Desespumants

Desespumants, also known as antifoaming agents, are chemical additives used to control or eliminate foam in industrial processes. They work by migrating to the air–liquid interface of foams, where they form a thin, non-wetting layer that destabilizes liquid films and promotes bubble rupture, leading to foam reduction. Some formulations also alter local surface properties to prevent the formation of new foam.

Common formulations include silicone-based antifoams, typically polydimethylsiloxane fluids dispersed in a solid carrier such as fumed silica; mineral oil or other hydrocarbon fluids; and oil-in-water or water-in-oil emulsions. There are also non-silicone antifoams based on fatty alcohols, esters, glycols, or lecithin, often used when silicone contamination is undesirable. Antifoams may be supplied as liquids, emulsions, or dry granules and can be tailored to operate across a range of temperatures, pH, and process fluids.

Performance depends on process conditions such as shear, mixing intensity, temperature, and the foaming source (protein foams, surfactant foams, or aeration). Silicone-based products are widely used in fermentation, dairy processing, and paper manufacture due to broad activity and stability, while non-silicone options are preferred when regulatory or product-compatibility constraints exist.

Applications span food and beverage processing, pharmaceuticals and cosmetics, pulp and paper, mining and mineral processing, oil and gas drilling, wastewater treatment, and chemical manufacturing.

Selection and safety: Choice factors include compatibility with process liquids, potential impact on product appearance or taste, regulatory status for food or pharmaceutical use, temperature range, and downstream processing. Storage should be in original containers, protected from moisture and heat; shelf life is typically several years for stable products.