Ceramic Membranes for Power Plant Boiler Feedwater

Against the backdrop of green and low-carbon development, thermal power plants widely use unconventional water sources such as reclaimed water, but its water quality is complex and fluctuates greatly, seriously threatening the boiler make-up water system and the safe operation of units. To this end, Jiuwu Hi-Tech, relying on high-packing ceramic membrane separation technology, has launched a customized pretreatment solution that efficiently intercepts impurities at the source, resists water quality shocks, and fully guarantees the long-term stable operation of the downstream desalination system. At present, this solution has been successfully applied in the scenario of producing pure water from reclaimed water in power plants.

Technical Problems Facing Boiler Make-up Water Pretreatment

The boiler make-up water desalination (RO) process has strict requirements on feed water SDI and turbidity. As water source structures become diversified, conventional pretreatment processes face three challenges:

Intensified water quality fluctuation: colloids and organic components in surface water and reclaimed water are complex.

Large footprint and investment: the long "reaction + sedimentation + multi-media filtration" process involves many structures and high land costs.

Poor tolerance of organic ultrafiltration membranes: weak resistance to fouling and chemicals, with the risk of fiber breakage during long-term operation, directly threatening the service life of downstream RO membranes.

Jiuwu Hi-Tech High-Packing Ceramic Membrane Pretreatment Process

Targeting the feed water quality standards at the front end of power plant pure water preparation, Jiuwu Hi-Tech adopts a pretreatment solution with high-packing ceramic membranes at its core, undertaking solid-liquid separation, colloid removal and suspended solids interception in the make-up water pretreatment stage.

PROCESS ROUTE

Raw water (surface water / reclaimed water / discharge water) → flocculation / pre-filtration → ceramic membrane filtration system → product water tank → reverse osmosis system (RO) → mixed bed / EDI → boiler make-up water

This process replaces the traditional multi-stage long flow of "clarifier + sand filter + organic ultrafiltration" and consolidates it into a compact physical separation unit, maintaining stable outlet water indicators when feed turbidity surges or loads fluctuate.

Performance Indicators and Operating Characteristics of the High-Packing Ceramic Membrane System

Applied to boiler pure water pretreatment in power plants, Jiuwu Hi-Tech's high-packing ceramic membrane system has the following technical features:

Stable outlet water indicators: The ceramic membrane has a concentrated pore size distribution and is capable of intercepting fine suspended solids and colloidal particles. System outlet turbidity is stably below 0.1 NTU and the SDI value is controlled within 2.0, effectively reducing colloidal silica and particulate organic matter, slowing down downstream RO membrane fouling and extending the chemical cleaning cycle.

Chemical corrosion and abrasion resistance: The inorganic material is chemically inert and allows operation across the full pH 0-14 range. High-concentration strong acids, strong alkalis and oxidants can be used for cleaning, with a high flux recovery rate. The material has high mechanical strength, with no risk of fiber breakage, and resists water flow scouring and hard particle abrasion.

High flux and footprint control: The design operating flux of ceramic membranes is higher than that of conventional organic membranes, and equipment integration is high. The footprint is only one-third to one-half that of a conventional clarification and filtration system, suitable for both new project layouts and existing plant retrofits.

Level of automation: The system is equipped with PLC/DCS interfaces. Feed water, product water, backwashing and CIP chemical cleaning are all automatically controlled by program, reducing manual intervention.

Engineering Application Scenarios

This pretreatment solution has been put into operation in power projects with various water quality conditions:

Surface water pretreatment for coal-fired and gas-fired units: For rivers and lakes with high sediment and high turbidity during flood seasons, it solves the interference of seasonal turbidity surges on the water supply capacity of the pure water system.

Pure water production from reclaimed water in power plants: Treating effluent from municipal wastewater plants or park reclaimed water, it intercepts residual biological flocs and macromolecular colloids in reclaimed water to avoid organic fouling of downstream desalination membranes.

Complex industrial wastewater reuse in captive power plants: Treating circulating blowdown and process reuse water of captive power stations in chemical, smelting and other enterprises, it maintains continuous water production under conditions of complex water quality and high shock loads.

The stable operation of the above application scenarios verifies the process adaptability of high-packing ceramic membranes under complex water quality conditions. Based on mature engineering practice and inorganic material technology R&D capabilities, Jiuwu Hi-Tech will continue to deepen the fit between membrane separation processes and power water systems, providing engineering support for energy enterprises to improve water resource recycling efficiency and unit operation safety.