Properties Of Wood Pellets Research Articles

Environmental and Socio-Economic Assessment of Biomass Pellets Biofuel in Hazara Division, Pakistan

A thorough life cycle assessment (LCA) was conducted to determine whether wood pellets were a viable substitute for non-renewable fuels like oil and gas, especially for heating. To evaluate the properties of wood pellets and their effects on the environment, the study was conducted in the Hazara division of Khyber Pakhtunkhwa, Pakistan. A few factors were investigated, including the carbon and water footprints and the identification of potential growth opportunities in the production of wood pellets. One kilogram of wood pellets served as the analysis reference unit. Raw materials were obtained from sawmills and furniture stores to make the wood pellets. Sawdust, a bio binder, and lubricating oil were used in the production process along with the pelletizer machine. SimaPro 9.2 software was used in the environmental footprint assessment to evaluate several environmental effects, including eutrophication, ozone depletion, abiotic depletion, rusting, human toxicity, and aquatic ecotoxicity. The highest contribution was shown by the wood pellets produced from the softwood sawdust as 149.8558 in marine aquatic ecotoxicity. The study’s findings showed that using lubricating oil during the production of wood pellets significantly affected the overall environmental results. The characterization of wood pellets showed that the Higher heating Values (HHV) resulted from burning wood pellets made from sawdust of Melia azedarach as 24.79 MJ/kg. Softwood mixed species recorded the highest water footprint and damage assessment impact and the highest carbon footprint of 0.186 CO2 e. With a 3.84 × 10−7 DALY (disability-adjusted life years) measurement, softwood mixed species showed the highest contribution to human health damage among the damage categories. In terms of cost, producing one kilogram of wood pellets from softwood mixed species was priced at 22 PKR, the lowest among the assessed species. The highest cost of 26 PKR was associated with producing wood pellets from Parthenium hysterophorus and Diospyros lotus.

The Use of Black Pine Bark for Improving the Properties of Wood Pellets

The requirement for alternative raw materials for fuel pellets that would enable the use of readily available low-cost renewable resources and waste materials, such as bark, has always attracted interest. The aim of the current work was to assess the effect of black pine (Pinus nigra L.) bark content (0%–100%) as well as densification temperature on the properties of black pine wood pellets produced in a single pellet die. The quality assessment of the pellets was carried out by the determination of radial compression strength, density, moisture content, ash content, and surface roughness. The results showed that adding black pine bark to the pellet feedstock resulted in the production of substantially smoother and moderately denser pellets, which also exhibited higher mechanical strength than that of the respective pellets of pure wood. Finally, it was shown that black pine bark can be a valuable raw material, which can induce improved bonding of biomass particles and may provide the opportunity to create pellets of favorable characteristics at a lower temperature compared to those made of pure wood.

PENGARUH VARIASI UKURAN SERBUK (MESH) DAN PERSENTASE PEREKAT TAPIOKA TERHADAP SIFAT FISIK PELLET KAYU GELAM

Utilization of the potential of biomass found in South Kalimantan with abundant raw materials, one of which is gelam wood which can be used as boiler fuel for steam power plants to reduce the use of coal fossil fuels. Gelam wood is processed into wood pellets using tapioca flour adhesive. The gelam wood pellet then carried out tests in the form of testing physical properties which included water content, ash content, volatile matter content, fixed carbon content, and calorific value. Wood pellets made from gelam were made using various sizes of powder (mesh) 40, 50, and 60 as well as using tapioca adhesive (percentage of adhesive 5%, 10%, and 15%. The gelam wood pellets were then tested for physical properties to determine their performance. The test results showed that wood pellets increased in moisture content, ash content, and volatile matter content along with the smaller size of gelam wood powder (mesh). While the carbon content and calorific value of wood pellets decreased along with the smaller size of the gelam wood powder (mesh). The addition of tapioca adhesive characteristics affect the physical properties of wood pellets, the higher the percentage of adhesive, the water content, volatile matter content, and ash content increase. Meanwhile, the addition of adhesive to wood pellets causes a decrease in carbon and calorific value.

