Think Out of the Box – GHG Emission Reduction by Changing the Way We Had Operated Before

To support the Company direction of GHG emission reduction in PTTEP operation, GBS, APEX and OMI have initiated fuel optimization to minimize fuel gas consumption. Over 80% of total fuel gas consumption is fed to Turbo Compressor to convert mechanical power to gas energy by compression system. To improve overall efficiency of fuel consumption, the whole gas compression process has been reviewed and analyzed. From preliminary review, there is a room to improve efficiency in part of gas cooling gas treatment process equipped with JT valve (Joule-Thomson, pressure reducing valve) that requires inlet pressure about 63-65 barg and outlet pressure of 55 barg to have cooling effect that decreases gas temperature from 45°C to 25°C. This cooling method takes huge energy from gas compressed in previous system. To improve overall process efficiency, the whole gas compression and cooling system was reviewed thoroughly. Consequently, it was found that the cooling margin of upstream equipment can compensate some cooling effect of JT valve leading to energy optimization of gas compression system without any additional modification and investment. After process tuning with the margin of Booster Compressor Discharge Cooler and Wet Gas / Gas Liquid Heat Exchanger upstream of JT valve, the required inlet pressure of JT valve can be reduced that leads to Booster Compressor discharge pressure declined from 64 barg to 61 barg while JT valve outlet temperature is still maintained at of 25°C as design condition without changing any other related operating condition of the systems before process tuning. The lower pressure of compressor discharge, the lesser fuel gas consumption is expected for energy transformation of compression system.