خيارات البحث
النتائج 1 - 10 من 11
RES [renewable energy sources] utilisation development in Lithuanian rural places
2016
Pazeraite, A., Lithuanian Energy Inst., Kaunas (Lithuania);Vytautas Magnus Univ., Kaunas (Lithuania) | Repoviene, R., Vytautas Magnus Univ., Kaunas (Lithuania);Lithuanian Energy Inst., Kaunas (Lithuania
Energy transition from the fossil fuel dominating to the one based on renewable energy sources (RES) takes acceleration with the internationally recognised need to stabilise the global warming. Therefore, there is a general consensus that the initiative of the wide use of RES is manifold in its nature making an impact not only on the environmental issues, but also adding to the so desired customer involvement and rural development as well. Rural dimension in reaching the EU targets should arguably be a priority as RES utilisation is decentralised in its nature. Despite the fact that EU with its main strategic documents gives a clear direction on RES utilisation through wider involvement of citizens, especially in rural places, there are certain grounds for stating that a current situation and future insights among EU Member States still differ. Lithuanian case was chosen to explore the sustainability gaps regarding the RES utilisation development in rural places. Literature review is employed to choose the most suitable way aiming to explore and evaluate the RES utilisation development in rural places regarding the sustainability issues. This article adds to understanding and evaluating the main obstacles of the well balanced RES utilisation development in rural places.
اظهر المزيد [+] اقل [-]Use of forest based biomass for bioenergy in EU-28
2014
Sikkema, R., European Commission, Ispra, Varese province, Lombardy reg. (Italy). Joint Research Centre. Inst. for Environment and Sustainability | Fiorese, G., European Commission, Ispra, Varese province, Lombardy reg. (Italy). Joint Research Centre. Inst. for Environment and Sustainability
Europe’s future wood demand for energy is expected to increase by 10 million to 200 million m3 in the period 2010- 2030. This will be supplied by both domestic sources (forests, industrial residues post-consumer wood waste), but also from sources outside Europe. The EU-28 predicts a near future (2020) gap between solid biomass supply and demand for renewable energy: 21.4 million tonnes of oil equivalents (MTOE). This is estimated via preliminary renewable energy action plans (NREAP’s) per country. The EU-28 expects wood pellet import will merely complete this gap of 21.4 MTOE, with more than 50 million tonnes of pellets. This implies a feedstock need of 125 million m3 of wood from forests and other sources outside the EU-28. A practical approach to include bioenergy in wood sector models should start with the input of wood pellets. Ideally, three types of bioenergy markets should be considered, in which pellets and the other major woody feedstock are included: 1. Large scale power production (the UK, Belgium, the Netherlands, all importing pellets from outside the EU-28); 2. Medium scale combined heat and power (CHP’s) including those in the forest sector (Nordic countries use pellets and chips for energy, merely imported from the EU-28); 3. Small scale residential heating (Germany, Austria and Italy, using wood pellets and logs from regional sources). We suggest starting with inclusion of medium scale CHP’s, followed by large scale power production. Small scale heating is relatively stable and should not have large impacts on future markets.
اظهر المزيد [+] اقل [-]The role of agriculture in ensuring the energy security in Poland
2014
Marks-Bielska, R., University of Warmia and Mazury in Olsztyn (Poland) | Kurowska, K., University of Warmia and Mazury in Olsztyn (Poland) | Kryszk, H., University of Warmia and Mazury in Olsztyn (Poland)
The purpose of this article has been to present a range of products which can be obtained from agricultural production and used for energy purposes. The domestic demand for plant material to be converted to biocomponents was assessed, including the demand for oilseed rape seeds and other grain used to make bioethanol in Poland. One of the ways to limit the adverse effect of fossil fuels on the environment is by using renewable resources. Agriculture is the producer of biomass used to make biocomponents for liquid fuels and raw materials for substitution of solid fuels. The EU, wishing to stimulate production of biomass for energy purposes, has brought to life several legal acts which force the use of biofuels in the European Community. Farmers who produce substrate for bio-fuel production were offered subsidies to energy crop plantations, at first paid from the state budget, and in 2007 – 2009 provided under the Common Agricultural Policy (CAP), which increased the farmers’ revenues from farming. The decisions approved of while reviewing the CAP are to improve – via the market mechanism – the production and export potential of the whole EU. This is to be achieved, for example, by abolishing the subsidies to energy crops, which ceased to be paid in 2010. Such subsidies improved (artificially) the profitability of energy crop plantations, while causing a relative decrease in food production in Europe. By participating in the CAP, Poland is obliged to undertake certain measures in the domestic policy that will comply with the decisions made on the EU level.
