The optimized scheme of flare gas recovery system in gas refinery by applying a network of ejectors accompanied by the optimized package of gas sweetening

In gas refineries and upstream industries of oil and gas it is possible to prohibit the entry of dangerous and poisonous gas such as COX, NOX, SOX that can have greenhouse effect on the planet earth by using flare gas and presenting a suitable procedural solution. In fact, the energy and special composition of flare gas can be exploited economically. In this research, first the composition of flared gas in phase۱۹ of gas refinery of South Pars has been specified and after that the flare gas recovery system which is composed of two parts of compressing network of ejectors and sweetening unit have been suggested. In these two parts, appropriate procedures have been presented for procedural challenges. By applying a network of ejectors to increase the middle and low pressure of flare gas of phase ۱۹ thecosts related to this part are reduced and finally by the optimized sweetening process in low functional pressure, it would be possible to recover gas in the presence of a great amount of acidic gas. The results obtained from simulation in HYSIS shows that by installing this system, it is possible to recover ۳۷۰۵۶۰ m۳/day of sweet gas alongside ۱۴۳۷۸۴ m۳/day of acidic gas and finally the produced sweetgas in phase ۱۹ of refinery will be increased by ۷.۴۹%. In addition, by returning the gas acid that is produced in flare gas recovery process to sulfur production unit, it is possible to increase byproducts of the refinery by ۴۸.۹%. By implementing this scheme ۹۷.۵% of flare gas is returned to the cycle and refinery will go through the process of sulfur removal. The overall results of economic analysis show that byusing this scheme and regarding the way that products are used, ۱۰۰ to ۲۶۰ million dollars is earned from the production of electricity and sulfur. Also, considering the remarkable amount of gas flaring that equals to ۱۲۰۸۶۴۰ the environmental analysis shows that the entry of these dangerous and poisonous gases to the environment is prohibited.

Keywords:

flare gas , gas ejector , gas sweetening , economic analysis , environmental analysis