Large-scale transportation and storage of wood pellets: Investigation of the change in physical properties

The change in physical properties of wood pellets, with a focus on particle size distributions due to pellet breakage and attrition, was studied in a large-scale (∼450ton/h) transportation system. Critical locations with a high probability of breakage through the whole transportation system were chosen and sampled to study the effect of transportation system design and operation on the mechanical properties of pellets. Bulk density, mechanical durability, moisture content, and particle size distribution of pellets were characterized for each sample. Analysis of variance showed that there were significant differences between the percentages of small particles (< 5.6mm) in the samples taken at different locations, especially at one with a vertical free fall of 7.8m. On average, this relatively long drop increased the proportion of particles < 5.6mm in the samples from 8.73% to 14.09%, and that of particles < 3.15mm from 4.82% to 9.01%. Moreover, the measurements showed a wide deviation in the mechanical durability values, between a minimum of 90.8% and a maximum of 98.7%, which were not correlated to the sampling points but related to pellet properties. It can be concluded that pellet transportation systems require more dedicated design strategies to prevent breakage and attrition.

Quality of Pinus sp. pellets with kraft lignin and starch addition

Pellets are widely used for power generation because they use renewable raw material with easy storage, transport and high energy density. However, the structural fragility, disintegrating during handling, transport and storage, is one of the main problems of pellets, but the addition of binders/additives can minimize this fragility. The objective of this study was to evaluate the properties of wood pellets with the addition of starch (corn and wheat) and kraft lignin in different proportions. Pellets were produced with the addition of starch (wheat and corn) and kraft lignin in the proportions of 1, 2, 3, 4 and 5% in relation to the mass of wood particles of Pinus sp., with 12% moisture (dry basis), classified in 3 and 1 mm sieves and compacted in a pelleting press in the laboratory, according to European standard EN 14961-2. Physical and mechanical properties of the pellets were evaluated and their densitometric profiles obtained from the Faxitron LX-60 X-ray equipment. Corn starch and kraft lignin additives at 4% improved pellet properties (density, fines and hardness), reducing their losses during handling, storage and transport.

A Study On The Biomass Energy Potential Of Turkey: Example Of Wood Pellets

Wood Pellet, one of the biomass fuels in renewable energy sources, stands out among all renewable energy sources with it’s ease of production technology, environmental friendliness and similar features. Wood pellets, which are fuel pellets of 6-10 mm diameter, which are obtained from the drying of wood waste, milling it into sawdust and then compressing it with high pressure, have become economically comparable with fossil fuels today. Wood pellet trade worldwide increased by more than 21% in 2018 compared to the previous year, reaching a trade volume of 22.3 million tons. The biggest pellet exporter countries in the world since 2012 are USA, Canada, Vietnam, Latvia and Russia respectively. These countries accounted for approximately 69% of the world export volume in 2018. Except for five countries, they continue to work on alternative energy sources and especially the production, technology, use and properties of wood pellets in China. In Turkey, there are studies on the production of wood pellets and the economy. However, these studies need to be updated both in terms of production and economics. In the study, analyzed the current data with the potential that Turkey has developed proposals for the use of this potential.

PREDICTION OF PROXIMATE ANALYSIS AND PROCESS TEMPERATURE OF TORREFIED AND PYROLYZED WOOD PELLETS BY NEAR-INFRARED SPECTROSCOPY COUPLED WITH MACHINE LEARNING

Near-Infrared (NIR) Spectroscopy is a time and cost-effective method to characterize the materials in the food, petrochemical, pharmaceutical, and agricultural industries. Proximate analysis of the carbon-containing materials and investigating the effectiveness of the heat treatments on the material are a particularly time-consuming process. This work presents the four regression methods, i.e., decision tree regression, support vector regression and two versions of ensembles of decision trees to predict the proximate analysis of biomass and heat treatment temperature. Thus, effective method has been proposed to reduce experimental effort and present the characterization of heat-treated biomass feedstock theoretically. Prediction results show that SVR and ENS2 regression methods calibrating the NIR spectra to the values of wood pellet properties achieved good performance with the coefficient of determination (R2) of 0.880- 0.984 and RMSE of 0.444- 5.308 for ash and volatile matter. This study suggests that machine learning-based regression methods with integrated NIR spectroscopy of biomass is promising as an alternative method for rapid characterization. Another possible application of the current study is that it can be used for processed fuel recognition prior to a fully automated fuel quality assessment system in the biomass industry.

