Demulsificantes

Demulsificantes, also known as demulsifiers, are chemical additives used to break emulsions—stable mixtures of two immiscible liquids, commonly oil and water. In many industrial processes, such as petroleum refining, oilfield production, and wastewater treatment, emulsions form inadvertently during extraction, storage or transport. Demulsificantes facilitate phase separation, allowing the separated liquids to be collected or disposed of more efficiently.

The primary mechanism of most demulsificantes involves molecules that selectively adsorb at the oil–water interface. By reducing interfacial tension and disrupting interfacial films containing surfactants, they destabilize the emulsion droplets. Typical demulsifier families include high‑molecular‑weight polymers, such as polyacrylamides or epoxy resins, as well as low‑molecular‑weight surfactant‑like agents like amines, fatty acids, or phosphonates. Selection depends on emulsion type, temperature, salinity, and the desired rate of separation. In oilfield applications, for instance, polymer demulsifiers are preferred for breaking water‑in‑oil emulsions, while surfactant‑based agents are more effective against oil‑in‑water mixtures.

Demulsificantes are added in small doses; typical concentrations range from 0.01 % to 1 % of the emulsion volume. Their use can significantly reduce energy consumption for mechanical separation and lower the volume of brine or wastewater requiring further treatment. However, environmental concerns arise, particularly regarding biodegradable pathways and potential toxicity to aquatic organisms. Consequently, many jurisdictions now regulate demulsifier usage, and manufacturers are investing in greener formulations.

Historically, demulsification techniques were developed alongside the growth of the petrochemical industry in the mid‑20th century. Modern advancements focus on tailored polymeric systems and the integration of demulsification steps into continuous processing lines, enhancing throughput while minimizing environmental impact.