Air Dispersion Study For LP Flare Package - CPF Upgrade Project – Phase II

Introduction

This case study explores the air dispersion study modeling conducted for the new flare package to evaluate its environmental impact, specifically focusing on the ground-level concentrations (GLCs) of various pollutants. The CPF Upgrade Project - Phase II, is an initiative by a prominent Oil and Gas Company involved in upgrading the Central Processing Facility (CPF) to accommodate increased production capacities. A significant aspect of this upgrade was the installation of a new low-pressure flare system, designed to manage and mitigate emissions from the facility during operational activities, including emergency events.

Project Overview:

The Air Dispersion Study for the LP Flare Package as part of the CPF Upgrade Project – Phase II was conducted to assess the environmental impact of emissions generated by the newly installed low-pressure flare system at the Central Processing Facility (CPF). This project was initiated to enhance production capabilities while ensuring compliance with Oman’s air quality regulations set forth by Ministerial Decision MD 41/2017.

Project Objective

• Evaluate the emissions produced during normal operation and potential emergency flare events.
• Model the dispersion of these emissions to predict ground-level concentrations (GLCs) of key pollutants including nitrogen dioxide (NO2), carbon monoxide (CO), and non-methane hydrocarbons (NMHC).
• Ensure that predicted emissions remained within established ambient air quality standards, thereby safeguarding the local environment and public health.

Methodology

The modeling process involved several key steps:

1. Meteorological Data Collection: Meteorological data were sourced from the nearest station in Ibri, Oman, to understand local wind patterns and atmospheric conditions.
2. Dispersion Modelling: A Simulation Software was employed to simulate the dispersion of air pollutants based on emission rates and meteorological parameters. The model accounts for various atmospheric factors such as turbulence, mixing height, and the influence of local topography.
3. Assessment Scenarios: The model was applied to predict GLCs under various operating scenarios and timeframes (1-hour, 3-hour, 8-hour, and 24-hour averages).
4. Compliance Evaluation: The results were compared against the thresholds set by MD 41/2017 to determine compliance with air quality regulations.

Key Findings

The modeling results indicated that the maximum predicted GLCs for all assessed pollutants from the LP flare remained within the limits prescribed by MD 41/2017.

Conclusion:

The comprehensive air dispersion modeling demonstrated that emissions from the LP Flare Package will remain within regulatory limits, confirming the project's alignment with environmental standards. This successful assessment underscores the plant’s commitment to sustainable and responsible operation within the Oil and Gas sector.

Ultimately, the findings of this study provide valuable insights for ongoing environmental management practices and future upgrades within the facility, reinforcing the importance of predictive air quality assessments in preserving air standards and public health. As a result, the CPF Upgrade Project – Phase II stands as a model for integrating operational efficiency with environmental compliance in the region.