Physical properties of wood pellets exposed to liquid water

Wood pellets have become a renewable substitute for coal in heat and power generation facilities. However, the hygroscopic nature of wood pellets is a long-standing problem in handling this product. Pellets may become wet during loading and unloading if a rain incident happens. In this research, three types of commercial wood pellets were exposed to liquid water. The durability, density, and porosity of pellets before and after wetting were measured. The commercial pellets were residential hardwood, residential softwood, and industrial softwood pellets. Predetermined volumes of water were added to increase the moisture contents of pellets to several levels ranging from 1.5 to 30% wet mass basis (wb). Exposure to liquid water caused localized swelling of pellets which dislodged particles from the surface of pellets. The data showed when moisture content (m.c.) increased to 10% wb, the pellet durability dropped from 99.5% to 97.5%. A slight increase in bulk density from an initial 690 kg/m3 was observed for pellets at 6–7% m.c (wb). The bulk density decreased to 500 kg/m3 when the adsorbed moisture was at 15% wb.

Physical, mechanical and energy characterization of wood pellets obtained from three common tropical species

BackgroundThe need for energy sources with low greenhouse gas emissions and sustainable production encourages the search for alternative biomass sources. However, the use of biomass fuels faces the problem of storage, transport and lower energy densities. Low-density values can negatively affect energy density, leading to an increase in transportation and storage costs. Use of pellets as alternative biomass source is a way to reduce the volume of biomass by densification, which improves their energy quality. They are produced by diverse biomass resources and mainly from wood materials. In all cases, it is important to evaluate the fuel characteristics, to determine their suitability on the heating system and handling properties.MethodsThe present study determines and compares data from proximate analysis, calorific values, physical and mechanical properties of wood pellets produced from the common tropical species Acacia wrightii, Ebenopsis ebano and Havardia pallens. Data were obtained from pellets produced from each species chips collected from an experimental plantation and analyzed through ANOVA and Kruskal–Wallis test at 0.05 significance level.ResultsThe results of diameter, length and length/diameter ratio didn’t show statistical differences (p > 0.05) among species. Acacia wrightii showed the highest density (1.2 g/cm3). Values on weight retained and compression test showed statistical differences (p = 0.05) among species. Havardia pallens was more resistant to compression strength than A. wrightii and Ebenopsis ebano. Statistical differences (p < 0.01) were also observed for the volatile matter and calorific value. E. ebano has the lowest volatile matter (72%), highest calorific value (19.6 MJ/kg) as well as the fixed carbon (21%).DiscussionThe pellets of the species studied have a high energy density, which makes them suitable for both commercial and industrial heating applications.A pellet with low compression resistance tends to disintegrate easily, due to moisture adsorption. The percentages obtained for the resistance index were higher than 97.5%, showing that the pellets studied are high-quality biofuels. Proximate analysis values also indicate good combustion parameters. Pellets of Acacia wrightii and Ebenopsis ebano are the more favorable raw material sources for energy purposes because of their high density, calorific value, low ash content and they also met majority of the international quality parameters.

Particulate Matter Production of Small Heat Source Depending on the Bark Content in Wood Pellets

Wood pellets as biofuel are more and more used in small heat sources in Europe. Standard wood pellets are produced from wood sawdust without bark. The paper deals about the impact of bark in wood pellets on their properties and combustion process. Special attention in this work is paid to production of particulate matter during combustion of wood pellets depending on bark content. There were experimentally produced spruce wood pellet samples with 0, 1, 2, 5, 10, and 20% content of bark. The density, moisture content, calorific value, ash content, and ash fusion temperature were detected on produced samples. Then, the combustion took place in a small heat source which was tested on an experimental device designed for the measuring of heat output and emission production. Based on the achieved results, we can conclude that bark content in pellets has a significant impact not only on wood pellet properties but also on performance and environmental characteristics of pellets. The results showed that growing bark content has negative impact on wood pellet properties, mainly decrease calorific value and ash fusion temperature, and increase ash content. Growing bark content in wood pellets also decreased heat output of heat source and increased gas emissions and particulate matter production.

