Question: are there alternatives to zeolites? do you enjoy designing solid materials and improving the ways of making them? what is the process of making solid materials sustainable? how does spray drying work?

Alexander Munnoch answered on 25 Nov 2021:

There are several alternatives to zeolites (not always better but sometimes they are). The four things that make zeolites especially useful are: 1. high surface area (300-600 m2/g), 2. The high surface area comes from pores on a length scale of 0.3-2.0 nm – meaning they can function as molecular sieves and 3. They are made from aluminium silicon oxides (so thermally stable to ~ 650 degrees celcius and 4. aluminosilicates (such as zeolites) are basically just rocks so they are environmentally friendly.

Common alternatives include activated carbon, Metal-Organic-Frameworks, Zeotypes, ion-exchange resins but they generally don’t have the full list of benefits.

I enjoy designing and making materials because of the diversity of materials and atomic structures possible, the crystal science is really interesting and I get to use some really cool/fun equipment.

Spray drying works by forcing a liquid out through a narrow nozzle/tube – a high enough shearing rate causes it to break-up into fine (fairly uniformly sized) droplets which are then contacted with a gas (normally about the boiling point of the liquid) – drying is rapid due to the small droplet size and you end up with a fine (usually free flowing) powder. It’s the way that baby milk formula is made industrially!