Hankison Alumina vs. DelSORB® HQ-A4 – What Is the Difference?

Although both products are activated alumina for desiccant dryers, they are not necessarily identical. Hankison Alumina is the general standard-grade activated alumina, while DelSORB® HQ-A4 is a specifically defined 4 mm premium-grade activated alumina. In this comparison, we look at the key technical differences and explain when it makes the most sense to choose one product over the other.

Are you unsure which type of activated alumina is right for your desiccant dryer? Contact us and we will help you identify the correct type.

At a Glance

Both products are activated alumina (Al₂O₃) used in desiccant dryers and are primarily designed to adsorb water vapor from compressed air.

The main difference is that Hankison Alumina is specified as general Hankison activated alumina, while Deltech / Hankison DelSORB® HQ-A4 is a specific 4 mm Premium HQ-A4 grade, which Hankison itself describes as its premium-grade activated alumina.

Property Hankison Alumina Deltech / Hankison DelSORB® HQ-A4
Type Activated alumina Activated alumina
Chemical material Aluminum oxide (Al₂O₃) Aluminum oxide (Al₂O₃)
Shape Smooth, spherical granules Smooth, spherical granules
Porosity High High
Specified surface area >300 m²/g >300 m²/g
Crush strength High High
Particle size 1/8″ / approx. 3.2 mm in older Hankison documentation 4 mm – HQ-A4
Typical application Desiccant dryers Desiccant dryers, premium grade
Available quantities 3, 5, 22.5, 45, 160 and 907 kg 3, 5, 22.5, 45, 160 and 907 kg
Hankison product status Hankison Alumina Hankison Premium HQ-A4
Best choice Standard/existing installations When HQ-A4 is specified or preferred as a premium solution

Important: The two products have very similar product descriptions at EKO-Filters. However, this does not necessarily mean that they should be considered 100% identical. HQ-A4 is specifically identified by Hankison as 4 mm premium activated alumina, while Hankison Alumina is also listed in older Hankison specifications as 1/8″ granules.

Hankison Alumina

Hankison Alumina is a synthetically manufactured aluminum oxide in spherical form. The material is highly porous and has a potential surface area of more than 300 m²/g. This makes it well suited for the adsorption of water vapor in compressed air and gas drying applications.

Depending on operating conditions and dryer design, the material can be used to achieve pressure dew points of approximately −40 °F to −100 °F.

Available Package Sizes

Part Number Quantity
99498104 3 kg
99498108 5 kg
99498103 22.5 kg
99498107 45 kg
99498106 160 kg
99498110 907 kg

When Does Hankison Alumina Make the Most Sense?

Hankison Alumina is a suitable choice if:

  • you need to refill an existing Hankison desiccant dryer,
  • the existing desiccant filling is specified as standard activated alumina,
  • you want to maintain the existing material specification,
  • the system was originally designed for the traditional Hankison alumina particle size.

An older Hankison specification lists a 1/8″ particle size for this alumina. This corresponds to approximately 3.2 mm.

Deltech / Hankison DelSORB® HQ-A4

Deltech / Hankison DelSORB® HQ-A4 is also activated alumina for desiccant dryers, but it is a more specifically defined HQ-A4 grade.

Hankison itself describes Premium HQ-A4 as 4 mm premium quality activated alumina.

HQ-A4 is a synthetically manufactured aluminum oxide with a spherical shape, high crush strength and a surface area of more than 300 m²/g.

Available Package Sizes

Part Number Quantity
E3650005 3 kg
E3650006 5 kg
E3650007 22.5 kg
E3650008 45 kg
E3650009 160 kg
E3650010 907 kg

When Does HQ-A4 Make the Most Sense?

HQ-A4 is particularly relevant if:

  • the dryer documentation specifically specifies HQ-A4,
  • the existing desiccant filling is Hankison Premium HQ-A4,
  • you want to use Hankison’s current premium-grade activated alumina,
  • you require 4 mm activated alumina where this is the specified particle size.

The Technical Difference

It is important not to focus only on the fact that both products are called “Alumina.”

Activated alumina is not a single specification. Its performance can be influenced by several factors, including:

  • particle size,
  • pore structure,
  • surface area,
  • crush strength,
  • dust formation and attrition,
  • water adsorption capacity,
  • bulk density,
  • regeneration conditions,
  • air temperature and pressure.

Therefore, two activated alumina products made from the same basic material can still have different performance characteristics in a desiccant dryer.

Particle Size Is the Most Noticeable Difference

Traditional Hankison Alumina is documented as 1/8″, while Hankison specifically identifies HQ-A4 as 4 mm.

The difference is:

  • 1/8″ = approx. 3.18 mm
  • HQ-A4 = 4 mm

This is not a dramatic difference, but particle size can affect pressure drop, contact conditions, bulk density and how the desiccant performs within the specific dryer vessel.

For this reason, you should not automatically replace 1/8″ Hankison Alumina with HQ-A4 without checking the dryer’s specification.

What Does This Mean for Drying Performance?

Both materials work according to the same basic principle:

Moist compressed air → desiccant → water molecules are adsorbed → dry air

Activated alumina has a large internal surface area where water molecules are adsorbed. As the desiccant gradually becomes saturated, it needs to be regenerated.

A typical heatless desiccant dryer uses two vessels:

  1. Tower A dries the compressed air
  2. Tower B is regenerated
  3. The towers switch functions
  4. The cycle is repeated

Hankison describes its heatless desiccant dryers as twin-tower systems using premium activated alumina and specifies pressure dew points down to −100 °F / approx. −73 °C for relevant models.

However, it is important to distinguish between the theoretical adsorption capacity of the desiccant and the actual pressure dew point performance of the complete drying system. The achievable dew point also depends on factors such as airflow, inlet temperature, operating pressure, regeneration, cycle time and dryer design.

Which Product Should You Choose?

Choose Hankison Alumina> if:

The existing system already uses Hankison Alumina/1/8″.

This is the most conservative solution because it maintains the existing desiccant type and particle size.

 

Choose DelSORB® HQ-A4 if:

The manufacturer’s specification states HQ-A4 or 4 mm premium activated alumina.

In this case, HQ-A4 is the natural choice because Hankison itself identifies HQ-A4 as its 4 mm premium-grade activated alumina.

 

If You Are Considering Switching from Hankison Alumina to HQ-A4

You should check:

  1. Desiccant dryer model/type
  2. Existing desiccant
  3. Particle size
  4. Filling quantity
  5. Bulk density
  6. Recommended regeneration flow
  7. Design pressure
  8. Required pressure dew point
  9. Manufacturer’s recommended desiccant

This is particularly important for older Deltech/Hankison systems, where the original specification may differ from the current HQ-A4 specification.

Are you unsure which type of desiccant your system requires? Contact us and we will help you identify the correct specification based on the desiccant dryer model and existing desiccant filling.

Assessment

When comparing the products based on the available documentation, the difference can best be described as follows:

Hankison Alumina = standard/original activated alumina for Hankison desiccant dryers

DelSORB® HQ-A4 = a specifically defined premium 4 mm activated alumina from Hankison

They are therefore the same basic type of desiccant, but HQ-A4 is not simply a generic name for any Hankison alumina. Hankison itself describes HQ-A4 as a premium 4 mm grade.

For a straightforward 1:1 service replacement, I would recommend choosing the same type of activated alumina that the dryer was originally specified for. For an upgrade, or for a system where the manufacturer specifically specifies HQ-A4, DelSORB® HQ-A4 is the natural choice.