High molar mass polyethers as defoamers of heavy crude oil

The presence of foam in the petroleum industry causes many problems in gas-liquid separators and its complete elimination, by employing a silicon-free defoamer agent, poses a significant challenge. In this research, a series of high molar masses polyethers was synthesized using different epoxide monomers (1,2-propylene oxide PO, 1,2-butylene oxide BO, 1,2-hexylene oxide HO and 1,2-dodecylene oxide DDO), varying their molar masses from 10,000 to 120,000 g/mol. The synthesis was performed by anionic ring-opening polymerization (AROP) using as initiation system an ammonium salt and triisobutylaluminum as complexing agent and monomer activator. All polymers were characterized by 1H NMR, SEC and TGA, experimentally evaluated as defoamer agents of gasified heavy crude oil (13.08 °API) and compared to a silicon based defoamer. Results revealed that PBO and PHO with molar masses above 80,000 g/mol show high activity as foam suppressors, similar to that of commercial silicon based defoamer agents.