Agricultural biomass is one of the most important renewable energy sources. As a byproduct of corn, soybean and sunflower production, large amounts of biomass are produced that can be used as an ...energy source through conversion. In order to assess the quality and the possibility of the use of biomass, its composition and calorific value must be determined. The use of nonlinear models allows for an easier estimation of the energy properties of biomass concerning certain input and output parameters. In this paper, RFR (Random Forest Regression) and SVM (Support Vector Machine) models were developed to determine their capabilities in estimating the HHV (higher heating value) of biomass based on input parameters of ultimate analysis. The developed models showed good performance in terms of HHV estimation, confirmed by the coefficient of determination for the RFR (R2 = 0.79) and SVM (R2 = 0.93) models. The developed models have shown promising results in accurately predicting the HHV of biomass from various sources. The use of these algorithms for biomass energy prediction has the potential for further development.
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Hazelnut fruit samples were collected over 2 years (2020 and 2021) and subjected to four different drying temperatures (100, 120, 140, and 160 °C) and four different drying times of 15, 30, 45, and ...60 min using conduction drying. The analyses performed showed that conduction drying at different temperatures and different drying times had a significant effect on the change in the composition of the hazelnut shell fuel and its mass properties. Comparing the untreated samples over two years and the samples after drying, it can be seen that in 2020, the drying treatment causes a decrease in the percentage of C and H, while in 2021, drying at 160 °C and 45 min causes an increase in C and H values. After treatment, the S content decreased on average, while the value of O increased or remained the same. The greatest increase in heating values (HHV and LHV) was observed at temperatures of 140 °C and 120 °C and the duration of 45 min. When drying was applied, a significant difference in mass change was observed at 120 °C, 100 °C, and 140 °C and 30 and 60 min process durations. The change in heating value is significantly affected by the parameters year of sampling, temperature, and time, while the change in mass of the hazelnut shell is most affected by drying time.
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A number of measures to diversify its energy supply sources and reduce its dependence on imported energy sources has been taken by the EU. These include pursuing new energy sources, such as renewable ...energy and liquefied natural gas; increasing the storage capacities; and investing in interconnectors and other infrastructure. However, these actions require long-term adjustment, while there is a need to find an option to meet the energy needs at a moment. One possible option is to utilize seed production wastes for energy production. This research paper aims to investigate the potential of utilizing seed production wastes (SPWs) for energy production in continental Croatia, and assess its feasibility. Eight different SPWs were used in this research, where their energy characteristics were determined and the theoretical thermal potential was calculated if they are used as raw material in the production of thermal energy through biomass and cogeneration power plants, or in biogas power plants. By using the available feedstock, it is theoretically possible to produce a total of 38,051.10 GJ of thermal energy by direct combustion of SPWs and 34,727.91 GJ by combustion of the produced biomethane. The SPWs of oilseed rape and beans contain the highest specific heat potential per hectare.
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Biomass as a renewable energy source includes energy crops that are not used for food but solely for biomass production with the goal of conversion to various forms of biofuel. Switchgrass, a ...perennial grass native to North America, has been explored as an energy crop for many years. It is suitable because it does not require much agrotechnical input, is highly resistant to pest infestation and disease development, and can provide very high biomass yields. The aim of this work was to determine the biomass quality of the mentioned plant in relation to the autumn and spring harvest, considering its use in direct combustion processes. Significant differences were found in the percentages of ash, carbon, nitrogen, sulfur, oxygen, and water, as well as in the percentages of micro and macro elements, in the harvest dates studied. Compared to the autumn, the moisture content decreased from 33.88% to 10.95% and ash content from 4.59% to 3.1% in the spring harvest, while the carbon content increased from 47.02% to 47.49%, dry matter from 38.91% to 89.22%, and heating value from 18.60 MJ kg−1 to 18.73 MJ kg−1. Shifting the harvest date from autumn to spring resulted in the production of higher quality biomass for use in combustion processes.
Globally, lignocellulosic biomass has great potential for industrial production of materials and products, but this resource must be used in an environmentally friendly, socially acceptable and ...sustainable manner. Wood and agricultural residues such as walnut shells as lignocellulosic biomass are one of the most affordable and important renewable resources in the world, which can partially replace fossil resources. The overall objective of the research is to provide background information that supports new applications of walnut shells in a biorefinery context and to increase the economic value of these non-wood forest products. This paper presents the properties characterization of liquefied biomass according to their chemical composition. All results were compared to liquefied wood. In this study, the liquefaction properties of five different walnut shell particle sizes were determined using glycerol as the liquefaction reagent under defined reaction conditions. The liquefied biomass was characterized for properties such as percentage residue, degree of liquefaction, and hydroxyl OH numbers. The chemical composition of the same biomass was investigated for its influence on the liquefaction properties. Accordingly, the main objective of this study was to determine the liquefaction properties of different particle sizes as a function of their chemical composition, also in comparison with the chemical composition of wood. The study revealed that walnut shell biomass can be effectively liquefied into glycerol using H2SO4 as the catalyst, with liquefaction efficiency ranging from 89.21 to 90.98%.
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The increasing amount of residual waste presents several opportunities to use biomass as a renewable energy source. Agricultural biomass is a raw material with a high ash content, which can be a ...problem in any form of energy conversion. To obtain better quality biofuel, excess mineral matter must be removed. Demineralization is a simple form of mixing and washing biomass with various liquids to reduce ash content. Water, acetic acid, hydrochloric acid and nitric acid are common solvents used for this purpose. Ash is composed of different micro (Zn, Cu, Fe) and macro elements (Mg, Ca, K), which can have different consequences for the use of biomass for thermal energy. Different solvents have different effects on the individual elements, with inorganic acids having the greatest effect in demineralization processes, with a reduction in ash content of up to 80% for corn and about 99% for soybeans.