اظهر المزيد [+] اقل [-]Load effect on the dynamic parameters of the wind station
2013
Komass, T., Latvia Univ. of Agriculture, Jelgava (Latvia)
The research paper discusses simulation of the loading process of the vertical axis wind turbine with the permanent magnet synchronous generator. Experimental and analytical studies were done in the year 2013. The research results show that electrical load on the wind turbine generator is important for the wind turbine performance. If the load is above or below the power gained from the wind energy, the turbine operation cannot be considered efficient and its dynamic parameters fail to achieve the efficiency level at the proper operation load when the load is built up strictly in accordance with the wind energy input. In the research, 3 separate virtual electrical loading models with static, discrete, dynamic electrical load were established. MATLAB SIMULINK simulated virtual model shows the importance of usage of the right amount of electrical load in the vertical axis wind turbine with the permanent magnet synchronous generator. Final research results showed that the most effective loading process of wind turbine generator is a dynamic load.
اظهر المزيد [+] اقل [-]Review about investigations of Salix spp. in Europe
2013
Pucka, I., Latvia Univ. of Agriculture, Jelgava (Latvia) | Lazdina, D., Latvian State Forest Research Inst. Silava, Salaspils (Latvia)
Willow species are nowadays extensively studied. Species are being investigated to evaluate their use and role in various sectors of national economy. The use of willows in short rotation coppice (SRC) for biomass and energy production has a priority in the European Union policy. There are many countries that have grants and financial aid system for so-called ‘green energy’ production. Willow species also have other economically and ecologically important features: resistance to contaminants, strong root system, high tannin contents, decorative, etc. Willow SRC systems are used for phytoremediation and in wastewater purification, in combination with biomass production. There are several countries of Eastern Europe researching adequacy of the willow SRC for the farmland contaminated by radionuclides segregated from the Chernobyl nuclear power plant disaster. Willows are used for quarry restoration, water sludge treatment, erosion control etc, but the most important field at the moment is the biomass production.
اظهر المزيد [+] اقل [-]The environmental aspects of energy crops growing in the condition of the Czech Republic
2017
Kopecky, M., University of South Bohemia, Ceske Budejovice (Czech Republic) | Moudry, J. jr., University of South Bohemia, Ceske Budejovice (Czech Republic) | Bernas, J., University of South Bohemia, Ceske Budejovice (Czech Republic) | Suchy, K., University of South Bohemia, Ceske Budejovice (Czech Republic)
Renewable energy resources have been developing very fast due to negative effects and finite reserves of the fossil fuels. Biomass is ranked among the most promising renewable energy resources within the Central Europe. Corn (Zea mays L.) is currently the most widely grown crop in the Czech Republic; nevertheless, the cultivation of corn provokes soil erosion by water. Perennial energy grass called tall wheatgrass (Elymus elongatus subsp. Ponticus cv. Szarvasi-1) is supposed to be a good and environment-friendly alternative to corn. Field trials including these two crops were established in the experimental locality of South Bohemia. Their yield potential was monitored during spring harvest periods (use for combustion). Dry phytomass was fundamentally analysed (N, C, H, S) and higher heating value was determined too. Universal Soil Loss Equation was calculated for both crop species. Corn provided much higher average yield in a three-year interval; corn phytomass reached higher heating value as well. The area of Elymus elongatus should enlarge considerably, if we wanted to get the identical amount of energy from corn and Elymus elongatus. However, we found that, compared to Zea mays L., water erosion theoretical land losses would be several times less serious for Elymus elongatus.
اظهر المزيد [+] اقل [-]Pyrolysis and acid hydrolysis of lignocellulosic biomass as a tool for monosaccharide obtaining
2020
Godina, D., Latvian State Inst. of Wood Chemistry, Riga (Latvia);University of Latvia, Riga (Latvia) | Pomilovskis, R., Latvian State Inst. of Wood Chemistry, Riga (Latvia) | Iljina, N., Latvian State Inst. of Wood Chemistry, Riga (Latvia));University of Latvia, Riga (Latvia) | Meile, K., Latvian State Inst. of Wood Chemistry, Riga (Latvia
Due to the ever increasing demand for energy resources, more and more attention is being paid to renewable energy resources. One such potential resource is lignocellulosic biomass that can be treated to acquire a carbohydrate rich substrate for further use in producing biofuels such as bioethanol or biobutanol. In this study, birch (Betula pendula) chips were used in fast pyrolysis to acquire bio-oil. This bio-oil was further hydrolyzed in pressurized reactor Parr 4554 to produce a carbohydrate rich feedstock. Hydrolysis conditions were optimized. Several conditions − three different temperatures (111, 121, 131 °C) and four different sulfuric acid concentrations (0.05, 0.1, 0.2, 0.5 M) were tested. The optimal conditions were 121 °C with 0.2 M sulfuric acid as a catalyst that allowed to acquire a solution with the total glucose concentration being 6.6% that can be further used as a feedstock for biofuel acquiring.
