The value of biomass energy: The case study of "Crni Vrh-Deževski" in the Gornjeibarsko forest area

Of all terrestrial ecosystems, forests are the most important carbon reservoirs. Therefore they deserve special care and protection. They are also an irreplaceable source of biomass for energy. Forest biomass has been used as a fuel since the earliest times, and since the late twentieth century, there has been a renewed interest in its use for the production of heat and electricity. Forest biomass has become interesting as a source of energy due to some of its characteristics, above all its availability and uniformity around the world, which implies that both developing and less developed countries can use biomass as a renewable source of energy. Furthermore, biomass fuel is considered to be CO2 neutral. However, its use is not risk-free. The risks are mainly related to the sustainability of forest systems and their productivity. Therefore, the forestry profession must be extremely cautious in using forest biomass and follow the prescribed allowable cut. This paper deals with the current state of biomass for energy, its estimates and properties as fuel. It studies the sustainability of biomass through the preservation of forest ecosystems and all multipurpose benefits of forests.

Water budgets for natural systems

Natural systems including constructed and natural wetlands as well as irrigated land areas,geofilters and ponds are capable of absorbing pollutant loadings, and in appropriatecircumstances can provide a low cost alternative to traditional chemical and biologicaltreatment. Many projects have shown reduction of nutrients, oxygen consuming substancesbut also more environmental haz.ardous compounds.Natural systems seem to have a great potential for treatment of leachate. Some parts of thesesystems belongs to biological treatment and other parts to "filtration" and therefore thesesystems could be seen as a mix of transformation and filtration together with the volumereducing effect by evaporation and transpiration. Method used in Sweden are mainly SoilPlant (SP) system there a large part of the treatment is removal of water by evapotranspiration.Irrigation of e.g. energy forest or land surfaces increases the possibility of natural evaporation.When an area of the landfill is irrigated the water balance will change. This paper focusesupon the water budget and water movement within the natural system.

MORPHOLOGICAL AND ELEMENTARY EVALUATION OF WOODEN CARBONACEOUS MATERIALS FROM ACTIVATED CARBON INDUSTRY

AVALIAÇÃO MORFOLÓGICA E ELEMENTAR DE MATERIAIS CARBONÁCEOS DE MADEIRA DA INDÚSTRIA DE CARBONO ATIVADA A preocupação mundial na redução dos gases de efeito estufa para a atmosfera, combinada com leis ambientais mais rigorosas, tem levado a um aumento dos estudos sobre a energia renovável. Esta pesquisa teve como objetivo caracterizar lascas de madeira e carvão ativado por microscopia eletrônica de varredura (MEV) e espectroscopia de energia dispersiva (EDS). Os cavacos são oriundos de uma floresta de Pinus elliottii voltada para fins energéticos e foram queimados em uma fornalha de uma caldeira de geração de vapor. Esse vapor gerado pela caldeira em fornalhas apropriadas é utilizado na ativação de carvão vegetal por pequenos produtores regionais. MEV indicou um aumento na porosidade do carvão vegetal com o processo de ativação, e a análise EDS indicou que tanto os cavacos quanto os carvões, com e sem ativação, não apresentaram contaminantes, como os metais pesados. Este estudo revelou uma baixa toxicidade dos materiais lignocelulósicos à base de Pinus elliottii. A queima de cavacos de madeira na caldeira e o processo de ativação de carvão vegetal não apresentaram riscos ambientais.Palavras-chave: energia florestal, carbonização, carvão ativado, metais, porosidade. ABSTRACT: The worldwide concern of reducing greenhouse gases into the atmosphere combined with more stringent environmental laws has led to an increase in studies of renewable energy. This research aimed to characterize wood chips and activated charcoal by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The chips came from an energy forest of Pinus elliottii and were burned in the furnace of a boiler for steam generation. This steam generated by the boiler in appropriate furnaces is used in the activation of wood charcoal from small regional producers. SEM showed an increase in the porosity of the charcoal with the activation process, and EDS analysis indicated both chips and charcoals, with and without activation, have no contaminants, such as heavy metals. This study revealed a low toxicity of lignocellulosic materials based on Pinus elliottii. The burning of wooden chips in the boiler as well as the activation process of wood charcoal did not present apparent environmental risks.Keywords: forestry energy, carbonization, activated carbon, metals, porosity.

FINANCIAL FEASIBILITY OF SHORT ROTATION ENERGY CROPS IN HUNGARY: A CASE STUDY

Biomass is a readily available, renewable and environmentally friendly source of energy. Exploiting renewable organic matter for energy production is showing a growing tendency worldwide including in Hungary. Forest plantations with large numbers of plants (short rotation coppices) that provide a homogeneous, locally available raw material of various fast growing deciduous wood species are broadly supported. In our research we have investigated the financial viability of a short rotation energy forest plantation in the Kunság region of Hungary. Both the EU and Hungary provide economic incentives for the creation and propagation of bio-energy producing facilities. Our results show that the enterprise could not generate profit for the period examined without the help of such subsidies. There are several obstacles that farmers are facing such as the initial high capital outlay, technological shortcomings of the harvesting methods, high logistics costs and suppressed purchasing prices.

Felled Trees as a Rockfall Protection System, Experimental Study for Numerical Models Calibration

In mountain areas, natural hazards, such as snow avalanches, landslides and rockfall threat towns, communication routes and people. It is known that forests have a major capacity to dissipate rockfall energy. Forest maintenance or storms can reduce forest’s protective capacity; after such a reduction, felled trees can be strategically left on the slopes in order to replace live trees. The efficacy of these devices and their optimal position can be analyzed by developing a numerical model describing the rock-wooden device interaction. To develop a relevant model of these wooden devices when impacted, the research was focused, in one hand, on a rigorous characterization of the fresh wood mechanical properties to recreate the real dynamic response of stems after the impact. In the other hand, the local impactor-wood stem interaction at the contact point was analyzed. Laboratory experiments using Charpy pendulum, presented in this text, have been carried out to assess the calibration of the numerical model. Experimental results of the impact force and their relation with stems mass and the impact energy level were treated and commented. A second serie of experiments has enabled to characterize the law describing the contact between the stem and the impactor.

Gaming Analysis among Different Participants in the Construction of Biomass Energy Forest Base

Through the analysis on the relations of the three main participants of the government, the enterprise and the farmers, the thesis has established the gaming model between the enterprise and the forest farmers and found that only when the additional benefit they each obtain is larger than the construction cost for the development they paid, optimal combination of Nash equilibrium can be accepted by enterprises and forest farmers and Pareto improvement will be possibly formed， the smooth development of energy forest construction can be ensured.

Energy Supply by Energy Forest in Enköping Sweden

Green structure can not only be used for energy saving system, but also can be an energy production source called bio-energy, to support the use of renewable energy sources for generating electricity and heat. The district heating system in Enköping has connected all mayor buildings in the town and also most of the single-family houses. In 1994 a CHP plant was commissioned on bio-energy and in 1997 an oil-fired boiler was converted to wood powder. Since then all electricity and all heat produced are based on bio-energy.