulate matter (PM) emissions from combustion-based heating systems have been identified as a major contributor to environmental issues and human health risks. Particularly, small-scale residential combustion was responsible for 58% of the total PM_2.5 emissions in Europe in 2020, with domestic heating using wood-based fuels accounting for around 56% of soot emissions. Reducing PM_2.5 emissions has become a major goal of European environmental policies, which have included it among the key targets of the Zero Pollution Action Plan. In this framework, this study presents a performance analysis of a newly developed PM abatement system consisting of a passive cyclone abatement system (PCAS) specifically designed for small residential pellet stoves. The system was tested under steady-state and non-steady-state operating conditions. The experimental results showed that the PCAS abatement system effectively captured PM at a rate of 10.64 mg/MJ, with great efficiency in capturing particles ≥ 10 µm. The heavy metal content in the captured material was below the limit values for agricultural application-destined soil. A Life Cycle Assessment showed that the PCAS could achieve net-zero PM emissions in 1 year and 8 months. Finally, the economic analysis revealed that the PCAS is significantly more cost-effective: over a 10-year period, it could save up to €4000 in installation, maintenance, and energy costs compared to conventional active systems. These findings highlight the effectiveness of this design of PCAS as in reducing PM emissions from residential heating systems and provide valuable insights for the development of future abatement systems. Full article

The combustion efficiency of wood pellets is partly affected by their average length. The ISO 17829 standard defines the methodology for assessing the average length of sample pellets, but the method does not always lead to representative data. Furthermore, a standard analysis is time-consuming as it requires manual measurement of the pellets using a caliper. This paper, whilst evaluating the effect of pellet length on combustion efficiency, proposes a pending-patented dimensional image processing method (DIP) for assessing pellet length. DIP allows the dimensional data of grouped and stacked pellets to be obtained by exploiting the shadows produced by pellets when exposed to a light source, assuming that different-sized pellets produce different shadows. Thus, the proposed method allows for the extraction of dimensional information from non-distinct objects, overcoming the reliance of classical image processing methods on object distance for effective segmentation. Combustion tests, carried out using pellets varying only in length, confirmed the influence of length on combustion efficiency. Shorter pellets, compared to longer ones, significantly reduced CO emissions by up to 94% (mg/MJ). However, they exhibited a higher fuel mass consumption rate (kg/h), with an increase of up to 22.8% compared to the longest sample. In addition, longer pellets produced fewer but larger shadows than shorter ones. Further studies are needed to correlate the number and size of shadows with samples’ average length so that DIP could be implemented in stoves and programmed to communicate with the control unit and automatically optimize the setting in order to improve combustion efficiency. Full article

This study investigates the role of peer effects in shaping the adoption of sustainable heating systems in two highly polluted communes in Southern Chile. Despite policies promoting cleaner alternatives, wood-burning stoves, a major source of particulate matter emissions, remain widespread. This research work addresses a critical gap in the literature by examining how peer influence—typically studied in relation to visible technologies like solar panels or electric vehicles—affects the adoption of less visible but essential sustainable heating technologies. The main objective of this study is to understand how peer networks can influence the attitudes of residents towards sustainable heating technologies in highly polluted urban environments. Employing a non-experimental, cross-sectional design with a sample of 244 participants, this study reveals that peer effects and health risk perception are significant predictors of positive attitudes towards sustainable heating systems. These findings contribute valuable insights for policymakers seeking to accelerate energy transitions in polluted regions. Full article

This study evaluated the suitability of two types of beech wood pellets as renewable, low-emission biofuel sources in order to combat the energy mix and poor air quality in Serbia. Key solid biofuel characteristics, including the heating values (18.5–18.7 MJ/kg), moisture content (5.54–7.16%), and volatile matter (82.4–84.4%) were assessed according to established standards. The elemental composition (mass fractions of 48.26–48.53% carbon, 6% hydrogen, 0.12–0.2% nitrogen, 0.02% sulfur, non-detected chlorine) and ash content (0.46–1.2%) demonstrated that the analyzed beech pellets met the criteria for high-quality classification, aligning with the ENplus A1 and ENplus A2 standards. The emissions of O₂, CO₂, CO, NO_x, SO₂, and TOC were quantified in the flue gas of an automatic residential pellet stove and compared with the existing literature. While combustion of the beech pellets yielded low emissions of SO₂ (6 mg/m³) and NO_x (188 mg/m³), the fluctuating CO (1456–2064 mg/m³) and TOC (26.75–61.46 mg/m³) levels were influenced by the appliance performance. These findings underscore the potential of beech wood pellets as a premium solid biofuel option for Serbian households, offering implications for both end-users and policymakers. Full article

