Sodium Bicarbonate — Frequently Asked Questions

Milled sodium bicarbonate is blown into a hot flue gas duct, where it decomposes in flight to sodium carbonate, carbon dioxide and water. The escaping gas leaves the residual solid with a greatly expanded internal surface area, and that highly porous soda then captures sulphur dioxide, hydrogen chloride and hydrogen fluoride far more efficiently than pre-made soda ash would.

Because the decomposition happens in the duct. Injecting ready-made sodium carbonate gives a dense particle with limited surface area; injecting bicarbonate generates the reactive surface in situ as the carbon dioxide escapes. That means much higher utilisation of the reagent, and the system needs no scrubber vessel, slurry handling or wastewater treatment.

Because it is hard enough to strip coatings but friable enough to break up on impact rather than cutting into the substrate, so soft materials such as aluminium, brick, stone and timber are not damaged. It is also water-soluble, so residue rinses away rather than having to be collected as grit, which matters when blasting in situ.

It depends entirely on the application. Flue gas treatment needs a finely milled grade to maximise surface area and reaction rate, blasting needs a controlled coarser grade matched to the substrate and the coating being removed, and formulation uses vary. Particle size is therefore a primary specification point rather than a detail.