Natural gas dew point temperature is a vital quality parameter. The effective control of this specification is important if the natural gas integrity and quality are to be maintained. The present work focuses on improving the dew point and condensation production rate of south Dabaa field dew point control unit (DPCU) located in the Egyptian western desert and owned to the South Dabaa Petroleum Company. Influence of the operational variables on outlet gas dew point and produced condensate were investigated. The simulation results illustrated that feed gas inlet temperature, composition and flow rate, Joule Thomson (JT) valve downstream, and upstream pressure and hot bypass flow rate have a great effect on the sales gas dew point as well as the condensate throughput. A field experiments were conducted to validate the simulation results. It is noticed that there is a good agreement between simulation and experimental results, considering the outlet gas dew point at different operating conditions. Lingo optimization software was used to find the plant optimum conditions. Two quadratic equations were developed based on regression analysis for calculating the dew point and plant condensate rate at any operational variables. The impact of replacing the existing JT valve by a turbo expander was studied. The simulation results indicate that the turbo expander is more effective in comparison with JT valve refrigeration system in decreasing the sales gas dew point and increasing the condensate production rate. •The improvement of dew point and condensation production rate of south Dabaa field dew point control unit (DPCU) – Egyptian western desert - is studied.•A simulation for the above mentioned unit has been developed using HYSYS.•Influence of operating conditions on natural gas dew point and condensation rate is studied.•Two correlations for relating gas dew point and condensate throughput to DPCU operational variables are developed.•An NLP algorithm is developed to find optimum operating conditions of DPCU. The considered operating conditions are gas inlet temperature, inlet gas flow rate, JT valve upstream pressure, JT valve downstream pressure, hot bypass flow rate, and gas composition.•The influence of replacement JT valve by a turbo expander refrigeration technique on the PDCU operation has been investigated.