Wood Pellets Research Articles

Greenhouse Gas Emission Estimation Using Extended Input–Output Tables for Thailand’s Biomass Pellet Industry

Greenhouse gas (GHG) emissions from Thailand’s biomass pellet production were comprehensively assessed, with a specific focus on wood and corn pellets. Employing the extended input and output tables, the anticipated economic and environmental effects of the rising demand for biomass pellets within the Asia–Pacific Economic Cooperation region, which is projected to see an increase exceeding 33% by the year 2050, were investigated. The estimations of CO2, CH4, and N2O emissions, which were conducted utilizing an open Leontief model based on the 2015 National Input–Output Tables, covered each stage of the production process. The results show that emissions from the production of corn pellets are expected to rise steadily, from 52.91 MtCO2e in 2022 to 75.77 MtCO2e by 2030, whereas emissions from wood pellet production are set to increase more substantially, from 210.30 to 301.18 MtCO2e within the same timeframe. Data derived from surveys and interviews with corn farmers and wood pellet manufacturers informed the lifecycle data for the biomass pellet supply chain from cradle to gate. The findings suggest that Thailand’s power sector could benefit significantly from the biomass potential in the northern part of Thailand, which boasts an estimated energy content of corncob at 39 ktoe (0.0016 TJ). Market demand scenarios were explored in two forms: one where it was assumed that all biomass pellets are to be exported to Japan and South Korea, expecting a combined demand of approximately 560,262 tons by 2030, and another positing that 10% of production will be reserved for the domestic market, with a forecasted annual increase of 10% from 2020 to 2050. This paper highlights the need to prioritize low-emission renewable energy sources, expand technologies with lower lifecycle emissions, optimize the biomass supply chain to enhance efficiency, and introduce sustainable energy practices. The detailed GHG emissions analysis provides critical insights for policy formulation, underscoring the importance of sustainable transitions in the context of increasing biomass demand.

Production of high-calorific hybrid biofuel pellets from urban plastic waste and agro-industrial by-products

Advances in waste-to-energy technology and sustainable fuel production drive significant changes in the energy industry. These innovative solutions not only address waste management challenges but also contribute to broadening the energy source matrix and reducing dependence on traditional fossil fuels. This study evaluates the incorporation of polyethylene and polypropylene urban plastic waste in various agro-industrial by-product blends, which combine beet pulp, radiata pine, and eucalyptus bark wastes. The generation of the hybrid biofuel from agro-industrial waste and domestic solid waste in pellet form is investigated to determine the optimal blends in terms of durability, ash generation and calorific value. Both urban plastics incorporated in the mixtures not only significantly increase the calorific energy value but also promote the binding of the solid biofuel components. The polypropylene-based urban plastic pellet exhibited superior binding capacity and lower ash generation, even in complex hydroxyl functional groups. It also displayed suitable properties for solid biofuels, such as low fine content, high durability, and dimensional stability. The highest resulting calorific value of 22.6 MJ/kg was determined for the mass ratio of the blend with 99% durability, 0.23% fines content, and 5.1% combustion ash generation. This new hybrid biofuel is presented as a sustainable option and a significant contribution in the field of waste-to-energy technology and renewable energy production. The production cost of the hybrid biofuel is competitive with wood-based biofuels, with only a 6.25% increase observed for pellets made from 50% wood and 20% beet pulp compared to traditional 100% wood pellets. However, significant cost reductions were achieved through specific configurations, resulting in savings of 14.8%. The novel hybrid biofuel requires only 9.2 MJ/kg to produce 22.6 MJ/kg, demonstrating significant energy impact and viability as a sustainable energy source in waste-to-energy technology and renewable energy production.

Recycling Production and Consumption Waste for Bioenergy Purposes: Status and Prospects

An analysis of the structure of forest and agro-industrial waste, solid municipal waste in the federal districts and Russia as a whole is presented. The volume and composition of waste is determined by the economic activity and specific characteristics of federal districts. It was noted that pelletizing is an effective technology for the disposal of many types of waste, but the great heterogeneity of feedstock and granulation methods prevent the production of high-quality pellets. The fuel component of pellet in the cost of thermal energy was evaluated, whichshowed that the most efficient in use – wood pellets, least efficient – pellets from solid municipal waste.

