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• The Alternative Use of Straw

  331-343

  Szilvia Mészáros

  Views:

  119

  The problem addressed in this work is to examine the feasibility of using straw in innovative and alternative ways, focusing on aspects of cost sensitivity in subject areas of building investment and energy compsumption. I analysed the energy efficient performance of a straw bale building and compared that with those of a conventional construction, a newly-constracted building and a passive house. In my study I assessed the figures of costs of emboided energy, primary energy consumption and carbon dioxide emission. I made calculations in terms of energy costs for a lifespan of 50 years. Considering that straw-bale construction uses an excellent and sustainable insulation material, its energy use is by 25.38% less than that of conventional construction.

• Efficient removal of salts from the residual dross of aluminium melting

  259-269

  István Illés

  Hanna Zakiyya

  Tamás Kékesi

  Views:

  119

  A residual dross of high quantity and high salt content arises from the hot (thermo-mechanical) treatment of the primary dross generated by the production of aluminium alloys from scrap. It contains a relatively low concentration of metal (5 – 10 %) but a high amount (30 - %) of chloride salts and some other components beside the oxide matrix. Due to the components dissolved in or reacted with water, this industrial residue - arising in thousands of tons also in Hungary – qualifies as hazardous and causes a real burden to the environment. According to the laboratory experiments aimed at an economical technology, the chlorides are dissolved within a few minutes when a liquid/solid ratio of 1:1 cm3/g (water volume:sample mass) is assured with an intensity of the horizontal shaking to prevent sedimentation. However, the filling ratio of the vessel also appears to have an effect. An implementation of relatively low cost would allow the recycling of the salt and the application of the final residue for alternative purposes.

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

  249-258

  Judit Tóth

  Robert Magda

  Views:

  152

  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.