In this study, first identifying potential of problem in case of failure to meet the design condition of the JouleThomson unit and then, the integration of this unit with a propane cooling is studied in order to improve the process performance. Heat loss from pipes and process equipment, the phenomenon of carryover in the separator, the conditions of the process inlet flow and the performance of the Joule-Thomson valve are some of the issues that are considered in this research as factors affecting on the process performance. For this purpose, based on real information, a simulation process was performed using ASPEN HYSYS V10.0 software. Using field measurements and experimental relations, were calculated the unit heat loss and its effect on the process. Then, were examined the effect of carryover on the separator and sensitivity analysis changes of temperature and pressure inlet on the dew point temperature unit. The performance of the Jules-Thomson valve was measured, and at the end, was investigated the creation and integration of the unit with a cooling cycle. The results showed that by re-insulating the pipes and separators, could be effected by 2 °C to 4 °C on the temperature of the outlet of the Joule-Thomson valve. Carryover and Jules-Thomson valve are not the main factors of the unit`s improper performance. As the inlet gas temperature decreases at constant pressure or the inlet gas pressure at constant temperature, the dew point temperature decreases. In the last step, a cooling cycle was designed and connected to the desired unit. To find the best performance for the cooling cycle, 10 scenarios were designed and examined in terms of energy consumption and economy. The optimal state was to connect the cooling cycle to the unit through a heat exchanger at the inlet at the separator inlet and after the JouleThomson valve that the dew point temperature of the outlet gas reached -15 ?C at pressure 7319 kPa. Keywords: gas refinery, dew point adjustment, separator, heat exchanger, Jules-Thomson valve, simulation and optimization.