Application End Evaluation of Electrostatic Precipitation for Control PM and NOx Emissions from Small-Scale Combustions

Electrostatic precipitators (ESPs) have shown promise in reducing particulate matter (PM) emissions, but their potential for simultaneous NOx reduction in small-scale combustion systems remains underexplored. This study focuses on using non-thermal plasma generated in a corona discharge to reduce PM and NOx emissions from small-scale combustion. ESP was specifically designed for a commercially available 15 kW boiler with wood pellet combustion and used with both positive and negative discharge polarity to control emissions without any chemical additives. ESP performance was evaluated across a range of specific input energies (SIE) in terms of particle mass and number concentrations and NOx concentrations obtained by continuous gas analysis. ESP ensured the reduction in PM concentrations from 48 mg/m3 to the magnitude of PM content in the ambient air. The highest precipitation efficiency was observed for particles in the 20–200 nm range. Concurrently, NOx emissions were reduced by up to 78%, from 178 mg/m3 to 39 mg/m3. These results were achieved at specific input energies of 36 for positive and 48 J/L for negative corona, which is significantly lower than those reported for many existing separate PM and NOx control systems. This study demonstrates the potential of ESPs as a compact, energy-efficient solution for simultaneous PM and NOx removal in small-scale combustion systems, offering promising implications for improving air pollution control technologies for small-scale combustion systems.

Testing Pellets Fuel Production from Sewage Sludge of Palm Oil Industry

The wastes from the palm oil production process were used in this study, such as wastewater sludge and cake decenter or decanter waste. That moisture was less than 40% and increased density by the cold pelletizing process. The aim is to use pellet fuel for heating. Analysis of pellet fuel consists of physical properties, proximate (moisture, ash, volatile matter and fixed carbon) and heating value. The results showed that cake decenter and wastewater sludge had similar high volatile matter. The decenter cake had a higher heating value than the wastewater sludge at 26.649 and 14.965 MJ/kg, respectively. The ash of decenter cake was lower than wastewater at 11.71% and 22.34%, respectively. Blending both raw materials for pelletization increased the volatile matter that did not mix with another material. Therefore, both materials can be used to produce pellet fuel that has an optimal shape and size. That was hard to break. The results of chemical property testing show that it is within acceptable limits and can be used as pellet fuel.

A Review of Cradle-to-Gate Greenhouse Gas Emission Factors for Canada’s Harvested Wood Products

Abstract With the previous decade’s (2010 through 2019) greenhouse gas emissions remaining the highest on record, focus on emissions mitigation efforts is paramount. Harvested wood products (HWPs) can store carbon for various timespans depending on the product and its end uses. Life cycle inventories (LCIs) are the base for life cycle analyses (LCAs), as they represent a comprehensive catalogue of the raw data essential to complete an LCA. However, most LCI documentation is in the form of case studies of different types of HWPs, with varying LCI results that reflect varied system boundaries, case-specific conditions, and assumptions. Our goal was to conduct a systematic literature review to evaluate, analyze, and synthesize previously reported Canadian HWP data and to initiate a Canadian database based on reported cradle-to-gate HWP emission factors. HWPs were categorized as lumber, traditional structural panels, mass timber, nonstructural panels, and wood pellets. Based on our analysis, we found that softwood lumber produced the lowest cradle-to-gate emission factor (61.99 kg of CO2 equivalent [CO2eq] per m3 HWP) while I-joists produced the highest (218.55 kg of CO2eq per m3 HWP). Resource extraction emissions accounted for most of the overall emissions for softwood lumber, oriented strand board, cross-laminated timber, and glue-laminated timber. Meanwhile, manufacturing accounted for most of the emissions for plywood, I-joists, cellulosic fiberboard, particleboard, and wood pellets. Substantial gaps exist in published LCI data and, when possible, publishing detailed LCI data is encouraged to support additional HWP life cycle analyses.

Confirmation of the feasibility of using agrobyproduct biochar in thermal power plants through oxygen pyrolysis and conventional pyrolysis

This study investigates the feasibility of utilizing agrobyproduct biochar as a substitute for fossil fuels in thermal power plants by comparing oxygen-rich and oxygen-lean pyrolysis processes. The biomass types examined include soybean pods (BE), bamboo (BB), and wood pellets (WP). Results demonstrate that oxygen-lean pyrolysis at high temperatures enhances biochar's carbon content and energy density. Mass yields varied, with WP showing the highest yield at 500℃ under oxygen-lean conditions. Elemental analysis indicated increased carbon content and improved fuel properties with higher pyrolysis temperatures. Proximate composition analysis revealed decreased volatile matter and increased fixed carbon and ash content, leading to higher fuel ratios. Calorific values increased significantly across all biomasses, particularly under oxygen-lean conditions. Gas analysis showed significant changes in O2, CO2, and CO concentrations with temperature variations. Combustion indices and physical properties like aromaticity and Hardgrove grindability index improved with higher temperatures. Optimal pyrolysis conditions were identified as 325℃ for WP, 350℃ for BB, and 300℃ for BE, with BE also performing well at 500℃. The study concludes that optimized agrobyproduct biochar can effectively replace conventional fossil fuels, offering high energy yield and enhanced combustion properties.