Variation in the physical properties of wood pellets and emission of aldehyde/ketone under different storage conditions

Considering self-heating and hazardous gaseous emission, the safety of wood pellets storage has become one of the important aspects for woody biomass utilization. In this study, the emissions of aldehydes/ketones were analyzed by high performance liquid chromatogram (HPLC). The properties of pellets stored in semi-closed tanks with different temperatures and relative humidity (RH) were also investigated. The emissions of aldehydes and ketones from pellets were increased with raising temperature and RH during storage, while the pellets’ physical properties (dimension, density, Meyer hardness and moisture content) were reduced, except for 70% and 90% RH runs. The fatty acids compositions were extracted from both the surface and the inner part of pellets, which were analyzed by gas chromatography–mass spectrometry (GC–MS). The interaction between pellets’ physical properties variation and unsaturated fatty acid oxidation was revealed by the investigation of differences of extracted unsaturated fatty acids concentration between the surface and the inner part of pellets, which affected the aldehydes and ketones emissions.

Changes in mechanical properties of wood pellets during artificial degradation in a laboratory environment

In stockpiles exposed to high relative humidity (RH) and rainfall, woody biomass pellets lose structural integrity, often assumed to be due to the uptake of moisture from the environment. In this study three different types of biomass pellet were artificially degraded in a laboratory environment under controlled exposure to RH (10% and 90% RH) and temperature (range of 10 to 30°C). White, torrefied and steam-exploded wood pellets were investigated. Daily shear tests were conducted with durability and moisture content measured. The exposure of all three pellet types to high RH coupled with elevated temperatures caused a substantial decrease of shear modulus with values of 50% to 92% decrease compared to fresh pellets after 4days of exposure.The steam exploded pellets saw the lowest drop in mechanical durability (5%) but saw the largest decrease in shear modulus, whilst the white wood pellets disintegrated in situ after 4days. In contrast storage at 10% RH did not cause any observable degradation, with mechanical behaviour of steam exploded and torrefied pellets showing an improvement. This paper presents both testing methodology as well as clear indication of the behaviour of three woody biomass pellets on exposure to high relative humidity.

Impact of supercritical extraction on solid fuel wood pellet properties and off-gassing during storage

Biofuel pellets derived from wood raw material are an important carbon neutral source of energy.

Physico-chemical properties of wood pellets from coppice of short rotation tropical hardwoods

The study investigated the physical and chemical properties of wood pellets from coppice of intensively cultured tropical hardwoods viz., Gmelina arborea, Acacia mangium and Paraserianthes falcataria. Proximate, ultimate and elemental analyses were performed to assess fuel properties of pellets from coppice feedstock. In general, physical and chemical properties of pellets from coppice biomass were within recommended limits for class A2 pellets under EN 14961-2. Pellets from coppice of tree species used in this study showed good potential for compressed solid fuel for industrial and residential heating applications.

Effect of process parameters and raw material characteristics on physical and mechanical properties of wood pellets made from sugar maple particles

The aim of the current study was to investigate the influence of process parameters and raw material characteristics on physical and mechanical properties of wood pellets made from particles of sugar maple trees of different vigor. Pellets were made in a single pelletizer while controlling temperature (75, 100 and 125 °C), moisture content (8.1, 11.2 and 17.2%), compression force (1500, 2000 and 2500 N) and particle size (<0.25, 0.25–0.5 and 0.5–1.0 mm). Particle size was the most important factor influencing friction in the die, followed by moisture content, compression force and temperature. Moisture content was the most important factor affecting pellet density, followed by temperature, compression force and raw material particle size. Temperature was the most important factor for pellet compression strength, followed by compression force, particle size and moisture content. Friction in the die decreased with increasing particle size and moisture content of the material and increased with increasing compression force. It decreased initially with increasing temperature from 75 °C to 100 °C, and then increased with temperature. Density and strength of pellets increased with temperature and compression force, decreased with increasing particle size, and decreased with increasing moisture content. Pelletizing should be performed at 100 °C to minimize friction and a moisture content of 11.2% to maximize density and compression strength of the pellets. Wood particles from sugar maple trees of low vigor were more suitable for making wood pellets in terms of friction in the pelletizer and compression strength than those from vigorous trees.

