Possibilities of increasing resource efficiency in nitrogen fertilizer production

Fertilizer production is one of the most important industries for ensuring a growing demand for food resources. Regrettably, this industry is characterized by high energy intensity. Even today, fossil fuel such as natural gas is the main raw material and the main source of primary energy in nitrogen fertilizer production. According to the data of the Ministry of Energy of the Republic of Lithuania, about 40 % of total natural gas consumption in Lithuania is used in the fertilizer production company. Evaluation of the possibilities to reduce energy intensity and use alternative resources in nitrogen fertilizer production is the main objective of this research. All the technological processes of nitrogen fertilizer production in the analyzed company are objects of research of this work. Recent researches into the area of cleaner chemical product production are reviewed and systematized. The methods of cleaner production (CP), industrial ecology, material flow analysis, environmental impact assessment, and evaluation of environmental efficiency are integrated into the methodology of this work. Results of the initial environmental analysis of nitrogen fertilizer production processes show that the analyzed company has already implemented several CP projects with a view to minimizing energy intensity and air emissions. Despite their efforts, an enormous amount of energy is wasted in the main and additional processes (for example, ammonia production, cooling process, and heat energy production). Several alternatives for resource efficiency and energy saving have been suggested when doing the research. This paper presents the results of the feasibility analysis of three case studies in which pollution prevention methods are applied jointly with industrial symbiosis.