Amplifying concerns: An exploration of community noise levels in rural communities impacted by wood pellet production

Wood pellets are increasingly promoted as a renewable and sustainable energy source, driving the global wood pellet market to a projected value of $16 billion by 2026. However, the rapid expansion of this industry disproportionately affects predominantly Black and low-income communities in the rural South, where approximately 100 pellet manufacturing plants are currently located in the United States. From August 2023 to March 2024, we conducted a noise exposure assessment in Gloster, Mississippi, a community affected by pellet production, and compared it to Mendenhall, a nearby community without industrial activity. In collaboration with a local organization, we measured noise metrics and found significantly higher A-weighted, C-weighted, and Z-weighted sound levels in Gloster, along with elevated decibels at multiple center frequencies. These findings suggest that wood pellet manufacturing can severely alter the soundscape of rural communities, raising environmental justice concerns. Our findings underscore the importance of investigating the cumulative health impacts of noise and other environmental burdens on these vulnerable communities to better inform policy.

Prediction of particulate matter during the combustion of wood pellets with the addition of face mask waste

The amount of plastic waste has increased enormously due to the using of protective equipment in order to slow down the viral transmission of COVID-19. The usage of protective face masks brought a huge environmental burden. Moreover, a lot of disposed masks enter the ocean or end on landfills, where they threaten the ecosystem. It is still necessary to deal with environmental-friendly disposal or to reuse and recycle of these masks. This article is focused on the disposal of FFP2 face masks by their co-combustion with wood. Due to the possibility of produced emissions, disintegrated masks were blended with spruce and beech sawdust and compared with pure wood. These materials were compressed into pellets with the aim of higher density. The emissions such as carbon monoxide, nitrogen oxides, sulphur oxides and particulate matter were measured during pellet combustion. The heat output of the automatic pellet boiler was also determined. The filters with captured particulate matter were sent to the investigation of dioxin and furan concentration. Except for this, the regression model has been created for the prediction the concentration of particulate matter. The results confirmed that the co-combustion of wood with FFP2 masks could be one of the environmental-friendly ways of face mask disposal when they are used as an additive in a small percentage. The fuel composition and operational conditions are also very important parameters during the combustion process. However, the concentration of gas emissions and particulate matter, as well as heat output, did not change significantly, when the content of FFP2 masks of 5 % or 10 % was used.

Coffee Grounds as an Additive to Wood Pellets

Coffee Grounds as an Additive to Wood Pellets

Novel packed-bed CFD model for pellet combustion: Validation and application to a stove

An advanced CFD (computational fluid dynamics) model has been developed to describe the combustion of wood pellets. It is based on a packed-bed approach and provides a realistic description of the combustion of pellets, resolved in 3D over the whole fuel bed. It considers the properties of the packed bed rather than the properties of the single fuel particles. Compared to a particle-based description, simulation times are shorter due to the reduced complexity. In the model, the local conditions in different parts of the fuel bed (temperatures, flow conditions, oxygen concentrations …) influence the various stages of the combustion process (drying, pyrolysis, charcoal gasification and combustion). The compaction of the fuel bed due to shrinkage of the fuel particles during conversion and the loss of the particle structure shortly before the conversion is complete are also included in the description. The formulation of the bed compaction, the radiation absorption model and the charcoal conversion reactions have been specifically tuned to the combustion of wood pellets. The detailed pyrolysis model includes not only the main components, but also higher hydrocarbon species and tars in a manner specific to the fuel considered. It has been combined with a chemical gas phase mechanism which is a reduction of a detailed mechanism developed for thermo-chemical biomass conversion. The model has been validated against measurement data from a lab-scale batch reactor, and then applied to simulate the fuel bed of a commercial pellet stove. The simulation results are in good agreement with the corresponding measurements.

