Natural Gas Condensate Recovery System Selection Study on Onshore Gas Terminal

Abstract

Petroliam Nasional Berhad (PETRONAS), established in 1974, is the largest oil and gas company in Malaysia and a key player in the global energy sector. The extraction of oil and gas is a complex, resource-intensive process that involves multiple stages of processing, demanding significant human labour, advanced equipment, and technology, making it a high-cost process. As with any business, profitability is a critical goal, particularly in capital-intensive industries such as oil and gas. To address these challenges, PETRONAS has implemented an innovative strategy to recycle excess gas, which would typically be flared, by capturing and converting it into valuable condensate. The recovery of natural gas condensate can be achieved through three primary methods, namely Joule-Thomson (JT) valve, turboexpander, and refrigeration systems. This study models each method using Aspen HYSYS to evaluate their efficiency in terms of both condensate yield and power requirements. The results of the study indicate the following gas production rates: 318,400 kg/h for the Joule-Thomson (JT) valve method, 316,900 kg/h for the turboexpander, and 316,500 kg/h for the refrigeration system. In terms of condensate production, the Joule-Thomson (JT) valve method yielded 9,463 kg/h, the turboexpander 8,146 kg/h, and the refrigeration system 7,760 kg/h. Power requirements were 16,685.7 kW for the Joule-Thomson (JT) valve method, none for the turboexpander (due to its energy recovery mechanism), and 823.923 kW for the refrigeration system. Based on the results, the turboexpander method proves to be the most efficient for condensate recovery, producing 8,146 kg/h without requiring power. Its energy recovery mechanism makes it the optimal choice for large-scale recovery systems, particularly when energy efficiency is a priority and the system operates under high pressure. On the other hand, the Joule-Thomson (JT) valve method is more suited to small-scale systems with lower gas pressures, while the refrigeration system is recommended for systems operating at lower to moderate pressures, especially when specific temperature conditions must be met.