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Climatic conditions are extremely important for the start and spread of forest fires. Flammability and the spread of fire are sensitive to the interactions of variables within ecosystems, such as ...weather, fuel, and topography. Certain variables are highly significant for forest fires and are applied in various models, particularly the moisture content of potential fuel, and its flammability or combustibility. However, such these models cannot determine the true values of the required variables, unlike actual empirical research. Areas with the highest number of fires show significant variability and differences in air temperature, humidity, and precipitation. These factors have a strong influence on flammability, combustibility, and moisture content of Mediterranean species. This study analyses the flammability and combustibility of two Mediterranean species important for the Adriatic area in Croatia: climazonal holm oak (Quercus ilex L.) and Aleppo pine (Pinus halepensis Mill.) as an important conifer for afforestation and reforestation. The results of linear correlation coefficients of flammability of these species at the studied localities show a statistically significant and very strong correlation between flammability and the moisture content of the tested sample, with the exception of Aleppo pine on the island of Rab. The analysis of variance of combustibility showed that there were no statistically significant differences between nearly all variables tested. The results indicate the significant effect of live fuel moisture content on the flammability and combustibility of natural fuels.
Biomass Pelletizing Process Dujmović, Marin; Šafran, Branimir; Jug, Matija ...
Drvna industrija,
03/2022, Volume:
73, Issue:
1
Journal Article
Peer reviewed
Open access
A review paper was designed as a lab-scale start-up guideline for general pelletizing process and technologies for biomass feedstock. The main body consists of summarized published research on the ...topic of all main parts of the biomass pelletizing process and technology, including machinery and their parts, optimal feedstock conditions as well as pellet forming processes and principles. This paper is more focused on the specific parameters necessary to obtain optimal pelletizing process that results in desired pellet quality, and less on feedstock preparation, final product post-treatment (e.g. cooling), handling (storage, transportation) or exact quality specifications. A summary of the suggested feedstock, technological and other parameters for the purpose of easier lab-scale start-up of biomass pellets production, which is based on the cited literature throughout this paper, is given in the last section.
Pregledni rad pripremljen je kao laboratorijski priručni materijal za osnovne procese i tehnologije peletiranja biomase. U njemu su sistematizirane spoznaje iz dostupnih izvora literature o temi glavnih dijelova procesa i tehnologije peletiranja biomase, uključujući strojeve i njihove pripadajuće dijelove, optimalne ulazne parametre sirovine, kao i načela i procese izrade peleta. Ovaj je priručni materijal više usmjeren na specifične parametre nužne za optimalan proces peletiranja radi dobivanja peleta željene kvalitete, a manje na pripremu sirovine, tretiranje proizvedenog peleta (npr. hlađenje), rukovanje peletima (skladištenje, transport) ili na određena kvalitativna svojstva peleta. Sažetak preporučenih tehnoloških parametara i ulaznih parametara sirovine, koji se temelji na informacijama iz navedene i citirane literature, nalazi se na kraju ovoga preglednog rada.
Wood is still the most widely used raw material for pulp and paper production in the world. However, due to the necessity to supply the paper industry with raw materials used in the extraction of ...cellulose fibres and the overexploitation of forests, new sources of primary pulp fibres had to be identified. The aim of this research is to highlight the important features of cereal crop residues and their utilization in the paper industry. As the chemical composition of plant materials is one of the most important indicators of how such materials can be used in paper production, the analysis of the chemical composition of straw with the highest grain production was performed. The straw, as a harvesting residue, is a fibre resource available from the annually renewable crops, produced abundantly in numerous regions all over the world. For the purpose of the research, wheat, triticale and barley straw were selected for the analysis. The analysis of carbohydrate, lignin and extraneous material (organic extractives and inorganic minerals) was performed in order to obtain the straw chemical composition. Based on the results of the chemical composition of all analysed straw, it was confi rmed that straw, as an agricultural by-product, is rich in cellulosic fibres and, therefore, a valuable raw material for the paper industry. Out of all analysed straw, based on the results of their chemical composition, triticale straw is considered potentially the best source of alternative cellulose fibres.
The objective of this study was to investigate the changes in the nutrient and fatty acid profiles of hazelnuts ( Corylus avellana ) and walnuts ( Juglans regia ) subjected to continuous drying. ...Samples from two consecutive years (2020 and 2021) were analyzed for nutritional value both before and after conduction drying. Thermal conduction drying was performed at 60 and 80°C at intervals of 15, 30, 45, and 60 min. The results showed that hazelnuts had increased ash, protein (from 16.4 to 18.7%), carbohydrate and starch content, while walnuts had a higher pH and fat content (from 60.97 to 71.02%). After drying, increasing temperatures resulted in significant changes in nutrient concentrations for both nuts, including changes in ash, protein, fat (hazelnuts from 58.69 to 71.48% at 60°C for 60 min), carbohydrate and starch content, and pH. Monounsaturated and polyunsaturated fatty acid content varied by sample and year, with notable trends such as the increase in oleic acid in walnuts from 82.26 to 83.67%. Longer drying times and higher temperatures correlated with an increase in monounsaturated fatty acids and a decrease in polyunsaturated fatty acids in both nut types. In conclusion, conduction drying, especially at higher temperatures and longer durations, significantly affects the nutrient and fatty acid profiles of hazelnuts and walnuts. The study provides new insights into the effects of drying conditions on the nutrient composition and fatty acid profiles of hazelnuts and walnuts and reveals significant changes that warrant further investigation. It sets the stage for future research to extend these findings to other nut species and alternative drying processes and highlights the importance of optimizing processing parameters for improved health benefits and sustainability.
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