Non-Aqueous and Crude Oil Foams

Abstract

D o s s i e rRe´sume´-Mousses non aqueuses et mousses pe´trolie`res -Les mousses produites a`partir de syste`mes non aqueux sont moins fre´quentes que les mousses a`base d'eau, mais elles jouent un roˆle important dans de nombreuses applications et proce´de´s industriels. La faible tension de surface des liquides a`base d'hydrocarbures limite l'adsorption des agents de surface classiques et par conse´quent diffe´rents compose´s et me´thodes doivent eˆtre conside´re´s afin de ge´ne´rer et de stabiliser les mousses a`base d'huile. De meˆme, le cassage des mousses non aqueuses inde´sirables ne´cessite des conside´rations spe´cifiques a`ces syste`mes. Les mousses de pe´trole pre´sentent un inte´reˆt particulier de par leur complexite´en raison de la grande varie´te´des compose´s et des gaz qui peuvent les constituer. Nous pre´sentons dans cet article un aperc¸u des principaux me´canismes reconnus comme importants pour la stabilite´des mousses non aqueuses avec une conside´ration toute particulie`re pour les mousses de pe´trole brut.Abstract -Non-Aqueous and Crude Oil Foams -Foams produced from non-aqueous media are less common than water-based foams but they play an important role in many industries and engineering processes. The low surface tension of hydrocarbon fluids limits the adsorption of common surface activity substances and different compounds and methods must be considered to generate and stabilize oil-based foam. Likewise, the destruction of unwanted non-aqueous based foam requires specific considerations not found with aqueous systems. Of particular interest are petroleum-based foams, which are highly complex due to the wide variety of compounds and gases that can be found. We provide an overview of the major mechanisms known to be important for non-aqueous foam stability with a spotlight on crude-oil foams.

Whipped oil stabilised by surfactant crystals

“…Such foams are lighter than the oil alone and of current interest in foods due to the reduced oil/fat content. The unwanted foaming of petroleum or crude oil is a major problem during gas–oil separation and appropriate antifoams need to be designed which involve specific considerations not encountered in aqueous systems 2–4. Since the surface tension of most hydrocarbon-containing oils is low (<35 mN m –1 ) compared with that for water (72 mN m –1 at 25 °C), the driving force for adsorption of many hydrocarbon-based surfactants to their surface is significantly reduced 5…”

Selection Criteria for Antifoams Used in the Acid Gas Sweetening Process

“…Moreover, the use of fluorosilicones is commonly used in severe foaming cases . This is because they have similar properties which include low surface tension, strong defoaming ability, low dosage requirement, are hydrophobic, and do not react with other additives in the absorption solvent.…”

“…Moreover, the use of fluorosilicones is commonly used in severe foaming cases. 110 This is because they have similar properties which include low surface tension, strong defoaming ability, low dosage requirement, are hydrophobic, and do not react with other additives in the absorption solvent. As such, a study that involved the synthesis and testing of fluorosilicone antifoam (which contains fluoroalkyl) has shown that this blended antifoam has a high affinity toward an aqueous or organic solution and demonstrated excellent and persistent antifoaming abilities.…”

Multiphase Microreactors Based on Liquid–Liquid and Gas–Liquid Dispersions Stabilized by Colloidal Catalytic Particles

“…Owing to the low surface tension of organic solvents (typically ranging from 14 to 50 mN m −1 ), the adsorption of common foam stabilizers at the gas–liquid interface is energetically unfavorable and requires stabilizers with low surface energy (e.g., fluorinated and polydimethylsiloxane surfactants), asphaltenes, or fatty acid crystals [14b, 18a, 164] . As a result, the generation of oil‐based foams is much more challenging compared to aqueous foams [164d, 165] …”