Marija Živković

The state and perspective of the natural gas sector in Serbia

ABSTRACT The strategy of long-term energy development of Serbia identifies an increase of share of natural gas in final energy consumption as one of the main aims. Serbia has signed a strategic agreement with the Russian Federation on cooperation in the oil and gas sector, within which the project South Stream pipeline is planned to be realized. In addition, the Republic of Serbia has signed the Treaty that establishes the Energy Community and accepted the obligation to implement the Energy Community acquis. In the natural gas sector it is related to establishing a fully liberated national and regional natural gas market. Overview and analysis of the current state concerning indigenous production, infrastructure, and consumption structure are presented as the basis for projections of the possible Serbian natural gas sector development. Three possible scenarios for future natural gas consumption, considering different influential parameters, have been developed by the Long-range Energy Alternatives Planning System (LEAP) software. Scenarios characterized by different levels and structures of consumption are analyzed in detail.

Effect of natural gas composition on methane number: A case of gas reservoirs in Serbia

ABSTRACT Natural gas is considered as the most environmentally acceptable fossil fuel, thus it is an alternative to petroleum derivate, dominantly used in internal combustion engines. Physical properties of a fuel as well as behavior during combustion process are affected by its composition. This article presents analysis of effect of natural gas composition on methane number (MN), conducted for natural gas deposits in Serbia. For empirically determination of MN: California air resources board (CARB) method and Linear and Anstalt für Verbrennungskraftmaschinen list (AVL) method have been applied. Effect of reactive hydrogen and carbon ratio, Wobbe index and content of inert matter on MN is discussed. For compositions characterized with total share of inert compounds higher than 5%, impact of inert components becomes significant, without observed dependency between reactive hydrogen and carbon and MN. An analysis has shown that carbon dioxide and nitrogen have differently affect MN. Carbon dioxide affects the increase of MN due to higher molar specific heat, appearance of dissociation, and higher activation energy.

Experimental investigation on emission and stability of dual feed biogas swirl combustor

Biomass is a renewable energy source with the highest potential to contribute in meeting energy needs and providing a secure and sustainable energy supply. For combustion of biogas (low calorific gas), an efficient technology is needed. It should provide stable combustion with low emission of pollutants such as CO and NOx over a wide operating range. This paper presents the experimental investigation on emission and stability of a premixed dual feed biogas swirl combustor with a pilot burner. For the experimental investigation, swirlers with swirl numbers 1.13 for the main burner and 1.98 for the pilot burner were used. The tests were performed at atmospheric conditions. The effects of carbon dioxide content, nominal thermal power, and equivalence ratio were analyzed and briefly discussed.