Advanced Water Treatment Solutions for Petroleum Refining Projects

Introduction

In the petroleum refining industry, effective water treatment is essential for operational efficiency and environmental compliance. Refineries generate various wastewater streams, including cooling water, process water, and sanitary sewage, each requiring specialized treatment methods. This case study explores a comprehensive water treatment solution implemented at a large-scale refinery, highlighting the project’s background, requirements, technical specifications, and outcomes.

Project Background

A major petroleum refinery located on the southwest coast of India faced challenges with its combined process and power cooling systems. The existing water treatment infrastructure was inadequate, leading to operational inefficiencies and environmental concerns. The refinery sought a robust solution to enhance water quality, ensure regulatory compliance, and improve overall plant performance.

Project Requirements

The refinery’s water treatment objectives included:

• Removal of Oil and Grease: Efficient separation of oil and grease from wastewater to prevent environmental contamination.
• Suspended Solids Reduction: Minimization of suspended solids to protect equipment and maintain water quality.
• Chemical Oxygen Demand (COD) Reduction: Lowering COD levels to meet discharge standards.
• Operational Efficiency: Implementation of a system that is easy to operate and maintain, with minimal downtime.

Technical Specifications

The proposed water treatment system incorporated the following components:

• API Oil-Water Separator: Designed to separate gross amounts of oil and suspended solids from industrial wastewater. en.wikipedia.org
• Coalescing Plate Separator: Utilizes inclined plate assemblies to enhance oil-water separation efficiency.
• Activated Carbon Filtration: Employed to remove dissolved organic compounds and further reduce COD levels.
• Dissolved Air Flotation (DAF) Unit: Used for the removal of fine suspended solids and oil droplets.
• pH Adjustment System: Ensures optimal conditions for chemical treatment processes.

The system was designed to handle a wastewater flow rate of 500 cubic meters per hour, with an influent oil and grease concentration of 1,500 mg/L, suspended solids at 2,000 mg/L, and COD levels at 5,000 mg/L.

Equipment Parameters

Project Outcomes

The implementation of the water treatment system resulted in:

• Oil and Grease Removal: Achieved a reduction to less than 50 mg/L, surpassing environmental discharge standards.
• Suspended Solids Reduction: Decreased to below 100 mg/L, ensuring protection of downstream equipment.
• COD Reduction: Lowered to 500 mg/L, facilitating compliance with stringent discharge regulations.
• Operational Efficiency: The automated system reduced manual intervention, leading to a 20% decrease in maintenance costs.

This case study underscores the critical role of advanced water treatment technologies in enhancing the sustainability and efficiency of petroleum refining operations.