Kis teljesítményű faalapú pellet tüzelő berendezés környezeti hatásainak vizsgálata I.

&lt;p&gt;Köztudott, hogy sokféle típusú és méretű dendromassza alapon működő hőtermelő egység működik szerte a világban. Általános jellemzőjük, hogy a tüzelés során különböző környezeti hatások forrásainak kell ezeket tekinteni. Legjellemzőbb környezetszennyező közegnek - számos egyéb mellett (pl: zaj, hamu, alapanyag beszállításból adódó környezeti terhelés, stb...) - a füstgázt tekintjük.&lt;/p&gt;&lt;p&gt;Kutatásom egyik alapcélja, hogy különböző fafajtából készült pelletek alaptulajdonságai, a tüzeléstechnikai paraméterek, valamint a környezeti terhelések között összefüggéseket keressek. Cikkemmel a jelenleg is folyamatban lévő kutatásomba szeretnék tehát betekintést nyújtani, ahol egy általános pellet tüzelésű kazán segítségével vizsgálom meg a tüzelés során létrejövő károsanyag kibocsátás és a pellet tulajdonságainak összefüggéseit.&lt;/p&gt;

Direct measurements of thermal properties of wood pellets: Elevated temperatures, fine fractions and moisture content

The self-heating propensity of biomass fuels is a major challenge to the large scale handling of e.g. wood pellets. The insulating properties in combination with exothermal processes sometimes lead to fires when larger volumes of wood pellets are stored. Recently, the thermal conductivity and specific heat of wood pellets have been investigated (Gou et al., 2013) through back-calculations of transient temperatures in wood bulk storage. Such properties are important in order to make simulations and predictions about safe storage and use. However, little information is available about the temperature dependence of these properties as well as the bulk properties of broken pellets, which is abundant in critical parts of a storage facility. In this study we show that the specific heat and thermal conductivity of wood pellets can be directly measured using the Transient Plane Source technique. We present data between 22 and 120°C for bulk wood pellets and investigate the change in conductivity for fine particle bulk material. In addition, we investigate the possibility of measuring on individual pellets while studying the moisture content dependence.

Влияние содержания и состава сложных полимерных соединений на физико-механические свойства древесных пеллет

Влияние содержания и состава сложных полимерных соединений на физико-механические свойства древесных пеллет

Effect of low and high storage temperatures on headspace gas concentrations and physical properties of wood pellets

Headspace gas concentrations and wood pellet properties were studied in sealed glass canisters at 5–40°C storage temperatures. CO2 and CO concentrations at 5, 10, 20 and 40°C at the end of 23–28 days of storage were 1600 and 200, 4700 and 1200, and 31 200 and 15 800 parts per million by volume (ppmv) respectively. Corresponding O2 concentration was about 19·49, 19·20, 18·0 and 2·07% respectively. Non-linear regression equations adequately described the gas concentrations in the storage container as a function of time. Safe level estimation functions developed were linear for O2 and logarithmic for CO and CO2 concentrations. Measured pellet properties moisture, length, diameter, unit, bulk and tapped density, durability, calorific value, ash content and percent fines were in the range of 4·6–5·02%, 14–15 mm, 6·4–6·5 mm, 1125–1175 kg m−3, 750–770 kg m−3, 825–840 kg m−3, 73–74%, 18·32–18·78 MJ kg−1, 0·65–0·74% and 0·13–0·15%. Durability values of pellets decreased by 13% at 40°C storage temperature and other properties changed marginally.

Optimization of the Production Process of Wood Pellets by Adding Additives

In this work are described the possibilities for improving efficiency of wood pellets production. The introductory part is devoted to analyzing the properties of wood pellets, combustion and production of pollutants when combusted it. The production of wood pellets and used pelleting machines was analyzed. The main task of this work is to introduce efficiency pelleting lines and cost reduction of the wood pellets production as fuel with a focus on the effects of adding additives. The results of experimental measurements and properties of wood pellets with different additives are presented in the final part.