scholarly journals HERBACEOUS BIOMASS SHREDDING FOR BIOFUEL COMPOSITIONS

Author(s):  
Eriks Kronbergs ◽  
Mareks Smits

The 2003 reform o f the EU Common agricultural policy stimulates farmers to grow more energy crops, including short rotation coppice and other perennial crops. Peat can be used as additive for manufacturing o f solid biofuel, because it improves density, durability o f stalk material briquettes (pellets) and avoid corrosion o f boilers. For these reason herbaceous biomass compositions with peat fo r solid biofuel production is recommended. The main conditioning operation before biomass compacting is shredding. It was stated that common reed stalk material particle size reduction during cutting (shredding) process increased energy consumption very significantly. The calculation o f energy consumption fo r common reed cutting to sizes 0.6 and 0.5 mm was giving results 31.3 k J kg'1 and 43.5 k J kg'1. The shredder cutter bar has to be designed with friction energy losses decreased to minimum. This aim can to be realized by reducing o f area o f cutter bar knives moving into stalk biomass and minimizing biomass pressure (Patent LV13447) on cutter bar.

Author(s):  
Eriks Kronbergs ◽  
Mareks Smits

Herbaceous biomass can be obtained using delayed harvesting method with moisture content less than 15% and directly densified without drying. Size reduction experiments of common reed stalks as cutting, flattening and densification have been carried out. As the result of reed stalk flattening, more than 8 strips can be obtained from this tubular structure. Average energy consumption 273 – 380 J kg-1 had been stated for reed stalk flattening. Specific cutting energy Escq value varies in 8 – 16 kJ m-2 in dependence of punch orientation angle according cross-section of reed specimen. Specific cutting energy for flattened stalk materials for reed density 600 kg m-3, varies Esc=13.3 – 27 J m kg-1. Densification experiments of compositions from peat particles, coarse wheat stalk and reed material particles from (1 - 2 mm) group with pressure 230 MPa indicated influence of peat proportion. Density 1.0 g cm-3 has been obtained in densification of straw stalk material particle compositions with peat, if peat proportion exceeds 20%.


2017 ◽  
Vol 31 (4) ◽  
pp. 575-581 ◽  
Author(s):  
Tajana Krička ◽  
Ana Matin ◽  
Nikola Bilandžija ◽  
Vanja Jurišić ◽  
Alan Antonović ◽  
...  

Abstract In the context of the growing demand for biomass, which is being encouraged by the EU directives on the promotion of the use of renewable energy, recent investigations have been increasingly focused on fast-growing energy crops. The aim of this study was to investigate the energy properties of three types of agricultural energy crops: Arundo donax L., Miscanthus × giganteus and Sida hermaphrodita. This investigation looked into the content of non-combustible and combustible matter, higher and lower heating values, lignocellulose content, and biomass macro-elements. The results indicate that the energy values of these crops are comparable, while their lignocellulose content shows significant variations. Thus, Arundo donax L. can best be utilised as solid biofuel due to its highest lignin content, while Miscanthus × giganteus and Sida hermaphrodita L. can be used for both liquid and solid biofuels production. As far as Arundo donax L. is concerned, a higher ash level should be taken into consideration.


Author(s):  
E. Repsa ◽  
E. Kronbergs ◽  
M. Smits

The paper present experimental investigation results of common reeds (Phragmites australis) particle compacting in closed die. Common reeds are important natural biomass resource in Latvia. Compacting of biomass is very complicated process for solid biofuel production and there are many factors influencing to this process. The quality parameters of compacted biomass are described by European countries standards for solid biofuel. Density is the most important quality parameter of biomass compacting. The paper present results of common reeds particles compacting mechanism in closed die. Maximum pressure 212 MPa had been achieved in compacting. For compacting process evaluation has been determined pressing energy and density of briquettes. The minimum of density 0.87 g cm-3 have briquettes with particle size 12 – 13 mm, but maximum density 1.03 – 1.04 g cm-3 two particle sizes < 0.5 mm and 32 – 33 mm briquettes. Maximum value of energy consumption for compacting (~172 kJ kg-1) has been obtained for reed particle size 32 – 33 mm, minimum value (~53 kJ kg-1) for particle size less than 0.5 mm.


