# Exergy and Exergoeconomic Analysis of the Gas Subcooled Process for the Brazilian Market: An Approach to Enhance Natural Gas Liquids Recovery

## TL;DR

This study evaluates different gas subcooled process designs in Brazil to improve natural gas liquids recovery by analyzing energy efficiency and costs.

## Contribution

The novel contribution is the detailed exergy and exergoeconomic analysis of four GSP configurations to identify thermodynamic and economic inefficiencies.

## Key findings

- The Turbo-Expander (TE) configuration achieves the highest exergy efficiency at 71%.
- The TEMR setup has the highest exergy destruction cost at US $5687/h due to energy-intensive refrigeration.
- The analysis provides actionable insights for improving GSP system design and infrastructure modernization.

## Abstract

The gas subcooled
process (GSP) is the most widely adopted natural
gas liquid (NGL) recovery method due to its adaptability to varying
gas compositions and its alignment with the market emphasis in Brazil
on lighter hydrocarbons. However, the process remains limited by high
energy consumption and significant thermodynamic inefficiencies, particularly
in the expansion and separation stages. To address these drawbacks,
this research employs a detailed exergy and exergoeconomic assessment
of four GSP configurations, termed Turbo-Expander (TE), Joule–Thomson
(JT), Turbo-Expander with Mechanical Refrigeration (TEMR), and Joule-Thomson
with Mechanical Refrigeration (JTMR), to identify and quantify the
sources of energy degradation and their associated economic impacts.
The results reveal that the TE configuration achieves the highest
exergy efficiency (71%) and demonstrates superior cost performance
by maximizing the shaft work recovery. Conversely, the TEMR setup
incurs the highest exergy destruction cost (US $ 5687/h), primarily
due to its energy-intensive refrigeration cycle. By integrating thermodynamic
and economic diagnostics at the equipment level, these research findings
provide actionable insights into improving GSP system design, support
infrastructure modernization, and guide investment decisions, thereby
contributing directly to the advancement of a more sustainable and
competitive natural gas sector in Brazil.