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• The green methanol - playing a role in sustainable energy management

  249-258

  Judit Tóth

  Robert Magda

  Views:

  140

  Global energy demand is constantly increasing, so the energy sources we use, and the efficiency of energy use are of paramount importance for the future of humanity. Methanol can play a key role in the sustainable use of natural resources, in the efficient and smooth transition from a fossil oil-based energy system as well as in reducing greenhouse gas emissions. Long-term thinking will result in an increase in the use of renewable energy sources, which will favour the spread of green methanol technology and thus the use of a carbon-neutral fuel. The raw materials for the production of green methanol may include municipal solid waste, agricultural waste, renewable hydrogen and carbon dioxide and the methanol has many uses, both as fuel and chemical feedstock. It also provides an opportunity to chemically store excess renewable energy from intermittent sources, thereby reducing dependence on fossil fuels. The price of electricity used for electrolysis is the main determinant of the economical production of green methanol, so the reduction of the cost of solar and wind energy greatly contributes to the competitiveness of carbon-based production.

• Modern use of geothermal energy in Nagyszénás (Case Study)

  106-115

  Krisztián Szolga

  Dénes Kocsis

  Views:

  174

  A project based on geothermal energy use in Nagyszénás, Békés County, Hungary, was finished on December 20, 2015. The construction investments were realized with the support of the European Union from tender funds won in the financial cycle of 2007-2013 in the total value of HUF 1.578 billion. The thermal water utilization investment was realized with unique technical solutions in the country, and as a result, a modern, economical heating system using green energy source was built, and now provides energy for the public institutions of the settlement and for the newly established bath complex. During construction and operation, several unforeseen technical problems arose, which could only be solved by using new technical elements. The high salinity and high temperature of the extracted thermal water required special engineering solutions. During operation, modifications and changes in technological elements were required at several points for the safe operation. The purpose of this article is to present these technical interventions, which made the reliable operation possible, thus the system provides a suitable alternative to natural gas-based heating.

• Role of Biomass in Urban Energy Management

  62-76

  János Szendrei

  Balázs Kocsi

  Edit Szűcs

  Views:

  121

  When making decisions on the use of energy, both on building and on city level, biomass plays certainly a role in looking for sustainable solutions. This study starts with highlighting some key points regarding urban energy management, including world urbanization trends, heat island effect of big cities and energy hierarchy in energy management. With these in mind, it is worth considering, how the shading effect of surrounding biomass can mitigate the heating needs as a wind barrier in the winter or decrease the cooling load as shadowing element in the summer, both for buildings and whole cities. These can be further enhanced by biomass integrated in the buildings’ envelope: green roofs and green walls can have significant energy conservation effects, according the characteristics of their different types. Lastly, urban disposal of biomass can lead to renewable energy generation, both in case of biogas production and waste incineration. These shading, covering and fuel possibilities all underline the importance of biomass in urban energy management.

• Global and Domestic Status and Prospects of Green Biomass Utilization

  85-105

  Gabriella Antal

  Views:

  135

  Nowadays, the energy consumption of global population is depending on fossil fuels, but the role of renewable energies has been increasing rapidly, primarily due to the depletion of fossil fuels, the appreciation of environmental problems and climate policies. Biomass is the fourth most important energy resource in the world, provided an estimated 70% of global renewable energy supply. However, the annual growth rate of biomass is lagging behind modern renewable energy sources. The type of biomass is very diverse and can be processed and utilised by different methods. Currently, in the "green chemistry" industry (the replacement of petroleum-based, synthetic chemical raw materials with bio-based compounds from plant biomass), the importance of combustion, pyrolysis, biogas, bioethanol, biodiesel and basic chemical compounds production have been increasing. The objectives of the present research is to analyse the global and domestic status of renewable energies and biomass production, furthermore the possibilities of utilization of perennial, herbaceous biomass plant, the giant reed (Arundo donax L.), with which has been conducting research for numerous years at the University of Debrecen.