Impact of amylose and amylopectin content in starch on wood pellet production

Impact of amylose and amylopectin content in starch on wood pellet production

Relating alkali release from a wood pellet with combustion progress: A modified random pore model supportive study

This paper concerns a miniature gasifier fed with a constant ambient-pressure flow of air to study the pyrolysis and subsequent combustion stage of a single wood pellet at T = 800 ℃. The alkali release and the concentration of simple gases were recorded simultaneously using an improved alkali surface ionisation detector and a mass spectrometer in time steps of 1 s and 1.2 s, respectively. It showed alkali release during both stages. During combustion, the MS data showed almost complete oxidation of the charred pellet to CO2. The derived alkali release, “O2 consumed”, and “CO2 produced” conversion rates all indicated very similar temporal growth and coalescence features with respect to the varying char pore surface area underlying the original random pore model of Bhatia and Perlmutter. But, also large, rapid signal accelerations near the end and marked peak-tails with O2 and CO2 after that, but not with the alkali release data. The latter features appear indicative of alkali–deprived char attributable to the preceding pyrolysis with flowing air. Except for the peak-tails, all other features were reproduced well with the modified model equations of Struis et al. and the parameter values resembled closely those reported for fir charcoal gasified with CO2 at T = 800 ℃.

Physical characteristics and combustion behavior of pellets from sawdust and refuse-derived fuel

Experimental research findings are reported on the ignition and combustion behavior, as well as mechanical properties of pellets from wood biomass (pine sawdust) and additives of refuse-derived fuel (cardboard, plastic and their mixture). The addition of RDF was found to increase the vibration durability and moisture resistance of pellets by 3.7–45.6% % compared to samples without additives. Cardboard and its mixture with plastic contributed to 2.7–5.8% greater density of pellets % compared to wood pellets. The impact resistance coefficient of pellets with waste decreased by 0.3– 2.3% compared to samples without additives. An increase in the proportion of cardboard and plastic led to longer delay times of the gas-phase and heterogeneous ignition. The ignition delay times decreased by a factor of 1.3–2.2 as a result of mixing cardboard with plastic compared to pellets with only cardboard or plastic. On the environmental side, the use of cardboard in pellets reduced the concentrations of carbon dioxide and carbon monoxide by 10–24 % and 5–46%, respectively, compared to samples without additives. By contrast, the addition of plastic waste increased CO2 and CO by 4–15% and 5–63%, respectively. The combustion of pellets with RDF was characterized by 22–78% lower concentrations of NOx. The results of a multi-criteria decision analysis revealed that the use of RDF in wood pellets increased the efficiency indicator by 1 to 12% compared to wood pellets.

Integrating process safety management into Canadian wood pellet facilities that generate combustible wood dust

Integrating process safety management into Canadian wood pellet facilities that generate combustible wood dust

Surface wood modification by radio-frequency inductive plasma at atmospheric pressure

ABSTRACT The pre-treatment of wood surfaces using a radio-frequency (RF) discharge is attractive for various wood applications, mainly because of the high efficiency and low production cost of the process. The main advantage of this technique is that the bulk properties of the material remain unchanged while the surface properties are enhanced. Samples of wood pellets were exposed to a late afterglow RF plasma flow at atmospheric pressure. Experiments have shown that the argon plasma flow contains a number of long-lived active particles that can destroy the cellulose shell of the granules. Scanning electron microscopy was used to analyze the morphological changes on the surface of the wood granules resulting from interaction with plasma. The optimal range of operating parameters is discussed, as well as the main active components involved in the processing process.

Unlocking Power: Impact of Physical and Mechanical Properties of Biomass Wood Pellets on Energy Release and Carbon Emissions in Power Sector

Abstract This study investigates the physical and mechanical properties of 12 biomass wood pellet samples utilised in a power generation, focusing on their implications for energy release and carbon emissions during combustion. Through comprehensive analysis involving bulk density measurements, compression tests, moisture analysis, calorimetry and controlled burning experiments, significant correlations among key properties are identified. Pellets with densities above 1100 kg/m3 demonstrate superior mechanical durability and strength, achieving maximum strengths of 0.6 to 0.8 kN with durability exceeding 99.4%. Optimal moisture content, typically between 6 and 7% is crucial for maximising density, bulk density, mechanical durability and fracture resistance, ensuring robust pellet structure and performance. The research underscores the impact of pellet dimensions, highlighting those longer lengths, > 12 mm enhance durability, while larger diameters > 8 mm exhibit reduced durability. Elemental analysis focusing on calcium, silicon and potassium plays a critical role in predicting and managing combustion system fouling, potentially reducing operational costs. Moreover, the study emphasises the significant influence of oxygen levels during combustion on CO2 emissions, achieving optimal results with moisture content in the 7–8% range for maximum higher heating value (HHV). The moisture content in the 14–15% range represents the lowest CO2 emission. The findings underscore the intricacy of the system and the interplay of parameters with one another. In accordance with the priority of each application, the selection of parameters warrants careful consideration. Graphical Abstract

