A heat integration case study for the dehydration and condensate stabilization units in LNG plants for economic and energy savings

Abstract

Liquefied Natural Gas, derived from natural gas is the cleanest fossil fuel, and it plays a critical role in global energy markets, although its production is costly. To partially reduce the cost, this study considers the hot section (pre-separation) of LNG process and integrates the Tri-Ethylene Glycol Dehydration and Condensate stabilization units for maximum energy savings using the Pinch Analysis technique, which is conducted through Aspen Energy Analyser V10. Plant simulations are used to verify the feasibility and functionality of the whole heat integration design. The energy analysis reveals ten heat exchange networks (HEN) comprising of two heaters and five coolers and one process heat exchanger for the base case simulation. Whereas the total energy required for the base case is 80.86 MW and indirect carbon emissions are 395.3 tonne/d. After integrating the units, the energy consumption for heating and cooling are reduced by 18.83% and 21.37%, respectively, while carbon emissions are reduced by 316.2 tonne/d.