Popular Ion Exchange Membranes for ED, BMED, Acid Recovery

INQUIRY

Ion exchange membranes (IEMs) are the core components of electrodialysis (ED), bipolar membrane electrodialysis (BMED), and diffusion dialysis. They enable selective transport of cations or anions, making them indispensable for acid/base recovery, desalination, and green chemical production.

Alfa Chemistry offers a portfolio of high-performance membranes including acid/alkali resistant grades, bipolar membranes, and acid blocking membranes. Engineered for harsh chemical environments, these membranes provide low area resistance, high burst strength, and excellent pH stability from 0 to 14.

Why Choose Alfa Chemistry Ion Exchange Membranes?

Our hot membranes are designed for demanding industrial processes:

High burst strength (>0.5 to >1.0 MPa) ensures long service life
Wide pH tolerance (0-14 for running and cleaning)
Low area resistance (3.6 – 4.3 Ω·cm²) for energy efficiency
Customizable dimensions (width up to 1150 mm, length on demand)
Proven in BMED for salt splitting (Na₂SO₄, NaCl, Li₂SO₄) and organic acid/alkali production

Key Selection Criteria for Ion Exchange Membranes

When selecting an ion exchange membrane for your process, evaluate the following parameters:

Parameter	What It Influences	Practical Guidance
Membrane Type	Cation exchange membrane (CEM) vs. Anion exchange membrane (AEM) vs. Bipolar membrane (BPM)	Use CEM for cation transport (e.g., Na+), AEM for anion transport (Cl-, SO4²-), BPM for water splitting into H+ and OH-.
Burst Strength	Mechanical robustness, resistance to hydraulic shocks	Higher is better for high-flow systems. CT-4 offers >0.5 MPa; AHT, ATD, BP-2 offer >0.9-1.0 MPa.
Area Resistance	Energy consumption, ion flux	Lower resistance reduces voltage drop. Values 3.6-4.3 Ω·cm² (0.5N NaCl) are typical for our membranes.
pH Range (Running/Cleaning)	Chemical stability in acids, alkalis, or organic media	Most membranes tolerate 0-14; ATD is optimized for acidic streams (running pH 0-4, cleaning 0-6).
Operating Temperature	Reaction kinetics and membrane lifetime	Standard range 25-40°C, AHT supports up to 60°C for alkali concentration.
Thickness	Mechanical strength and diffusion resistance	0.10 – 0.28 mm. Thicker membranes (e.g., BP-2 0.28 mm) offer higher durability for bipolar applications.

Product Spotlight: Hot Ion Exchange Membranes

Below are the most popular membranes from Alfa Chemistry, each tailored to specific applications:

Catalog	Product Name	Application	Burst Strength	Area Resistance	Thickness	Temperature	Price
ACIR-HP004	CT-4 Acid/Alkali Resistance Membrane	Acid/alkali concentration, cation membrane for BMED	>0.5 MPa	3.6 Ω·cm²	0.10 mm	25-40°C	Inquiry
ACIR-HP005	AHT Acid/Alkali Resistance Membrane	Alkali concentration, H2SO4 concentration, anion membrane for BMED	>0.9 MPa	4.1 Ω·cm²	0.22 mm	25-60°C	Inquiry
ACIR-HP006	ATD Acid Block Membrane	HCl/HNO3 concentration & removal, anion membrane for BMED	>1.0 MPa	4.3 Ω·cm²	0.16 mm	25-40°C	Inquiry
ACIR-HP007	BP-2 Bipolar Membrane	Salt splitting (Na2SO4, NaCl, Li salts), organic acid/alkali production (lactic acid, TMAH, etc.)	>1.0 MPa	–	0.28 mm	25-40°C	Inquiry

Application Deep Dive: Bipolar Membrane Electrodialysis (BMED)

BMED combines bipolar membranes with cation and anion exchange membranes to convert salt solutions into corresponding acids and bases without additional chemicals. Alfa Chemistry provides complete membrane stacks:

Na2SO4 splitting: Use BP-2 (bipolar) + CT-4 (cation) + AHT (anion) → H2SO4 and NaOH
Chloride/nitrate conversion: ATD/CT-4 combination for HCl/HNO3 recovery
Lithium hydroxide production: From Li2SO4, LiCl, Li2CO3 brines → low-cost, clean LiOH
Organic acids: L-lactic acid, malic acid, Vitamin C, EDTA – replace conventional precipitation
Organic bases: Triethylamine, TMAH (tetramethylammonium hydroxide) – efficient and green

The BP-2 Bipolar Membrane features >1.0 MPa burst strength and 0.28 mm thickness, ensuring durability in continuous operation.

Acid & Alkali Concentration with CT-4, AHT and ATD

For acid recovery from pickling baths or metal finishing waste, the CT-4 membrane serves as a robust cation membrane, while AHT and ATD provide superior anion selectivity. ATD is specifically designed for HCl/HNO3 streams with running pH as low as 0-4, effectively blocking acid anions while allowing proton transport. AHT handles alkali concentration up to 60°C, making it ideal for caustic recovery.

Technical Specifications at a Glance

Property	CT-4	AHT	ATD	BP-2
Matrix	Reinforced polymer	Reinforced polymer	Reinforced polymer	Bipolar (CEM+AEM)
pH (running)	0-14	0-14	0-4	0-14
Burst strength (MPa)	>0.5	>0.9	>1.0	>1.0
Thickness (mm)	0.10	0.22	0.16	0.28
Max temp (°C)	40	60	40	40
Area resistance (Ω·cm²)	3.6	4.1	4.3	–

Packaging, Handling & Customization

All membranes are shipped in plastic or wooden cases to prevent damage. Standard width is 1100-1150 mm, length can be customized to your stack dimensions. For pilot or full-scale ED/BMED systems, Alfa Chemistry provides technical support for membrane selection, stack configuration, and process optimization.