Physical and Energy Properties of Fuel Pellets Produced from Sawdust with Potato Pulp Addition

This paper presents the findings of a study of the pelleting process of pine sawdust with the addition of waste in the form of potato pulp (as a natural binder), in the context of producing fuel pellets. The process of pelleting was carried out for sawdust and for a mixture of sawdust and potato pulp (10, 15, 20, and 25%). The highest moisture content was obtained in the case of pellets produced from a mixture of straw with a 25% potato pulp content, i.e., 26.54% (with a potato pulp moisture content of 85.08%). Increasing the potato pulp content in a mixture with sawdust from 10 to 25% reduced the power demand of the pelletizer by approx. 20% (from 7.35 to 5.92 kW). The obtained density values for pellets made from a mixture of sawdust and potato pulp (over 1000 kg∙m−3) with a potato pulp content of 10% make it possible to conclude that the obtained pellets meet the requirements of the ISO 17225-2:2021-11 standard. Increasing the potato pulp content from 0 to 25% caused a slight decrease in the heat of combustion, i.e., from 20.45 to 20.32 MJ∙kg−1, as well as in the calorific value, from 19.02 to 18.83 MJ∙kg−1 (both for dry sawdust matter and the mixture). The results of the laboratory tests were used to verify the densification process of mixtures of sawdust and potato pulp under industrial conditions at the PANBAH plant, using pelleting mixtures with a 5%, 10%, and 25% content of potato pulp. Industrial research also confirmed that the use of the addition of potato pulp in a mixture with sawdust significantly reduces the power demand of the pelletizer, and it also increases the kinetic strength of the obtained pellets.

The Impact of Additives on Gaseous Pollutants from the Combustion of Various Solid Fuels

This article compares the emission of gaseous pollutants such as CO2, CO, NO, SO2, and HCl emissions from the combustion of the selected most popular solid fuels in a low-power boiler. The process was carried out under controlled conditions on a laboratory stand equipped with a Moderator Unica Vento Eko 25 kW boiler. Solid fuels were selected for comparison, such as hard coal with granulation above 60 mm, hard coal with a granulation of 25–80 mm, hard coal with a granulation of 8–25 mm, wood pellets, and mixed firewood. The experiment was carried out in two stages. In stage 1, previously selected solid fuels were combusted under controlled repeatable conditions, while simultaneously measuring gaseous components in the exhaust gases in real time. On the other hand, the second stage involves the combustion of the same fuels under the same conditions with combustion additives that modify the combustion process in terms of reducing the emission of pollutants. At the same time, in the second stage, gaseous components in the exhaust gas were also measured in real time. The experiments carried out have shown that, in addition to the additive, a testing system should be used to assess the profitability and improve the efficiency of energy production and distribution after using a given additive for fuel combustion. Implementation of the use of solid fuel activators on a common scale should also entail research on the emission of dioxins and furans, which may be emitted in increased amounts under the influence of some components contained in combustion modifiers.

Thermal Characteristics of Malaysian Khaya Senegalensis Wood Fuel Pellets: Densification-Induced Changes at Different Feedstock Moisture Levels

This study investigates the thermal behaviour of Malaysian Khaya senegalensis wood energy pellets, examining the effects of densification at different feedstock moisture levels. Densified wood pellets are promising renewable energy sources, but the impact of densification on thermal characteristics, considering various moisture contents, is underexplored. The main objective is to quantify the thermal characteristics, which involved proximate analysis such as energy pellets’ ash content, fixed carbon, volatile matter, and calorific value. In this research, Malaysian Khaya senegalensis wood was converted into pellets through a densification process, spanning from of 4-20% feedstock moisture levels. The manufactured pellets were then subjected to various tests to characterize the thermal properties. Results reveal compelling insights on the relationships between densification, moisture content, and thermal properties. Densification significantly influenced thermal attributes, with effects tied to initial moisture content. Varying moisture levels led to distinct thermal responses, reflecting interactions between densification-induced changes in moisture and thermal responses. In this study, the best moisture content for ash content was found to be 16%, with 3.24% ash content, 16% moisture content with volatile matter of 85.24%, fixed carbon of 12% from 20% moisture content, and 16% moisture content with calorific value of 19.65 MJ/kg. These findings aid Khaya senegalensis wood pellet densification optimization for improved thermal performance. Understanding densification's impact on thermal behaviour under varying moisture conditions enhances pellet efficiency as sustainable energy sources. This research contributes to biomass pellet knowledge for renewable energy applications, advancing efficient and eco-friendly energy solutions.