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Abstract: Many of the modern practices in waste management at the same time represent means of reduction of greenhouse gas (GHG) emissions. The main focus in this paper is given to the measures for recovering energy from municipal solid waste (MSW): Utilization of landfill gas for electricity production, Utilization of refuse derived fuel (RDF) in cement industry, Thermal treatment (Incineration) of MSW, Mechanical-biological treatment, and to one measure without energy recovery – Landfill gas flaring, for all of which it was found that could generate substantial GHG emission savings. The economic side of the implementation of these measures, considering the GHG emission reduction, is analysed in order to determine the priority between them. With respect to the cost-effectiveness, marginal costs (expressed as € per ton of reduced or avoided CO2eq) are calculated for all the measures. It was determined that around 1 million tons of CO2 can be avoided in 2020, which is 2.7% of projected GHG emissions in Croatia, while the energy that could be recovered from waste is 8.3 PJ in 2020, which represents about 3% of the total final energy consumption in 2008. The measures Utilization of landfill gas for electricity production and Landfill gas flaring showed the greatest economic benefit. [Copyright &y& Elsevier]

Abstract: In the Republic of Croatia there are some medium temperature geothermal sources by means of which it is possible to produce electricity. However, only recently concrete initiatives for the construction of geothermal power plants have been started. Consequently, the paper provides proposals of the possible cycles for the Republic of Croatia. On the example of the most prospective geothermal source in the Republic of Croatia detailed analysis for the proposed energy conversion cycles is performed: for Organic Rankine Cycle (ORC) and Kalina cycle. On the basis of analysis results both the most suitable cycle for selected and for other geothermal sources in the Republic of Croatia are proposed. It is ORC which in case of the most prospective geothermal source in the Republic of Croatia has better both the thermal efficiency (the First Law efficiency) and the exergetic efficiency (the Second Law efficiency): 14.1% vs. 10.6% and 52% vs. 44%. The ORC gives net power of 5270kW with mass flow rate 80.13kg/s, while the Kalina cycle gives net power of 3949kW with mass flow rate 35.717kg/s. [Copyright &y& Elsevier]