Contemporary Advancement in Green Demulsification Technique: A Review

Emulsion has been confirmed to be a major challenge in the production and transportation of crude oil. Emulsion typically forms as soon as the well begins to produce and the water volume subsequently inclines with years of production. Corrosion of facilities, reduction of pumping efficiency of pumps, crude oil quality reduction and poisoning of refinery catalysts are some of the negative impacts of oilfield emulsion. Technological advancements have aided the incorporation of different classes of demulsification techniques to overcome the challenges imposed by emulsions. The techniques are mechanical, chemical and biological methods. The chemical method which is the most widely utilized, uses synthesized chemicals termed demulsifiers to separate emulsion components. The chemical method is posed with different forms of limitations regarding the high cost, ineffectiveness of demulsification process, unavailability of demulsifiers, negative effect on crude oil quality and environmental consequences from disposal of separated formation waters. Due to these challenges, green demulsifiers have been identified as a major alternative to the synthetic demulsifiers. Green demulsifiers, derived from plant sources, offered advantages such as biodegradability, renewability and sustainability. This review examined the current state of green demulsifiers for oil-water separation, highlighting their sources, performance, factors influencing their performances, opportunities and future challenges. The review also encompassed emulsion classes, stability and summary of other demulsification techniques. From the review, green demulsifiers showed potential for emulsion treatment in a laboratory scale with a maximum efficiency of 97.5%. Limitations such as slow separation rates, scalability and industrial application, reproducibility and variability in performance need to be addressed. Further research is necessary to investigate the environmental impact of these green demulsifier formulations. Nonetheless, green demulsifiers have the potential to enable oil companies to adopt sustainable and environmentally friendly demulsification practices if fully improved on and harnessed.