Abdolrasoul Shahpari - Department of Chemical Engineering - Health, Safety & Environment, Najafabad Branch, Islamic Azad University, Najafabad, Iran
Farham Aminsharei - Human Ecology and Sustainable Development Research Center, Najafabad Branch, Islamic Azad University, Najafabad, Iran
Majid Ghashang - Human Ecology and Sustainable Development Research Center, Najafabad Branch, Islamic Azad University, Najafabad, Iran

Methane is the main component of natural gases which has a potential for global warming of more than 25 times that of Carbondioxide. Methane is the second greenhouse gas to be released by human activities, and almost a third of these emissions are indifferent sections of oil production and processing, transfer and storage of natural gas. The purpose of this study is to estimate theamount of Methane emission to the atmosphere due to the startup and shutdown of Siemens gas compressors in Gas TransmissionOperation District No. 2. For the present study, first the total number of Siemens compressors, model and type of each compressorin District No. 2 were determined. Then the similar compressors were placed in the same group and for each group the compressorinformation of one station was collected as a pilot and transferred to the PHAST software, and the modeling and outputs werereceived and recorded. The amount of Methane emission in year 2017 in the process of startup and shutdown of Siemenscompressors was found as below: type C compressors the amount of 202814 kg, type D compressors 183841 kg, and type Ecompressors 227098 kg of Methane emission to the atmosphere. According to the obtained information, it can be concluded thatin 2017, this gas transmission District has released a total of 613.753 tons of Methane gas from the above-mentioned process in theatmosphere, which has a global warming potential of 15343.825 tons of Carbon dioxide equivalent

Methane emission, Gas compressors, Global warming, PHAST software, Greenhouse gases.