Residential wood combustion (RWC) is a significant source of gaseous and particulate emissions causing adverse health and environmental effects. Several factors affect emissions, but the effects of the fuel wood species on emissions are currently not well understood. In this study, the Nordic wood species (named BirchA, BirchB, Spruce, SpruceDry, Pine and Alder) were combusted in a modern stove, and the emissions were studied. The lowest emissions were obtained from the combustion of BirchA and the highest from Spruce and Alder. The fine particle mass (PM_2.5) was mainly composed of elemental carbon (50–70% of PM_2.5), which is typical in modern appliances. The lowest PAH concentrations were measured from BirchA (total PAH 107 µg/m³) and Pine (250 µg/m³). In the ignition batch, the PAH concentration was about 4-fold (416 µg/m³). The PAHs did not correlate with other organic compounds, and thus, volatile organic compounds (VOCs) or organic carbon (OC) concentrations cannot be used as an indicator of PAH emissions. Two birch species from different origins with a similar chemical composition but different density produced partially different emission profiles. This study indicates that emission differences may be due more to the physical properties of the wood and the combustion conditions than to the wood species themselves. Full article

A couple of air quality (AQ) parameters were monitored with two types of low-cost sensors (LCSs) before, during and after the garden fence rebuilding of a dwelling house, located at the junction of a main road and a side street in a suburban area of Budapest, Hungary. The AQ variables, recorded concurrently indoors and outdoors, were particulate matter (PM₁, PM_2.5, PM₁₀) and some gaseous trace pollutants, such as CO₂, formaldehyde (HCHO) and volatile organic compounds (VOCs). Medium-size aerosol (PM_2.5-1), coarse particulate (PM_10-2.5) and indoor-to-outdoor (I/O) ratios were calculated. The I/O ratios showed that indoor fine and medium-size PM was mostly of outdoor origin; its increased levels were observed during the renovation. The related pollution events were characterized by peaks as high as 100, 95 and 37 µg/m³ for PM₁, PM_2.5-1 and PM_10-2.5, respectively. Besides the renovation, some indoor sources (e.g., gas-stove cooking) also contributed to the in-house PM₁, PM_2.5-1 and PM_10-2.5 levels, which peaked as high as 160, 255 and 220 µg/m³, respectively. In addition, these sources enhanced the indoor levels of CO₂, HCHO and, rarely, VOCs. Increased and highly fluctuating VOC levels were observed in the outdoor air (average: 0.012 mg/m³), mainly due to the use of paints and thinners during the reconstruction, though the use of a nearby wood stove for heating was an occasional contributing factor. The acquired results show the influence of the fence renovation-related activities on the indoor air quality in terms of aerosols and gaseous components, though to a low extent. The utilization of high-resolution LCS-assisted monitoring of gases and PM_x helped to reveal the changes in several AQ parameters and to assign some dominant emission sources. Full article

Biomass, due to its neutrality in terms of greenhouse gas emissions into the atmosphere during its life cycle, is considered an interesting renewable source for energy production as an alternative to the use of more polluting fossil fuels. Among the different wood fuels, pellets are convenient for use in dedicated stoves, and pellet heating systems have a high energy efficiency. The aim of this work was to estimate the economic and global warming potential (GWP100a) generated along the thermal energy supply chain of wood pellets, starting from the production of raw biomass from dedicated poplar cultivations and ending with the use of pellets in stoves by the end-user to produce thermal energy and ash. The Eco-Efficiency Indicator (EEI) was used to link the economic and environmental performance for eight proposed scenarios, obtained by combining different levels of mechanisation for poplar harvesting and wood biomass management before arrival at the pellet plant. For the thermal energy produced by the poplar wood pellet, the GWP100a ranged from 1.5 × 10⁻² to 2.1 × 10⁻² kg CO₂−eq MJ⁻¹ for three-year-old plantations and from 1.9 × 10⁻² to 2.4 × 10⁻² kg CO₂−eq MJ⁻¹, for six-year-old plantations. In terms of eco-efficiency of the baseline scenario (EEIb), the most favourable scenarios remain those linked to the use of biomass from three-year-old poplar plantations, with EEIb values ranging from 0.31 to 0.60 € kgCO₂−eq⁻¹, compared to from 0.29 to 0.36 € kgCO₂−eq⁻¹ for pellets obtained from biomass produced from six-year-old poplar plantations. In terms of the Global Eco-Efficiency Indicator (EEIg), which also takes into account the positive effect on the reduction of greenhouse gases due to the storage of carbon in the soil by the plantations and the reduction of emissions from avoided fossil fuels, the most favourable scenarios remain those linked to the use of biomass from three-year-old poplar plantations, with EEIg values that vary in the range of 0.60 ÷ 1.04 € kgCO₂−eq⁻¹, compared to 0.55 ÷ 0.62 € kg CO₂−eq⁻¹ for thermal energy obtained using biomass from six-year-old poplar plantations. Full article

In this research, a thermoelectric generator is used to absorb waste heat on the walls of a wood charcoal burning stove to produce electrical energy. The research was carried out using 4 Thermoelectric Generators (TEGs) attached to the outer wall of the furnace. The walls of the charcoal stove’s combustion chamber are designed with aluminum plates. A water block cooling system with water flow is used to overcome the increase in heat at the cold side of TEG. The DC water pump power used to circulate the water block is 215 L/h, 275 L/h, 320 L/h, 350 L/h, 375 L/h, and 400 L/h. This research aims to find the most optimal water flow rate at a water block. Temperature measurements are carried out on the recent and bloodless facets of the TEG, and the temperature of the inlet and outlet water of the water block. Changes in TEG voltage, current, and output power are recorded with a multimeter connected to the acquisition data. Analysis of energy balance and heat transfer was carried out in the furnace’s combustion chamber. The experimental results show that the cooling water flow rate of 275 L/h can produce the highest electrical power, around 11.17 W. The use of TEGs as a medium for generating electrical energy from wasted heat through the furnace’s walls can meet some of a household’s electrical energy needs. Full article

