| Abstract [eng] |
One of the most important stages in ammonia manufacturing is the synthesis gas production process. Most commonly used synthesis gas production method is two-step steam methane conversion. Throughout the process, outside the equipment, natural gas is being burned to maintain constant temperature. During combustion of natural gas, a significant amount of CO2 is emitted into the atmosphere. In order to achieve the objectives of the European Green Agreement, it is vital to improve existing synthesis gas production technologies. For the Master Thesis, a research was conducted, which aims to find out how to reduce the amount of natural gas burned in the process of synthesis gas production. During the study, the concentration of ambient oxygen used in the production was increased and the change in the amount of natural gas combusted was monitored. The outcome showed that increasing the oxygen concentration in the air by 30 %, results in 4900 kg/h reduced natural gas combustion and, at the same time, 13450 kg/h less CO2 emissions into the atmosphere. According to technological improvement, construction solutions are provided. The synthesis gas production line that is under development in the project is located in Jonalaukis village, near the confluence of the Neris and Šventoji rivers, nearby Jonava. The location of the plant was determined by the convenient geographical location with the close-by highway and railway lines that connect the company with major Lithuanian cities and the Baltic Sea port. The plot of the modernized production facility occupies 1.3 ha. The plot is located in the north - eastern part of the factory territory. The technological line occupies 1231 m2, which is 9.5 % of the plot area. In the technological line that is being improved, engineering systems are designed: water, air, oxygen, natural gas. A financial and economic evaluation of the technological improvement was performed. It was determined that 1.39 million Eur should be invested in modernization. After the improvement, 30.78 Eur are saved after producing 1 ton of ammonia from synthesis gas. Net profit increases by 14.44 million Eur. It is predicted that the investment will pay off after 2.09 yr and the activity will become profitable following the sales of 110160 tons of the product. Following an environmental assessment of synthesis gas production, the greatest damage to nature is caused by the emissions of pollutants into the ambient air. Gas emissions are cleaned using a homogeneous purification appliance. The planned improvement would reduce emissions of carbon dioxide, nitrogen oxides and carbon monoxide into the atmosphere. The safety and health requirements for the designed production line are also presented. Potential occupational risks have been identified and preventive measures have been taken to reduce them. Information on harmful substances used in production and their limit values are provided. Requirements for safe production and fire safety are also presented. |