اظهر المزيد [+] اقل [-]Heat of winter cereal crops
2015
Jansone, I., Latvia Univ. of Agriculture, Jelgava (Latvia);State Stende Cereals Breeding Inst., Dizstende, Libagi parish, Talsi Municipality (Latvia) | Gaile, Z., Latvia Univ. of Agriculture, Jelgava (Latvia)
Heat is one of the most important types of energy at northern latitudes. In 2013 the total consumption of renewable energy resources (RER) in Latvia was 68 PJ. The heating systems can function on plant or other organic material, for example, wood chips or agricultural residues. By using local biomass resources it is possible to reduce the pollution of atmosphere caused by greenhouse gas emissions. Different variety of winter wheat (Triticum aestivum), triticale (Triticosecale) and rye (Secale cereale) were used in the research. The following aspects were determined during the research: dry matter yield, chemical composition and the higher heating value of grains and straw. The evaluation of grains and straw of winter cereals showed that the higher heating value (MJ kgE-1) was acquired from the straw of winter cereals, whereas the grains had the highest dry matter yield, thus the grains of winter cereals had the highest heating yield from one hectare (GJ haE-1).
اظهر المزيد [+] اقل [-]Potential areas of low productivity agriculture lands for SRC [short rotation coppice] energy wood production in Vidzeme region [Latvia]
2015
Makovskis, K., Latvian State Forest Research Inst. Silava, Salaspils (Latvia) | Lazdina, D., Latvian State Forest Research Inst. Silava, Salaspils (Latvia)
Aim of the paper is to identify low productivity lands distribution in Vidzeme region, identify enterprises that could use wood chips from willow plantations established on these lands as the main resource in electricity and heat production and calculate produced wood ash amount from these enterprises that could be used as fertilizer and could be recycled in SRC plantations. For better soil fertility evaluation and economic turn predictions all agricultural lands are evaluated in quality units, where one quality unit in money is equal to 5.38 EUR or 70 kg of rye. According to studies, traditional farming in lands, which are below 38 quality units, could be unproductive. In Vidzeme region are 501,880 ha of agriculture lands from which 206,574 ha (52%) are lands with quality assessment under 38 units. According to local farmers’ opinion, the real quality unit, below which economically profitable farming is impossible, are 25 quality units. There are 87,900 ha of agricultural lands under 25 quality units, which represent 18% from all agricultural lands in region. These lands could be used by growing SRC plantations in 2013; the region has 48 enterprises that used wood chips, with total amount of 170,500 oven-dried tonnes per year. Wood chips from SRC plantation could be used in these enterprises. To fulfil the wood chip demand in the region, about 17,000 – 34,000 ha of agricultural land should be planted with SRC plantations. To increase the yields from these lands, fertilization is recommended. In this region are more than 300 enterprises, which use wood as the main resource for electricity or heat production leading to 14,000 oven-dried tons of wood ash production every year.
اظهر المزيد [+] اقل [-]Energy agriculture as an example of multifunctional development of agriculture and rural areas in Poland
2015
Chodkowska-Miszczuk, J., Nicolaus Copernicus Univ., Torun (Poland) | Bieganska, J., Nicolaus Copernicus Univ., Torun (Poland) | Rogatka, K., Nicolaus Copernicus Univ., Torun (Poland) | Wasilewicz-Pszczolkowska, M., University of Warmia and Mazury in Olsztyn (Poland)
The paper aims at analyzing agricultural production for energy generation purposes, including the production of agricultural biogas, as an opportunity for functional diversification of agriculture and for multifunctional rural development in Poland. There have been many changes observed in Polish agriculture. New directions of crop production and of the use of agricultural products have emerged. One of the changes is the increasing significance of the production of agricultural biogas and energy from biogas. There have been built both small-scale and large-scale biogas plants. Most of the agricultural biogas plants are located in northern, western and south-western Poland, i.e. in the areas where there are relatively large farms which can provide a supply of substrates necessary for the production of agricultural biogas. The formation of biogas plants and the use of agricultural production for generating energy are an eagerly anticipated trend contributing to the dissemination of renewable energy sources, the functional diversification of agriculture, the development of additional economic activities in rural areas, and the increase in the energy security of particular regions and the entire country.
اظهر المزيد [+] اقل [-]