Hyperbranched Poly(amido amine) Demulsifiers Using Diaminonaphthalene as the Central Core and Their Demulsification Performance in Oil-in-Water and Water-in-Oil Emulsions

Abstract

Hyperbranched poly(amido amine) demulsifiers (PNDA-1 or PNDA-2) were synthesized with 1,5-diaminonaphthalene or 1,8-diaminonaphthalene as the central core by an improved "one-pot" method. Fourier transform infrared spectroscopy, nuclear magnetic resonance hydrogen spectra, and thermogravimetric analysis were utilized to explore their structure and thermal stability. It indicated that the two hyperbranched demulsifiers had good thermal stability. To evaluate their demulsification performance, some important factors such as concentration of the demulsifier, types of emulsion, temperature, and settling time were systematically investigated. When 80 mg/L of PNDA-1 or PNDA-2 was used in oily wastewater (O/W emulsion) at room temperature for 4 h, the light transmittance of the separated water reached 73.7 and 59.3%, respectively. The corresponding oil removal rate reached as high as 99.62 and 99.50%, respectively. After demulsifying with the concentration of 80 mg/L at 70 °C for 120 min, the demulsification efficiency (DE) of PNDA-1 and PNDA-2 in the crude oil emulsion (W/O emulsion) reached 92 and 83%, respectively. The DE of PNDA-1 is obviously better than that of PNDA-2 in both O/W and W/O emulsions. The possible demulsification mechanism was discussed by the interfacial tension, zeta potential, and micrograph analysis. The current work provided new hyperbranched demulsifiers, and the discussion on the mechanism also provided some references for the research of a demulsifier.

Fundamental Basis for Action of a Chemical Demulsifier Revisited after 30 Years: HLDNas the Primary Criterion for Water-in-Crude Oil Emulsion Breaking

“…Lastly, in 2021, the top oil companies have all announced that they will make changes in their funding priorities into more sustainable processes . This generates the need for a better understanding of complex systems formulated with new surfactant molecules and ionic liquids with high demulsification performance. − Further efforts and funding in fundamental and applied research are thus foreseeable.…”

Demulsification of W/O emulsions using highly branched polymer demulsifier with 2,6‐naphthalenedicarboxylate as centronucleus

“…It is obvious that the similarity of the centronucleus with asphaltene is conducive to the separation of oil-water emulsion. 15 Although they have relatively good demulsification performance, the use of naphthalene diamine has potential contamination risks. For the purpose of improving the performance of demulsifiers and reducing the use of toxic chemicals, 2,6-naphthalenedicarboxylate was used as the centronucleus to synthesize a PNDC demulsifier by an efficient "one-pot" strategy in this work.…”

“…In our recent work, the PNDA‐1 and PNDA‐2 demuslifiers were synthesized using 1,5‐naphthalene diamine or 1,8‐naphthalene diamine as centronucleus to break the O/W and W/O emulsions. It is obvious that the similarity of the centronucleus with asphaltene is conducive to the separation of oil–water emulsion 15 . Although they have relatively good demulsification performance, the use of naphthalene diamine has potential contamination risks.…”