Optimising the performance of the condensate stabilisation unit in LNG Processes

Today, Liquefied Petroleum Gas, Natural Gas Liquids Recovery, and Condensate Stabilisation have gained significant interest, given their increased selling prices and market demands. Nevertheless, many operational units do not meet the desired profits and lack proper optimisation initiatives. In this study, a case study from the operating condensate stabilisation unit within the liquefied natural gas process is considered, where a sensitivity analysis of key process operating parameters is applied to investigate process performance. The process is optimised to achieve the highest efficient performance, maximum productivity rate, and minimum energy consumption. Based on the available production data and operating conditions, an existing condensate stabilisation unit is simulated using the Aspen HYSYS V10 simulator, which is based on the Peng-Robinson equation of state. The most significant process variables and constraints that directly affect the performance, and production of condensation stabilisation units are highlighted to demonstrate the connection among process operating conditions and the influence on process objectives. The optimal process operating conditions are determined to achieve a stable column operation. The most effective process variables based on the sensitivity analysis are stabiliser column pressure, stabiliser feed temperature, the outlet temperature of process gas from the wellhead, and stabiliser bottom temperature. After collecting process data from the sensitivity analysis, MATLAB has been used to formulate and solve the multi-objective optimisation problem. Beginning with a natural gas feed flow of 554 MMSCFD, a condensate with 956.9 barrel/day standard liquid volume flow and a reboiler load of 0.86MW have been achieved. After performing the singular optimisation problem in MATLAB, the condensate standard liquid volume flow is increased to 1273 barrels/day, and the reboiler load has decreased to 0.79MW.