Air pollution and the increasing production of greenhouse gases has prompted greater use of renewable energy sources; the EU has set a target that the use of green energy should be at 32 percent by 2030. With this in mind, in the last 10 years, the demand for pellets in Italy has more than doubled, making Italy the second largest consumer in Europe. The quality of the pellets burned in stoves is crucial to indoor and outdoor pollution. Among other parameters, moisture and ash are used to classify pellets according to EN ISO 17225:2014. This work involved the analysis of the organic and inorganic fraction of both some finished products on the Italian market and some raw materials (e.g., wood chips) sampled according to the technical standard EN 14778:2011. The analytical results showed the presence of some substances potentially harmful to human health such as formaldehyde, acetone, toluene and styrene for the organic fraction and nickel, lead and vanadium for the inorganic fraction. The chemometric approach showed that it is the inorganic fraction which is most responsible for the diversification of the samples under study. The detection of some substances may be a warning bell about the impact of such materials, both for the environment and for human health. Full article

Based on the decision of representatives from the West African region and feedback from locals in Togo, an advanced continuous-feed, forced-draft, biomass cookstove named “Apeli” was developed. The stove was tested in modified ISO measurements based on the ISO 19867-1:2018 standard. This included a long shutdown operation using wood pellets and short shutdown operations using wood pellets, bamboo pellets, wheat straw pellets and palm kernel shells. Due to the fast shutdown capability, the short shutdown was chosen for more realistic results using this stove type. For cold start and long shutdown operation using wood pellets, the thermal efficiency is determined as 44.1% at a 1116 W power output by emitting 0.272 g CO and 17.2 mg PM 2.5 per MJ_d at high load. At low load, the efficiency is 38.0% at a 526 W power output by emitting 1.1 g CO and 45.1 mg PM 2.5 per MJ_d. Due to a misinterpretation of the standard, the burnout duration of the tests with long shutdown is approx. 1.5 min shorter than required. Using a worst-case approximation, values for a theoretical ISO-conforming measurement were calculated and rated according to the ISO 19867-3:2018 standard. The results showed that the Apeli would correspond to Tier 4 for efficiency and PM 2.5 as well as Tier 5 for CO in high-power operation using wood pellets. The use of alternative fuels is possible, but can lead to higher emissions compared to the use of wood pellets. With regard to possibly using the biochar produced in the process for soil application, it has been demonstrated that the PAH content ensures European BioChar-Agro-Organic limitations. The first results of a field test in Togo have shown that operating and feeding the stove by the target group is easy. The required permanent presence of the user during cooking with this stove seems to have a limited influence on acceptance, which seems to primarily depend on the age of the user. Moreover, it can be concluded that the Apeli has good potential to be mass-produced locally at low costs with a reliable supply of spare parts. This can contribute not only to improving clean cooking, but also to fighting air pollution and deforestation caused by solid fuel burning due to the reduced consumption of resources in the form of fuel, especially wood. Full article

The adoption of energy-efficient, clean, and safe cookstoves can improve the health of poor sub-Saharan households and reduce mortality and poverty, as identified in the United Nations’ Sustainable Development Goals (SDGs). Despite multiple interventions to increase the adoption of improved stoves and clean fuels, few interventions have borne fruit on a significant scale. The lack of adoption is shared in South Africa. (1) Background: The deleterious health hazards associated with flame-based cooking mainly affect women and children due to using portable and cheap paraffin (kerosene) cookstoves or self-constructed metal barrel wood stoves. A shift to improved cookstoves requires significant changes in users’ behaviour. Understanding and addressing the motivations for cookstove adoption and long-term use is critical for successfully implementing behavioural change campaigns. (2) Methods: A case study methodology is employed to evaluate the effectiveness of a behaviour-centred design (BCD) approach aimed at influencing cookstove-related motivations among low-income households in Dunoon, South Africa; the study gathers data via structured observations, co-creative workshops, and card-based choice questionnaires before and after a pilot intervention. (3) Results: The survey conducted before and after the abridged BCD intervention implementation in Dunoon indicates that the majority of touchpoints achieved significant success in influencing the selected cookstove-related motivations of the sampled households, further corroborated by an observed shift in household cookstove ownership patterns targeted by the intervention. (4) Conclusions: A BCD approach suggests possible methods for understanding and influencing the complex motivations determining cookstove use in a context similar to South Africa. The results suggest that linking pertinent motivations to a selected set of touchpoints as part of a cookstove-related campaign can influence cookstove-related motivations linked to the adoption of improved flame-based cookstoves in a localised South African low-income context. Full article