2018 ◽  
Vol 10 ◽  
pp. 02006 ◽  
Author(s):  
Tatiana Ivanova ◽  
Bohumil Havrland ◽  
Radek Novotny ◽  
Alexandru Muntean ◽  
Petr Hutla

Biomass is doubtless a very significant source of renewable energy being worldwide abundant with high energy potential. This paper deals with assessment energy consumption at especially grinding and briquetting processes, which should result in essential economy of energy at solid biofuel production. Various types of raw materials were used at the experiment such as hemp (Cannabis sativa L.) biomass, two species of Miscanthus (Miscanthus sinensis, Miscanthus x gigantheus) and apple wood biomass. These materials were dried, grinded and pressed by piston press having pressing chamber diameter of 65 mm. Materials were grinded into three fractions (4 mm, 8 mm and 12 mm). Material throughput (kg.h-1) and energy consumption (kWh.t-1) were registered. As to results: the highest throughput at both grinding cases as well as briquetting was found at apple wood biomass; however the energy consumption during briquetting of apple wood was relatively high. The worst results concerning throughput and energy consumption (especially at briquetting) were found at hemp biomass. Nevertheless, briquettes made of hemp had the best mechanical durability. Both Miscunthus species (herbaceous biomass) have very similar parameters and showed quite good relation between throughput and energy consumption at the used machines.


Author(s):  
Ēriks Kronbergs ◽  
Mareks Šmits

The main steps of rural policy to the development of renewable energy resources are energy crop production. Latvia can provide for the use of approximately 0.36 million ha of the unused now agricultural land for herbaceous energy crop growing. More than 230 million tones of peat are available for solid biofuel production. Peat is recomended as additive because it improves density and burning properties of herbaceous material solid biofuel. Herbaceous stalk material can be harvested in winter season with humidity less than 15% and used for compacting without drying. The aim of experimental investigation is to determine conditioning methods for solid biofuel production with minimum energy consumption. Common reed stalk material is used for experiments, because it experimentally stated ultimate tensile strength is 256 ± 27 N mm-2. This value testifies that common reeds are twice strongest material than cereal crop stalk materials and conditioning mechanization equipment of common reeds would be useful for other energy crops.


Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4209
Author(s):  
Rita Remeikienė ◽  
Ligita Gasparėnienė ◽  
Aleksandra Fedajev ◽  
Marek Szarucki ◽  
Marija Đekić ◽  
...  

The main goal of setting energy efficiency priorities is to find ways to reduce energy consumption without harming consumers and the environment. The renovation of buildings can be considered one of the main aspects of energy efficiency in the European Union (EU). In the EU, only 5% of the renovation projects have been able to yield energy-saving at the deep renovation level. No other study has thus far ranked the EU member states according to achieved results in terms of increased usage in renewable sources, a decrease in energy usage and import, and reduction in harmful gas emissions due to energy usage. The main purpose of this article is to perform a comparative analysis of EU economies according to selected indicators related to the usage of renewable resources, energy efficiency, and emissions of harmful gasses as a result of energy usage. The methodological contribution of our study is related to developing a complex and robust research method for investment efficiency assessment allowing the study of three groups of indicators related to the usage of renewable energy sources, energy efficiency, and ecological aspects of energy. It was based on the PROMETHEE II method and allows testing it in other time periods, as well as modifying it for research purposes. The EU member states were categorized by such criteria as energy from renewables and biofuels, final energy consumption from renewables and biofuels, gross electricity generation from renewables and biofuels and import dependency, and usage of renewables and biofuels for heating and cooling. The results of energy per unit of Gross Domestic Product (GDP), Greenhouse gasses (GHG) emissions per million inhabitants (ECO2), energy per capita, the share of CO2 emissions from public electricity, and heat production from total CO2 emissions revealed that Latvia, Sweden, Portugal, Croatia, Austria, Lithuania, Romania, Denmark, and Finland are the nine most advanced countries in the area under consideration. In the group of the most advanced countries, energy consumption from renewables and biofuels is higher than the EU average.


2021 ◽  
Vol 11 (11) ◽  
pp. 5108
Author(s):  
María Esther Liébana-Durán ◽  
Begoña Serrano-Lanzarote ◽  
Leticia Ortega-Madrigal

In order to achieve the EU emission reduction goals, it is essential to renovate the building stock, by improving energy efficiency and promoting total decarbonisation. According to the 2018/844/EU Directive, 3% of Public Administration buildings should be renovated every year. So as to identify the measures to be applied in those buildings and obtain the greatest reduction in energy consumption at the lowest cost, the Directive 2010/31/EU proposed a cost-optimisation-based methodology. The implementation of this allowed to carry out studies in detail in actual scenarios for the energy renovation of thermal envelopes of public schools in the city of Valencia. First, primary school buildings were analysed and classified into three representative types. For each type, 21 sets of measures for improving building thermal envelopes were proposed, considering the global cost, in order to learn about the savings obtained, the repayment term for the investment made, the percentage reduction in energy consumption and the level of compliance with regulatory requirements. The result and conclusions will help Public Administration in Valencia to draw up an energy renovation plan for public building schools in the city.


Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1570
Author(s):  
Tomasz Rokicki ◽  
Aleksandra Perkowska ◽  
Bogdan Klepacki ◽  
Piotr Bórawski ◽  
Aneta Bełdycka-Bórawska ◽  
...  

The paper’s main purpose was to identify and present the current situation and changes in energy consumption in agriculture in the European Union (EU) countries. The specific objectives were the determination of the degree of concentration of energy consumption in agriculture in the EU countries, showing the directions of their changes, types of energy used, and changes in this respect, establishing the correlation between energy consumption and changes in the economic and agricultural situation in the EU countries. All member states of the European Union were deliberately selected for research on 31 December 2018 (28 countries). The research period covered the years 2005–2018. The sources of materials were the literature on the subject, and data from Eurostat. Descriptive, tabular, and graphical methods were used to analyze and present materials, dynamics indicators with a stable base, Gini concentration coefficient, concentration analysis using the Lorenz curve, coefficient of variation, Kendall’s tau correlation coefficient, and Spearman’s rank correlation coefficient. A high concentration of energy consumption in agriculture was found in several EU countries, the largest in countries with the largest agricultural sector, i.e., France and Poland. There were practically no changes in the concentration level. Only in the case of renewable energy, a gradual decrease in concentration was visible. More and more countries developed technologies that allow the use of this type of energy. However, the EU countries differed in terms of the structure of the energy sources used. The majority of the basis was liquid fuels, while stable and gaseous fuels were abandoned in favor of electricity and renewable sources—according to which, in the EU countries, the research hypothesis was confirmed: a gradual diversification of energy sources used in agriculture, with a systematic increase in the importance of renewable energy sources. The second research hypothesis was also confirmed, according to which the increase in the consumption of renewable energy in agriculture is closely related to the economy’s parameters. The use of renewable energy is necessary and results from concern for the natural environment. Therefore, economic factors may have a smaller impact.


2021 ◽  
Vol 195 ◽  
pp. 110775
Author(s):  
Congyu Zhang ◽  
Shih-Hsin Ho ◽  
Wei-Hsin Chen ◽  
Chun Fong Eng ◽  
Chin-Tsan Wang

2021 ◽  
Vol 13 (14) ◽  
pp. 7650
Author(s):  
Astrida Miceikienė ◽  
Kristina Gesevičienė ◽  
Daiva Rimkuvienė

The reduction of GHG emissions is one of the priorities of the EU countries. The majority of studies show that financial support and environmental taxes are one of the most effective measures for the mitigation of the negative consequences of climate change. The EU countries employ different environmental support measures and environmental taxes to reduce GHG emissions. There is a shortage of new studies on these measures. The aim of the present study is to compare the effectiveness of the environmental support measures of the EU countries with the effectiveness of environmental taxes in relation to the reduction of GHG emissions. This study is characterized by the broad scope of its data analysis and its systematic approach to the EU’s environmental policy measures. An empirical study was performed for the EU countries with the aim of addressing this research problem and substantiating theoretical insights. A total of 27 EU member states from 2009 to 2018 were selected as research samples. The research is based on a cause-and-effect relationship, where the factors affecting environmental pollution (environmental taxes and subsidies) are the cause, and GHG emissions are the effect. Statistical research methods were used in the empirical study: descriptive statistics, the Shapiro–Wilk test, one-way analysis of variance (ANOVA), simple regression and cluster analysis. The results show that the older member countries of the EU, which had directed the financial measures of environmental policy towards a reduction in energy consumption, managed to achieve a greater reduction in GHG emissions compared to the countries which had not applied those measures. The Central and Eastern European countries are characterized by lower environmental taxes and lower expenditure allocated to environmental protection. The countries with a higher GDP per capita have greater GHG emissions that the countries with lower GDP per capita. This is associated with greater consumption, waste, and energy consumption. The study conducted gives rise to a discussion regarding data sufficiency in the assessment and forecasting of GHG emissions and their environmental consequences.


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