Design of 1,000-100,000 Liter/Hour Single-Stage Reverse Osmosis Systems for Refineries

1. Background Requirements:

Oil refineries are high water consuming industries and are used for cooling, boiler make-up, and process reactions. Because the raw water may contain suspended solids, salts, oils and organic contaminants leading to equipment fouling, corrosion and loss of efficiency. The single-stage reverse osmosis system effectively removes 97%~99% of dissolved salts and impurities through physical filtration to provide stable, high-purity water to meet the stringent water quality requirements of the oil refining process.

2. Overall Design

• Continuous and stable water production
• Water production capacity: 1-100,000 L/H
• Inlet water standard: conductivity ≤ 2000 μS/cm
• Energy-saving: Low energy consumption design with China Energy Efficiency Commission labeling
• Adaptability: Compatible with complex raw water conditions in refineries (oil, high salt, fluctuating water quality).

3. System Composition

3.1 Pre-treatment System

• Multi-media filter: remove suspended solids, rust, colloid (precision 10-20 μm).
• Activated carbon filter: adsorb oil, organic matter and residual chlorine (to protect RO membrane from oxidation).
• Water softening filter/Dosing device: reduce water hardness and prevent scaling
• Precision security filter: 5 μm filter element intercepts small particles to ensure that the feed water SDI ≤ 5.

3.2 Reverse Osmosis Host

• Membrane module: choose anti-pollution rolled composite membrane or low-pressure composite membrane. Single membrane water production 1.5m³/h, according to the site conditions combined with the realization of high efficiency capacity.
• High-pressure pump: frequency control stainless steel high-efficiency centrifugal pump (pressure 0.6 ~ 1.5 MPa)
• Desalination rate: ≥98
• Conductivity of produced water ≤50 μS/cm.
• Recovery rate: 60%~75% (adjusted according to the salinity of raw water to reduce the discharge of concentrated water).

3.3 Post-treatment System and Intelligent Control

• PH adjustment
• PLC control system for real-time monitoring of pressure, flow, conductivity, automatic flushing and alarm.
• Data remote access to support integration with refinery DCS system to achieve centralized management.

4. Daily Maintenance

• Record pressure and conductivity data daily.
• Monthly cleaning of pretreatment filter media, checking the sealing.
• Chemically clean RO membrane (citric acid + NaOH) every 3~6 months.
• Usually replace RO membrane every 3 years
• Backup pumps and membrane housings are prepared to ensure quick switchover in case of failure.