Magnesium hydroxide (Mg(OH)2) is a viable alternative to caustic soda that is increasingly being used in the maritime industry, particularly in scrubbers for vessels using heavy fuel oil (HFO).

Similar to caustic soda, magnesium hydroxide is used in the exhaust gas cleaning process to neutralize acidic sulphur oxides and reduce harmful emissions from ships. However, unlike caustic soda, magnesium hydroxide is considered a safer and more sustainable alternative.

One of the key advantages of magnesium hydroxide is that it is non-hazardous, non-corrosive, and non-toxic. This means that it poses less risk to human health and the environment compared to caustic soda, which can be dangerous if mishandled or spilled.

In addition, magnesium hydroxide has a lower pH compared to caustic soda, which can help to reduce the potential for corrosion in the scrubber system. It also has a lower solubility, which means that less of it is required to achieve the same neutralization effect as caustic soda.

Switching from caustic soda to magnesium hydroxide in the storage tank is a straightforward process that typically requires only minor modifications to the tank and the pumping system. One of the key considerations when switching to magnesium hydroxide is ensuring that the chemical is kept in suspension in the tank, as it tends to settle over time. To prevent settling, a constant pumping flow is needed to keep the chemical well mixed and distributed evenly throughout the tank.