2nd Conference for Engineering Sciences and Technology - CEST2 29-31 October 2019 - Sabratha –Libya 1 The effect of some design parameters in natural gas purification unit by using Aspen HYSYS simulation Ezeddin H. Alshbuki 1* , Mufida Mohamed Bey 2 1 Alshbuki.Ezeddin@sabu.edu.ly, 2 bey.mufida@sabu.edu.ly 1, 2 Department of Industrial Engineering, Faculty of Engineering, Sabratha University, Libya *Corresponding author email: azden.hasan@gmail.com ABSTRACT More recently, the demand for energy has increased to meet the growing need for it because of the continuous development in all areas of life. The importance of the subject must be achieved by focusing on the sources of this energy, including the energy produced by natural gas, which has increased interest in manufacturing in recent years, which is a clean source of energy compared to the energy produced from crude oil, for example, we find that Libya came in the center The eighth in the Arab reserves of 1.5 trillion cubic meters, according to data from the OAPEC, the reserves of OPEC countries of proven natural gas represents 27% of the global reserve. The natural gas industry is considered one of the most important oil industries. The industry is undergoing several stages, the most important of which is the phase of removing H2S gas and CO2 from natural gas components due to problems such as environmental pollution and corrosion of operating equipment. The aim of this study is to increase the concentration of CH4 and natural gas purification by Diethanolamine ( DEA) from these pollutants, which were discussed in this study using the Aspen HYSYS program to simulate the steady state of typical natural gas composition of this phase by changing several parameters Design and operation such as operating temperature, gas flow rate, diameter and number of trays for absorption column. In order to achieve the best results of the degree of purity of methane after the purification phase where a rate of about 1245 kgmole/h ( 25 MMSCFD ) reached a purity of 93% for methane and the number of trays 20, including a space of 0.5 m. When comparing the results obtained for pure methane and acid gases after the purification process, it was consistent with the actual and typical results applied as well as the rest of the design parts of the purification column. Keywords:Aspen Hysys,Tray Spacing, Gas flow rate 1. Introduction Acid gas removal is an important process in various branches of the hydrocarbon processing industry, primarily in natural gas processing and refining. Acid gas removal is also an essential part of other processes, such as coal gasification where carbon dioxide, hydrogen sulfide, carbonyl sulfides and other contaminants need to be removed. Acid gas is defined as gas containing significant amounts of contaminants, such as hydrogen sulfide (H2S), carbon dioxide (CO2), and other acidic gases. Sour gas is gas contaminated with H2S. This term comes from the rotten smell due to sulfur content [1]. Thus, “gas sweetening” refers to H2S removal, because it improves the odor of the gas being processed, while “acid gas removal” refers to the removal of both CO2 and H2S.Acid gas removal is an important process in various branches of the hydrocarbon processing industry, primarily in natural gas processing and refining. Natural gas mainly consists of a large quantity of methane along with heavier hydrocarbons such as higher alkanes and alkenes; moreover, in the raw state, it often contains a considerable amount of